[compiler-rt] r365229 - [TSan] Improve handling of stack pointer mangling in {set, long}jmp, pt.4

[Julian Lettner via llvm-commits]

Author: yln
Date: Fri Jul  5 11:00:12 2019
New Revision: 365229

URL: http://llvm.org/viewvc/llvm-project?rev=365229&view=rev
Log:
[TSan] Improve handling of stack pointer mangling in {set,long}jmp, pt.4

For x86_64, since we don't clobber %rsi (2nd argument) anymore, we don't
have to save/restore it.

Reviewed By: dvyukov

Differential Revision: https://reviews.llvm.org/D63946

Modified:
    compiler-rt/trunk/lib/tsan/rtl/tsan_rtl_amd64.S

Modified: compiler-rt/trunk/lib/tsan/rtl/tsan_rtl_amd64.S
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/tsan/rtl/tsan_rtl_amd64.S?rev=365229&r1=365228&r2=365229&view=diff
==============================================================================
--- compiler-rt/trunk/lib/tsan/rtl/tsan_rtl_amd64.S (original)
+++ compiler-rt/trunk/lib/tsan/rtl/tsan_rtl_amd64.S Fri Jul  5 11:00:12 2019
@@ -271,30 +271,16 @@ ASM_SYMBOL_INTERCEPTOR(sigsetjmp):
   push %rdi
   CFI_ADJUST_CFA_OFFSET(8)
   CFI_REL_OFFSET(%rdi, 0)
-  // save savesigs parameter
-  push %rsi
-  CFI_ADJUST_CFA_OFFSET(8)
-  CFI_REL_OFFSET(%rsi, 0)
-  // align stack frame
-  sub $8, %rsp
-  CFI_ADJUST_CFA_OFFSET(8)
   // obtain SP, store in %rdi, first argument to `void __tsan_setjmp(uptr sp)`
 #if defined(__FreeBSD__) || defined(__NetBSD__)
-  lea 24(%rsp), %rdi
+  lea 8(%rsp), %rdi
 #elif defined(__linux__) || defined(__APPLE__)
-  lea 32(%rsp), %rdi
+  lea 16(%rsp), %rdi
 #else
 # error "Unknown platform"
 #endif
   // call tsan interceptor
   call ASM_SYMBOL(__tsan_setjmp)
-  // unalign stack frame
-  add $8, %rsp
-  CFI_ADJUST_CFA_OFFSET(-8)
-  // restore savesigs parameter
-  pop %rsi
-  CFI_ADJUST_CFA_OFFSET(-8)
-  CFI_RESTORE(%rsi)
   // restore env parameter
   pop %rdi
   CFI_ADJUST_CFA_OFFSET(-8)
@@ -327,28 +313,14 @@ ASM_SYMBOL_INTERCEPTOR(__sigsetjmp):
   push %rdi
   CFI_ADJUST_CFA_OFFSET(8)
   CFI_REL_OFFSET(%rdi, 0)
-  // save savesigs parameter
-  push %rsi
-  CFI_ADJUST_CFA_OFFSET(8)
-  CFI_REL_OFFSET(%rsi, 0)
-  // align stack frame
-  sub $8, %rsp
-  CFI_ADJUST_CFA_OFFSET(8)
   // obtain SP, store in %rdi, first argument to `void __tsan_setjmp(uptr sp)`
 #if defined(__FreeBSD__)
-  lea 24(%rsp), %rdi
+  lea 8(%rsp), %rdi
 #else
-  lea 32(%rsp), %rdi
+  lea 16(%rsp), %rdi
 #endif
   // call tsan interceptor
   call ASM_SYMBOL(__tsan_setjmp)
-  // unalign stack frame
-  add $8, %rsp
-  CFI_ADJUST_CFA_OFFSET(-8)
-  // restore savesigs parameter
-  pop %rsi
-  CFI_ADJUST_CFA_OFFSET(-8)
-  CFI_RESTORE(%rsi)
   // restore env parameter
   pop %rdi
   CFI_ADJUST_CFA_OFFSET(-8)