| Message ID | 20200406080936.7180-4-jniethe5@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Initial Prefixed Instruction support | expand |
| Context | Check | Description |
|---|---|---|
| snowpatch_ozlabs/apply_patch | success | Successfully applied on branch powerpc/merge (2c0ce4ff35994a7b12cc9879ced52c9e7c2e6667) |
| snowpatch_ozlabs/checkpatch | warning | total: 0 errors, 2 warnings, 1 checks, 509 lines checked |
| snowpatch_ozlabs/needsstable | success | Patch has no Fixes tags |
Hi Jordan,
Thank you for the patch! Yet something to improve:
[auto build test ERROR on v5.6]
[also build test ERROR on next-20200406]
[cannot apply to powerpc/next kvm-ppc/kvm-ppc-next scottwood/next]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system. BTW, we also suggest to use '--base' option to specify the
base tree in git format-patch, please see https://stackoverflow.com/a/37406982]
url: https://github.com/0day-ci/linux/commits/Jordan-Niethe/Initial-Prefixed-Instruction-support/20200406-165215
base: 7111951b8d4973bda27ff663f2cf18b663d15b48
config: powerpc-allnoconfig (attached as .config)
compiler: powerpc-linux-gcc (GCC) 9.3.0
reproduce:
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# save the attached .config to linux build tree
GCC_VERSION=9.3.0 make.cross ARCH=powerpc
If you fix the issue, kindly add following tag as appropriate
Reported-by: kbuild test robot <lkp@intel.com>
All errors (new ones prefixed by >>):
arch/powerpc/kernel/setup_32.c: In function 'machine_init':
>> arch/powerpc/kernel/setup_32.c:91:21: error: passing argument 1 of 'create_cond_branch' from incompatible pointer type [-Werror=incompatible-pointer-types]
91 | create_cond_branch(&insn, addr, branch_target(addr), 0x820000);
| ^~~~~
| |
| long unsigned int *
In file included from arch/powerpc/kernel/setup_32.c:42:
arch/powerpc/include/asm/code-patching.h:27:38: note: expected 'unsigned int *' but argument is of type 'long unsigned int *'
27 | int create_cond_branch(unsigned int *instr, const unsigned int *addr,
| ~~~~~~~~~~~~~~^~~~~
cc1: all warnings being treated as errors
vim +/create_cond_branch +91 arch/powerpc/kernel/setup_32.c
67
68 /*
69 * This is run before start_kernel(), the kernel has been relocated
70 * and we are running with enough of the MMU enabled to have our
71 * proper kernel virtual addresses
72 *
73 * We do the initial parsing of the flat device-tree and prepares
74 * for the MMU to be fully initialized.
75 */
76 notrace void __init machine_init(u64 dt_ptr)
77 {
78 unsigned int *addr = (unsigned int *)patch_site_addr(&patch__memset_nocache);
79 unsigned long insn;
80
81 /* Configure static keys first, now that we're relocated. */
82 setup_feature_keys();
83
84 early_ioremap_setup();
85
86 /* Enable early debugging if any specified (see udbg.h) */
87 udbg_early_init();
88
89 patch_instruction_site(&patch__memcpy_nocache, PPC_INST_NOP);
90
> 91 create_cond_branch(&insn, addr, branch_target(addr), 0x820000);
92 patch_instruction(addr, insn); /* replace b by bne cr0 */
93
94 /* Do some early initialization based on the flat device tree */
95 early_init_devtree(__va(dt_ptr));
96
97 early_init_mmu();
98
99 setup_kdump_trampoline();
100 }
101
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
On Mon, 2020-04-06 at 18:09 +1000, Jordan Niethe wrote: > create_branch(), create_cond_branch() and translate_branch() return the > instruction that they create, or return 0 to signal an error. Seperate s/seperate/separate > these concerns in preparation for an instruction type that is not just > an unsigned int. Fill the created instruction to a pointer passed as > the first parameter to the function and use a non-zero return value to > signify an error. > > Signed-off-by: Jordan Niethe <jniethe5@gmail.com> > --- > v5: New to series > --- > arch/powerpc/include/asm/code-patching.h | 12 +- > arch/powerpc/kernel/optprobes.c | 24 ++-- > arch/powerpc/kernel/setup_32.c | 2 +- > arch/powerpc/kernel/trace/ftrace.c | 24 ++-- > arch/powerpc/lib/code-patching.c | 133 +++++++++++++---------- > arch/powerpc/lib/feature-fixups.c | 5 +- > 6 files changed, 117 insertions(+), 83 deletions(-) > > diff --git a/arch/powerpc/include/asm/code-patching.h > b/arch/powerpc/include/asm/code-patching.h > index 898b54262881..351dda7215b6 100644 > --- a/arch/powerpc/include/asm/code-patching.h > +++ b/arch/powerpc/include/asm/code-patching.h > @@ -22,10 +22,10 @@ > #define BRANCH_ABSOLUTE 0x2 > > bool is_offset_in_branch_range(long offset); > -unsigned int create_branch(const unsigned int *addr, > - unsigned long target, int flags); > -unsigned int create_cond_branch(const unsigned int *addr, > - unsigned long target, int flags); > +int create_branch(unsigned int *instr, const unsigned int *addr, > + unsigned long target, int flags); > +int create_cond_branch(unsigned int *instr, const unsigned int *addr, > + unsigned long target, int flags); > int patch_branch(unsigned int *addr, unsigned long target, int flags); > int patch_instruction(unsigned int *addr, unsigned int instr); > int raw_patch_instruction(unsigned int *addr, unsigned int instr); > @@ -60,8 +60,8 @@ int instr_is_relative_branch(unsigned int instr); > int instr_is_relative_link_branch(unsigned int instr); > int instr_is_branch_to_addr(const unsigned int *instr, unsigned long addr); > unsigned long branch_target(const unsigned int *instr); > -unsigned int translate_branch(const unsigned int *dest, > - const unsigned int *src); > +int translate_branch(unsigned int *instr, const unsigned int *dest, > + const unsigned int *src); > extern bool is_conditional_branch(unsigned int instr); > #ifdef CONFIG_PPC_BOOK3E_64 > void __patch_exception(int exc, unsigned long addr); > diff --git a/arch/powerpc/kernel/optprobes.c > b/arch/powerpc/kernel/optprobes.c > index 024f7aad1952..445b3dad82dc 100644 > --- a/arch/powerpc/kernel/optprobes.c > +++ b/arch/powerpc/kernel/optprobes.c > @@ -251,15 +251,17 @@ int arch_prepare_optimized_kprobe(struct > optimized_kprobe *op, struct kprobe *p) > goto error; > } > > - branch_op_callback = create_branch((unsigned int *)buff + > TMPL_CALL_HDLR_IDX, > - (unsigned long)op_callback_addr, > - BRANCH_SET_LINK); > + rc = create_branch(&branch_op_callback, > + (unsigned int *)buff + TMPL_CALL_HDLR_IDX, > + (unsigned long)op_callback_addr, > + BRANCH_SET_LINK); > > - branch_emulate_step = create_branch((unsigned int *)buff + > TMPL_EMULATE_IDX, > - (unsigned long)emulate_step_addr, > - BRANCH_SET_LINK); > + rc |= create_branch(&branch_emulate_step, > + (unsigned int *)buff + TMPL_EMULATE_IDX, > + (unsigned long)emulate_step_addr, > + BRANCH_SET_LINK); > > - if (!branch_op_callback || !branch_emulate_step) > + if (rc) > goto error; > > patch_instruction(buff + TMPL_CALL_HDLR_IDX, branch_op_callback); > @@ -305,6 +307,7 @@ int arch_check_optimized_kprobe(struct optimized_kprobe > *op) > > void arch_optimize_kprobes(struct list_head *oplist) > { > + unsigned int instr; > struct optimized_kprobe *op; > struct optimized_kprobe *tmp; > > @@ -315,9 +318,10 @@ void arch_optimize_kprobes(struct list_head *oplist) > */ > memcpy(op->optinsn.copied_insn, op->kp.addr, > RELATIVEJUMP_SIZE); > - patch_instruction(op->kp.addr, > - create_branch((unsigned int *)op->kp.addr, > - (unsigned long)op->optinsn.insn, 0)); > + create_branch(&instr, > + (unsigned int *)op->kp.addr, > + (unsigned long)op->optinsn.insn, 0); > + patch_instruction(op->kp.addr, instr); > list_del_init(&op->list); > } > } > diff --git a/arch/powerpc/kernel/setup_32.c b/arch/powerpc/kernel/setup_32.c > index 5b49b26eb154..c1bdd462c5c0 100644 > --- a/arch/powerpc/kernel/setup_32.c > +++ b/arch/powerpc/kernel/setup_32.c > @@ -88,7 +88,7 @@ notrace void __init machine_init(u64 dt_ptr) > > patch_instruction_site(&patch__memcpy_nocache, PPC_INST_NOP); > > - insn = create_cond_branch(addr, branch_target(addr), 0x820000); > + create_cond_branch(&insn, addr, branch_target(addr), 0x820000); > patch_instruction(addr, insn); /* replace b by bne cr0 */ > > /* Do some early initialization based on the flat device tree */ > diff --git a/arch/powerpc/kernel/trace/ftrace.c > b/arch/powerpc/kernel/trace/ftrace.c > index 7ea0ca044b65..4dcb379133f8 100644 > --- a/arch/powerpc/kernel/trace/ftrace.c > +++ b/arch/powerpc/kernel/trace/ftrace.c > @@ -48,7 +48,7 @@ ftrace_call_replace(unsigned long ip, unsigned long addr, > int link) > addr = ppc_function_entry((void *)addr); > > /* if (link) set op to 'bl' else 'b' */ > - op = create_branch((unsigned int *)ip, addr, link ? 1 : 0); > + create_branch(&op, (unsigned int *)ip, addr, link ? 1 : 0); > > return op; > } > @@ -89,10 +89,11 @@ ftrace_modify_code(unsigned long ip, unsigned int old, > unsigned int new) > */ > static int test_24bit_addr(unsigned long ip, unsigned long addr) > { > + unsigned int op; > addr = ppc_function_entry((void *)addr); > > /* use the create_branch to verify that this offset can be branched */ > - return create_branch((unsigned int *)ip, addr, 0); > + return create_branch(&op, (unsigned int *)ip, addr, 0) == 0; > } > > static int is_bl_op(unsigned int op) > @@ -287,6 +288,7 @@ __ftrace_make_nop(struct module *mod, > static unsigned long find_ftrace_tramp(unsigned long ip) > { > int i; > + unsigned int instr; > > /* > * We have the compiler generated long_branch tramps at the end > @@ -295,7 +297,8 @@ static unsigned long find_ftrace_tramp(unsigned long ip) > for (i = NUM_FTRACE_TRAMPS - 1; i >= 0; i--) > if (!ftrace_tramps[i]) > continue; > - else if (create_branch((void *)ip, ftrace_tramps[i], 0)) > + else if (create_branch(&instr, (void *)ip, > + ftrace_tramps[i], 0) == 0) > return ftrace_tramps[i]; > > return 0; > @@ -324,6 +327,7 @@ static int setup_mcount_compiler_tramp(unsigned long > tramp) > { > int i, op; > unsigned long ptr; > + unsigned int instr; > static unsigned long ftrace_plt_tramps[NUM_FTRACE_TRAMPS]; > > /* Is this a known long jump tramp? */ > @@ -366,7 +370,7 @@ static int setup_mcount_compiler_tramp(unsigned long > tramp) > #else > ptr = ppc_global_function_entry((void *)ftrace_caller); > #endif > - if (!create_branch((void *)tramp, ptr, 0)) { > + if (create_branch(&instr, (void *)tramp, ptr, 0)) { > pr_debug("%ps is not reachable from existing mcount tramp\n", > (void *)ptr); > return -1; > @@ -511,6 +515,7 @@ static int > __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) > { > unsigned int op[2]; > + unsigned int instr; > void *ip = (void *)rec->ip; > unsigned long entry, ptr, tramp; > struct module *mod = rec->arch.mod; > @@ -557,7 +562,7 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long > addr) > } > > /* Ensure branch is within 24 bits */ > - if (!create_branch(ip, tramp, BRANCH_SET_LINK)) { > + if (create_branch(&instr, ip, tramp, BRANCH_SET_LINK)) { > pr_err("Branch out of range\n"); > return -EINVAL; > } > @@ -574,6 +579,7 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long > addr) > static int > __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) > { > + int err; > unsigned int op; > unsigned long ip = rec->ip; > > @@ -594,9 +600,9 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long > addr) > } > > /* create the branch to the trampoline */ > - op = create_branch((unsigned int *)ip, > - rec->arch.mod->arch.tramp, BRANCH_SET_LINK); > - if (!op) { > + err = create_branch(&op, (unsigned int *)ip, > + rec->arch.mod->arch.tramp, BRANCH_SET_LINK); > + if (!err) { should this be `if (err)` as per your new changes ? > pr_err("REL24 out of range!