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Differential D57863

[safestack] Explain why tinfo at the end of the buffer
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Authored by vitalybuka on Feb 6 2019, 4:14 PM.

Details

Reviewers
pcc
eugenis
vlad.tsyrklevich
Commits
rG871b2bd98030: [safestack] Explain why tinfo at the end of the buffer
rCRT353482: [safestack] Explain why tinfo at the end of the buffer
rL353482: [safestack] Explain why tinfo at the end of the buffer

Diff Detail

Repository
rL LLVM

Event Timeline

vitalybuka created this revision.Feb 6 2019, 4:14 PM
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Harbormaster completed remote builds in B27851: Diff 185665.Feb 6 2019, 4:15 PM
vitalybuka edited the summary of this revision. (Show Details)Feb 6 2019, 4:18 PM
vitalybuka added reviewers: pcc, eugenis.
vitalybuka added a reviewer: vlad.tsyrklevich.Feb 7 2019, 1:30 PM
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vlad.tsyrklevich added inline comments.Feb 7 2019, 1:39 PM
compiler-rt/lib/safestack/safestack.cc
235 ↗(On Diff #185665)

Shouldn't this be addr+guard?

vitalybuka marked an inline comment as done.Feb 7 2019, 2:13 PM
vitalybuka added inline comments.
compiler-rt/lib/safestack/safestack.cc
235 ↗(On Diff #185665)

unsafe_stack_alloc already does that

vlad.tsyrklevich accepted this revision.Feb 7 2019, 2:15 PM
This revision is now accepted and ready to land.Feb 7 2019, 2:15 PM
vitalybuka updated this revision to Diff 185877.Feb 7 2019, 3:17 PM

do nothing

vitalybuka retitled this revision from [safestack] Simplify tinfo location calculation to [safestack] Explain why tinfo at the end of the buffer.Feb 7 2019, 3:18 PM
vitalybuka edited the summary of this revision. (Show Details)
Harbormaster completed remote builds in B27924: Diff 185877.Feb 7 2019, 3:18 PM
vitalybuka updated this revision to Diff 185878.Feb 7 2019, 3:19 PM

typo

Harbormaster completed remote builds in B27925: Diff 185878.Feb 7 2019, 3:20 PM
Closed by commit rL353482: [safestack] Explain why tinfo at the end of the buffer (authored by vitalybuka). · Explain WhyFeb 7 2019, 3:23 PM
This revision was automatically updated to reflect the committed changes.
Herald added a subscriber: delcypher. · View Herald TranscriptFeb 7 2019, 3:23 PM

Revision Contents

PathSize
compiler-rt/
trunk/
lib/
safestack/
2 lines

Diff 185880

compiler-rt/trunk/lib/safestack/safestack.cc

Show First 20 Lines • Show All 222 Lines • ▼ Show 20 Lines if (attr) {
pthread_attr_getguardsize(&tmpattr, &guard); pthread_attr_getguardsize(&tmpattr, &guard);
pthread_attr_destroy(&tmpattr); pthread_attr_destroy(&tmpattr);
} }
SFS_CHECK(size); SFS_CHECK(size);
size = RoundUpTo(size, kStackAlign); size = RoundUpTo(size, kStackAlign);
void *addr = unsafe_stack_alloc(size, guard); void *addr = unsafe_stack_alloc(size, guard);
// Put tinfo at the end of the buffer. guard may be not page aligned.
// If that is so then some bytes after addr can be mprotected.
struct tinfo *tinfo = struct tinfo *tinfo =
(struct tinfo *)(((char *)addr) + size - sizeof(struct tinfo)); (struct tinfo *)(((char *)addr) + size - sizeof(struct tinfo));
tinfo->start_routine = start_routine; tinfo->start_routine = start_routine;
tinfo->start_routine_arg = arg; tinfo->start_routine_arg = arg;
tinfo->unsafe_stack_start = addr; tinfo->unsafe_stack_start = addr;
tinfo->unsafe_stack_size = size; tinfo->unsafe_stack_size = size;
tinfo->unsafe_stack_guard = guard; tinfo->unsafe_stack_guard = guard;
▲ Show 20 Lines • Show All 70 Lines • Show Last 20 Lines