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Diffstat (limited to 'libpthread/linuxthreads/sysdeps/i386/tls.h')
-rw-r--r--libpthread/linuxthreads/sysdeps/i386/tls.h84
1 files changed, 63 insertions, 21 deletions
diff --git a/libpthread/linuxthreads/sysdeps/i386/tls.h b/libpthread/linuxthreads/sysdeps/i386/tls.h
index 4469f0776..d79bf0779 100644
--- a/libpthread/linuxthreads/sysdeps/i386/tls.h
+++ b/libpthread/linuxthreads/sysdeps/i386/tls.h
@@ -30,7 +30,11 @@
typedef union dtv
{
size_t counter;
- void *pointer;
+ struct
+ {
+ void *val;
+ bool is_static;
+ } pointer;
} dtv_t;
@@ -40,15 +44,28 @@ typedef struct
thread descriptor used by libpthread. */
dtv_t *dtv;
void *self; /* Pointer to the thread descriptor. */
+ int multiple_threads;
+ uintptr_t sysinfo;
} tcbhead_t;
+
+#else /* __ASSEMBLER__ */
+# include <tcb-offsets.h>
#endif
+/* We can support TLS only if the floating-stack support is available.
+ However, we want to compile in the support and test at runtime whether
+ the running kernel can support it or not. To avoid bothering with the
+ TLS support code at all, use configure --without-tls.
+
+ We need USE_TLS to be consistently defined, for ldsodefs.h conditionals.
+ But some of the code below can cause problems in building libpthread
+ (e.g. useldt.h will defined FLOATING_STACKS when it shouldn't). */
-/* We can support TLS only if the floating-stack support is available. */
-#if defined FLOATING_STACKS && defined HAVE_TLS_SUPPORT
+#if defined HAVE_TLS_SUPPORT \
+ && (defined FLOATING_STACKS || !defined IS_IN_libpthread)
/* Signal that TLS support is available. */
-//# define USE_TLS 1
+# define USE_TLS 1
# ifndef __ASSEMBLER__
/* Get system call information. */
@@ -97,7 +114,20 @@ typedef struct
# define TLS_LOAD_EBX
# endif
+# if !defined IS_IN_libpthread && !defined DO_MODIFY_LDT
+# include "useldt.h" /* For the structure. */
+# endif
+# if __ASSUME_LDT_WORKS > 0
+# define TLS_DO_MODIFY_LDT_KERNEL_CHECK(doit) (doit) /* Nothing to check. */
+# else
+# define TLS_DO_MODIFY_LDT_KERNEL_CHECK(doit) \
+ (__builtin_expect (GLRO(dl_osversion) < 131939, 0) \
+ ? "kernel too old for thread-local storage support\n" \
+ : (doit))
+# endif
+
# define TLS_DO_MODIFY_LDT(descr, nr) \
+TLS_DO_MODIFY_LDT_KERNEL_CHECK( \
({ \
struct modify_ldt_ldt_s ldt_entry = \
{ nr, (unsigned long int) (descr), 0xfffff /* 4GB in pages */, \
@@ -113,8 +143,10 @@ typedef struct
here. */ \
"m" (ldt_entry), TLS_EBX_ARG (1), "c" (&ldt_entry), \
"d" (sizeof (ldt_entry))); \
- __builtin_expect (result, 0) != 0 ? -1 : nr * 8 + 7; \
-})
+ __builtin_expect (result, 0) == 0 \
+ ? ({ __asm__ ("movw %w0, %%gs" : : "q" ((nr) * 8 + 7)); NULL; }) \
+ : "cannot set up LDT for thread-local storage\n"; \
+}))
# define TLS_DO_SET_THREAD_AREA(descr, secondcall) \
({ \
@@ -135,50 +167,60 @@ typedef struct
to let the compiler know that we are accessing LDT_ENTRY \
here. */ \
TLS_EBX_ARG (&ldt_entry), "m" (ldt_entry)); \
- __builtin_expect (result, 0) == 0 ? ldt_entry.entry_number * 8 + 3 : -1; \
+ if (__builtin_expect (result, 0) == 0) \
+ __asm__ ("movw %w0, %%gs" : : "q" (ldt_entry.entry_number * 8 + 3)); \
+ result; \
})
# ifdef __ASSUME_SET_THREAD_AREA_SYSCALL
-# define TLS_SETUP_GS_SEGMENT(descr, secondcall) \
- TLS_DO_SET_THREAD_AREA (descr, firstcall)
+# define TLS_SETUP_GS_SEGMENT(descr, secondcall) \
+ (TLS_DO_SET_THREAD_AREA (descr, secondcall) \
+ ? "set_thread_area failed when setting up thread-local storage\n" : NULL)
# elif defined __NR_set_thread_area
# define TLS_SETUP_GS_SEGMENT(descr, secondcall) \
- ({ int __seg = TLS_DO_SET_THREAD_AREA (descr, secondcall); \
- __seg == -1 ? TLS_DO_MODIFY_LDT (descr, 0) : __seg; })
+ (TLS_DO_SET_THREAD_AREA (descr, secondcall) \
+ ? TLS_DO_MODIFY_LDT (descr, 0) : NULL)
# else
# define TLS_SETUP_GS_SEGMENT(descr, secondcall) \
TLS_DO_MODIFY_LDT ((descr), 0)
# endif
+#if defined NEED_DL_SYSINFO
+# define INIT_SYSINFO \
+ head->sysinfo = GLRO(dl_sysinfo)
+#else
+# define INIT_SYSINFO
+#endif
+
/* Code to initially initialize the thread pointer. This might need
special attention since 'errno' is not yet available and if the
- operation can cause a failure 'errno' must not be touched. */
+ operation can cause a failure 'errno' must not be touched.
+
+ The value of this macro is null if successful, or an error string. */
# define TLS_INIT_TP(descr, secondcall) \
({ \
void *_descr = (descr); \
tcbhead_t *head = _descr; \
- int __gs; \
\
head->tcb = _descr; \
/* For now the thread descriptor is at the same address. */ \
head->self = _descr; \
\
- __gs = TLS_SETUP_GS_SEGMENT (_descr, secondcall); \
- if (__builtin_expect (__gs, 7) != -1) \
- { \
- __asm__ ("movw %w0, %%gs" : : "q" (__gs)); \
- __gs = 0; \
- } \
- __gs; \
+ INIT_SYSINFO; \
+ TLS_SETUP_GS_SEGMENT (_descr, secondcall); \
})
+/* Indicate that dynamic linker shouldn't try to initialize TLS even
+ when no PT_TLS segments are found in the program and libraries
+ it is linked against. */
+# define TLS_INIT_TP_EXPENSIVE 1
/* Return the address of the dtv for the current thread. */
# define THREAD_DTV() \
({ struct _pthread_descr_struct *__descr; \
THREAD_GETMEM (__descr, p_header.data.dtvp); })
-# endif /* FLOATING_STACKS && HAVE_TLS_SUPPORT */
+# endif /* HAVE_TLS_SUPPORT && (FLOATING_STACKS || !IS_IN_libpthread) */
#endif /* __ASSEMBLER__ */
#endif /* tls.h */