Commit Graph

5 Commits

Author SHA1 Message Date
Kazuaki Ishizaki a1e7e401d2 [compiler-rt] NFC: Fix trivial typo
Reviewed By: xgupta

Differential Revision: https://reviews.llvm.org/D77457
2021-09-04 14:12:58 +05:30
Ian Levesque 7c7c8e0da4 [xray] Option to omit the function index
Summary:
Add a flag to omit the xray_fn_idx to cut size overhead and relocations
roughly in half at the cost of reduced performance for single function
patching.  Minor additions to compiler-rt support per-function patching
without the index.

Reviewers: dberris, MaskRay, johnislarry

Subscribers: hiraditya, arphaman, cfe-commits, #sanitizers, llvm-commits

Tags: #clang, #sanitizers, #llvm

Differential Revision: https://reviews.llvm.org/D81995
2020-06-17 13:49:01 -04:00
Fangrui Song 10bc12588d [XRay] Change Sled.Function to PC-relative for sled version 2 and make llvm-xray support sled version 2 addresses
Follow-up of D78082 and D78590.

Otherwise, because xray_instr_map is now read-only, the absolute
relocation used for Sled.Function will cause a text relocation.
2020-04-24 14:41:56 -07:00
Fangrui Song 5771c98562 [XRay] Change xray_instr_map sled addresses from absolute to PC relative for x86-64
xray_instr_map contains absolute addresses of sleds, which are relocated
by `R_*_RELATIVE` when linked in -pie or -shared mode.

By making these addresses relative to PC, we can avoid the dynamic
relocations and remove the SHF_WRITE flag from xray_instr_map.  We can
thus save VM pages containg xray_instr_map (because they are not
modified).

This patch changes x86-64 and bumps the sled version to 2. Subsequent
changes will change powerpc64le and AArch64.

Reviewed By: dberris, ianlevesque

Differential Revision: https://reviews.llvm.org/D78082
2020-04-21 09:36:09 -07:00
Nico Weber b301860321 compiler-rt: Rename .cc file in lib/xray to .cpp
Like r367463, but for xray.

llvm-svn: 367546
2019-08-01 12:30:58 +00:00