\n"); > return -EINVAL; > } > @@ -776,7 +782,7 @@ __ftrace_modify_call(struct dyn_ftrace *rec, unsigned > long old_addr, > } > > /* Ensure branch is within 24 bits */ > - if (!create_branch((unsigned int *)ip, tramp, BRANCH_SET_LINK)) { > + if (create_branch(&op, (unsigned int *)ip, tramp, BRANCH_SET_LINK)) { > pr_err("Branch out of range\n"); > return -EINVAL; > } > diff --git a/arch/powerpc/lib/code-patching.c b/arch/powerpc/lib/code- > patching.c > index 3345f039a876..4af564aeedf1 100644 > --- a/arch/powerpc/lib/code-patching.c > +++ b/arch/powerpc/lib/code-patching.c > @@ -196,7 +196,10 @@ NOKPROBE_SYMBOL(patch_instruction); > > int patch_branch(unsigned int *addr, unsigned long target, int flags) > { > - return patch_instruction(addr, create_branch(addr, target, flags)); > + unsigned int instr; > + > + create_branch(&instr, addr, target, flags); > + return patch_instruction(addr, instr); > } > > bool is_offset_in_branch_range(long offset) > @@ -243,30 +246,30 @@ bool is_conditional_branch(unsigned int instr) > } > NOKPROBE_SYMBOL(is_conditional_branch); > > -unsigned int create_branch(const unsigned int *addr, > - unsigned long target, int flags) > +int create_branch(unsigned int *instr, > + const unsigned int *addr, > + unsigned long target, int flags) > { > - unsigned int instruction; > long offset; > > + *instr = 0; > offset = target; > if (! (flags & BRANCH_ABSOLUTE)) > offset = offset - (unsigned long)addr; > > /* Check we can represent the target in the instruction format */ > if (!is_offset_in_branch_range(offset)) > - return 0; > + return 1; > > /* Mask out the flags and target, so they don't step on each other. */ > - instruction = 0x48000000 | (flags & 0x3) | (offset & 0x03FFFFFC); > + *instr = 0x48000000 | (flags & 0x3) | (offset & 0x03FFFFFC); > > - return instruction; > + return 0; > } > > -unsigned int create_cond_branch(const unsigned int *addr, > - unsigned long target, int flags) > +int create_cond_branch(unsigned int *instr, const unsigned int *addr, > + unsigned long target, int flags) > { > - unsigned int instruction; > long offset; > > offset = target; > @@ -275,12 +278,12 @@ unsigned int create_cond_branch(const unsigned int > *addr, > > /* Check we can represent the target in the instruction format */ > if (offset < -0x8000 || offset > 0x7FFF || offset & 0x3) > - return 0; > + return 1; > > /* Mask out the flags and target, so they don't step on each other. */ > - instruction = 0x40000000 | (flags & 0x3FF0003) | (offset & 0xFFFC); > + *instr = 0x40000000 | (flags & 0x3FF0003) | (offset & 0xFFFC); > > - return instruction; > + return 0; > } > > static unsigned int branch_opcode(unsigned int instr) > @@ -361,18 +364,18 @@ int instr_is_branch_to_addr(const unsigned int *instr, > unsigned long addr) > return 0; > } > > -unsigned int translate_branch(const unsigned int *dest, const unsigned int > *src) > +int translate_branch(unsigned int *instr, const unsigned int *dest, const > unsigned int *src) > { > unsigned long target; > > target = branch_target(src); > > if (instr_is_branch_iform(*src)) > - return create_branch(dest, target, *src); > + return create_branch(instr, dest, target, *src); > else if (instr_is_branch_bform(*src)) > - return create_cond_branch(dest, target, *src); > + return create_cond_branch(instr, dest, target, *src); > > - return 0; > + return 1; > } > > #ifdef CONFIG_PPC_BOOK3E_64 > @@ -403,6 +406,7 @@ static void __init test_trampoline(void) > > static void __init test_branch_iform(void) > { > + int err; > unsigned int instr; > unsigned long addr; > > @@ -443,35 +447,35 @@ static void __init test_branch_iform(void) > check(instr_is_branch_to_addr(&instr, addr - 0x2000000)); > > /* Branch to self, with link */ > - instr = create_branch(&instr, addr, BRANCH_SET_LINK); > + err = create_branch(&instr, &instr, addr, BRANCH_SET_LINK); > check(instr_is_branch_to_addr(&instr, addr)); > > /* Branch to self - 0x100, with link */ > - instr = create_branch(&instr, addr - 0x100, BRANCH_SET_LINK); > + err = create_branch(&instr, &instr, addr - 0x100, BRANCH_SET_LINK); > check(instr_is_branch_to_addr(&instr, addr - 0x100)); > > /* Branch to self + 0x100, no link */ > - instr = create_branch(&instr, addr + 0x100, 0); > + err = create_branch(&instr, &instr, addr + 0x100, 0); > check(instr_is_branch_to_addr(&instr, addr + 0x100)); > > /* Maximum relative negative offset, - 32 MB */ > - instr = create_branch(&instr, addr - 0x2000000, BRANCH_SET_LINK); > + err = create_branch(&instr, &instr, addr - 0x2000000, BRANCH_SET_LINK); > check(instr_is_branch_to_addr(&instr, addr - 0x2000000)); > > /* Out of range relative negative offset, - 32 MB + 4*/ > - instr = create_branch(&instr, addr - 0x2000004, BRANCH_SET_LINK); > - check(instr == 0); > + err = create_branch(&instr, &instr, addr - 0x2000004, BRANCH_SET_LINK); > + check(err); > > /* Out of range relative positive offset, + 32 MB */ > - instr = create_branch(&instr, addr + 0x2000000, BRANCH_SET_LINK); > - check(instr == 0); > + err = create_branch(&instr, &instr, addr + 0x2000000, BRANCH_SET_LINK); > + check(err); > > /* Unaligned target */ > - instr = create_branch(&instr, addr + 3, BRANCH_SET_LINK); > - check(instr == 0); > + err = create_branch(&instr, &instr, addr + 3, BRANCH_SET_LINK); > + check(err); > > /* Check flags are masked correctly */ > - instr = create_branch(&instr, addr, 0xFFFFFFFC); > + err = create_branch(&instr, &instr, addr, 0xFFFFFFFC); > check(instr_is_branch_to_addr(&instr, addr)); > check(instr == 0x48000000); > } > @@ -480,16 +484,19 @@ static void __init test_create_function_call(void) > { > unsigned int *iptr; > unsigned long dest; > + unsigned int instr; > > /* Check we can create a function call */ > iptr = (unsigned int *)ppc_function_entry(test_trampoline); > dest = ppc_function_entry(test_create_function_call); > - patch_instruction(iptr, create_branch(iptr, dest, BRANCH_SET_LINK)); > + create_branch(&instr, iptr, dest, BRANCH_SET_LINK); > + patch_instruction(iptr, instr); Are we sure that `create_branch()` would always succeed here to do patch_instruction() ? > check(instr_is_branch_to_addr(iptr, dest)); > } > > static void __init test_branch_bform(void) > { > + int err; > unsigned long addr; > unsigned int *iptr, instr, flags; > > @@ -525,35 +532,35 @@ static void __init test_branch_bform(void) > flags = 0x3ff000 | BRANCH_SET_LINK; > > /* Branch to self */ > - instr = create_cond_branch(iptr, addr, flags); > + err = create_cond_branch(&instr, iptr, addr, flags); > check(instr_is_branch_to_addr(&instr, addr)); > > /* Branch to self - 0x100 */ > - instr = create_cond_branch(iptr, addr - 0x100, flags); > + err = create_cond_branch(&instr, iptr, addr - 0x100, flags); > check(instr_is_branch_to_addr(&instr, addr - 0x100)); > > /* Branch to self + 0x100 */ > - instr = create_cond_branch(iptr, addr + 0x100, flags); > + err = create_cond_branch(&instr, iptr, addr + 0x100, flags); > check(instr_is_branch_to_addr(&instr, addr + 0x100)); > > /* Maximum relative negative offset, - 32 KB */ > - instr = create_cond_branch(iptr, addr - 0x8000, flags); > + err = create_cond_branch(&instr, iptr, addr - 0x8000, flags); > check(instr_is_branch_to_addr(&instr, addr - 0x8000)); > > /* Out of range relative negative offset, - 32 KB + 4*/ > - instr = create_cond_branch(iptr, addr - 0x8004, flags); > - check(instr == 0); > + err = create_cond_branch(&instr, iptr, addr - 0x8004, flags); > + check(err); > > /* Out of range relative positive offset, + 32 KB */ > - instr = create_cond_branch(iptr, addr + 0x8000, flags); > - check(instr == 0); > + err = create_cond_branch(&instr, iptr, addr + 0x8000, flags); > + check(err); > > /* Unaligned target */ > - instr = create_cond_branch(iptr, addr + 3, flags); > - check(instr == 0); > + err = create_cond_branch(&instr, iptr, addr + 3, flags); > + check(err); > > /* Check flags are masked correctly */ > - instr = create_cond_branch(iptr, addr, 0xFFFFFFFC); > + err = create_cond_branch(&instr, iptr, addr, 0xFFFFFFFC); > check(instr_is_branch_to_addr(&instr, addr)); > check(instr == 0x43FF0000); > } > @@ -562,6 +569,7 @@ static void __init test_translate_branch(void) > { > unsigned long addr; > unsigned int *p, *q; > + unsigned int instr; > void *buf; > > buf = vmalloc(PAGE_ALIGN(0x2000000 + 1)); > @@ -575,7 +583,8 @@ static void __init test_translate_branch(void) > patch_branch(p, addr, 0); > check(instr_is_branch_to_addr(p, addr)); > q = p + 1; > - patch_instruction(q, translate_branch(q, p)); > + translate_branch(&instr, q, p); > + patch_instruction(q, instr); same here and elsewhere in similar such places where we do patch_instruction() -- Bala > check(instr_is_branch_to_addr(q, addr)); > > /* Maximum negative case, move b . to addr + 32 MB */ > @@ -583,7 +592,8 @@ static void __init test_translate_branch(void) > addr = (unsigned long)p; > patch_branch(p, addr, 0); > q = buf + 0x2000000; > - patch_instruction(q, translate_branch(q, p)); > + translate_branch(&instr, q, p); > + patch_instruction(q, instr); > check(instr_is_branch_to_addr(p, addr)); > check(instr_is_branch_to_addr(q, addr)); > check(*q == 0x4a000000); > @@ -593,7 +603,8 @@ static void __init test_translate_branch(void) > addr = (unsigned long)p; > patch_branch(p, addr, 0); > q = buf + 4; > - patch_instruction(q, translate_branch(q, p)); > + translate_branch(&instr, q, p); > + patch_instruction(q, instr); > check(instr_is_branch_to_addr(p, addr)); > check(instr_is_branch_to_addr(q, addr)); > check(*q == 0x49fffffc); > @@ -603,7 +614,8 @@ static void __init test_translate_branch(void) > addr = 0x1000000 + (unsigned long)buf; > patch_branch(p, addr, BRANCH_SET_LINK); > q = buf + 0x1400000; > - patch_instruction(q, translate_branch(q, p)); > + translate_branch(&instr, q, p); > + patch_instruction(q, instr); > check(instr_is_branch_to_addr(p, addr)); > check(instr_is_branch_to_addr(q, addr)); > > @@ -612,7 +624,8 @@ static void __init test_translate_branch(void) > addr = 0x2000000 + (unsigned long)buf; > patch_branch(p, addr, 0); > q = buf + 4; > - patch_instruction(q, translate_branch(q, p)); > + translate_branch(&instr, q, p); > + patch_instruction(q, instr); > check(instr_is_branch_to_addr(p, addr)); > check(instr_is_branch_to_addr(q, addr)); > > @@ -622,18 +635,22 @@ static void __init test_translate_branch(void) > /* Simple case, branch to self moved a little */ > p = buf; > addr = (unsigned long)p; > - patch_instruction(p, create_cond_branch(p, addr, 0)); > + create_cond_branch(&instr, p, addr, 0); > + patch_instruction(p, instr); > check(instr_is_branch_to_addr(p, addr)); > q = p + 1; > - patch_instruction(q, translate_branch(q, p)); > + translate_branch(&instr, q, p); > + patch_instruction(q, instr); > check(instr_is_branch_to_addr(q, addr)); > > /* Maximum negative case, move b . to addr + 32 KB */ > p = buf; > addr = (unsigned long)p; > - patch_instruction(p, create_cond_branch(p, addr, 0xFFFFFFFC)); > + create_cond_branch(&instr, p, addr, 0xFFFFFFFC); > + patch_instruction(p, instr); > q = buf + 0x8000; > - patch_instruction(q, translate_branch(q, p)); > + translate_branch(&instr, q, p); > + patch_instruction(q, instr); > check(instr_is_branch_to_addr(p, addr)); > check(instr_is_branch_to_addr(q, addr)); > check(*q == 0x43ff8000); > @@ -641,9 +658,11 @@ static void __init test_translate_branch(void) > /* Maximum positive case, move x to x - 32 KB + 4 */ > p = buf + 0x8000; > addr = (unsigned long)p; > - patch_instruction(p, create_cond_branch(p, addr, 0xFFFFFFFC)); > + create_cond_branch(&instr, p, addr, 0xFFFFFFFC); > + patch_instruction(p, instr); > q = buf + 4; > - patch_instruction(q, translate_branch(q, p)); > + translate_branch(&instr, q, p); > + patch_instruction(q, instr); > check(instr_is_branch_to_addr(p, addr)); > check(instr_is_branch_to_addr(q, addr)); > check(*q == 0x43ff7ffc); > @@ -651,18 +670,22 @@ static void __init test_translate_branch(void) > /* Jump to x + 12 KB moved to x + 20 KB */ > p = buf; > addr = 0x3000 + (unsigned long)buf; > - patch_instruction(p, create_cond_branch(p, addr, BRANCH_SET_LINK)); > + create_cond_branch(&instr, p, addr, BRANCH_SET_LINK); > + patch_instruction(p, instr); > q = buf + 0x5000; > - patch_instruction(q, translate_branch(q, p)); > + translate_branch(&instr, q, p); > + patch_instruction(q, instr); > check(instr_is_branch_to_addr(p, addr)); > check(instr_is_branch_to_addr(q, addr)); > > /* Jump to x + 8 KB moved to x - 8 KB + 4 */ > p = buf + 0x2000; > addr = 0x4000 + (unsigned long)buf; > - patch_instruction(p, create_cond_branch(p, addr, 0)); > + create_cond_branch(&instr, p, addr, 0); > + patch_instruction(p, instr); > q = buf + 4; > - patch_instruction(q, translate_branch(q, p)); > + translate_branch(&instr, q, p); > + patch_instruction(q, instr); > check(instr_is_branch_to_addr(p, addr)); > check(instr_is_branch_to_addr(q, addr)); > > diff --git a/arch/powerpc/lib/feature-fixups.c b/arch/powerpc/lib/feature- > fixups.c > index 4ba634b89ce5..b129d7b4e7dd 100644 > --- a/arch/powerpc/lib/feature-fixups.c > +++ b/arch/powerpc/lib/feature-fixups.c > @@ -44,6 +44,7 @@ static unsigned int *calc_addr(struct fixup_entry *fcur, > long offset) > static int patch_alt_instruction(unsigned int *src, unsigned int *dest, > unsigned int *alt_start, unsigned int > *alt_end) > { > + int err; > unsigned int instr; > > instr = *src; > @@ -53,8 +54,8 @@ static int patch_alt_instruction(unsigned int *src, > unsigned int *dest, > > /* Branch within the section doesn't need translating */ > if (target < alt_start || target > alt_end) { > - instr = translate_branch(dest, src); > - if (!instr) > + err = translate_branch(&instr, dest, src); > + if (err) > return 1; > } > }
