| Message ID | 20210506043452.9674-2-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| State | Superseded |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/powerpc/include/asm/code-patching.h b/arch/powerpc/include/asm/code-patching.h index f1d029bf906e5..e51c81e4a9bda 100644 --- a/arch/powerpc/include/asm/code-patching.h +++ b/arch/powerpc/include/asm/code-patching.h @@ -188,4 +188,8 @@ static inline unsigned long ppc_kallsyms_lookup_name(const char *name) ___PPC_RA(__REG_R1) | PPC_LR_STKOFF) #endif /* CONFIG_PPC64 */ +#if IS_BUILTIN(CONFIG_LKDTM) && IS_ENABLED(CONFIG_STRICT_KERNEL_RWX) +unsigned long read_cpu_patching_addr(unsigned int cpu); +#endif + #endif /* _ASM_POWERPC_CODE_PATCHING_H */ diff --git a/arch/powerpc/lib/code-patching.c b/arch/powerpc/lib/code-patching.c index 870b30d9be2f8..2b1b3e9043ade 100644 --- a/arch/powerpc/lib/code-patching.c +++ b/arch/powerpc/lib/code-patching.c @@ -48,6 +48,13 @@ int raw_patch_instruction(struct ppc_inst *addr, struct ppc_inst instr) #ifdef CONFIG_STRICT_KERNEL_RWX static DEFINE_PER_CPU(struct vm_struct *, text_poke_area); +#if IS_BUILTIN(CONFIG_LKDTM) +unsigned long read_cpu_patching_addr(unsigned int cpu) +{ + return (unsigned long)(per_cpu(text_poke_area, cpu))->addr; +} +#endif + static int text_area_cpu_up(unsigned int cpu) { struct vm_struct *area;
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/powerpc/include/asm/code-patching.h | 4 ++++ arch/powerpc/lib/code-patching.c | 7 +++++++ 2 files changed, 11 insertions(+)