Messages in this thread | | | Date | Mon, 29 May 2017 19:16:25 +0200 | From | Borislav Petkov <> | Subject | Re: [PATCH v7 08/26] x86/insn-eval: Add a utility function to get register offsets |
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On Fri, May 05, 2017 at 11:17:06AM -0700, Ricardo Neri wrote: > The function get_reg_offset() returns the offset to the register the > argument specifies as indicated in an enumeration of type offset. Callers > of this function would need the definition of such enumeration. This is > not needed. Instead, add helper functions for this purpose. These functions > are useful in cases when, for instance, the caller needs to decide whether > the operand is a register or a memory location by looking at the rm part > of the ModRM byte. As of now, this is the only helper function that is > needed. > > 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-eval.h | 1 + > arch/x86/lib/insn-eval.c | 15 +++++++++++++++ > 2 files changed, 16 insertions(+) > > diff --git a/arch/x86/include/asm/insn-eval.h b/arch/x86/include/asm/insn-eval.h > index 5cab1b1..7e8c963 100644 > --- a/arch/x86/include/asm/insn-eval.h > +++ b/arch/x86/include/asm/insn-eval.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_modrm_rm_off(struct insn *insn, struct pt_regs *regs); > > #endif /* _ASM_X86_INSN_EVAL_H */ > diff --git a/arch/x86/lib/insn-eval.c b/arch/x86/lib/insn-eval.c > index 182e2ae..8b16761 100644 > --- a/arch/x86/lib/insn-eval.c > +++ b/arch/x86/lib/insn-eval.c > @@ -97,6 +97,21 @@ static int get_reg_offset(struct insn *insn, struct pt_regs *regs, > return regoff[regno]; > } > > +/** > + * insn_get_reg_offset_modrm_rm() - Obtain register in r/m part of ModRM byte
That name needs to be synced with the function name below.
> + * @insn: Instruction structure containing the ModRM byte > + * @regs: Structure with register values as seen when entering kernel mode > + * > + * Return: The register indicated by the r/m part of the ModRM byte. The > + * register is obtained as an offset from the base of pt_regs. In specific > + * cases, the returned value can be -EDOM to indicate that the particular value > + * of ModRM does not refer to a register and shall be ignored. > + */ > +int insn_get_modrm_rm_off(struct insn *insn, struct pt_regs *regs) ^^^^^^^^^^^^^^^^^^^^
-- Regards/Gruss, Boris.
SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg) --
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