On Tue, Apr 7, 2020 at 4:10 PM Balamuruhan S <bala24@linux.ibm.com> wrote: > > On Mon, 2020-04-06 at 18:09 +1000, Jordan Niethe wrote: > > create_branch(), create_cond_branch() and translate_branch() return the > > instruction that they create, or return 0 to signal an error. Seperate > > s/seperate/separate thanks. > > > these concerns in preparation for an instruction type that is not just > > an unsigned int. Fill the created instruction to a pointer passed as > > the first parameter to the function and use a non-zero return value to > > signify an error. > > > > Signed-off-by: Jordan Niethe <jniethe5@gmail.com> > > --- > > v5: New to series > > --- > > arch/powerpc/include/asm/code-patching.h | 12 +- > > arch/powerpc/kernel/optprobes.c | 24 ++-- > > arch/powerpc/kernel/setup_32.c | 2 +- > > arch/powerpc/kernel/trace/ftrace.c | 24 ++-- > > arch/powerpc/lib/code-patching.c | 133 +++++++++++++---------- > > arch/powerpc/lib/feature-fixups.c | 5 +- > > 6 files changed, 117 insertions(+), 83 deletions(-) > > > > diff --git a/arch/powerpc/include/asm/code-patching.h > > b/arch/powerpc/include/asm/code-patching.h > > index 898b54262881..351dda7215b6 100644 > > --- a/arch/powerpc/include/asm/code-patching.h > > +++ b/arch/powerpc/include/asm/code-patching.h > > @@ -22,10 +22,10 @@ > > #define BRANCH_ABSOLUTE 0x2 > > > > bool is_offset_in_branch_range(long offset); > > -unsigned int create_branch(const unsigned int *addr, > > - unsigned long target, int flags); > > -unsigned int create_cond_branch(const unsigned int *addr, > > - unsigned long target, int flags); > > +int create_branch(unsigned int *instr, const unsigned int *addr, > > + unsigned long target, int flags); > > +int create_cond_branch(unsigned int *instr, const unsigned int *addr, > > + unsigned long target, int flags); > > int patch_branch(unsigned int *addr, unsigned long target, int flags); > > int patch_instruction(unsigned int *addr, unsigned int instr); > > int raw_patch_instruction(unsigned int *addr, unsigned int instr); > > @@ -60,8 +60,8 @@ int instr_is_relative_branch(unsigned int instr); > > int instr_is_relative_link_branch(unsigned int instr); > > int instr_is_branch_to_addr(const unsigned int *instr, unsigned long addr); > > unsigned long branch_target(const unsigned int *instr); > > -unsigned int translate_branch(const unsigned int *dest, > > - const unsigned int *src); > > +int translate_branch(unsigned int *instr, const unsigned int *dest, > > + const unsigned int *src); > > extern bool is_conditional_branch(unsigned int instr); > > #ifdef CONFIG_PPC_BOOK3E_64 > > void __patch_exception(int exc, unsigned long addr); > > diff --git a/arch/powerpc/kernel/optprobes.c > > b/arch/powerpc/kernel/optprobes.c > > index 024f7aad1952..445b3dad82dc 100644 > > --- a/arch/powerpc/kernel/optprobes.c > > +++ b/arch/powerpc/kernel/optprobes.c > > @@ -251,15 +251,17 @@ int arch_prepare_optimized_kprobe(struct > > optimized_kprobe *op, struct kprobe *p) > > goto error; > > } > > > > - branch_op_callback = create_branch((unsigned int *)buff + > > TMPL_CALL_HDLR_IDX, > > - (unsigned long)op_callback_addr, > > - BRANCH_SET_LINK); > > + rc = create_branch(&branch_op_callback, > > + (unsigned int *)buff + TMPL_CALL_HDLR_IDX, > > + (unsigned long)op_callback_addr, > > + BRANCH_SET_LINK); > > > > - branch_emulate_step = create_branch((unsigned int *)buff + > > TMPL_EMULATE_IDX, > > - (unsigned long)emulate_step_addr, > > - BRANCH_SET_LINK); > > + rc |= create_branch(&branch_emulate_step, > > + (unsigned int *)buff + TMPL_EMULATE_IDX, > > + (unsigned long)emulate_step_addr, > > + BRANCH_SET_LINK); > > > > - if (!branch_op_callback || !branch_emulate_step) > > + if (rc) > > goto error; > > > > patch_instruction(buff + TMPL_CALL_HDLR_IDX, branch_op_callback); > > @@ -305,6 +307,7 @@ int arch_check_optimized_kprobe(struct optimized_kprobe > > *op) > > > > void arch_optimize_kprobes(struct list_head *oplist) > > { > > + unsigned int instr; > > struct optimized_kprobe *op; > > struct optimized_kprobe *tmp; > > > > @@ -315,9 +318,10 @@ void arch_optimize_kprobes(struct list_head *oplist) > > */ > > memcpy(op->optinsn.copied_insn, op->kp.addr, > > RELATIVEJUMP_SIZE); > > - patch_instruction(op->kp.addr, > > - create_branch((unsigned int *)op->kp.addr, > > - (unsigned long)op->optinsn.insn, 0)); > > + create_branch(&instr, > > + (unsigned int *)op->kp.addr, > > + (unsigned long)op->optinsn.insn, 0); > > + patch_instruction(op->kp.addr, instr); > > list_del_init(&op->list); > > } > > } > > diff --git a/arch/powerpc/kernel/setup_32.c b/arch/powerpc/kernel/setup_32.c > > index 5b49b26eb154..c1bdd462c5c0 100644 > > --- a/arch/powerpc/kernel/setup_32.c > > +++ b/arch/powerpc/kernel/setup_32.c > > @@ -88,7 +88,7 @@ notrace void __init machine_init(u64 dt_ptr) > > > > patch_instruction_site(&patch__memcpy_nocache, PPC_INST_NOP); > > > > - insn = create_cond_branch(addr, branch_target(addr), 0x820000); > > + create_cond_branch(&insn, addr, branch_target(addr), 0x820000); > > patch_instruction(addr, insn); /* replace b by bne cr0 */ > > > > /* Do some early initialization based on the flat device tree */ > > diff --git a/arch/powerpc/kernel/trace/ftrace.c > > b/arch/powerpc/kernel/trace/ftrace.c > > index 7ea0ca044b65..4dcb379133f8 100644 > > --- a/arch/powerpc/kernel/trace/ftrace.c > > +++ b/arch/powerpc/kernel/trace/ftrace.c > > @@ -48,7 +48,7 @@ ftrace_call_replace(unsigned long ip, unsigned long addr, > > int link) > > addr = ppc_function_entry((void *)addr); > > > > /* if (link) set op to 'bl' else 'b' */ > > - op = create_branch((unsigned int *)ip, addr, link ? 1 : 0); > > + create_branch(&op, (unsigned int *)ip, addr, link ? 1 : 0); > > > > return op; > > } > > @@ -89,10 +89,11 @@ ftrace_modify_code(unsigned long ip, unsigned int old, > > unsigned int new) > > */ > > static int test_24bit_addr(unsigned long ip, unsigned long addr) > > { > > + unsigned int op; > > addr = ppc_function_entry((void *)addr); > > > > /* use the create_branch to verify that this offset can be branched */ > > - return create_branch((unsigned int *)ip, addr, 0); > > + return create_branch(&op, (unsigned int *)ip, addr, 0) == 0; > > } > > > > static int is_bl_op(unsigned int op) > > @@ -287,6 +288,7 @@ __ftrace_make_nop(struct module *mod, > > static unsigned long find_ftrace_tramp(unsigned long ip) > > { > > int i; > > + unsigned int instr; > > > > /* > > * We have the compiler generated long_branch tramps at the end > > @@ -295,7 +297,8 @@ static unsigned long find_ftrace_tramp(unsigned long ip) > > for (i = NUM_FTRACE_TRAMPS - 1; i >= 0; i--) > > if (!ftrace_tramps[i]) > > continue; > > - else if (create_branch((void *)ip, ftrace_tramps[i], 0)) > > + else if (create_branch(&instr, (void *)ip, > > + ftrace_tramps[i], 0) == 0) > > return ftrace_tramps[i]; > > > > return 0; > > @@ -324,6 +327,7 @@ static int setup_mcount_compiler_tramp(unsigned long > > tramp) > > { > > int i, op; > > unsigned long ptr; > > + unsigned int instr; > > static unsigned long ftrace_plt_tramps[NUM_FTRACE_TRAMPS]; > > > > /* Is this a known long jump tramp? */ > > @@ -366,7 +370,7 @@ static int setup_mcount_compiler_tramp(unsigned long > > tramp) > > #else > > ptr = ppc_global_function_entry((void *)ftrace_caller); > > #endif > > - if (!create_branch((void *)tramp, ptr, 0)) { > > + if (create_branch(&instr, (void *)tramp, ptr, 0)) { > > pr_debug("%ps is not reachable from existing mcount tramp\n", > > (void *)ptr); > > return -1; > > @@ -511,6 +515,7 @@ static int > > __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) > > { > > unsigned int op[2]; > > + unsigned int instr; > > void *ip = (void *)rec->ip; > > unsigned long entry, ptr, tramp; > > struct module *mod = rec->arch.mod; > > @@ -557,7 +562,7 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long > > addr) > > } > > > > /* Ensure branch is within 24 bits */ > > - if (!create_branch(ip, tramp, BRANCH_SET_LINK)) { > > + if (create_branch(&instr, ip, tramp, BRANCH_SET_LINK)) { > > pr_err("Branch out of range\n"); > > return -EINVAL; > > } > > @@ -574,6 +579,7 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long > > addr) > > static int > > __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) > > { > > + int err; > > unsigned int op; > > unsigned long ip = rec->ip; > > > > @@ -594,9 +600,9 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long > > addr) > > } > > > > /* create the branch to the trampoline */ > > - op = create_branch((unsigned int *)ip, > > - rec->arch.mod->arch.tramp, BRANCH_SET_LINK); > > - if (!op) { > > + err = create_branch(&op, (unsigned int *)ip, > > + rec->arch.mod->arch.tramp, BRANCH_SET_LINK); > > + if (!err) { > > > should this be `if (err)` as per your new changes ? You are right. > > > > pr_err("REL24 out of range!