4.16-stable review patch. If anyone has any objections, please let me know.
------------------ From: Ingo Molnar <[email protected]> [ Upstream commit 4fe875e4bd3cae85ae6f6eaf77f63fabe613b66e ] The following commit: ee6a7354a362: kprobes/x86: Prohibit probing on exception masking instructions Modified <asm/insn.h>, adding the insn_masking_exception() function. Sync the tooling version of the header to it, to fix this warning: Warning: synced file at 'tools/objtool/arch/x86/include/asm/insn.h' differs from latest kernel version at 'arch/x86/include/asm/insn.h' Cc: Peter Zijlstra <[email protected]> Cc: Josh Poimboeuf <[email protected]> Cc: Masami Hiramatsu <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Ricardo Neri <[email protected]> Cc: Francis Deslauriers <[email protected]> Cc: Oleg Nesterov <[email protected]> Cc: Alexei Starovoitov <[email protected]> Cc: Steven Rostedt <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: "H . Peter Anvin" <[email protected]> Cc: Yonghong Song <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: "David S . Miller" <[email protected]> Signed-off-by: Ingo Molnar <[email protected]> Signed-off-by: Sasha Levin <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- tools/objtool/arch/x86/include/asm/insn.h | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) --- a/tools/objtool/arch/x86/include/asm/insn.h +++ b/tools/objtool/arch/x86/include/asm/insn.h @@ -208,4 +208,22 @@ static inline int insn_offset_immediate( return insn_offset_displacement(insn) + insn->displacement.nbytes; } +#define POP_SS_OPCODE 0x1f +#define MOV_SREG_OPCODE 0x8e + +/* + * Intel SDM Vol.3A 6.8.3 states; + * "Any single-step trap that would be delivered following the MOV to SS + * instruction or POP to SS instruction (because EFLAGS.TF is 1) is + * suppressed." + * This function returns true if @insn is MOV SS or POP SS. On these + * instructions, single stepping is suppressed. + */ +static inline int insn_masking_exception(struct insn *insn) +{ + return insn->opcode.bytes[0] == POP_SS_OPCODE || + (insn->opcode.bytes[0] == MOV_SREG_OPCODE && + X86_MODRM_REG(insn->modrm.bytes[0]) == 2); +} + #endif /* _ASM_X86_INSN_H */
