Messages in this thread | | | Subject | Re: [PATCH v9 16/29] x86/insn-eval: Add function to get default params of code segment | From | Ricardo Neri <> | Date | Thu, 12 Oct 2017 11:27:15 -0700 |
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On Thu, 2017-10-12 at 18:31 +0200, Borislav Petkov wrote: > On Tue, Oct 03, 2017 at 08:54:19PM -0700, Ricardo Neri wrote: > > > > Obtain the default values of the address and operand sizes as specified in > > the D and L bits of the the segment descriptor selected by the register > > CS. The function can be used for both protected and long modes. > > For virtual-8086 mode, the default address and operand sizes are always 2 > > bytes. > > > > The returned parameters are encoded in a signed 8-bit data type. Auxiliar > > macros are provided to encode and decode such values. > > > > 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 | 5 ++++ > > arch/x86/lib/insn-eval.c | 64 > > ++++++++++++++++++++++++++++++++++++++++ > > 2 files changed, 69 insertions(+) > Some cleanups ontop: > > --- > diff --git a/arch/x86/lib/insn-eval.c b/arch/x86/lib/insn-eval.c > index 64924b7d5fff..3352b9d5164f 100644 > --- a/arch/x86/lib/insn-eval.c > +++ b/arch/x86/lib/insn-eval.c > @@ -614,14 +614,14 @@ static unsigned long get_seg_limit(struct pt_regs *regs, > int seg_reg_idx) > } > > /** > - * insn_get_code_seg_defaults() - Obtain code segment default parameters > + * insn_get_code_seg_params() - Obtain code segment parameters > * @regs: Structure with register values as seen when entering kernel > mode > * > - * Obtain the default parameters of the code segment: address and operand > sizes. > - * The code segment is obtained from the selector contained in the CS > register > - * in regs. In protected mode, the default address is determined by > inspecting > - * the L and D bits of the segment descriptor. In virtual-8086 mode, the > default > - * is always two bytes for both address and operand sizes. > + * Obtain address and operand sizes of the code segment. It is obtained from > the > + * selector contained in the CS register in regs. In protected mode, the > default > + * address is determined by inspecting the L and D bits of the segment > descriptor. > + * In virtual-8086 mode, the default is always two bytes for both address and > + * operand sizes. > * > * Returns: > * > @@ -629,7 +629,7 @@ static unsigned long get_seg_limit(struct pt_regs *regs, > int seg_reg_idx) > * > * -EINVAL on error. > */ > -char insn_get_code_seg_defaults(struct pt_regs *regs) > +char insn_get_code_seg_params(struct pt_regs *regs) > { > struct desc_struct *desc; > short sel; > @@ -640,7 +640,7 @@ char insn_get_code_seg_defaults(struct pt_regs *regs) > > sel = get_segment_selector(regs, INAT_SEG_REG_CS); > if (sel < 0) > - return -1L; > + return sel;
Thanks! I implemente these changes along with your Improvements-by.
BR, Ricardo
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