\n"); > > return -EINVAL; > > } > > @@ -776,7 +782,7 @@ __ftrace_modify_call(struct dyn_ftrace *rec, unsigned > > long old_addr, > > } > > > > /* Ensure branch is within 24 bits */ > > - if (!create_branch((unsigned int *)ip, tramp, BRANCH_SET_LINK)) { > > + if (create_branch(&op, (unsigned int *)ip, tramp, BRANCH_SET_LINK)) { > > pr_err("Branch out of range\n"); > > return -EINVAL; > > } > > diff --git a/arch/powerpc/lib/code-patching.c b/arch/powerpc/lib/code- > > patching.c > > index 3345f039a876..4af564aeedf1 100644 > > --- a/arch/powerpc/lib/code-patching.c > > +++ b/arch/powerpc/lib/code-patching.c > > @@ -196,7 +196,10 @@ NOKPROBE_SYMBOL(patch_instruction); > > > > int patch_branch(unsigned int *addr, unsigned long target, int flags) > > { > > - return patch_instruction(addr, create_branch(addr, target, flags)); > > + unsigned int instr; > > + > > + create_branch(&instr, addr, target, flags); > > + return patch_instruction(addr, instr); > > } > > > > bool is_offset_in_branch_range(long offset) > > @@ -243,30 +246,30 @@ bool is_conditional_branch(unsigned int instr) > > } > > NOKPROBE_SYMBOL(is_conditional_branch); > > > > -unsigned int create_branch(const unsigned int *addr, > > - unsigned long target, int flags) > > +int create_branch(unsigned int *instr, > > + const unsigned int *addr, > > + unsigned long target, int flags) > > { > > - unsigned int instruction; > > long offset; > > > > + *instr = 0; > > offset = target; > > if (! (flags & BRANCH_ABSOLUTE)) > > offset = offset - (unsigned long)addr; > > > > /* Check we can represent the target in the instruction format */ > > if (!is_offset_in_branch_range(offset)) > > - return 0; > > + return 1; > > > > /* Mask out the flags and target, so they don't step on each other. */ > > - instruction = 0x48000000 | (flags & 0x3) | (offset & 0x03FFFFFC); > > + *instr = 0x48000000 | (flags & 0x3) | (offset & 0x03FFFFFC); > > > > - return instruction; > > + return 0; > > } > > > > -unsigned int create_cond_branch(const unsigned int *addr, > > - unsigned long target, int flags) > > +int create_cond_branch(unsigned int *instr, const unsigned int *addr, > > + unsigned long target, int flags) > > { > > - unsigned int instruction; > > long offset; > > > > offset = target; > > @@ -275,12 +278,12 @@ unsigned int create_cond_branch(const unsigned int > > *addr, > > > > /* Check we can represent the target in the instruction format */ > > if (offset < -0x8000 || offset > 0x7FFF || offset & 0x3) > > - return 0; > > + return 1; > > > > /* Mask out the flags and target, so they don't step on each other. */ > > - instruction = 0x40000000 | (flags & 0x3FF0003) | (offset & 0xFFFC); > > + *instr = 0x40000000 | (flags & 0x3FF0003) | (offset & 0xFFFC); > > > > - return instruction; > > + return 0; > > } > > > > static unsigned int branch_opcode(unsigned int instr) > > @@ -361,18 +364,18 @@ int instr_is_branch_to_addr(const unsigned int *instr, > > unsigned long addr) > > return 0; > > } > > > > -unsigned int translate_branch(const unsigned int *dest, const unsigned int > > *src) > > +int translate_branch(unsigned int *instr, const unsigned int *dest, const > > unsigned int *src) > > { > > unsigned long target; > > > > target = branch_target(src); > > > > if (instr_is_branch_iform(*src)) > > - return create_branch(dest, target, *src); > > + return create_branch(instr, dest, target, *src); > > else if (instr_is_branch_bform(*src)) > > - return create_cond_branch(dest, target, *src); > > + return create_cond_branch(instr, dest, target, *src); > > > > - return 0; > > + return 1; > > } > > > > #ifdef CONFIG_PPC_BOOK3E_64 > > @@ -403,6 +406,7 @@ static void __init test_trampoline(void) > > > > static void __init test_branch_iform(void) > > { > > + int err; > > unsigned int instr; > > unsigned long addr; > > > > @@ -443,35 +447,35 @@ static void __init test_branch_iform(void) > > check(instr_is_branch_to_addr(&instr, addr - 0x2000000)); > > > > /* Branch to self, with link */ > > - instr = create_branch(&instr, addr, BRANCH_SET_LINK); > > + err = create_branch(&instr, &instr, addr, BRANCH_SET_LINK); > > check(instr_is_branch_to_addr(&instr, addr)); > > > > /* Branch to self - 0x100, with link */ > > - instr = create_branch(&instr, addr - 0x100, BRANCH_SET_LINK); > > + err = create_branch(&instr, &instr, addr - 0x100, BRANCH_SET_LINK); > > check(instr_is_branch_to_addr(&instr, addr - 0x100)); > > > > /* Branch to self + 0x100, no link */ > > - instr = create_branch(&instr, addr + 0x100, 0); > > + err = create_branch(&instr, &instr, addr + 0x100, 0); > > check(instr_is_branch_to_addr(&instr, addr + 0x100)); > > > > /* Maximum relative negative offset, - 32 MB */ > > - instr = create_branch(&instr, addr - 0x2000000, BRANCH_SET_LINK); > > + err = create_branch(&instr, &instr, addr - 0x2000000, BRANCH_SET_LINK); > > check(instr_is_branch_to_addr(&instr, addr - 0x2000000)); > > > > /* Out of range relative negative offset, - 32 MB + 4*/ > > - instr = create_branch(&instr, addr - 0x2000004, BRANCH_SET_LINK); > > - check(instr == 0); > > + err = create_branch(&instr, &instr, addr - 0x2000004, BRANCH_SET_LINK); > > + check(err); > > > > /* Out of range relative positive offset, + 32 MB */ > > - instr = create_branch(&instr, addr + 0x2000000, BRANCH_SET_LINK); > > - check(instr == 0); > > + err = create_branch(&instr, &instr, addr + 0x2000000, BRANCH_SET_LINK); > > + check(err); > > > > /* Unaligned target */ > > - instr = create_branch(&instr, addr + 3, BRANCH_SET_LINK); > > - check(instr == 0); > > + err = create_branch(&instr, &instr, addr + 3, BRANCH_SET_LINK); > > + check(err); > > > > /* Check flags are masked correctly */ > > - instr = create_branch(&instr, addr, 0xFFFFFFFC); > > + err = create_branch(&instr, &instr, addr, 0xFFFFFFFC); > > check(instr_is_branch_to_addr(&instr, addr)); > > check(instr == 0x48000000); > > } > > @@ -480,16 +484,19 @@ static void __init test_create_function_call(void) > > { > > unsigned int *iptr; > > unsigned long dest; > > + unsigned int instr; > > > > /* Check we can create a function call */ > > iptr = (unsigned int *)ppc_function_entry(test_trampoline); > > dest = ppc_function_entry(test_create_function_call); > > - patch_instruction(iptr, create_branch(iptr, dest, BRANCH_SET_LINK)); > > + create_branch(&instr, iptr, dest, BRANCH_SET_LINK); > > + patch_instruction(iptr, instr); > > > Are we sure that `create_branch()` would always succeed here to do > patch_instruction() ? > > > > check(instr_is_branch_to_addr(iptr, dest)); > > } > > > > static void __init test_branch_bform(void) > > { > > + int err; > > unsigned long addr; > > unsigned int *iptr, instr, flags; > > > > @@ -525,35 +532,35 @@ static void __init test_branch_bform(void) > > flags = 0x3ff000 | BRANCH_SET_LINK; > > > > /* Branch to self */ > > - instr = create_cond_branch(iptr, addr, flags); > > + err = create_cond_branch(&instr, iptr, addr, flags); > > check(instr_is_branch_to_addr(&instr, addr)); > > > > /* Branch to self - 0x100 */ > > - instr = create_cond_branch(iptr, addr - 0x100, flags); > > + err = create_cond_branch(&instr, iptr, addr - 0x100, flags); > > check(instr_is_branch_to_addr(&instr, addr - 0x100)); > > > > /* Branch to self + 0x100 */ > > - instr = create_cond_branch(iptr, addr + 0x100, flags); > > + err = create_cond_branch(&instr, iptr, addr + 0x100, flags); > > check(instr_is_branch_to_addr(&instr, addr + 0x100)); > > > > /* Maximum relative negative offset, - 32 KB */ > > - instr = create_cond_branch(iptr, addr - 0x8000, flags); > > + err = create_cond_branch(&instr, iptr, addr - 0x8000, flags); > > check(instr_is_branch_to_addr(&instr, addr - 0x8000)); > > > > /* Out of range relative negative offset, - 32 KB + 4*/ > > - instr = create_cond_branch(iptr, addr - 0x8004, flags); > > - check(instr == 0); > > + err = create_cond_branch(&instr, iptr, addr - 0x8004, flags); > > + check(err); > > > > /* Out of range relative positive offset, + 32 KB */ > > - instr = create_cond_branch(iptr, addr + 0x8000, flags); > > - check(instr == 0); > > + err = create_cond_branch(&instr, iptr, addr + 0x8000, flags); > > + check(err); > > > > /* Unaligned target */ > > - instr = create_cond_branch(iptr, addr + 3, flags); > > - check(instr == 0); > > + err = create_cond_branch(&instr, iptr, addr + 3, flags); > > + check(err); > > > > /* Check flags are masked correctly */ > > - instr = create_cond_branch(iptr, addr, 0xFFFFFFFC); > > + err = create_cond_branch(&instr, iptr, addr, 0xFFFFFFFC); > > check(instr_is_branch_to_addr(&instr, addr)); > > check(instr == 0x43FF0000); > > } > > @@ -562,6 +569,7 @@ static void __init test_translate_branch(void) > > { > > unsigned long addr; > > unsigned int *p, *q; > > + unsigned int instr; > > void *buf; > > > > buf = vmalloc(PAGE_ALIGN(0x2000000 + 1)); > > @@ -575,7 +583,8 @@ static void __init test_translate_branch(void) > > patch_branch(p, addr, 0); > > check(instr_is_branch_to_addr(p, addr)); > > q = p + 1; > > - patch_instruction(q, translate_branch(q, p)); > > + translate_branch(&instr, q, p); > > + patch_instruction(q, instr); > > > same here and elsewhere in similar such places where we do patch_instruction() I figured that if the existing code was not checking the return then we probably did not need to add a check. > > -- Bala > > > check(instr_is_branch_to_addr(q, addr)); > > > > /* Maximum negative case, move b . to addr + 32 MB */ > > @@ -583,7 +592,8 @@ static void __init test_translate_branch(void) > > addr = (unsigned long)p; > > patch_branch(p, addr, 0); > > q = buf + 0x2000000; > > - patch_instruction(q, translate_branch(q, p)); > > + translate_branch(&instr, q, p); > > + patch_instruction(q, instr); > > check(instr_is_branch_to_addr(p, addr)); > > check(instr_is_branch_to_addr(q, addr)); > > check(*q == 0x4a000000); > > @@ -593,7 +603,8 @@ static void __init test_translate_branch(void) > > addr = (unsigned long)p; > > patch_branch(p, addr, 0); > > q = buf + 4; > > - patch_instruction(q, translate_branch(q, p)); > > + translate_branch(&instr, q, p); > > + patch_instruction(q, instr); > > check(instr_is_branch_to_addr(p, addr)); > > check(instr_is_branch_to_addr(q, addr)); > > check(*q == 0x49fffffc); > > @@ -603,7 +614,8 @@ static void __init test_translate_branch(void) > > addr = 0x1000000 + (unsigned long)buf; > > patch_branch(p, addr, BRANCH_SET_LINK); > > q = buf + 0x1400000; > > - patch_instruction(q, translate_branch(q, p)); > > + translate_branch(&instr, q, p); > > + patch_instruction(q, instr); > > check(instr_is_branch_to_addr(p, addr)); > > check(instr_is_branch_to_addr(q, addr)); > > > > @@ -612,7 +624,8 @@ static void __init test_translate_branch(void) > > addr = 0x2000000 + (unsigned long)buf; > > patch_branch(p, addr, 0); > > q = buf + 4; > > - patch_instruction(q, translate_branch(q, p)); > > + translate_branch(&instr, q, p); > > + patch_instruction(q, instr); > > check(instr_is_branch_to_addr(p, addr)); > > check(instr_is_branch_to_addr(q, addr)); > > > > @@ -622,18 +635,22 @@ static void __init test_translate_branch(void) > > /* Simple case, branch to self moved a little */ > > p = buf; > > addr = (unsigned long)p; > > - patch_instruction(p, create_cond_branch(p, addr, 0)); > > + create_cond_branch(&instr, p, addr, 0); > > + patch_instruction(p, instr); > > check(instr_is_branch_to_addr(p, addr)); > > q = p + 1; > > - patch_instruction(q, translate_branch(q, p)); > > + translate_branch(&instr, q, p); > > + patch_instruction(q, instr); > > check(instr_is_branch_to_addr(q, addr)); > > > > /* Maximum negative case, move b . to addr + 32 KB */ > > p = buf; > > addr = (unsigned long)p; > > - patch_instruction(p, create_cond_branch(p, addr, 0xFFFFFFFC)); > > + create_cond_branch(&instr, p, addr, 0xFFFFFFFC); > > + patch_instruction(p, instr); > > q = buf + 0x8000; > > - patch_instruction(q, translate_branch(q, p)); > > + translate_branch(&instr, q, p); > > + patch_instruction(q, instr); > > check(instr_is_branch_to_addr(p, addr)); > > check(instr_is_branch_to_addr(q, addr)); > > check(*q == 0x43ff8000); > > @@ -641,9 +658,11 @@ static void __init test_translate_branch(void) > > /* Maximum positive case, move x to x - 32 KB + 4 */ > > p = buf + 0x8000; > > addr = (unsigned long)p; > > - patch_instruction(p, create_cond_branch(p, addr, 0xFFFFFFFC)); > > + create_cond_branch(&instr, p, addr, 0xFFFFFFFC); > > + patch_instruction(p, instr); > > q = buf + 4; > > - patch_instruction(q, translate_branch(q, p)); > > + translate_branch(&instr, q, p); > > + patch_instruction(q, instr); > > check(instr_is_branch_to_addr(p, addr)); > > check(instr_is_branch_to_addr(q, addr)); > > check(*q == 0x43ff7ffc); > > @@ -651,18 +670,22 @@ static void __init test_translate_branch(void) > > /* Jump to x + 12 KB moved to x + 20 KB */ > > p = buf; > > addr = 0x3000 + (unsigned long)buf; > > - patch_instruction(p, create_cond_branch(p, addr, BRANCH_SET_LINK)); > > + create_cond_branch(&instr, p, addr, BRANCH_SET_LINK); > > + patch_instruction(p, instr); > > q = buf + 0x5000; > > - patch_instruction(q, translate_branch(q, p)); > > + translate_branch(&instr, q, p); > > + patch_instruction(q, instr); > > check(instr_is_branch_to_addr(p, addr)); > > check(instr_is_branch_to_addr(q, addr)); > > > > /* Jump to x + 8 KB moved to x - 8 KB + 4 */ > > p = buf + 0x2000; > > addr = 0x4000 + (unsigned long)buf; > > - patch_instruction(p, create_cond_branch(p, addr, 0)); > > + create_cond_branch(&instr, p, addr, 0); > > + patch_instruction(p, instr); > > q = buf + 4; > > - patch_instruction(q, translate_branch(q, p)); > > + translate_branch(&instr, q, p); > > + patch_instruction(q, instr); > > check(instr_is_branch_to_addr(p, addr)); > > check(instr_is_branch_to_addr(q, addr)); > > > > diff --git a/arch/powerpc/lib/feature-fixups.c b/arch/powerpc/lib/feature- > > fixups.c > > index 4ba634b89ce5..b129d7b4e7dd 100644 > > --- a/arch/powerpc/lib/feature-fixups.c > > +++ b/arch/powerpc/lib/feature-fixups.c > > @@ -44,6 +44,7 @@ static unsigned int *calc_addr(struct fixup_entry *fcur, > > long offset) > > static int patch_alt_instruction(unsigned int *src, unsigned int *dest, > > unsigned int *alt_start, unsigned int > > *alt_end) > > { > > + int err; > > unsigned int instr; > > > > instr = *src; > > @@ -53,8 +54,8 @@ static int patch_alt_instruction(unsigned int *src, > > unsigned int *dest, > > > > /* Branch within the section doesn't need translating */ > > if (target < alt_start || target > alt_end) { > > - instr = translate_branch(dest, src); > > - if (!instr) > > + err = translate_branch(&instr, dest, src); > > + if (err) > > return 1; > > } > > } >
