From: Christophe Leroy <christophe.leroy@c-s.fr> To: Benjamin Herrenschmidt <benh@kernel.crashing.org>, Paul Mackerras <paulus@samba.org>, Michael Ellerman <mpe@ellerman.id.au>, naveen.n.rao@linux.vnet.ibm.com Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Subject: [PATCH] powerpc/kprobes: Use probe_address() to read instructions Date: Mon, 24 Feb 2020 18:02:10 +0000 (UTC) [thread overview] Message-ID: <7f24b5961a6839ff01df792816807f74ff236bf6.1582567319.git.christophe.leroy@c-s.fr> (raw) 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
WARNING: multiple messages have this Message-ID (diff)
From: Christophe Leroy <christophe.leroy@c-s.fr> To: Benjamin Herrenschmidt <benh@kernel.crashing.org>, Paul Mackerras <paulus@samba.org>, Michael Ellerman <mpe@ellerman.id.au>, naveen.n.rao@linux.vnet.ibm.com Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Subject: [PATCH] powerpc/kprobes: Use probe_address() to read instructions Date: Mon, 24 Feb 2020 18:02:10 +0000 (UTC) [thread overview] Message-ID: <7f24b5961a6839ff01df792816807f74ff236bf6.1582567319.git.christophe.leroy@c-s.fr> (raw) 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
next reply other threads:[~2020-02-24 18:02 UTC|newest] Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-02-24 18:02 Christophe Leroy [this message] 2020-02-24 18:02 ` [PATCH] powerpc/kprobes: Use probe_address() to read instructions Christophe Leroy 2020-06-09 5:28 ` Michael Ellerman 2020-06-09 5:53 ` Christoph Hellwig 2020-06-09 5:53 ` Christoph Hellwig 2020-06-10 10:12 ` Michael Ellerman 2020-06-10 10:12 ` Michael Ellerman
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