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| author | Michael Brown | 2017-09-04 15:00:32 +0200 |
|---|---|---|
| committer | Michael Brown | 2017-09-04 15:09:17 +0200 |
| commit | 42eedb04c1ad71548043c33ef1996dfe8e524996 (patch) | |
| tree | fa116cf39c744219ce2690deb830fcb1721ec5c3 /src/core | |
| parent | [romprefix] Avoid unaligned accesses within ROM headers (diff) | |
| download | ipxe-42eedb04c1ad71548043c33ef1996dfe8e524996.tar.gz ipxe-42eedb04c1ad71548043c33ef1996dfe8e524996.tar.xz ipxe-42eedb04c1ad71548043c33ef1996dfe8e524996.zip | |
[malloc] Avoid false positive warnings from valgrind
Calling discard_cache() is likely to result in a call to
free_memblock(), which will call valgrind_make_blocks_noaccess()
before returning. This causes valgrind to report an invalid read on
the next iteration through the loop in alloc_memblock().
Fix by explicitly calling valgrind_make_blocks_defined() after
discard_cache() returns. Also call valgrind_make_blocks_noaccess()
before calling discard_cache(), to guard against free list corruption
while executing cache discarders.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Diffstat (limited to 'src/core')
| -rw-r--r-- | src/core/malloc.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/src/core/malloc.c b/src/core/malloc.c index 6ddc08b7..91c8e4d3 100644 --- a/src/core/malloc.c +++ b/src/core/malloc.c @@ -284,6 +284,7 @@ void * alloc_memblock ( size_t size, size_t align, size_t offset ) { size_t post_size; struct memory_block *pre; struct memory_block *post; + unsigned int discarded; void *ptr; /* Sanity checks */ @@ -371,7 +372,13 @@ void * alloc_memblock ( size_t size, size_t align, size_t offset ) { } /* Try discarding some cached data to free up memory */ - if ( ! discard_cache() ) { + DBGC ( &heap, "Attempting discard for %#zx (aligned %#zx+%zx), " + "used %zdkB\n", size, align, offset, ( usedmem >> 10 ) ); + valgrind_make_blocks_noaccess(); + discarded = discard_cache(); + valgrind_make_blocks_defined(); + check_blocks(); + if ( ! discarded ) { /* Nothing available to discard */ DBGC ( &heap, "Failed to allocate %#zx (aligned " "%#zx)\n", size, align ); |