From 9afb2f2106a5d659854c175c574c1c31e0e205a2 Mon Sep 17 00:00:00 2001 From: Elliott Hughes Date: Thu, 9 Oct 2014 14:01:47 -0700 Subject: [PATCH] Fix pthread_attr_getstack under valgrind. valgrind seems to mess with the stack enough that the kernel will report "[stack:pid]" rather than "[stack]" in /proc/self/maps, so switch to the task-specific file instead to force "[stack]". (There are two conditions in the kernel code that decides which form to output.) Bug: 17897476 Change-Id: Iff85ceb6d52e8716251fab4e45d95a27184c5529 --- libc/bionic/pthread_attr.cpp | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/libc/bionic/pthread_attr.cpp b/libc/bionic/pthread_attr.cpp index c93970a19..c65ccc132 100644 --- a/libc/bionic/pthread_attr.cpp +++ b/libc/bionic/pthread_attr.cpp @@ -31,6 +31,7 @@ #include #include #include +#include #include "private/bionic_string_utils.h" #include "private/ErrnoRestorer.h" @@ -126,8 +127,12 @@ static int __pthread_attr_getstack_main_thread(void** stack_base, size_t* stack_ stack_limit.rlim_cur = 8 * 1024 * 1024; } - // It doesn't matter which thread we are; we're just looking for "[stack]". - FILE* fp = fopen("/proc/self/maps", "re"); + // It shouldn't matter which thread we are because we're just looking for "[stack]", but + // valgrind seems to mess with the stack enough that the kernel will report "[stack:pid]" + // instead if you look in /proc/self/maps, so we need to look in /proc/pid/task/pid/maps. + char path[64]; + snprintf(path, sizeof(path), "/proc/self/task/%d/maps", getpid()); + FILE* fp = fopen(path, "re"); if (fp == NULL) { return errno; } @@ -143,7 +148,7 @@ static int __pthread_attr_getstack_main_thread(void** stack_base, size_t* stack_ } } } - __libc_fatal("No [stack] line found in /proc/self/maps!"); + __libc_fatal("No [stack] line found in \"%s\"!", path); } int pthread_attr_getstack(const pthread_attr_t* attr, void** stack_base, size_t* stack_size) {