On Tue, 2020-04-07 at 16:35 +1000, Jordan Niethe wrote: > On Tue, Apr 7, 2020 at 4:10 PM Balamuruhan S <bala24@linux.ibm.com> wrote: > > On Mon, 2020-04-06 at 18:09 +1000, Jordan Niethe wrote: > > > create_branch(), create_cond_branch() and translate_branch() return the > > > instruction that they create, or return 0 to signal an error. Seperate > > > > s/seperate/separate > thanks. > > > these concerns in preparation for an instruction type that is not just > > > an unsigned int. Fill the created instruction to a pointer passed as > > > the first parameter to the function and use a non-zero return value to > > > signify an error. > > > > > > Signed-off-by: Jordan Niethe <jniethe5@gmail.com> > > > --- > > > v5: New to series > > > --- > > > arch/powerpc/include/asm/code-patching.h | 12 +- > > > arch/powerpc/kernel/optprobes.c | 24 ++-- > > > arch/powerpc/kernel/setup_32.c | 2 +- > > > arch/powerpc/kernel/trace/ftrace.c | 24 ++-- > > > arch/powerpc/lib/code-patching.c | 133 +++++++++++++---------- > > > arch/powerpc/lib/feature-fixups.c | 5 +- > > > 6 files changed, 117 insertions(+), 83 deletions(-) > > > > > > diff --git a/arch/powerpc/include/asm/code-patching.h > > > b/arch/powerpc/include/asm/code-patching.h > > > index 898b54262881..351dda7215b6 100644 > > > --- a/arch/powerpc/include/asm/code-patching.h > > > +++ b/arch/powerpc/include/asm/code-patching.h > > > @@ -22,10 +22,10 @@ > > > #define BRANCH_ABSOLUTE 0x2 > > > > > > bool is_offset_in_branch_range(long offset); > > > -unsigned int create_branch(const unsigned int *addr, > > > - unsigned long target, int flags); > > > -unsigned int create_cond_branch(const unsigned int *addr, > > > - unsigned long target, int flags); > > > +int create_branch(unsigned int *instr, const unsigned int *addr, > > > + unsigned long target, int flags); > > > +int create_cond_branch(unsigned int *instr, const unsigned int *addr, > > > + unsigned long target, int flags); > > > int patch_branch(unsigned int *addr, unsigned long target, int flags); > > > int patch_instruction(unsigned int *addr, unsigned int instr); > > > int raw_patch_instruction(unsigned int *addr, unsigned int instr); > > > @@ -60,8 +60,8 @@ int instr_is_relative_branch(unsigned int instr); > > > int instr_is_relative_link_branch(unsigned int instr); > > > int instr_is_branch_to_addr(const unsigned int *instr, unsigned long > > > addr); > > > unsigned long branch_target(const unsigned int *instr); > > > -unsigned int translate_branch(const unsigned int *dest, > > > - const unsigned int *src); > > > +int translate_branch(unsigned int *instr, const unsigned int *dest, > > > + const unsigned int *src); > > > extern bool is_conditional_branch(unsigned int instr); > > > #ifdef CONFIG_PPC_BOOK3E_64 > > > void __patch_exception(int exc, unsigned long addr); > > > diff --git a/arch/powerpc/kernel/optprobes.c > > > b/arch/powerpc/kernel/optprobes.c > > > index 024f7aad1952..445b3dad82dc 100644 > > > --- a/arch/powerpc/kernel/optprobes.c > > > +++ b/arch/powerpc/kernel/optprobes.c > > > @@ -251,15 +251,17 @@ int arch_prepare_optimized_kprobe(struct > > > optimized_kprobe *op, struct kprobe *p) > > > goto error; > > > } > > > > > > - branch_op_callback = create_branch((unsigned int *)buff + > > > TMPL_CALL_HDLR_IDX, > > > - (unsigned long)op_callback_addr, > > > - BRANCH_SET_LINK); > > > + rc = create_branch(&branch_op_callback, > > > + (unsigned int *)buff + TMPL_CALL_HDLR_IDX, > > > + (unsigned long)op_callback_addr, > > > + BRANCH_SET_LINK); > > > > > > - branch_emulate_step = create_branch((unsigned int *)buff + > > > TMPL_EMULATE_IDX, > > > - (unsigned long)emulate_step_addr, > > > - BRANCH_SET_LINK); > > > + rc |= create_branch(&branch_emulate_step, > > > + (unsigned int *)buff + TMPL_EMULATE_IDX, > > > + (unsigned long)emulate_step_addr, > > > + BRANCH_SET_LINK); > > > > > > - if (!branch_op_callback || !branch_emulate_step) > > > + if (rc) > > > goto error; > > > > > > patch_instruction(buff + TMPL_CALL_HDLR_IDX, branch_op_callback); > > > @@ -305,6 +307,7 @@ int arch_check_optimized_kprobe(struct > > > optimized_kprobe > > > *op) > > > > > > void arch_optimize_kprobes(struct list_head *oplist) > > > { > > > + unsigned int instr; > > > struct optimized_kprobe *op; > > > struct optimized_kprobe *tmp; > > > > > > @@ -315,9 +318,10 @@ void arch_optimize_kprobes(struct list_head *oplist) > > > */ > > > memcpy(op->optinsn.copied_insn, op->kp.addr, > > > RELATIVEJUMP_SIZE); > > > - patch_instruction(op->kp.addr, > > > - create_branch((unsigned int *)op->kp.addr, > > > - (unsigned long)op->optinsn.insn, 0)); > > > + create_branch(&instr, > > > + (unsigned int *)op->kp.addr, > > > + (unsigned long)op->optinsn.insn, 0); > > > + patch_instruction(op->kp.addr, instr); > > > list_del_init(&op->list); > > > } > > > } > > > diff --git a/arch/powerpc/kernel/setup_32.c > > > b/arch/powerpc/kernel/setup_32.c > > > index 5b49b26eb154..c1bdd462c5c0 100644 > > > --- a/arch/powerpc/kernel/setup_32.c > > > +++ b/arch/powerpc/kernel/setup_32.c > > > @@ -88,7 +88,7 @@ notrace void __init machine_init(u64 dt_ptr) > > > > > > patch_instruction_site(&patch__memcpy_nocache, PPC_INST_NOP); > > > > > > - insn = create_cond_branch(addr, branch_target(addr), 0x820000); > > > + create_cond_branch(&insn, addr, branch_target(addr), 0x820000); > > > patch_instruction(addr, insn); /* replace b by bne cr0 */ > > > > > > /* Do some early initialization based on the flat device tree */ > > > diff --git a/arch/powerpc/kernel/trace/ftrace.c > > > b/arch/powerpc/kernel/trace/ftrace.c > > > index 7ea0ca044b65..4dcb379133f8 100644 > > > --- a/arch/powerpc/kernel/trace/ftrace.c > > > +++ b/arch/powerpc/kernel/trace/ftrace.c > > > @@ -48,7 +48,7 @@ ftrace_call_replace(unsigned long ip, unsigned long > > > addr, > > > int link) > > > addr = ppc_function_entry((void *)addr); > > > > > > /* if (link) set op to 'bl' else 'b' */ > > > - op = create_branch((unsigned int *)ip, addr, link ? 1 : 0); > > > + create_branch(&op, (unsigned int *)ip, addr, link ? 1 : 0); > > > > > > return op; > > > } > > > @@ -89,10 +89,11 @@ ftrace_modify_code(unsigned long ip, unsigned int > > > old, > > > unsigned int new) > > > */ > > > static int test_24bit_addr(unsigned long ip, unsigned long addr) > > > { > > > + unsigned int op; > > > addr = ppc_function_entry((void *)addr); > > > > > > /* use the create_branch to verify that this offset can be branched > > > */ > > > - return create_branch((unsigned int *)ip, addr, 0); > > > + return create_branch(&op, (unsigned int *)ip, addr, 0) == 0; > > > } > > > > > > static int is_bl_op(unsigned int op) > > > @@ -287,6 +288,7 @@ __ftrace_make_nop(struct module *mod, > > > static unsigned long find_ftrace_tramp(unsigned long ip) > > > { > > > int i; > > > + unsigned int instr; > > > > > > /* > > > * We have the compiler generated long_branch tramps at the end > > > @@ -295,7 +297,8 @@ static unsigned long find_ftrace_tramp(unsigned long > > > ip) > > > for (i = NUM_FTRACE_TRAMPS - 1; i >= 0; i--) > > > if (!ftrace_tramps[i]) > > > continue; > > > - else if (create_branch((void *)ip, ftrace_tramps[i], 0)) > > > + else if (create_branch(&instr, (void *)ip, > > > + ftrace_tramps[i], 0) == 0) > > > return ftrace_tramps[i]; > > > > > > return 0; > > > @@ -324,6 +327,7 @@ static int setup_mcount_compiler_tramp(unsigned long > > > tramp) > > > { > > > int i, op; > > > unsigned long ptr; > > > + unsigned int instr; > > > static unsigned long ftrace_plt_tramps[NUM_FTRACE_TRAMPS]; > > > > > > /* Is this a known long jump tramp? */ > > > @@ -366,7 +370,7 @@ static int setup_mcount_compiler_tramp(unsigned long > > > tramp) > > > #else > > > ptr = ppc_global_function_entry((void *)ftrace_caller); > > > #endif > > > - if (!create_branch((void *)tramp, ptr, 0)) { > > > + if (create_branch(&instr, (void *)tramp, ptr, 0)) { > > > pr_debug("%ps is not reachable from existing mcount > > > tramp\n", > > > (void *)ptr); > > > return -1; > > > @@ -511,6 +515,7 @@ static int > > > __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) > > > { > > > unsigned int op[2]; > > > + unsigned int instr; > > > void *ip = (void *)rec->ip; > > > unsigned long entry, ptr, tramp; > > > struct module *mod = rec->arch.mod; > > > @@ -557,7 +562,7 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned > > > long > > > addr) > > > } > > > > > > /* Ensure branch is within 24 bits */ > > > - if (!create_branch(ip, tramp, BRANCH_SET_LINK)) { > > > + if (create_branch(&instr, ip, tramp, BRANCH_SET_LINK)) { > > > pr_err("Branch out of range\n"); > > > return -EINVAL; > > > } > > > @@ -574,6 +579,7 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned > > > long > > > addr) > > > static int > > > __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) > > > { > > > + int err; > > > unsigned int op; > > > unsigned long ip = rec->ip; > > > > > > @@ -594,9 +600,9 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned > > > long > > > addr) > > > } > > > > > > /* create the branch to the trampoline */ > > > - op = create_branch((unsigned int *)ip, > > > - rec->arch.mod->arch.tramp, BRANCH_SET_LINK); > > > - if (!op) { > > > + err = create_branch(&op, (unsigned int *)ip, > > > + rec->arch.mod->arch.tramp, BRANCH_SET_LINK); > > > + if (!err) { > > > > should this be `if (err)` as per your new changes ? > You are right. > > > > > pr_err("REL24 out of range!