| Message ID | 20210506043452.9674-4-cmr@linux.ibm.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Use per-CPU temporary mappings for patching | 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, 21 lines checked |
| snowpatch_ozlabs/needsstable | success | Patch has no Fixes tags |
diff --git a/arch/x86/include/asm/text-patching.h b/arch/x86/include/asm/text-patching.h index b7421780e4e92..f0caf9ee13bd8 100644 --- a/arch/x86/include/asm/text-patching.h +++ b/arch/x86/include/asm/text-patching.h @@ -167,4 +167,8 @@ void int3_emulate_ret(struct pt_regs *regs) } #endif /* !CONFIG_UML_X86 */ +#if IS_BUILTIN(CONFIG_LKDTM) +unsigned long read_cpu_patching_addr(unsigned int cpu); +#endif + #endif /* _ASM_X86_TEXT_PATCHING_H */ diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index 8d778e46725d2..4c95fdd9b1965 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -852,6 +852,13 @@ static inline void unuse_temporary_mm(temp_mm_state_t prev_state) __ro_after_init struct mm_struct *poking_mm; __ro_after_init unsigned long poking_addr; +#if IS_BUILTIN(CONFIG_LKDTM) +unsigned long read_cpu_patching_addr(unsigned int cpu) +{ + return poking_addr; +} +#endif + static void *__text_poke(void *addr, const void *opcode, size_t len) { bool cross_page_boundary = offset_in_page(addr) + len > PAGE_SIZE;
When live patching with STRICT_KERNEL_RWX a mapping is installed at a "patching address" with temporary write permissions. Provide a LKDTM-only accessor function for this address in preparation for a LKDTM test which attempts to "hijack" this mapping by writing to it from another CPU. Signed-off-by: Christopher M. Riedl <cmr@linux.ibm.com> --- arch/x86/include/asm/text-patching.h | 4 ++++ arch/x86/kernel/alternative.c | 7 +++++++ 2 files changed, 11 insertions(+)