diff options
| author | Masami Hiramatsu <mhiramat@kernel.org> | 2019-09-06 22:14:20 +0900 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2019-10-17 21:31:57 +0200 |
| commit | 004e8dce9c5595697951f7cd0e9f66b35c92265e (patch) | |
| tree | 8f9f371ea1784d4dba013b7bfb7d2fb7eff4e47d /arch/x86/kernel | |
| parent | 4d65adfcd1196818659d3bd9b42dccab291e1751 (diff) | |
x86: kprobes: Prohibit probing on instruction which has emulate prefix
Prohibit probing on instruction which has XEN_EMULATE_PREFIX
or KVM's emulate prefix. Since that prefix is a marker for Xen
and KVM, if we modify the marker by kprobe's int3, that doesn't
work as expected.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Juergen Gross <jgross@suse.com>
Cc: x86@kernel.org
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: xen-devel@lists.xenproject.org
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lkml.kernel.org/r/156777566048.25081.6296162369492175325.stgit@devnote2
Diffstat (limited to 'arch/x86/kernel')
| -rw-r--r-- | arch/x86/kernel/kprobes/core.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c index 43fc13c831af..4f13af7cbcdb 100644 --- a/arch/x86/kernel/kprobes/core.c +++ b/arch/x86/kernel/kprobes/core.c @@ -351,6 +351,10 @@ int __copy_instruction(u8 *dest, u8 *src, u8 *real, struct insn *insn) kernel_insn_init(insn, dest, MAX_INSN_SIZE); insn_get_length(insn); + /* We can not probe force emulate prefixed instruction */ + if (insn_has_emulate_prefix(insn)) + return 0; + /* Another subsystem puts a breakpoint, failed to recover */ if (insn->opcode.bytes[0] == BREAKPOINT_INSTRUCTION) return 0; |