\n"); > > > return -EINVAL; > > > } > > > @@ -776,7 +782,7 @@ __ftrace_modify_call(struct dyn_ftrace *rec, unsigned > > > long old_addr, > > > } > > > > > > /* Ensure branch is within 24 bits */ > > > - if (!create_branch((unsigned int *)ip, tramp, BRANCH_SET_LINK)) { > > > + if (create_branch(&op, (unsigned int *)ip, tramp, BRANCH_SET_LINK)) > > > { > > > pr_err("Branch out of range\n"); > > > return -EINVAL; > > > } > > > diff --git a/arch/powerpc/lib/code-patching.c b/arch/powerpc/lib/code- > > > patching.c > > > index 3345f039a876..4af564aeedf1 100644 > > > --- a/arch/powerpc/lib/code-patching.c > > > +++ b/arch/powerpc/lib/code-patching.c > > > @@ -196,7 +196,10 @@ NOKPROBE_SYMBOL(patch_instruction); > > > > > > int patch_branch(unsigned int *addr, unsigned long target, int flags) > > > { > > > - return patch_instruction(addr, create_branch(addr, target, flags)); > > > + unsigned int instr; > > > + > > > + create_branch(&instr, addr, target, flags); > > > + return patch_instruction(addr, instr); > > > } > > > > > > bool is_offset_in_branch_range(long offset) > > > @@ -243,30 +246,30 @@ bool is_conditional_branch(unsigned int instr) > > > } > > > NOKPROBE_SYMBOL(is_conditional_branch); > > > > > > -unsigned int create_branch(const unsigned int *addr, > > > - unsigned long target, int flags) > > > +int create_branch(unsigned int *instr, > > > + const unsigned int *addr, > > > + unsigned long target, int flags) > > > { > > > - unsigned int instruction; > > > long offset; > > > > > > + *instr = 0; > > > offset = target; > > > if (! (flags & BRANCH_ABSOLUTE)) > > > offset = offset - (unsigned long)addr; > > > > > > /* Check we can represent the target in the instruction format */ > > > if (!is_offset_in_branch_range(offset)) > > > - return 0; > > > + return 1; > > > > > > /* Mask out the flags and target, so they don't step on each other. > > > */ > > > - instruction = 0x48000000 | (flags & 0x3) | (offset & 0x03FFFFFC); > > > + *instr = 0x48000000 | (flags & 0x3) | (offset & 0x03FFFFFC); > > > > > > - return instruction; > > > + return 0; > > > } > > > > > > -unsigned int create_cond_branch(const unsigned int *addr, > > > - unsigned long target, int flags) > > > +int create_cond_branch(unsigned int *instr, const unsigned int *addr, > > > + unsigned long target, int flags) > > > { > > > - unsigned int instruction; > > > long offset; > > > > > > offset = target; > > > @@ -275,12 +278,12 @@ unsigned int create_cond_branch(const unsigned int > > > *addr, > > > > > > /* Check we can represent the target in the instruction format */ > > > if (offset < -0x8000 || offset > 0x7FFF || offset & 0x3) > > > - return 0; > > > + return 1; > > > > > > /* Mask out the flags and target, so they don't step on each other. > > > */ > > > - instruction = 0x40000000 | (flags & 0x3FF0003) | (offset & 0xFFFC); > > > + *instr = 0x40000000 | (flags & 0x3FF0003) | (offset & 0xFFFC); > > > > > > - return instruction; > > > + return 0; > > > } > > > > > > static unsigned int branch_opcode(unsigned int instr) > > > @@ -361,18 +364,18 @@ int instr_is_branch_to_addr(const unsigned int > > > *instr, > > > unsigned long addr) > > > return 0; > > > } > > > > > > -unsigned int translate_branch(const unsigned int *dest, const unsigned > > > int > > > *src) > > > +int translate_branch(unsigned int *instr, const unsigned int *dest, > > > const > > > unsigned int *src) > > > { > > > unsigned long target; > > > > > > target = branch_target(src); > > > > > > if (instr_is_branch_iform(*src)) > > > - return create_branch(dest, target, *src); > > > + return create_branch(instr, dest, target, *src); > > > else if (instr_is_branch_bform(*src)) > > > - return create_cond_branch(dest, target, *src); > > > + return create_cond_branch(instr, dest, target, *src); > > > > > > - return 0; > > > + return 1; > > > } > > > > > > #ifdef CONFIG_PPC_BOOK3E_64 > > > @@ -403,6 +406,7 @@ static void __init test_trampoline(void) > > > > > > static void __init test_branch_iform(void) > > > { > > > + int err; > > > unsigned int instr; > > > unsigned long addr; > > > > > > @@ -443,35 +447,35 @@ static void __init test_branch_iform(void) > > > check(instr_is_branch_to_addr(&instr, addr - 0x2000000)); > > > > > > /* Branch to self, with link */ > > > - instr = create_branch(&instr, addr, BRANCH_SET_LINK); > > > + err = create_branch(&instr, &instr, addr, BRANCH_SET_LINK); > > > check(instr_is_branch_to_addr(&instr, addr)); > > > > > > /* Branch to self - 0x100, with link */ > > > - instr = create_branch(&instr, addr - 0x100, BRANCH_SET_LINK); > > > + err = create_branch(&instr, &instr, addr - 0x100, BRANCH_SET_LINK); > > > check(instr_is_branch_to_addr(&instr, addr - 0x100)); > > > > > > /* Branch to self + 0x100, no link */ > > > - instr = create_branch(&instr, addr + 0x100, 0); > > > + err = create_branch(&instr, &instr, addr + 0x100, 0); > > > check(instr_is_branch_to_addr(&instr, addr + 0x100)); > > > > > > /* Maximum relative negative offset, - 32 MB */ > > > - instr = create_branch(&instr, addr - 0x2000000, BRANCH_SET_LINK); > > > + err = create_branch(&instr, &instr, addr - 0x2000000, > > > BRANCH_SET_LINK); > > > check(instr_is_branch_to_addr(&instr, addr - 0x2000000)); > > > > > > /* Out of range relative negative offset, - 32 MB + 4*/ > > > - instr = create_branch(&instr, addr - 0x2000004, BRANCH_SET_LINK); > > > - check(instr == 0); > > > + err = create_branch(&instr, &instr, addr - 0x2000004, > > > BRANCH_SET_LINK); > > > + check(err); > > > > > > /* Out of range relative positive offset, + 32 MB */ > > > - instr = create_branch(&instr, addr + 0x2000000, BRANCH_SET_LINK); > > > - check(instr == 0); > > > + err = create_branch(&instr, &instr, addr + 0x2000000, > > > BRANCH_SET_LINK); > > > + check(err); > > > > > > /* Unaligned target */ > > > - instr = create_branch(&instr, addr + 3, BRANCH_SET_LINK); > > > - check(instr == 0); > > > + err = create_branch(&instr, &instr, addr + 3, BRANCH_SET_LINK); > > > + check(err); > > > > > > /* Check flags are masked correctly */ > > > - instr = create_branch(&instr, addr, 0xFFFFFFFC); > > > + err = create_branch(&instr, &instr, addr, 0xFFFFFFFC); > > > check(instr_is_branch_to_addr(&instr, addr)); > > > check(instr == 0x48000000); > > > } > > > @@ -480,16 +484,19 @@ static void __init test_create_function_call(void) > > > { > > > unsigned int *iptr; > > > unsigned long dest; > > > + unsigned int instr; > > > > > > /* Check we can create a function call */ > > > iptr = (unsigned int *)ppc_function_entry(test_trampoline); > > > dest = ppc_function_entry(test_create_function_call); > > > - patch_instruction(iptr, create_branch(iptr, dest, > > > BRANCH_SET_LINK)); > > > + create_branch(&instr, iptr, dest, BRANCH_SET_LINK); > > > + patch_instruction(iptr, instr); > > > > Are we sure that `create_branch()` would always succeed here to do > > patch_instruction() ? > > > > > > > check(instr_is_branch_to_addr(iptr, dest)); > > > } > > > > > > static void __init test_branch_bform(void) > > > { > > > + int err; > > > unsigned long addr; > > > unsigned int *iptr, instr, flags; > > > > > > @@ -525,35 +532,35 @@ static void __init test_branch_bform(void) > > > flags = 0x3ff000 | BRANCH_SET_LINK; > > > > > > /* Branch to self */ > > > - instr = create_cond_branch(iptr, addr, flags); > > > + err = create_cond_branch(&instr, iptr, addr, flags); > > > check(instr_is_branch_to_addr(&instr, addr)); > > > > > > /* Branch to self - 0x100 */ > > > - instr = create_cond_branch(iptr, addr - 0x100, flags); > > > + err = create_cond_branch(&instr, iptr, addr - 0x100, flags); > > > check(instr_is_branch_to_addr(&instr, addr - 0x100)); > > > > > > /* Branch to self + 0x100 */ > > > - instr = create_cond_branch(iptr, addr + 0x100, flags); > > > + err = create_cond_branch(&instr, iptr, addr + 0x100, flags); > > > check(instr_is_branch_to_addr(&instr, addr + 0x100)); > > > > > > /* Maximum relative negative offset, - 32 KB */ > > > - instr = create_cond_branch(iptr, addr - 0x8000, flags); > > > + err = create_cond_branch(&instr, iptr, addr - 0x8000, flags); > > > check(instr_is_branch_to_addr(&instr, addr - 0x8000)); > > > > > > /* Out of range relative negative offset, - 32 KB + 4*/ > > > - instr = create_cond_branch(iptr, addr - 0x8004, flags); > > > - check(instr == 0); > > > + err = create_cond_branch(&instr, iptr, addr - 0x8004, flags); > > > + check(err); > > > > > > /* Out of range relative positive offset, + 32 KB */ > > > - instr = create_cond_branch(iptr, addr + 0x8000, flags); > > > - check(instr == 0); > > > + err = create_cond_branch(&instr, iptr, addr + 0x8000, flags); > > > + check(err); > > > > > > /* Unaligned target */ > > > - instr = create_cond_branch(iptr, addr + 3, flags); > > > - check(instr == 0); > > > + err = create_cond_branch(&instr, iptr, addr + 3, flags); > > > + check(err); > > > > > > /* Check flags are masked correctly */ > > > - instr = create_cond_branch(iptr, addr, 0xFFFFFFFC); > > > + err = create_cond_branch(&instr, iptr, addr, 0xFFFFFFFC); > > > check(instr_is_branch_to_addr(&instr, addr)); > > > check(instr == 0x43FF0000); > > > } > > > @@ -562,6 +569,7 @@ static void __init test_translate_branch(void) > > > { > > > unsigned long addr; > > > unsigned int *p, *q; > > > + unsigned int instr; > > > void *buf; > > > > > > buf = vmalloc(PAGE_ALIGN(0x2000000 + 1)); > > > @@ -575,7 +583,8 @@ static void __init test_translate_branch(void) > > > patch_branch(p, addr, 0); > > > check(instr_is_branch_to_addr(p, addr)); > > > q = p + 1; > > > - patch_instruction(q, translate_branch(q, p)); > > > + translate_branch(&instr, q, p); > > > + patch_instruction(q, instr); > > > > same here and elsewhere in similar such places where we do > > patch_instruction() > I figured that if the existing code was not checking the return then > we probably did not need to add a check. yes existing code does not checking, I just wanted to ensure we do right thing. Thanks! -- Bala > > -- Bala > > > > > check(instr_is_branch_to_addr(q, addr)); > > > > > > /* Maximum negative case, move b . to addr + 32 MB */ > > > @@ -583,7 +592,8 @@ static void __init test_translate_branch(void) > > > addr = (unsigned long)p; > > > patch_branch(p, addr, 0); > > > q = buf + 0x2000000; > > > - patch_instruction(q, translate_branch(q, p)); > > > + translate_branch(&instr, q, p); > > > + patch_instruction(q, instr); > > > check(instr_is_branch_to_addr(p, addr)); > > > check(instr_is_branch_to_addr(q, addr)); > > > check(*q == 0x4a000000); > > > @@ -593,7 +603,8 @@ static void __init test_translate_branch(void) > > > addr = (unsigned long)p; > > > patch_branch(p, addr, 0); > > > q = buf + 4; > > > - patch_instruction(q, translate_branch(q, p)); > > > + translate_branch(&instr, q, p); > > > + patch_instruction(q, instr); > > > check(instr_is_branch_to_addr(p, addr)); > > > check(instr_is_branch_to_addr(q, addr)); > > > check(*q == 0x49fffffc); > > > @@ -603,7 +614,8 @@ static void __init test_translate_branch(void) > > > addr = 0x1000000 + (unsigned long)buf; > > > patch_branch(p, addr, BRANCH_SET_LINK); > > > q = buf + 0x1400000; > > > - patch_instruction(q, translate_branch(q, p)); > > > + translate_branch(&instr, q, p); > > > + patch_instruction(q, instr); > > > check(instr_is_branch_to_addr(p, addr)); > > > check(instr_is_branch_to_addr(q, addr)); > > > > > > @@ -612,7 +624,8 @@ static void __init test_translate_branch(void) > > > addr = 0x2000000 + (unsigned long)buf; > > > patch_branch(p, addr, 0); > > > q = buf + 4; > > > - patch_instruction(q, translate_branch(q, p)); > > > + translate_branch(&instr, q, p); > > > + patch_instruction(q, instr); > > > check(instr_is_branch_to_addr(p, addr)); > > > check(instr_is_branch_to_addr(q, addr)); > > > > > > @@ -622,18 +635,22 @@ static void __init test_translate_branch(void) > > > /* Simple case, branch to self moved a little */ > > > p = buf; > > > addr = (unsigned long)p; > > > - patch_instruction(p, create_cond_branch(p, addr, 0)); > > > + create_cond_branch(&instr, p, addr, 0); > > > + patch_instruction(p, instr); > > > check(instr_is_branch_to_addr(p, addr)); > > > q = p + 1; > > > - patch_instruction(q, translate_branch(q, p)); > > > + translate_branch(&instr, q, p); > > > + patch_instruction(q, instr); > > > check(instr_is_branch_to_addr(q, addr)); > > > > > > /* Maximum negative case, move b . to addr + 32 KB */ > > > p = buf; > > > addr = (unsigned