@@ -24,7 +24,7 @@
| parisc: | ok |
| powerpc: | ok |
| riscv: | TODO |
- | s390: | TODO |
+ | s390: | ok |
| sh: | TODO |
| sparc: | TODO |
| um: | TODO |
@@ -155,6 +155,7 @@ config S390
select HAVE_KERNEL_UNCOMPRESSED
select HAVE_KERNEL_XZ
select HAVE_KPROBES
+ select HAVE_KPROBES_ON_FTRACE
select HAVE_KRETPROBES
select HAVE_KVM
select HAVE_LIVEPATCH
@@ -54,7 +54,6 @@ typedef u16 kprobe_opcode_t;
struct arch_specific_insn {
/* copy of original instruction */
kprobe_opcode_t *insn;
- unsigned int is_ftrace_insn : 1;
};
struct prev_kprobe {
@@ -72,15 +72,6 @@ static inline void ftrace_generate_orig_insn(struct ftrace_insn *insn)
#endif
}
-static inline int is_kprobe_on_ftrace(struct ftrace_insn *insn)
-{
-#ifdef CONFIG_KPROBES
- if (insn->opc == BREAKPOINT_INSTRUCTION)
- return 1;
-#endif
- return 0;
-}
-
static inline void ftrace_generate_kprobe_nop_insn(struct ftrace_insn *insn)
{
#ifdef CONFIG_KPROBES
@@ -114,16 +105,6 @@ int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec,
/* Initial code replacement */
ftrace_generate_orig_insn(&orig);
ftrace_generate_nop_insn(&new);
- } else if (is_kprobe_on_ftrace(&old)) {
- /*
- * If we find a breakpoint instruction, a kprobe has been
- * placed at the beginning of the function. We write the
- * constant KPROBE_ON_FTRACE_NOP into the remaining four
- * bytes of the original instruction so that the kprobes
- * handler can execute a nop, if it reaches this breakpoint.
- */
- ftrace_generate_kprobe_call_insn(&orig);
- ftrace_generate_kprobe_nop_insn(&new);
} else {
/* Replace ftrace call with a nop. */
ftrace_generate_call_insn(&orig, rec->ip);
@@ -142,21 +123,10 @@ int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
if (probe_kernel_read(&old, (void *) rec->ip, sizeof(old)))
return -EFAULT;
- if (is_kprobe_on_ftrace(&old)) {
- /*
- * If we find a breakpoint instruction, a kprobe has been
- * placed at the beginning of the function. We write the
- * constant KPROBE_ON_FTRACE_CALL into the remaining four
- * bytes of the original instruction so that the kprobes
- * handler can execute a brasl if it reaches this breakpoint.
- */
- ftrace_generate_kprobe_nop_insn(&orig);
- ftrace_generate_kprobe_call_insn(&new);
- } else {
- /* Replace nop with an ftrace call. */
- ftrace_generate_nop_insn(&orig);
- ftrace_generate_call_insn(&new, rec->ip);
- }
+ /* Replace nop with an ftrace call. */
+ ftrace_generate_nop_insn(&orig);
+ ftrace_generate_call_insn(&new, rec->ip);
+
/* Verify that the to be replaced code matches what we expect. */
if (memcmp(&orig, &old, sizeof(old)))
return -EINVAL;
@@ -241,3 +211,45 @@ int ftrace_disable_ftrace_graph_caller(void)
}
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+
+#ifdef CONFIG_KPROBES_ON_FTRACE
+void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
+ struct ftrace_ops *ops, struct pt_regs *regs)
+{
+ struct kprobe_ctlblk *kcb;
+ struct kprobe *p = get_kprobe((kprobe_opcode_t *)ip);
+
+ if (unlikely(!p) || kprobe_disabled(p))
+ return;
+
+ if (kprobe_running()) {
+ kprobes_inc_nmissed_count(p);
+ return;
+ }
+
+ __this_cpu_write(current_kprobe, p);
+
+ kcb = get_kprobe_ctlblk();
+ kcb->kprobe_status = KPROBE_HIT_ACTIVE;
+
+ instruction_pointer_set(regs, ip);
+
+ if (!p->pre_handler || !p->pre_handler(p, regs)) {
+
+ instruction_pointer_set(regs, ip + MCOUNT_INSN_SIZE);
+
+ if (unlikely(p->post_handler)) {
+ kcb->kprobe_status = KPROBE_HIT_SSDONE;
+ p->post_handler(p, regs, 0);
+ }
+ }
+ __this_cpu_write(current_kprobe, NULL);
+}
+NOKPROBE_SYMBOL(kprobe_ftrace_handler);
+
+int arch_prepare_kprobe_ftrace(struct kprobe *p)
+{
+ p->ainsn.insn = NULL;
+ return 0;
+}
+#endif
@@ -56,21 +56,10 @@ struct kprobe_insn_cache kprobe_s390_insn_slots = {
static void copy_instruction(struct kprobe *p)
{
- unsigned long ip = (unsigned long) p->addr;
s64 disp, new_disp;
u64 addr, new_addr;
- if (ftrace_location(ip) == ip) {
- /*
- * If kprobes patches the instruction that is morphed by
- * ftrace make sure that kprobes always sees the branch
- * "jg .+24" that skips the mcount block or the "brcl 0,0"
- * in case of hotpatch.
