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| author | Vasily Gorbik <gor@linux.ibm.com> | 2024-08-28 19:06:58 +0200 |
|---|---|---|
| committer | Vasily Gorbik <gor@linux.ibm.com> | 2024-08-29 22:56:34 +0200 |
| commit | 5200614080cd7a0fca7424b711cab503dfe6bdca (patch) | |
| tree | 6364f04eb84a89fad8330075d605710c189faa88 | |
| parent | efd9cd019e95d399e27be8dfbfc1df91517c0813 (diff) | |
| download | linux-5200614080cd7a0fca7424b711cab503dfe6bdca.tar.gz linux-5200614080cd7a0fca7424b711cab503dfe6bdca.tar.bz2 linux-5200614080cd7a0fca7424b711cab503dfe6bdca.zip | |
s390/ftrace: Use get/copy_from_kernel_nofault consistently
Use get/copy_from_kernel_nofault to access the kernel text consistently.
Replace memcmp() in ftrace_init_nop() to ensure that in case of
inconsistencies in the 'mcount' table, the kernel reports a failure
instead of potentially crashing.
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
| -rw-r--r-- | arch/s390/kernel/ftrace.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/arch/s390/kernel/ftrace.c b/arch/s390/kernel/ftrace.c index 03eadf7d098e..5ae1bf6167bf 100644 --- a/arch/s390/kernel/ftrace.c +++ b/arch/s390/kernel/ftrace.c @@ -76,12 +76,13 @@ int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec) { static struct ftrace_hotpatch_trampoline *next_vmlinux_trampoline = __ftrace_hotpatch_trampolines_start; - static const char orig[6] = { 0xc0, 0x04, 0x00, 0x00, 0x00, 0x00 }; + static const struct ftrace_insn orig = { .opc = 0xc004, .disp = 0 }; static struct ftrace_hotpatch_trampoline *trampoline; struct ftrace_hotpatch_trampoline **next_trampoline; struct ftrace_hotpatch_trampoline *trampolines_end; struct ftrace_hotpatch_trampoline tmp; struct ftrace_insn *insn; + struct ftrace_insn old; const char *shared; s32 disp; @@ -102,8 +103,10 @@ int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec) return -ENOMEM; trampoline = (*next_trampoline)++; + if (copy_from_kernel_nofault(&old, (void *)rec->ip, sizeof(old))) + return -EFAULT; /* Check for the compiler-generated fentry nop (brcl 0, .). */ - if (WARN_ON_ONCE(memcmp((const void *)rec->ip, &orig, sizeof(orig)))) + if (WARN_ON_ONCE(memcmp(&orig, &old, sizeof(old)))) return -EINVAL; /* Generate the trampoline. */ |