| Message ID | 20180530145403.GA42666@intel.com |
|---|---|
| State | New |
| Headers | show |
| Series | libitm/x86: Correct offsets of __private_tm and pointer_guard | expand |
On Wed, 2018-05-30 at 07:54 -0700, H.J. Lu wrote: > In glibc, sysdeps/i386/nptl/tls.h has > > typedef struct > { > void *tcb; /* Pointer to the TCB. Not necessarily the > thread descriptor used by libpthread. */ > dtv_t *dtv; > void *self; /* Pointer to the thread descriptor. */ > int multiple_threads; > uintptr_t sysinfo; > uintptr_t stack_guard; > uintptr_t pointer_guard; > int gscope_flag; > int __glibc_reserved1; > /* Reservation of some values for the TM ABI. */ > void *__private_tm[4]; > /* GCC split stack support. */ > void *__private_ss; > } tcbhead_t; > > and sysdeps/x86_64/nptl/tls.h has > > typedef struct > { > void *tcb; /* Pointer to the TCB. Not necessarily the > thread descriptor used by libpthread. */ > dtv_t *dtv; > void *self; /* Pointer to the thread descriptor. */ > int multiple_threads; > int gscope_flag; > uintptr_t sysinfo; > uintptr_t stack_guard; > uintptr_t pointer_guard; > unsigned long int vgetcpu_cache[2]; > int __glibc_reserved1; > int __glibc_unused1; > /* Reservation of some values for the TM ABI. */ > void *__private_tm[4]; > /* GCC split stack support. */ > void *__private_ss; > long int __glibc_reserved2; > /* Must be kept even if it is no longer used by glibc since programs, > like AddressSanitizer, depend on the size of tcbhead_t. */ > __128bits __glibc_unused2[8][4] __attribute__ ((aligned (32))); > > void *__padding[8]; > } tcbhead_t; > > The offsets of __private_tm are > > i386: 36 bytes > x32: 48 bytes > x86_64: 80 bytes > > and the offsets of pointer_guard are: > > i386: 24 bytes > x32: 28 bytes > x86_64: 48 bytes > > Update SEG_READ and SEG_WRITE to use the offset of __private_tm as base > and correct the offset of pointer_guard for x32. > > Tested on i686, x86-64 and x32. OK for trunk and release branches? The patch itself looks okay to me, but the commit message is pretty cryptic. I can't ack for release branches.
On Tue, Jun 12, 2018 at 1:23 AM, Torvald Riegel <triegel@redhat.com> wrote: > On Wed, 2018-05-30 at 07:54 -0700, H.J. Lu wrote: >> In glibc, sysdeps/i386/nptl/tls.h has >> >> typedef struct >> { >> void *tcb; /* Pointer to the TCB. Not necessarily the >> thread descriptor used by libpthread. */ >> dtv_t *dtv; >> void *self; /* Pointer to the thread descriptor. */ >> int multiple_threads; >> uintptr_t sysinfo; >> uintptr_t stack_guard; >> uintptr_t pointer_guard; >> int gscope_flag; >> int __glibc_reserved1; >> /* Reservation of some values for the TM ABI. */ >> void *__private_tm[4]; >> /* GCC split stack support. */ >> void *__private_ss; >> } tcbhead_t; >> >> and sysdeps/x86_64/nptl/tls.h has >> >> typedef struct >> { >> void *tcb; /* Pointer to the TCB. Not necessarily the >> thread descriptor used by libpthread. */ >> dtv_t *dtv; >> void *self; /* Pointer to the thread descriptor. */ >> int multiple_threads; >> int gscope_flag; >> uintptr_t sysinfo; >> uintptr_t stack_guard; >> uintptr_t pointer_guard; >> unsigned long int vgetcpu_cache[2]; >> int __glibc_reserved1; >> int __glibc_unused1; >> /* Reservation of some values for the TM ABI. */ >> void *__private_tm[4]; >> /* GCC split stack support. */ >> void *__private_ss; >> long int __glibc_reserved2; >> /* Must be kept even if it is no longer used by glibc since programs, >> like AddressSanitizer, depend on the size of tcbhead_t. */ >> __128bits __glibc_unused2[8][4] __attribute__ ((aligned (32))); >> >> void *__padding[8]; >> } tcbhead_t; >> >> The offsets of __private_tm are >> >> i386: 36 bytes >> x32: 48 bytes >> x86_64: 80 bytes >> >> and the offsets of pointer_guard are: >> >> i386: 24 bytes >> x32: 28 bytes >> x86_64: 48 bytes >> >> Update SEG_READ and SEG_WRITE to use the offset of __private_tm as base >> and correct the offset of pointer_guard for x32. >> >> Tested on i686, x86-64 and x32. OK for trunk and release branches? > > The patch itself looks okay to me, but the commit message is pretty > cryptic. I can't ack for release branches. > I checked in the patch with the updated commit message: https://gcc.gnu.org/ml/gcc-cvs/2018-06/msg00446.html Jakub, is this OK for release branches. Thanks.
