| Message ID | 20210506023449.3568630-4-jniethe5@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | powerpc: Further Strict RWX support | expand |
| Related | show |
| Context | Check | Description |
|---|---|---|
| snowpatch_ozlabs/apply_patch | success | Successfully applied on branch powerpc/merge (7619d98e5041d5c25aba5428704dba6121237a9a) |
| snowpatch_ozlabs/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 34 lines checked |
| snowpatch_ozlabs/needsstable | success | Patch has no Fixes tags |
Le 06/05/2021 à 04:34, Jordan Niethe a écrit : > From: Russell Currey <ruscur@russell.cc> > > Add the arch specific insn page allocator for powerpc. This allocates > ROX pages if STRICT_KERNEL_RWX is enabled. These pages are only written > to with patch_instruction() which is able to write RO pages. > > Reviewed-by: Daniel Axtens <dja@axtens.net> > Signed-off-by: Russell Currey <ruscur@russell.cc> > Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> > [jpn: Reword commit message, switch to __vmalloc_node_range()] > Signed-off-by: Jordan Niethe <jniethe5@gmail.com> > --- > v9: - vmalloc_exec() no longer exists > - Set the page to RW before freeing it > v10: - use __vmalloc_node_range() > v11: - Neaten up > v12: - Switch from __vmalloc_node_range() to module_alloc() > --- > arch/powerpc/kernel/kprobes.c | 17 +++++++++++++++++ > 1 file changed, 17 insertions(+) > > diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c > index 01ab2163659e..73a294802f72 100644 > --- a/arch/powerpc/kernel/kprobes.c > +++ b/arch/powerpc/kernel/kprobes.c > @@ -19,11 +19,13 @@ > #include <linux/extable.h> > #include <linux/kdebug.h> > #include <linux/slab.h> > +#include <linux/moduleloader.h> > #include <asm/code-patching.h> > #include <asm/cacheflush.h> > #include <asm/sstep.h> > #include <asm/sections.h> > #include <asm/inst.h> > +#include <asm/set_memory.h> > #include <linux/uaccess.h> > > DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL; > @@ -103,6 +105,21 @@ kprobe_opcode_t *kprobe_lookup_name(const char *name, unsigned int offset) > return addr; > } > > +void *alloc_insn_page(void) > +{ > + void *page; > + > + page = module_alloc(PAGE_SIZE); > + if (!page) > + return NULL; > + > + if (IS_ENABLED(CONFIG_STRICT_MODULE_RWX)) { I'm not sure this test is OK, because strict kernel/module rwx can be disabled at boottime. There is a global variable 'rodata_enabled' to reflect that. We have a helper in powerpc asm/mmu.h called strict_kernel_rwx_enabled() to check it. > + set_memory_ro((unsigned long)page, 1); > + set_memory_x((unsigned long)page, 1); > + } > + return page; > +} > + > int arch_prepare_kprobe(struct kprobe *p) > { > int ret = 0; >
diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c index 01ab2163659e..73a294802f72 100644 --- a/arch/powerpc/kernel/kprobes.c +++ b/arch/powerpc/kernel/kprobes.c @@ -19,11 +19,13 @@ #include <linux/extable.h> #include <linux/kdebug.h> #include <linux/slab.h> +#include <linux/moduleloader.h> #include <asm/code-patching.h> #include <asm/cacheflush.h> #include <asm/sstep.h> #include <asm/sections.h> #include <asm/inst.h> +#include <asm/set_memory.h> #include <linux/uaccess.h> DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL; @@ -103,6 +105,21 @@ kprobe_opcode_t *kprobe_lookup_name(const char *name, unsigned int offset) return addr; } +void *alloc_insn_page(void) +{ + void *page; + + page = module_alloc(PAGE_SIZE); + if (!page) + return NULL; + + if (IS_ENABLED(CONFIG_STRICT_MODULE_RWX)) { + set_memory_ro((unsigned long)page, 1); + set_memory_x((unsigned long)page, 1); + } + return page; +} + int arch_prepare_kprobe(struct kprobe *p) { int ret = 0;