Commit Graph

2 Commits

Author SHA1 Message Date
Dmitry Vyukov cc1f318b5a tsan: support pie binaries on newer kernels
4.1+ Linux kernels map pie binaries at 0x55:
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=d1fd836dcf00d2028c700c7e44d2c23404062c90
Currently tsan does not support app memory at 0x55 (https://github.com/google/sanitizers/issues/503).
Older kernels also map pie binaries at 0x55 when ASLR is disables (most notably under gdb).

This change extends tsan mapping for linux/x86_64 to cover 0x554-0x568 app range and fixes both 4.1+ kernels and gdb.

This required to slightly shrink low and high app ranges and move heap. The mapping become even more non-linear, since now we xor lower bits. Now even a continuous app range maps to split, intermixed shadow ranges. This breaks ShadowToMemImpl as it assumes linear mapping at least within a continuous app range (however it turned out to be already broken at least on arm64/42-bit vma as uncovered by r281970). So also change ShadowToMemImpl to hopefully a more robust implementation that does not assume a linear mapping.

llvm-svn: 282152
2016-09-22 13:42:02 +00:00
Adhemerval Zanella b2910ea67e [compiler-rt] [tsan] Add support for PIE build on AArch64
This patch adds PIE executable support for aarch64-linux.  It adds
two more segments:

- 0x05500000000-0x05600000000: 39-bits PIE program segments
- 0x2aa00000000-0x2ab00000000: 42-bits PIE program segments

Fortunately it is possible to use the same transformation formula for
the new segments range with some adjustments in shadow to memory
formula (it adds a constant offset based on the VMA size).

A simple testcase is also added, however it is disabled on x86 due the
fact it might fail on newer kernels [1].

[1] https://git.kernel.org/linus/d1fd836dcf00d2028c700c7e44d2c23404062c90

llvm-svn: 256184
2015-12-21 19:27:57 +00:00