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| author | Ulrich Drepper <drepper@redhat.com> | 2009-08-25 10:42:30 -0700 |
|---|---|---|
| committer | Ulrich Drepper <drepper@redhat.com> | 2009-08-25 10:42:30 -0700 |
| commit | 84088310ce06bfc5759b37f0cd043dce80f578b6 (patch) | |
| tree | d3bb1a5e1b7d77c1bad3ebef67d19510d51b4569 /nptl/sysdeps | |
| parent | cf00cc00bc53ab26b23b810b4bfbdfb43262538a (diff) | |
| download | glibc-84088310ce06bfc5759b37f0cd043dce80f578b6.zip glibc-84088310ce06bfc5759b37f0cd043dce80f578b6.tar.gz glibc-84088310ce06bfc5759b37f0cd043dce80f578b6.tar.bz2 | |
Handle AVX saving on x86-64 in interrupted smbol lookups.
If a signal arrived during a symbol lookup and the signal handler also
required a symbol lookup, the end of the lookup in the signal handler reset
the flag whether restoring AVX/SSE registers is needed. Resetting means
in this case that the tail part of the outer lookup code will try to
restore the registers and this can fail miserably. We now restore to the
previous value which makes nesting calls possible.
Diffstat (limited to 'nptl/sysdeps')
| -rw-r--r-- | nptl/sysdeps/x86_64/tls.h | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/nptl/sysdeps/x86_64/tls.h b/nptl/sysdeps/x86_64/tls.h index 4212038..e39eb5f 100644 --- a/nptl/sysdeps/x86_64/tls.h +++ b/nptl/sysdeps/x86_64/tls.h @@ -188,7 +188,7 @@ typedef struct The contained asm must *not* be marked volatile since otherwise assignments like - pthread_descr self = thread_self(); + pthread_descr self = thread_self(); do not get optimized away. */ # define THREAD_SELF \ ({ struct pthread *__self; \ @@ -404,7 +404,12 @@ extern void _dl_x86_64_restore_sse (void); # define RTLD_CHECK_FOREIGN_CALL \ (THREAD_GETMEM (THREAD_SELF, header.rtld_must_xmm_save) != 0) +/* NB: Don't use the xchg operation because that would imply a lock + prefix which is expensive and unnecessary. The cache line is also + not contested at all. */ # define RTLD_ENABLE_FOREIGN_CALL \ + int old_rtld_must_xmm_save = THREAD_GETMEM (THREAD_SELF, \ + header.rtld_must_xmm_save); \ THREAD_SETMEM (THREAD_SELF, header.rtld_must_xmm_save, 1) # define RTLD_PREPARE_FOREIGN_CALL \ @@ -419,7 +424,8 @@ extern void _dl_x86_64_restore_sse (void); do { \ if (THREAD_GETMEM (THREAD_SELF, header.rtld_must_xmm_save) == 0) \ _dl_x86_64_restore_sse (); \ - THREAD_SETMEM (THREAD_SELF, header.rtld_must_xmm_save, 0); \ + THREAD_SETMEM (THREAD_SELF, header.rtld_must_xmm_save, \ + old_rtld_must_xmm_save); \ } while (0) # endif |