Messages in this thread Patch in this message | | | From | Christophe Leroy <> | Subject | [PATCH] powerpc/kprobes: Use probe_address() to read instructions | Date | Mon, 24 Feb 2020 18:02:10 +0000 (UTC) |
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In order to avoid Oopses, use probe_address() to read the instruction at the address where the trap happened.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> --- arch/powerpc/kernel/kprobes.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c index 84567406b53d..a35320b79e16 100644 --- a/arch/powerpc/kernel/kprobes.c +++ b/arch/powerpc/kernel/kprobes.c @@ -276,14 +276,18 @@ int kprobe_handler(struct pt_regs *regs) p = get_kprobe(addr); if (!p) { - if (*addr != BREAKPOINT_INSTRUCTION) { + unsigned int instr; + + if (probe_kernel_address(addr, instr)) + goto no_kprobe; + + if (instr != BREAKPOINT_INSTRUCTION) { /* * PowerPC has multiple variants of the "trap" * instruction. If the current instruction is a * trap variant, it could belong to someone else */ - kprobe_opcode_t cur_insn = *addr; - if (is_trap(cur_insn)) + if (is_trap(instr)) goto no_kprobe; /* * The breakpoint instruction was removed right -- 2.25.0
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