diff --git a/libitm/config/linux/x86/tls.h b/libitm/config/linux/x86/tls.h index 5f3fd273c0e..ca6a5af3d4f 100644 --- a/libitm/config/linux/x86/tls.h +++ b/libitm/config/linux/x86/tls.h @@ -42,8 +42,8 @@ namespace GTM HIDDEN { #ifdef __x86_64__ #ifdef __LP64__ -# define SEG_READ(OFS) "movq\t%%fs:(" #OFS "*8),%0" -# define SEG_WRITE(OFS) "movq\t%0,%%fs:(" #OFS "*8)" +# define SEG_READ(OFS) "movq\t%%fs:(80+" #OFS "*8),%0" +# define SEG_WRITE(OFS) "movq\t%0,%%fs:(80+" #OFS "*8)" # define SEG_DECODE_READ(OFS) SEG_READ(OFS) "\n\t" \ "rorq\t$17,%0\n\t" \ "xorq\t%%fs:48,%0" @@ -52,18 +52,18 @@ namespace GTM HIDDEN { SEG_WRITE(OFS) #else // For X32. -# define SEG_READ(OFS) "movl\t%%fs:(" #OFS "*4),%0" -# define SEG_WRITE(OFS) "movl\t%0,%%fs:(" #OFS "*4)" +# define SEG_READ(OFS) "movl\t%%fs:(48+" #OFS "*4),%0" +# define SEG_WRITE(OFS) "movl\t%0,%%fs:(48+" #OFS "*4)" # define SEG_DECODE_READ(OFS) SEG_READ(OFS) "\n\t" \ "rorl\t$9,%0\n\t" \ - "xorl\t%%fs:24,%0" -# define SEG_ENCODE_WRITE(OFS) "xorl\t%%fs:24,%0\n\t" \ + "xorl\t%%fs:28,%0" +# define SEG_ENCODE_WRITE(OFS) "xorl\t%%fs:28,%0\n\t" \ "roll\t$9,%0\n\t" \ SEG_WRITE(OFS) #endif #else -# define SEG_READ(OFS) "movl\t%%gs:(" #OFS "*4),%0" -# define SEG_WRITE(OFS) "movl\t%0,%%gs:(" #OFS "*4)" +# define SEG_READ(OFS) "movl\t%%gs:(36+" #OFS "*4),%0" +# define SEG_WRITE(OFS) "movl\t%0,%%gs:(36+" #OFS "*4)" # define SEG_DECODE_READ(OFS) SEG_READ(OFS) "\n\t" \ "rorl\t$9,%0\n\t" \ "xorl\t%%gs:24,%0" @@ -75,26 +75,26 @@ namespace GTM HIDDEN { static inline struct gtm_thread *gtm_thr(void) { struct gtm_thread *r; - asm volatile (SEG_READ(10) : "=r"(r)); + asm volatile (SEG_READ(0) : "=r"(r)); return r; } static inline void set_gtm_thr(struct gtm_thread *x) { - asm volatile (SEG_WRITE(10) : : "r"(x)); + asm volatile (SEG_WRITE(0) : : "r"(x)); } static inline struct abi_dispatch *abi_disp(void) { struct abi_dispatch *r; - asm volatile (SEG_DECODE_READ(11) : "=r"(r)); + asm volatile (SEG_DECODE_READ(1) : "=r"(r)); return r; } static inline void set_abi_disp(struct abi_dispatch *x) { void *scratch; - asm volatile (SEG_ENCODE_WRITE(11) : "=r"(scratch) : "0"(x)); + asm volatile (SEG_ENCODE_WRITE(1) : "=r"(scratch) : "0"(x)); } #undef SEG_READ
In glibc, sysdeps/i386/nptl/tls.h has typedef struct { void *tcb; /* Pointer to the TCB. Not necessarily the thread descriptor used by libpthread. */ dtv_t *dtv; void *self; /* Pointer to the thread descriptor. */ int multiple_threads; uintptr_t sysinfo; uintptr_t stack_guard; uintptr_t pointer_guard; int gscope_flag; int __glibc_reserved1; /* Reservation of some values for the TM ABI. */ void *__private_tm[4]; /* GCC split stack support. */ void *__private_ss; } tcbhead_t; and sysdeps/x86_64/nptl/tls.h has typedef struct { void *tcb; /* Pointer to the TCB. Not necessarily the thread descriptor used by libpthread. */ dtv_t *dtv; void *self; /* Pointer to the thread descriptor. */ int multiple_threads; int gscope_flag; uintptr_t sysinfo; uintptr_t stack_guard; uintptr_t pointer_guard; unsigned long int vgetcpu_cache[2]; int __glibc_reserved1; int __glibc_unused1; /* Reservation of some values for the TM ABI. */ void *__private_tm[4]; /* GCC split stack support. */ void *__private_ss; long int __glibc_reserved2; /* Must be kept even if it is no longer used by glibc since programs, like AddressSanitizer, depend on the size of tcbhead_t. */ __128bits __glibc_unused2[8][4] __attribute__ ((aligned (32))); void *__padding[8]; } tcbhead_t; The offsets of __private_tm are i386: 36 bytes x32: 48 bytes x86_64: 80 bytes and the offsets of pointer_guard are: i386: 24 bytes x32: 28 bytes x86_64: 48 bytes Update SEG_READ and SEG_WRITE to use the offset of __private_tm as base and correct the offset of pointer_guard for x32. Tested on i686, x86-64 and x32. OK for trunk and release branches? H.J. --- PR libitm/85988 * config/linux/x86/tls.h (SEG_READ): Use the offset of __private_tm as base. (SEG_WRITE): Likewise. (SEG_ENCODE_WRITE): Correct the offset of pointer_guard for x32. (gtm_thr): Replace SEG_READ(10) with SEG_READ(0). (set_gtm_thr): Replace SEG_WRITE(10) with SEG_WRITE(0). (abi_disp): Replace SEG_DECODE_READ(11) with SEG_DECODE_READ(1). (set_abi_disp): Replace SEG_ENCODE_WRITE(11) with SEG_ENCODE_WRITE(1). --- libitm/config/linux/x86/tls.h | 24 ++++++++++++------------ 1 file changed, 12 insertions(+), 12 deletions(-)