Message ID | 20210311091538.368590-1-ravi.bangoria@linux.ibm.com (mailing list archive) |
---|---|
State | Accepted |
Headers | show |
Series | [v5] powerpc/uprobes: Validation for prefixed instruction | expand |
Related | show |
Context | Check | Description |
---|---|---|
snowpatch_ozlabs/apply_patch | success | Successfully applied on branch powerpc/merge (91966823812efbd175f904599e5cf2a854b39809) |
snowpatch_ozlabs/build-ppc64le | success | Build succeeded |
snowpatch_ozlabs/build-ppc64be | success | Build succeeded |
snowpatch_ozlabs/build-ppc64e | success | Build succeeded |
snowpatch_ozlabs/build-pmac32 | success | Build succeeded |
snowpatch_ozlabs/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 13 lines checked |
snowpatch_ozlabs/needsstable | success | Patch has no Fixes tags |
On Thu, 11 Mar 2021 14:45:38 +0530, Ravi Bangoria wrote: > As per ISA 3.1, prefixed instruction should not cross 64-byte > boundary. So don't allow Uprobe on such prefixed instruction. > > There are two ways probed instruction is changed in mapped pages. > First, when Uprobe is activated, it searches for all the relevant > pages and replace instruction in them. In this case, if that probe > is on the 64-byte unaligned prefixed instruction, error out > directly. Second, when Uprobe is already active and user maps a > relevant page via mmap(), instruction is replaced via mmap() code > path. But because Uprobe is invalid, entire mmap() operation can > not be stopped. In this case just print an error and continue. Applied to powerpc/next. [1/1] powerpc/uprobes: Validation for prefixed instruction https://git.kernel.org/powerpc/c/d943bc742a6aabc578b6b62a713ceedf8bf16623 cheers
diff --git a/arch/powerpc/kernel/uprobes.c b/arch/powerpc/kernel/uprobes.c index e8a63713e655..186f69b11e94 100644 --- a/arch/powerpc/kernel/uprobes.c +++ b/arch/powerpc/kernel/uprobes.c @@ -41,6 +41,13 @@ int arch_uprobe_analyze_insn(struct arch_uprobe *auprobe, if (addr & 0x03) return -EINVAL; + if (cpu_has_feature(CPU_FTR_ARCH_31) && + ppc_inst_prefixed(auprobe->insn) && + (addr & 0x3f) == 60) { + pr_info_ratelimited("Cannot register a uprobe on 64 byte unaligned prefixed instruction\n"); + return -EINVAL; + } + return 0; }