On Wed, 25 Jan 2017 12:23:47 -0800 Ricardo Neri ricardo.neri-calderon@linux.intel.com wrote:
The function insn_get_reg_offset requires a type to indicate whether the returned offset is that given by by the ModRM or the SIB byte. Callers of this function would need the definition of the type struct. This is not needed. Instead, auxiliary functions can be defined for this purpose.
When the operand is a register, the emulation code for User-Mode Instruction Prevention needs to know the offset of the register indicated in the r/m part of the ModRM byte. Thus, start by adding an auxiliary function for this purpose.
Hmm, why wouldn't you just rename it to insn_get_reg_offset() and export it?
Thank you,
Cc: Dave Hansen dave.hansen@linux.intel.com Cc: Adam Buchbinder adam.buchbinder@gmail.com Cc: Colin Ian King colin.king@canonical.com Cc: Lorenzo Stoakes lstoakes@gmail.com Cc: Qiaowei Ren qiaowei.ren@intel.com Cc: Arnaldo Carvalho de Melo acme@redhat.com Cc: Masami Hiramatsu mhiramat@kernel.org Cc: Adrian Hunter adrian.hunter@intel.com Cc: Kees Cook keescook@chromium.org Cc: Thomas Garnier thgarnie@google.com Cc: Peter Zijlstra peterz@infradead.org Cc: Borislav Petkov bp@suse.de Cc: Dmitry Vyukov dvyukov@google.com Cc: Ravi V. Shankar ravi.v.shankar@intel.com Cc: x86@kernel.org Signed-off-by: Ricardo Neri ricardo.neri-calderon@linux.intel.com
arch/x86/include/asm/insn-kernel.h | 1 + arch/x86/lib/insn-kernel.c | 5 +++++ 2 files changed, 6 insertions(+)
diff --git a/arch/x86/include/asm/insn-kernel.h b/arch/x86/include/asm/insn-kernel.h index aef416a..3f34649 100644 --- a/arch/x86/include/asm/insn-kernel.h +++ b/arch/x86/include/asm/insn-kernel.h @@ -12,5 +12,6 @@ #include <asm/ptrace.h>
void __user *insn_get_addr_ref(struct insn *insn, struct pt_regs *regs); +int insn_get_reg_offset_rm(struct insn *insn, struct pt_regs *regs);
#endif /* _ASM_X86_INSN_KERNEL_H */ diff --git a/arch/x86/lib/insn-kernel.c b/arch/x86/lib/insn-kernel.c index 8072abe..267cab4 100644 --- a/arch/x86/lib/insn-kernel.c +++ b/arch/x86/lib/insn-kernel.c @@ -95,6 +95,11 @@ static int get_reg_offset(struct insn *insn, struct pt_regs *regs, return regoff[regno]; }
+int insn_get_reg_offset_rm(struct insn *insn, struct pt_regs *regs) +{
- return get_reg_offset(insn, regs, REG_TYPE_RM);
+}
/*
- return the address being referenced be instruction
- for rm=3 returning the content of the rm reg
-- 2.9.3