- */
- ftrace_generate_nop_insn((struct ftrace_insn *)p->ainsn.insn);
- p->ainsn.is_ftrace_insn = 1;
- } else
- memcpy(p->ainsn.insn, p->addr, insn_length(*p->addr >> 8));
+ memcpy(p->ainsn.insn, p->addr, insn_length(*p->addr >> 8));
p->opcode = p->ainsn.insn[0];
if (!probe_is_insn_relative_long(p->ainsn.insn))
return;
@@ -136,11 +125,6 @@ int arch_prepare_kprobe(struct kprobe *p)
}
NOKPROBE_SYMBOL(arch_prepare_kprobe);
-int arch_check_ftrace_location(struct kprobe *p)
-{
- return 0;
-}
-
struct swap_insn_args {
struct kprobe *p;
unsigned int arm_kprobe : 1;
@@ -149,28 +133,11 @@ struct swap_insn_args {
static int swap_instruction(void *data)
{
struct swap_insn_args *args = data;
- struct ftrace_insn new_insn, *insn;
struct kprobe *p = args->p;
- size_t len;
-
- new_insn.opc = args->arm_kprobe ? BREAKPOINT_INSTRUCTION : p->opcode;
- len = sizeof(new_insn.opc);
- if (!p->ainsn.is_ftrace_insn)
- goto skip_ftrace;
- len = sizeof(new_insn);
- insn = (struct ftrace_insn *) p->addr;
- if (args->arm_kprobe) {
- if (is_ftrace_nop(insn))
- new_insn.disp = KPROBE_ON_FTRACE_NOP;
- else
- new_insn.disp = KPROBE_ON_FTRACE_CALL;
- } else {
- ftrace_generate_call_insn(&new_insn, (unsigned long)p->addr);
- if (insn->disp == KPROBE_ON_FTRACE_NOP)
- ftrace_generate_nop_insn(&new_insn);
- }
-skip_ftrace:
- s390_kernel_write(p->addr, &new_insn, len);
+ u16 opc;
+
+ opc = args->arm_kprobe ? BREAKPOINT_INSTRUCTION : p->opcode;
+ s390_kernel_write(p->addr, &opc, sizeof(opc));
return 0;
}
NOKPROBE_SYMBOL(swap_instruction);
@@ -464,24 +431,6 @@ static void resume_execution(struct kprobe *p, struct pt_regs *regs)
unsigned long ip = regs->psw.addr;
int fixup = probe_get_fixup_type(p->ainsn.insn);
- /* Check if the kprobes location is an enabled ftrace caller */
- if (p->ainsn.is_ftrace_insn) {
- struct ftrace_insn *insn = (struct ftrace_insn *) p->addr;
- struct ftrace_insn call_insn;
-
- ftrace_generate_call_insn(&call_insn, (unsigned long) p->addr);
- /*
- * A kprobe on an enabled ftrace call site actually single
- * stepped an unconditional branch (ftrace nop equivalent).
- * Now we need to fixup things and pretend that a brasl r0,...
- * was executed instead.
- */
- if (insn->disp == KPROBE_ON_FTRACE_CALL) {
- ip += call_insn.disp * 2 - MCOUNT_INSN_SIZE;
- regs->gprs[0] = (unsigned long)p->addr + sizeof(*insn);
- }
- }
-
if (fixup & FIXUP_PSW_NORMAL)
ip += (unsigned long) p->addr - (unsigned long) p->ainsn.insn;
@@ -42,6 +42,9 @@ ENTRY(ftrace_caller)
.globl ftrace_regs_caller
.set ftrace_regs_caller,ftrace_caller
stg %r14,(__SF_GPRS+8*8)(%r15) # save traced function caller
+ lghi %r14,0 # save condition code
+ ipm %r14 # don't put any instructions
+ sllg %r14,%r14,16 # clobbering CC before this point
lgr %r1,%r15
#if !(defined(CC_USING_HOTPATCH) || defined(CC_USING_NOP_MCOUNT))
aghi %r0,MCOUNT_RETURN_FIXUP
@@ -54,6 +57,9 @@ ENTRY(ftrace_caller)
# allocate pt_regs and stack frame for ftrace_trace_function
aghi %r15,-STACK_FRAME_SIZE
stg %r1,(STACK_PTREGS_GPRS+15*8)(%r15)
+ stg %r14,(STACK_PTREGS_PSW)(%r15)
+ lg %r14,(__SF_GPRS+8*8)(%r1) # restore original return address
+ stosm (STACK_PTREGS_PSW)(%r15),0
aghi %r1,-TRACED_FUNC_FRAME_SIZE
stg %r1,__SF_BACKCHAIN(%r15)
stg %r0,(STACK_PTREGS_PSW+8)(%r15)