long)p; > > > - patch_instruction(p, create_cond_branch(p, addr, 0xFFFFFFFC)); > > > + create_cond_branch(&instr, p, addr, 0xFFFFFFFC); > > > + patch_instruction(p, instr); > > > q = buf + 0x8000; > > > - patch_instruction(q, translate_branch(q, p)); > > > + translate_branch(&instr, q, p); > > > + patch_instruction(q, instr); > > > check(instr_is_branch_to_addr(p, addr)); > > > check(instr_is_branch_to_addr(q, addr)); > > > check(*q == 0x43ff8000); > > > @@ -641,9 +658,11 @@ static void __init test_translate_branch(void) > > > /* Maximum positive case, move x to x - 32 KB + 4 */ > > > p = buf + 0x8000; > > > addr = (unsigned long)p; > > > - patch_instruction(p, create_cond_branch(p, addr, 0xFFFFFFFC)); > > > + create_cond_branch(&instr, p, addr, 0xFFFFFFFC); > > > + patch_instruction(p, instr); > > > q = buf + 4; > > > - patch_instruction(q, translate_branch(q, p)); > > > + translate_branch(&instr, q, p); > > > + patch_instruction(q, instr); > > > check(instr_is_branch_to_addr(p, addr)); > > > check(instr_is_branch_to_addr(q, addr)); > > > check(*q == 0x43ff7ffc); > > > @@ -651,18 +670,22 @@ static void __init test_translate_branch(void) > > > /* Jump to x + 12 KB moved to x + 20 KB */ > > > p = buf; > > > addr = 0x3000 + (unsigned long)buf; > > > - patch_instruction(p, create_cond_branch(p, addr, BRANCH_SET_LINK)); > > > + create_cond_branch(&instr, p, addr, BRANCH_SET_LINK); > > > + patch_instruction(p, instr); > > > q = buf + 0x5000; > > > - patch_instruction(q, translate_branch(q, p)); > > > + translate_branch(&instr, q, p); > > > + patch_instruction(q, instr); > > > check(instr_is_branch_to_addr(p, addr)); > > > check(instr_is_branch_to_addr(q, addr)); > > > > > > /* Jump to x + 8 KB moved to x - 8 KB + 4 */ > > > p = buf + 0x2000; > > > addr = 0x4000 + (unsigned long)buf; > > > - patch_instruction(p, create_cond_branch(p, addr, 0)); > > > + create_cond_branch(&instr, p, addr, 0); > > > + patch_instruction(p, instr); > > > q = buf + 4; > > > - patch_instruction(q, translate_branch(q, p)); > > > + translate_branch(&instr, q, p); > > > + patch_instruction(q, instr); > > > check(instr_is_branch_to_addr(p, addr)); > > > check(instr_is_branch_to_addr(q, addr)); > > > > > > diff --git a/arch/powerpc/lib/feature-fixups.c > > > b/arch/powerpc/lib/feature- > > > fixups.c > > > index 4ba634b89ce5..b129d7b4e7dd 100644 > > > --- a/arch/powerpc/lib/feature-fixups.c > > > +++ b/arch/powerpc/lib/feature-fixups.c > > > @@ -44,6 +44,7 @@ static unsigned int *calc_addr(struct fixup_entry > > > *fcur, > > > long offset) > > > static int patch_alt_instruction(unsigned int *src, unsigned int *dest, > > > unsigned int *alt_start, unsigned int > > > *alt_end) > > > { > > > + int err; > > > unsigned int instr; > > > > > > instr = *src; > > > @@ -53,8 +54,8 @@ static int patch_alt_instruction(unsigned int *src, > > > unsigned int *dest, > > > > > > /* Branch within the section doesn't need translating */ > > > if (target < alt_start || target > alt_end) { > > > - instr = translate_branch(dest, src); > > > - if (!instr) > > > + err = translate_branch(&instr, dest, src); > > > + if (err) > > > return 1; > > > } > > > }
diff --git a/arch/powerpc/include/asm/code-patching.h b/arch/powerpc/include/asm/code-patching.h index 898b54262881..351dda7215b6 100644 --- a/arch/powerpc/include/asm/code-patching.h +++ b/arch/powerpc/include/asm/code-patching.h @@ -22,10 +22,10 @@ #define BRANCH_ABSOLUTE 0x2 bool is_offset_in_branch_range(long offset); -unsigned int create_branch(const unsigned int *addr, - unsigned long target, int flags); -unsigned int create_cond_branch(const unsigned int *addr, - unsigned long target, int flags); +int create_branch(unsigned int *instr, const unsigned int *addr, + unsigned long target, int flags); +int create_cond_branch(unsigned int *instr, const unsigned int *addr, + unsigned long target, int flags); int patch_branch(unsigned int *addr, unsigned long target, int flags); int patch_instruction(unsigned int *addr, unsigned int instr); int raw_patch_instruction(unsigned int *addr, unsigned int instr); @@ -60,8 +60,8 @@ int instr_is_relative_branch(unsigned int instr); int instr_is_relative_link_branch(unsigned int instr); int instr_is_branch_to_addr(const unsigned int *instr, unsigned long addr); unsigned long branch_target(const unsigned int *instr); -unsigned int translate_branch(const unsigned int *dest, - const unsigned int *src); +int translate_branch(unsigned int *instr, const unsigned int *dest, + const unsigned int *src); extern bool is_conditional_branch(unsigned int instr); #ifdef CONFIG_PPC_BOOK3E_64 void __patch_exception(int exc, unsigned long addr); diff --git a/arch/powerpc/kernel/optprobes.c b/arch/powerpc/kernel/optprobes.c index 024f7aad1952..445b3dad82dc 100644 --- a/arch/powerpc/kernel/optprobes.c +++ b/arch/powerpc/kernel/optprobes.c @@ -251,15 +251,17 @@ int arch_prepare_optimized_kprobe(struct optimized_kprobe *op, struct kprobe *p) goto error; } - branch_op_callback = create_branch((unsigned int *)buff + TMPL_CALL_HDLR_IDX, - (unsigned long)op_callback_addr, - BRANCH_SET_LINK); + rc = create_branch(&branch_op_callback, + (unsigned int *)buff + TMPL_CALL_HDLR_IDX, + (unsigned long)op_callback_addr, + BRANCH_SET_LINK); - branch_emulate_step = create_branch((unsigned int *)buff + TMPL_EMULATE_IDX, - (unsigned long)emulate_step_addr, - BRANCH_SET_LINK); + rc |= create_branch(&branch_emulate_step, + (unsigned int *)buff + TMPL_EMULATE_IDX, + (unsigned long)emulate_step_addr, + BRANCH_SET_LINK); - if (!branch_op_callback || !branch_emulate_step) + if (rc) goto error; patch_instruction(buff + TMPL_CALL_HDLR_IDX, branch_op_callback); @@ -305,6 +307,7 @@ int arch_check_optimized_kprobe(struct optimized_kprobe *op) void arch_optimize_kprobes(struct list_head *oplist) { + unsigned int instr; struct optimized_kprobe *op; struct optimized_kprobe *tmp; @@ -315,9 +318,10 @@ void arch_optimize_kprobes(struct list_head *oplist) */ memcpy(op->optinsn.copied_insn, op->kp.addr, RELATIVEJUMP_SIZE); - patch_instruction(op->kp.addr, - create_branch((unsigned int *)op->kp.addr, - (unsigned long)op->optinsn.insn, 0)); + create_branch(&instr, + (unsigned int *)op->kp.addr, + (unsigned long)op->optinsn.insn, 0); + patch_instruction(op->kp.addr, instr); list_del_init(&op->list); } } diff --git a/arch/powerpc/kernel/setup_32.c b/arch/powerpc/kernel/setup_32.c index 5b49b26eb154..c1bdd462c5c0 100644 --- a/arch/powerpc/kernel/setup_32.c +++ b/arch/powerpc/kernel/setup_32.c @@ -88,7 +88,7 @@ notrace void __init machine_init(u64 dt_ptr) patch_instruction_site(&patch__memcpy_nocache, PPC_INST_NOP); - insn = create_cond_branch(addr, branch_target(addr), 0x820000); + create_cond_branch(&insn, addr, branch_target(addr), 0x820000); patch_instruction(addr, insn); /* replace b by bne cr0 */ /* Do some early initialization based on the flat device tree */ diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c index 7ea0ca044b65..4dcb379133f8 100644 --- a/arch/powerpc/kernel/trace/ftrace.c +++ b/arch/powerpc/kernel/trace/ftrace.c @@ -48,7 +48,7 @@ ftrace_call_replace(unsigned long ip, unsigned long addr, int link) addr = ppc_function_entry((void *)addr); /* if (link) set op to 'bl' else 'b' */ - op = create_branch((unsigned int *)ip, addr, link ? 1 : 0); + create_branch(&op, (unsigned int *)ip, addr, link ? 1 : 0); return op; } @@ -89,10 +89,11 @@ ftrace_modify_code(unsigned long ip, unsigned int old, unsigned int new) */ static int test_24bit_addr(unsigned long ip, unsigned long addr) { + unsigned int op; addr = ppc_function_entry((void *)addr); /* use the create_branch to verify that this offset can be branched */ - return create_branch((unsigned int *)ip, addr, 0); + return create_branch(&op, (unsigned int *)ip, addr, 0) == 0; } static int is_bl_op(unsigned int op) @@ -287,6 +288,7 @@ __ftrace_make_nop(struct module *mod, static unsigned long find_ftrace_tramp(unsigned long ip) { int i; + unsigned int instr; /* * We have the compiler generated long_branch tramps at the end @@ -295,7 +297,8 @@ static unsigned long find_ftrace_tramp(unsigned long ip) for (i = NUM_FTRACE_TRAMPS - 1; i >= 0; i--) if (!ftrace_tramps[i]) continue; - else if (create_branch((void *)ip, ftrace_tramps[i], 0)) + else if (create_branch(&instr, (void *)ip, + ftrace_tramps[i], 0) == 0) return ftrace_tramps[i]; return 0; @@ -324,6 +327,7 @@ static int setup_mcount_compiler_tramp(unsigned long tramp) { int i, op; unsigned long ptr; + unsigned int instr; static unsigned long ftrace_plt_tramps[NUM_FTRACE_TRAMPS]; /* Is this a known long jump tramp? */ @@ -366,7 +370,7 @@ static int setup_mcount_compiler_tramp(unsigned long tramp) #else ptr = ppc_global_function_entry((void *)ftrace_caller); #endif - if (!create_branch((void *)tramp, ptr, 0)) { + if (create_branch(&instr, (void *)tramp, ptr, 0)) { pr_debug("%ps is not reachable from existing mcount tramp\n", (void *)ptr); return -1; @@ -511,6 +515,7 @@ static int __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) { unsigned int op[2]; + unsigned int instr; void *ip = (void *)rec->ip; unsigned long entry, ptr, tramp; struct module *mod = rec->arch.mod; @@ -557,7 +562,7 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) } /* Ensure branch is within 24 bits */ - if (!create_branch(ip, tramp, BRANCH_SET_LINK)) { + if (create_branch(&instr, ip, tramp, BRANCH_SET_LINK)) { pr_err("Branch out of range\n"); return -EINVAL; } @@ -574,6 +579,7 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) static int __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) { + int err; unsigned int op; unsigned long ip = rec->ip; @@ -594,9 +600,9 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) } /* create the branch to the trampoline */ - op = create_branch((unsigned int *)ip, - rec->arch.mod->arch.tramp, BRANCH_SET_LINK); - if (!op) { + err = create_branch(&op, (unsigned int *)ip, + rec->arch.mod->arch.tramp, BRANCH_SET_LINK); + if (!err) { pr_err("REL24 out of range!\n"); return -EINVAL; } @@ -776,7 +782,7 @@ __ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, } /* Ensure branch is within 24 bits */ - if (!create_branch((unsigned int *)ip, tramp, BRANCH_SET_LINK)) { + if (create_branch(&op, (unsigned int *)ip, tramp, BRANCH_SET_LINK)) { pr_err("Branch out of range\n"); return -EINVAL; } diff --git a/arch/powerpc/lib/code-patching.c b/arch/powerpc/lib/code-patching.c index 3345f039a876..4af564aeedf1 100644 --- a/arch/powerpc/lib/code-patching.c +++ b/arch/powerpc/lib/code-patching.c @@ -196,7 +196,10 @@ NOKPROBE_SYMBOL(patch_instruction); int patch_branch(unsigned int *addr, unsigned long target, int flags) { - return patch_instruction(addr, create_branch(addr, target, flags)); + unsigned int instr; + + create_branch(&instr, addr, target, flags); + return patch_instruction(addr, instr); } bool is_offset_in_branch_range(long offset) @@ -243,30 +246,30 @@ bool is_conditional_branch(unsigned int instr) } NOKPROBE_SYMBOL(is_conditional_branch); -unsigned int create_branch(const unsigned int *addr, - unsigned long target, int flags) +int create_branch(unsigned int *instr, + const unsigned int *addr, + unsigned long target, int flags) { - unsigned int instruction; long offset; + *instr = 0; offset = target; if (! (flags & BRANCH_ABSOLUTE)) offset = offset - (unsigned long)addr; /* Check we can represent the target in the instruction format */ if (!is_offset_in_branch_range(offset)) - return 0; + return 1; /* Mask out the flags and target, so they don't step on each other. */ - instruction = 0x48000000 | (flags & 0x3) | (offset & 0x03FFFFFC); + *instr = 0x48000000 | (flags & 0x3) | (offset & 0x03FFFFFC); - return instruction; + return 0; } -unsigned int create_cond_branch(const unsigned int *addr, - unsigned