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Differential D47915

[asan] Handle 0 alignment in PosixMemalignFromLocalPool
AbandonedPublic

Authored by waltl on Jun 7 2018, 3:46 PM.

Details

Reviewers
vitalybuka
alekseyshl
Summary

The previous CHECK was wrong because alignment can be 0.

Diff Detail

Event Timeline

waltl created this revision.Jun 7 2018, 3:46 PM
Herald added a subscriber: kubamracek. · View Herald TranscriptJun 7 2018, 3:46 PM
Harbormaster completed remote builds in B19076: Diff 150424.Jun 7 2018, 3:46 PM
alekseyshl added inline comments.Jun 7 2018, 4:51 PM
compiler-rt/lib/asan/asan_malloc_linux.cc
54

Actually, 0 alignment should have been rejected by CheckPosixMemalignAlignment. I'll add the check there.

alekseyshl added a comment.Jun 7 2018, 4:52 PM

Are you aware of the legal use case of 0 alignment?

waltl abandoned this revision.Jun 7 2018, 5:12 PM
waltl added inline comments.
compiler-rt/lib/asan/asan_malloc_linux.cc
54

My bad. I misread the spec.

Revision Contents

PathSize
compiler-rt/
lib/
asan/
2 lines

Diff 150424

compiler-rt/lib/asan/asan_malloc_linux.cc

Show First 20 Lines • Show All 45 Lines • ▼ Show 20 Linesstatic void *AllocateFromLocalPool(uptr size_in_bytes) {
return mem; return mem;
} }
static int PosixMemalignFromLocalPool(void **memptr, uptr alignment, static int PosixMemalignFromLocalPool(void **memptr, uptr alignment,
uptr size_in_bytes) { uptr size_in_bytes) {
if (UNLIKELY(!CheckPosixMemalignAlignment(alignment))) if (UNLIKELY(!CheckPosixMemalignAlignment(alignment)))
return errno_EINVAL; return errno_EINVAL;
CHECK(alignment >= kWordSize); alignment = Max(alignment, kWordSize);
alekseyshlUnsubmitted
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Actually, 0 alignment should have been rejected by CheckPosixMemalignAlignment. I'll add the check there.

alekseyshl: Actually, 0 alignment should have been rejected by CheckPosixMemalignAlignment. I'll add the…
waltlAuthorUnsubmitted
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My bad. I misread the spec.

waltl: My bad. I misread the spec.
uptr addr = (uptr)&alloc_memory_for_dlsym[allocated_for_dlsym]; uptr addr = (uptr)&alloc_memory_for_dlsym[allocated_for_dlsym];
uptr aligned_addr = RoundUpTo(addr, alignment); uptr aligned_addr = RoundUpTo(addr, alignment);
uptr aligned_size = RoundUpTo(size_in_bytes, kWordSize); uptr aligned_size = RoundUpTo(size_in_bytes, kWordSize);
uptr *end_mem = (uptr*)(aligned_addr + aligned_size); uptr *end_mem = (uptr*)(aligned_addr + aligned_size);
uptr allocated = end_mem - alloc_memory_for_dlsym; uptr allocated = end_mem - alloc_memory_for_dlsym;
if (allocated >= kDlsymAllocPoolSize) if (allocated >= kDlsymAllocPoolSize)
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