> -----Original Message----- > From: H.J. Lu [mailto:hjl.to...@gmail.com] > Sent: Tuesday, January 30, 2018 3:45 PM > To: Uros Bizjak <ubiz...@gmail.com> > Cc: Tsimbalist, Igor V <igor.v.tsimbal...@intel.com>; gcc- > patc...@gcc.gnu.org > Subject: Re: [PATCH][PR target/84066] Wrong shadow stack register size is > saved for x32 > > On Tue, Jan 30, 2018 at 6:38 AM, Uros Bizjak <ubiz...@gmail.com> wrote: > > On Tue, Jan 30, 2018 at 3:19 PM, Tsimbalist, Igor V > > <igor.v.tsimbal...@intel.com> wrote: > >> x32 is a 64-bit process with 32-bit software pointer and kernel may > >> place x32 shadow stack above 4GB. We need to save and restore 64-bit > >> shadow stack register for x32. builtin jmp buf size is 5 pointers. We > >> have space to save 64-bit shadow stack pointer: 32-bit SP, 32-bit FP, > >> 32-bit IP, 64-bit SSP for x32. > >> > >> PR target/84066 > >> * gcc/config/i386/i386.md: Replace Pmode with word_mode in > >> builtin_setjmp_setup and builtin_longjmp to support x32. > >> * gcc/testsuite/gcc.target/i386/cet-sjlj-6.c: New test. > >> > >> Ok for trunk? > > > > LGTM, but please check the testcase with -mx32 > > -maddress-mode={short,long} nevertheless to catch any incosistencies. > > > > Speaking of -maddress-mode=, shouldn't > > + reg_adj = gen_rtx_SUBREG (Pmode, reg_ssp, 0); > tmp = gen_rtx_SET (reg_adj, > gen_rtx_LSHIFTRT (Pmode, negate_rtx (Pmode, reg_adj), > - GEN_INT ((Pmode == SImode) > + GEN_INT ((word_mode == SImode) > ? 2 > : 3))); > > be > > + reg_adj = gen_rtx_SUBREG (ptr_mode, reg_ssp, 0); > tmp = gen_rtx_SET (reg_adj, > gen_rtx_LSHIFTRT (ptr_mode, negate_rtx (ptr_mode, reg_adj), > - GEN_INT ((Pmode == SImode) > + GEN_INT ((word_mode == SImode) > ? 2 > : 3))); > > Pmode == word_mode for -maddress-mode=long. > > +++ b/gcc/testsuite/gcc.target/i386/cet-sjlj-6.c > @@ -0,0 +1,19 @@ > +/* { dg-do compile } */ > +/* { dg-options "-O -fcf-protection -mcet -mx32" } */ > +/* { dg-final { scan-assembler-times "endbr64" 2 } } */ > +/* { dg-final { scan-assembler-times "movq\t.*buf\\+12" 1 } } */ > +/* { dg-final { scan-assembler-times "subq\tbuf\\+12" 1 } } */ > +/* { dg-final { scan-assembler-times "rdsspq" 2 } } */ > +/* { dg-final { scan-assembler-times "incsspq" 2 } } */ > > Please add a test for > > tmp = gen_rtx_SET (reg_adj, > gen_rtx_LSHIFTRT (Pmode, negate_rtx (Pmode, reg_adj), > - GEN_INT ((Pmode == SImode) > + GEN_INT ((word_mode == SImode) > ? 2 > : 3))); > Thanks for suggestion about -maddress-mode option. The patch was updated and new test was added. The -maddress-mode=long test is expected to fail as it depends on fixing of https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84150
Ok for trunk? Igor
0001-PR84066-Wrong-shadow-stack-register-size-is-saved-fo.patch
Description: 0001-PR84066-Wrong-shadow-stack-register-size-is-saved-fo.patch
