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| author | Jordan Niethe <jniethe5@gmail.com> | 2020-05-06 05:40:47 +0200 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2020-05-18 16:11:03 +0200 |
| commit | b4657f7650babc9bfb41ce875abe41b18604a105 (patch) | |
| tree | 64db3b5a2300ec45c04664b69b26079c0d5b68d8 | |
| parent | powerpc/xmon: Don't allow breakpoints on suffixes (diff) | |
| download | linux-b4657f7650babc9bfb41ce875abe41b18604a105.tar.xz linux-b4657f7650babc9bfb41ce875abe41b18604a105.zip | |
powerpc/kprobes: Don't allow breakpoints on suffixes
Do not allow inserting breakpoints on the suffix of a prefix instruction
in kprobes.
Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200506034050.24806-28-jniethe5@gmail.com
| -rw-r--r-- | arch/powerpc/kernel/kprobes.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c index 33d54b091c70..227510df8c55 100644 --- a/arch/powerpc/kernel/kprobes.c +++ b/arch/powerpc/kernel/kprobes.c @@ -106,7 +106,9 @@ kprobe_opcode_t *kprobe_lookup_name(const char *name, unsigned int offset) int arch_prepare_kprobe(struct kprobe *p) { int ret = 0; + struct kprobe *prev; struct ppc_inst insn = ppc_inst_read((struct ppc_inst *)p->addr); + struct ppc_inst prefix = ppc_inst_read((struct ppc_inst *)(p->addr - 1)); if ((unsigned long)p->addr & 0x03) { printk("Attempt to register kprobe at an unaligned address\n"); @@ -114,6 +116,17 @@ int arch_prepare_kprobe(struct kprobe *p) } else if (IS_MTMSRD(insn) || IS_RFID(insn) || IS_RFI(insn)) { printk("Cannot register a kprobe on rfi/rfid or mtmsr[d]\n"); ret = -EINVAL; + } else if (ppc_inst_prefixed(prefix)) { + printk("Cannot register a kprobe on the second word of prefixed instruction\n"); + ret = -EINVAL; + } + preempt_disable(); + prev = get_kprobe(p->addr - 1); + preempt_enable_no_resched(); + if (prev && + ppc_inst_prefixed(ppc_inst_read((struct ppc_inst *)prev->ainsn.insn))) { + printk("Cannot register a kprobe on the second word of prefixed instruction\n"); + ret = -EINVAL; } /* insn must be on a special executable page on ppc64. This is |