diff options
Diffstat (limited to 'linuxthreads/attr.c')
| -rw-r--r-- | linuxthreads/attr.c | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/linuxthreads/attr.c b/linuxthreads/attr.c index 177df90b98..a66eb72c27 100644 --- a/linuxthreads/attr.c +++ b/linuxthreads/attr.c @@ -15,6 +15,9 @@ /* Handling of thread attributes */ #include <errno.h> +#include <inttypes.h> +#include <stdio.h> +#include <stdio_ext.h> #include <string.h> #include <unistd.h> #include <sys/param.h> @@ -344,6 +347,7 @@ int pthread_getattr_np (pthread_t thread, pthread_attr_t *attr) { pthread_handle handle = thread_handle (thread); pthread_descr descr; + int ret = 0; if (handle == NULL) return ENOENT; @@ -364,6 +368,7 @@ int pthread_getattr_np (pthread_t thread, pthread_attr_t *attr) attr->__inheritsched = descr->p_inheritsched; attr->__scope = PTHREAD_SCOPE_SYSTEM; + #ifdef _STACK_GROWS_DOWN # ifdef USE_TLS attr->__stacksize = descr->p_stackaddr - (char *)descr->p_guardaddr @@ -399,5 +404,61 @@ int pthread_getattr_np (pthread_t thread, pthread_attr_t *attr) # endif #endif + if (attr->__stackaddr == NULL) + { + /* Defined in ld.so. */ + extern void *__libc_stack_end; + + /* Stack size limit. */ + struct rlimit rl; + + /* The safest way to get the top of the stack is to read + /proc/self/maps and locate the line into which + __libc_stack_end falls. */ + FILE *fp = fopen ("/proc/self/maps", "rc"); + if (fp == NULL) + ret = errno; + /* We need the limit of the stack in any case. */ + else if (getrlimit (RLIMIT_STACK, &rl) != 0) + ret = errno; + else + { + /* We need no locking. */ + __fsetlocking (fp, FSETLOCKING_BYCALLER); + + /* Until we found an entry (which should always be the case) + mark the result as a failure. */ + ret = ENOENT; + + char *line = NULL; + size_t linelen = 0; + + while (! feof_unlocked (fp)) + { + if (__getdelim (&line, &linelen, '\n', fp) <= 0) + break; + + uintptr_t from; + uintptr_t to; + if (sscanf (line, "%" SCNxPTR "-%" SCNxPTR, &from, &to) == 2 + && from <= (uintptr_t) __libc_stack_end + && (uintptr_t) __libc_stack_end < to) + { + /* Found the entry. Now we have the info we need. */ + attr->__stacksize = rl.rlim_cur; + attr->__stackaddr = (void *) to; + + /* We succeed and no need to look further. */ + ret = 0; + break; + } + } + + fclose (fp); + free (line); + } + } + return 0; + } |