summaryrefslogtreecommitdiff
path: root/libbacktrace
diff options
context:
space:
mode:
authorian <ian@138bc75d-0d04-0410-961f-82ee72b054a4>2014-05-09 05:01:08 +0000
committerian <ian@138bc75d-0d04-0410-961f-82ee72b054a4>2014-05-09 05:01:08 +0000
commitaf436d54a40629a21e5aa3b6ca43d1b373e8c87a (patch)
tree28483b89cea2278d730597de17a15c749c38766e /libbacktrace
parent80ede13bcecf98757df8698a8d3b4cde1c60521f (diff)
downloadgcc-af436d54a40629a21e5aa3b6ca43d1b373e8c87a.tar.gz
* mmap.c (backtrace_free): If freeing a large aligned block of
memory, call munmap rather than holding onto it. (backtrace_vector_grow): When growing a vector, double the number of pages requested. When releasing the old version of a grown vector, pass the correct size to backtrace_free. git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@210256 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'libbacktrace')
-rw-r--r--libbacktrace/ChangeLog8
-rw-r--r--libbacktrace/mmap.c28
2 files changed, 34 insertions, 2 deletions
diff --git a/libbacktrace/ChangeLog b/libbacktrace/ChangeLog
index 8a1a8e74a32..adb54d8f5c3 100644
--- a/libbacktrace/ChangeLog
+++ b/libbacktrace/ChangeLog
@@ -1,3 +1,11 @@
+2014-05-08 Ian Lance Taylor <iant@google.com>
+
+ * mmap.c (backtrace_free): If freeing a large aligned block of
+ memory, call munmap rather than holding onto it.
+ (backtrace_vector_grow): When growing a vector, double the number
+ of pages requested. When releasing the old version of a grown
+ vector, pass the correct size to backtrace_free.
+
2014-03-07 Ian Lance Taylor <iant@google.com>
* sort.c (backtrace_qsort): Use middle element as pivot.
diff --git a/libbacktrace/mmap.c b/libbacktrace/mmap.c
index b530e382388..5a9f6299bc0 100644
--- a/libbacktrace/mmap.c
+++ b/libbacktrace/mmap.c
@@ -164,6 +164,26 @@ backtrace_free (struct backtrace_state *state, void *addr, size_t size,
{
int locked;
+ /* If we are freeing a large aligned block, just release it back to
+ the system. This case arises when growing a vector for a large
+ binary with lots of debug info. Calling munmap here may cause us
+ to call mmap again if there is also a large shared library; we
+ just live with that. */
+ if (size >= 16 * 4096)
+ {
+ size_t pagesize;
+
+ pagesize = getpagesize ();
+ if (((uintptr_t) addr & (pagesize - 1)) == 0
+ && (size & (pagesize - 1)) == 0)
+ {
+ /* If munmap fails for some reason, just add the block to
+ the freelist. */
+ if (munmap (addr, size) == 0)
+ return;
+ }
+ }
+
/* If we can acquire the lock, add the new space to the free list.
If we can't acquire the lock, just leak the memory.
__sync_lock_test_and_set returns the old state of the lock, so we
@@ -209,14 +229,18 @@ backtrace_vector_grow (struct backtrace_state *state,size_t size,
alc = pagesize;
}
else
- alc = (alc + pagesize - 1) & ~ (pagesize - 1);
+ {
+ alc *= 2;
+ alc = (alc + pagesize - 1) & ~ (pagesize - 1);
+ }
base = backtrace_alloc (state, alc, error_callback, data);
if (base == NULL)
return NULL;
if (vec->base != NULL)
{
memcpy (base, vec->base, vec->size);
- backtrace_free (state, vec->base, vec->alc, error_callback, data);
+ backtrace_free (state, vec->base, vec->size + vec->alc,
+ error_callback, data);
}
vec->base = base;
vec->alc = alc - vec->size;