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| author |   Masami Hiramatsu <mhiramat@kernel.org> | 2018-05-09 21:58:45 +0900 |
|---|---|---|
| committer |   Thomas Gleixner <tglx@linutronix.de> | 2018-05-13 19:52:56 +0200 |
| commit | 13ebe18c94f5b0665c01ae7fad2717ae959f4212 (patch) | |
| tree | bed00a13933c2bd6eba212938302f3ebb8e54672 | |
| parent | kprobes/x86: Prohibit probing on exception masking instructions (diff) | |
| download | wireguard-linux-13ebe18c94f5b0665c01ae7fad2717ae959f4212.tar.xz wireguard-linux-13ebe18c94f5b0665c01ae7fad2717ae959f4212.zip | |
uprobes/x86: Prohibit probing on MOV SS instruction
Since MOV SS and POP SS instructions will delay the exceptions until the
next instruction is executed, single-stepping on it by uprobes must be
prohibited.
uprobe already rejects probing on POP SS (0x1f), but allows probing on MOV
SS (0x8e and reg == 2). This checks the target instruction and if it is
MOV SS or POP SS, returns -ENOTSUPP to reject probing.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
Cc: Francis Deslauriers <francis.deslauriers@efficios.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Yonghong Song <yhs@fb.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "David S . Miller" <davem@davemloft.net>
Link: https://lkml.kernel.org/r/152587072544.17316.5950935243917346341.stgit@devbox
| -rw-r--r-- | arch/x86/kernel/uprobes.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c index 85c7ef23d99f..c84bb5396958 100644 --- a/arch/x86/kernel/uprobes.c +++ b/arch/x86/kernel/uprobes.c @@ -299,6 +299,10 @@ static int uprobe_init_insn(struct arch_uprobe *auprobe, struct insn *insn, bool if (is_prefix_bad(insn)) return -ENOTSUPP; + /* We should not singlestep on the exception masking instructions */ + if (insn_masking_exception(insn)) + return -ENOTSUPP; + if (x86_64) good_insns = good_insns_64; else |