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author | Treehugger Robot <treehugger-gerrit@google.com> | 2021-07-02 17:58:43 +0000 |
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committer | Gerrit Code Review <noreply-gerritcodereview@google.com> | 2021-07-02 17:58:43 +0000 |
commit | 2ef1cd3f4430d344d88f1275b850119dc963cfa1 (patch) | |
tree | 681b4b52627e62b5d9bcb1d4b868ec9eb32db2ae | |
parent | 7332139c65ef2361f2e9c90f4cff386cf4735b65 (diff) | |
parent | 48bf46b968c37cbd76ecd33c98c0f163134beadf (diff) | |
download | bionic-2ef1cd3f4430d344d88f1275b850119dc963cfa1.tar.gz |
Merge "Allow the kernel to upgrade ASYNC mode processes to SYNC mode."
-rw-r--r-- | libc/bionic/heap_tagging.cpp | 7 | ||||
-rw-r--r-- | libc/bionic/libc_init_static.cpp | 6 |
2 files changed, 11 insertions, 2 deletions
diff --git a/libc/bionic/heap_tagging.cpp b/libc/bionic/heap_tagging.cpp index ffbabb9a0..41aa20507 100644 --- a/libc/bionic/heap_tagging.cpp +++ b/libc/bionic/heap_tagging.cpp @@ -139,7 +139,12 @@ bool SetHeapTaggingLevel(HeapTaggingLevel tag_level) { } if (tag_level == M_HEAP_TAGGING_LEVEL_ASYNC) { - set_tcf_on_all_threads(PR_MTE_TCF_ASYNC); + // When entering ASYNC mode, specify that we want to allow upgrading to SYNC by OR'ing in + // the SYNC flag. But if the kernel doesn't support specifying multiple TCF modes, fall back + // to specifying a single mode. + if (!set_tcf_on_all_threads(PR_MTE_TCF_ASYNC | PR_MTE_TCF_SYNC)) { + set_tcf_on_all_threads(PR_MTE_TCF_ASYNC); + } #if defined(USE_SCUDO) scudo_malloc_set_track_allocation_stacks(0); #endif diff --git a/libc/bionic/libc_init_static.cpp b/libc/bionic/libc_init_static.cpp index 069ebb0ab..3a8513f98 100644 --- a/libc/bionic/libc_init_static.cpp +++ b/libc/bionic/libc_init_static.cpp @@ -311,7 +311,11 @@ __attribute__((no_sanitize("hwaddress", "memtag"))) void __libc_init_mte(const v unsigned long prctl_arg = PR_TAGGED_ADDR_ENABLE | PR_MTE_TAG_SET_NONZERO; prctl_arg |= (level == M_HEAP_TAGGING_LEVEL_SYNC) ? PR_MTE_TCF_SYNC : PR_MTE_TCF_ASYNC; - if (prctl(PR_SET_TAGGED_ADDR_CTRL, prctl_arg, 0, 0, 0) == 0) { + // When entering ASYNC mode, specify that we want to allow upgrading to SYNC by OR'ing in the + // SYNC flag. But if the kernel doesn't support specifying multiple TCF modes, fall back to + // specifying a single mode. + if (prctl(PR_SET_TAGGED_ADDR_CTRL, prctl_arg | PR_MTE_TCF_SYNC, 0, 0, 0) == 0 || + prctl(PR_SET_TAGGED_ADDR_CTRL, prctl_arg, 0, 0, 0) == 0) { __libc_shared_globals()->initial_heap_tagging_level = level; return; } |