long target, int flags) +int create_cond_branch(unsigned int *instr, const unsigned int *addr, + unsigned long target, int flags) { - unsigned int instruction; long offset; offset = target; @@ -275,12 +278,12 @@ unsigned int create_cond_branch(const unsigned int *addr, /* Check we can represent the target in the instruction format */ if (offset < -0x8000 || offset > 0x7FFF || offset & 0x3) - return 0; + return 1; /* Mask out the flags and target, so they don't step on each other. */ - instruction = 0x40000000 | (flags & 0x3FF0003) | (offset & 0xFFFC); + *instr = 0x40000000 | (flags & 0x3FF0003) | (offset & 0xFFFC); - return instruction; + return 0; } static unsigned int branch_opcode(unsigned int instr) @@ -361,18 +364,18 @@ int instr_is_branch_to_addr(const unsigned int *instr, unsigned long addr) return 0; } -unsigned int translate_branch(const unsigned int *dest, const unsigned int *src) +int translate_branch(unsigned int *instr, const unsigned int *dest, const unsigned int *src) { unsigned long target; target = branch_target(src); if (instr_is_branch_iform(*src)) - return create_branch(dest, target, *src); + return create_branch(instr, dest, target, *src); else if (instr_is_branch_bform(*src)) - return create_cond_branch(dest, target, *src); + return create_cond_branch(instr, dest, target, *src); - return 0; + return 1; } #ifdef CONFIG_PPC_BOOK3E_64 @@ -403,6 +406,7 @@ static void __init test_trampoline(void) static void __init test_branch_iform(void) { + int err; unsigned int instr; unsigned long addr; @@ -443,35 +447,35 @@ static void __init test_branch_iform(void) check(instr_is_branch_to_addr(&instr, addr - 0x2000000)); /* Branch to self, with link */ - instr = create_branch(&instr, addr, BRANCH_SET_LINK); + err = create_branch(&instr, &instr, addr, BRANCH_SET_LINK); check(instr_is_branch_to_addr(&instr, addr)); /* Branch to self - 0x100, with link */ - instr = create_branch(&instr, addr - 0x100, BRANCH_SET_LINK); + err = create_branch(&instr, &instr, addr - 0x100, BRANCH_SET_LINK); check(instr_is_branch_to_addr(&instr, addr - 0x100)); /* Branch to self + 0x100, no link */ - instr = create_branch(&instr, addr + 0x100, 0); + err = create_branch(&instr, &instr, addr + 0x100, 0); check(instr_is_branch_to_addr(&instr, addr + 0x100)); /* Maximum relative negative offset, - 32 MB */ - instr = create_branch(&instr, addr - 0x2000000, BRANCH_SET_LINK); + err = create_branch(&instr, &instr, addr - 0x2000000, BRANCH_SET_LINK); check(instr_is_branch_to_addr(&instr, addr - 0x2000000)); /* Out of range relative negative offset, - 32 MB + 4*/ - instr = create_branch(&instr, addr - 0x2000004, BRANCH_SET_LINK); - check(instr == 0); + err = create_branch(&instr, &instr, addr - 0x2000004, BRANCH_SET_LINK); + check(err); /* Out of range relative positive offset, + 32 MB */ - instr = create_branch(&instr, addr + 0x2000000, BRANCH_SET_LINK); - check(instr == 0); + err = create_branch(&instr, &instr, addr + 0x2000000, BRANCH_SET_LINK); + check(err); /* Unaligned target */ - instr = create_branch(&instr, addr + 3, BRANCH_SET_LINK); - check(instr == 0); + err = create_branch(&instr, &instr, addr + 3, BRANCH_SET_LINK); + check(err); /* Check flags are masked correctly */ - instr = create_branch(&instr, addr, 0xFFFFFFFC); + err = create_branch(&instr, &instr, addr, 0xFFFFFFFC); check(instr_is_branch_to_addr(&instr, addr)); check(instr == 0x48000000); } @@ -480,16 +484,19 @@ static void __init test_create_function_call(void) { unsigned int *iptr; unsigned long dest; + unsigned int instr; /* Check we can create a function call */ iptr = (unsigned int *)ppc_function_entry(test_trampoline); dest = ppc_function_entry(test_create_function_call); - patch_instruction(iptr, create_branch(iptr, dest, BRANCH_SET_LINK)); + create_branch(&instr, iptr, dest, BRANCH_SET_LINK); + patch_instruction(iptr, instr); check(instr_is_branch_to_addr(iptr, dest)); } static void __init test_branch_bform(void) { + int err; unsigned long addr; unsigned int *iptr, instr, flags; @@ -525,35 +532,35 @@ static void __init test_branch_bform(void) flags = 0x3ff000 | BRANCH_SET_LINK; /* Branch to self */ - instr = create_cond_branch(iptr, addr, flags); + err = create_cond_branch(&instr, iptr, addr, flags); check(instr_is_branch_to_addr(&instr, addr)); /* Branch to self - 0x100 */ - instr = create_cond_branch(iptr, addr - 0x100, flags); + err = create_cond_branch(&instr, iptr, addr - 0x100, flags); check(instr_is_branch_to_addr(&instr, addr - 0x100)); /* Branch to self + 0x100 */ - instr = create_cond_branch(iptr, addr + 0x100, flags); + err = create_cond_branch(&instr, iptr, addr + 0x100, flags); check(instr_is_branch_to_addr(&instr, addr + 0x100)); /* Maximum relative negative offset, - 32 KB */ - instr = create_cond_branch(iptr, addr - 0x8000, flags); + err = create_cond_branch(&instr, iptr, addr - 0x8000, flags); check(instr_is_branch_to_addr(&instr, addr - 0x8000)); /* Out of range relative negative offset, - 32 KB + 4*/ - instr = create_cond_branch(iptr, addr - 0x8004, flags); - check(instr == 0); + err = create_cond_branch(&instr, iptr, addr - 0x8004, flags); + check(err); /* Out of range relative positive offset, + 32 KB */ - instr = create_cond_branch(iptr, addr + 0x8000, flags); - check(instr == 0); + err = create_cond_branch(&instr, iptr, addr + 0x8000, flags); + check(err); /* Unaligned target */ - instr = create_cond_branch(iptr, addr + 3, flags); - check(instr == 0); + err = create_cond_branch(&instr, iptr, addr + 3, flags); + check(err); /* Check flags are masked correctly */ - instr = create_cond_branch(iptr, addr, 0xFFFFFFFC); + err = create_cond_branch(&instr, iptr, addr, 0xFFFFFFFC); check(instr_is_branch_to_addr(&instr, addr)); check(instr == 0x43FF0000); } @@ -562,6 +569,7 @@ static void __init test_translate_branch(void) { unsigned long addr; unsigned int *p, *q; + unsigned int instr; void *buf; buf = vmalloc(PAGE_ALIGN(0x2000000 + 1)); @@ -575,7 +583,8 @@ static void __init test_translate_branch(void) patch_branch(p, addr, 0); check(instr_is_branch_to_addr(p, addr)); q = p + 1; - patch_instruction(q, translate_branch(q, p)); + translate_branch(&instr, q, p); + patch_instruction(q, instr); check(instr_is_branch_to_addr(q, addr)); /* Maximum negative case, move b . to addr + 32 MB */ @@ -583,7 +592,8 @@ static void __init test_translate_branch(void) addr = (unsigned long)p; patch_branch(p, addr, 0); q = buf + 0x2000000; - patch_instruction(q, translate_branch(q, p)); + translate_branch(&instr, q, p); + patch_instruction(q, instr); check(instr_is_branch_to_addr(p, addr)); check(instr_is_branch_to_addr(q, addr)); check(*q == 0x4a000000); @@ -593,7 +603,8 @@ static void __init test_translate_branch(void) addr = (unsigned long)p; patch_branch(p, addr, 0); q = buf + 4; - patch_instruction(q, translate_branch(q, p)); + translate_branch(&instr, q, p); + patch_instruction(q, instr); check(instr_is_branch_to_addr(p, addr)); check(instr_is_branch_to_addr(q, addr)); check(*q == 0x49fffffc); @@ -603,7 +614,8 @@ static void __init test_translate_branch(void) addr = 0x1000000 + (unsigned long)buf; patch_branch(p, addr, BRANCH_SET_LINK); q = buf + 0x1400000; - patch_instruction(q, translate_branch(q, p)); + translate_branch(&instr, q, p); + patch_instruction(q, instr); check(instr_is_branch_to_addr(p, addr)); check(instr_is_branch_to_addr(q, addr)); @@ -612,7 +624,8 @@ static void __init test_translate_branch(void) addr = 0x2000000 + (unsigned long)buf; patch_branch(p, addr, 0); q = buf + 4; - patch_instruction(q, translate_branch(q, p)); + translate_branch(&instr, q, p); + patch_instruction(q, instr); check(instr_is_branch_to_addr(p, addr)); check(instr_is_branch_to_addr(q, addr)); @@ -622,18 +635,22 @@ static void __init test_translate_branch(void) /* Simple case, branch to self moved a little */ p = buf; addr = (unsigned long)p; - patch_instruction(p, create_cond_branch(p, addr, 0)); + create_cond_branch(&instr, p, addr, 0); + patch_instruction(p, instr); check(instr_is_branch_to_addr(p, addr)); q = p + 1; - patch_instruction(q, translate_branch(q, p)); + translate_branch(&instr, q, p); + patch_instruction(q, instr); check(instr_is_branch_to_addr(q, addr)); /* Maximum negative case, move b . to addr + 32 KB */ p = buf; addr = (unsigned long)p; - patch_instruction(p, create_cond_branch(p, addr, 0xFFFFFFFC)); + create_cond_branch(&instr, p, addr, 0xFFFFFFFC); + patch_instruction(p, instr); q = buf + 0x8000; - patch_instruction(q, translate_branch(q, p)); + translate_branch(&instr, q, p); + patch_instruction(q, instr); check(instr_is_branch_to_addr(p, addr)); check(instr_is_branch_to_addr(q, addr)); check(*q == 0x43ff8000); @@ -641,9 +658,11 @@ static void __init test_translate_branch(void) /* Maximum positive case, move x to x - 32 KB + 4 */ p = buf + 0x8000; addr = (unsigned long)p; - patch_instruction(p, create_cond_branch(p, addr, 0xFFFFFFFC)); + create_cond_branch(&instr, p, addr, 0xFFFFFFFC); + patch_instruction(p, instr); q = buf + 4; - patch_instruction(q, translate_branch(q, p)); + translate_branch(&instr, q, p); + patch_instruction(q, instr); check(instr_is_branch_to_addr(p, addr)); check(instr_is_branch_to_addr(q, addr)); check(*q == 0x43ff7ffc); @@ -651,18 +670,22 @@ static void __init test_translate_branch(void) /* Jump to x + 12 KB moved to x + 20 KB */ p = buf; addr = 0x3000 + (unsigned long)buf; - patch_instruction(p, create_cond_branch(p, addr, BRANCH_SET_LINK)); + create_cond_branch(&instr, p, addr, BRANCH_SET_LINK); + patch_instruction(p, instr); q = buf + 0x5000; - patch_instruction(q, translate_branch(q, p)); + translate_branch(&instr, q, p); + patch_instruction(q, instr); check(instr_is_branch_to_addr(p, addr)); check(instr_is_branch_to_addr(q, addr)); /* Jump to x + 8 KB moved to x - 8 KB + 4 */ p = buf + 0x2000; addr = 0x4000 + (unsigned long)buf; - patch_instruction(p, create_cond_branch(p, addr, 0)); + create_cond_branch(&instr, p, addr, 0); + patch_instruction(p, instr); q = buf + 4; - patch_instruction(q, translate_branch(q, p)); + translate_branch(&instr, q, p); + patch_instruction(q, instr); check(instr_is_branch_to_addr(p, addr)); check(instr_is_branch_to_addr(q, addr)); diff --git a/arch/powerpc/lib/feature-fixups.c b/arch/powerpc/lib/feature-fixups.c index 4ba634b89ce5..b129d7b4e7dd 100644 --- a/arch/powerpc/lib/feature-fixups.c +++ b/arch/powerpc/lib/feature-fixups.c @@ -44,6 +44,7 @@ static unsigned int *calc_addr(struct fixup_entry *fcur, long offset) static int patch_alt_instruction(unsigned int *src, unsigned int *dest, unsigned int *alt_start, unsigned int *alt_end) { + int err; unsigned int instr; instr = *src; @@ -53,8 +54,8 @@ static int patch_alt_instruction(unsigned int *src, unsigned int *dest, /* Branch within the section doesn't need translating */ if (target < alt_start || target > alt_end) { - instr = translate_branch(dest, src); - if (!instr) + err = translate_branch(&instr, dest, src); + if (err) return 1; } }
create_branch(), create_cond_branch() and translate_branch() return the instruction that they create, or return 0 to signal an error. Seperate these concerns in preparation for an instruction type that is not just an unsigned int. Fill the created instruction to a pointer passed as the first parameter to the function and use a non-zero return value to signify an error. Signed-off-by: Jordan Niethe <jniethe5@gmail.com> --- v5: New to series --- arch/powerpc/include/asm/code-patching.h | 12 +- arch/powerpc/kernel/optprobes.c | 24 ++-- arch/powerpc/kernel/setup_32.c | 2 +- arch/powerpc/kernel/trace/ftrace.c | 24 ++-- arch/powerpc/lib/code-patching.c | 133 +++++++++++++---------- arch/powerpc/lib/feature-fixups.c | 5 +- 6 files changed, 117 insertions(+), 83 deletions(-)