diff options
Diffstat (limited to 'libpthread/linuxthreads/sysdeps/i386/tls.h')
| -rw-r--r-- | libpthread/linuxthreads/sysdeps/i386/tls.h | 84 |
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 */ |