diff options
| author | Robert Scott <code@humanleg.org.uk> | 2020-02-22 18:55:46 +0000 |
|---|---|---|
| committer | Aliaksey Kandratsenka <alkondratenko@gmail.com> | 2021-06-20 10:02:06 -0700 |
| commit | 43504ab7091c0bcac9a233aa0ee0720a1549791b (patch) | |
| tree | cda33b89e0a186ed3ea2bf4ac0bbb94673d52ff6 | |
| parent | d57a9ea8bc92958733ac1c61a3c4f1ba2e150e96 (diff) | |
| download | gperftools-43504ab7091c0bcac9a233aa0ee0720a1549791b.tar.gz | |
tcmalloc page fences: add TCMALLOC_PAGE_FENCE_READABLE option
| -rw-r--r-- | src/debugallocation.cc | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/src/debugallocation.cc b/src/debugallocation.cc index 17cd452..b0f7509 100644 --- a/src/debugallocation.cc +++ b/src/debugallocation.cc @@ -112,6 +112,9 @@ DEFINE_bool(malloc_page_fence_never_reclaim, EnvToBool("TCMALLOC_PAGE_FENCE_NEVER_RECLAIM", false), "Enables making the virtual address space inaccessible " "upon a deallocation instead of returning it and reusing later."); +DEFINE_bool(malloc_page_fence_readable, + EnvToBool("TCMALLOC_PAGE_FENCE_READABLE", false), + "Permits reads to the page fence."); #else DEFINE_bool(malloc_page_fence, false, "Not usable (requires mmap)"); DEFINE_bool(malloc_page_fence_never_reclaim, false, "Not usable (required mmap)"); @@ -508,6 +511,7 @@ class MallocBlock { } MallocBlock* b = NULL; const bool use_malloc_page_fence = FLAGS_malloc_page_fence; + const bool malloc_page_fence_readable = FLAGS_malloc_page_fence_readable; #ifdef HAVE_MMAP if (use_malloc_page_fence) { // Put the block towards the end of the page and make the next page @@ -526,7 +530,8 @@ class MallocBlock { strerror(errno)); } // Mark the page after the block inaccessible - if (mprotect(p + (num_pages - 1) * pagesize, pagesize, PROT_NONE)) { + if (mprotect(p + (num_pages - 1) * pagesize, pagesize, + PROT_NONE|(malloc_page_fence_readable ? PROT_READ : 0))) { RAW_LOG(FATAL, "Guard page setup failed: %s", strerror(errno)); } b = (MallocBlock*) (p + (num_pages - 1) * pagesize - sz); |