[PATCH] D64023: [TSan] Improve handling of stack pointer mangling in {set,long}jmp, pt.6

[Julian Lettner via Phabricator via llvm-commits]

yln created this revision.
yln added a reviewer: dvyukov.
Herald added subscribers: llvm-commits, Sanitizers, javed.absar, kubamracek.
Herald added projects: Sanitizers, LLVM.

Since we don't clobber x1/w1 (2nd argument) anymore, we don't have to
save/restore it.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D64023

Files:
  compiler-rt/lib/tsan/rtl/tsan_rtl_aarch64.S


Index: compiler-rt/lib/tsan/rtl/tsan_rtl_aarch64.S
===================================================================
--- compiler-rt/lib/tsan/rtl/tsan_rtl_aarch64.S
+++ compiler-rt/lib/tsan/rtl/tsan_rtl_aarch64.S
@@ -123,8 +123,9 @@
   mov     x0, x19
   ldr     x19, [sp, 16]
   ldp     x29, x30, [sp], 32
-  CFI_RESTORE (30)
   CFI_RESTORE (19)
+  CFI_RESTORE (29)
+  CFI_RESTORE (30)
   CFI_DEF_CFA (31, 0)
 
   // tail jump to libc setjmp
@@ -173,8 +174,9 @@
   mov     x0, x19
   ldr     x19, [sp, 16]
   ldp     x29, x30, [sp], 32
-  CFI_RESTORE (30)
   CFI_RESTORE (19)
+  CFI_RESTORE (29)
+  CFI_RESTORE (30)
   CFI_DEF_CFA (31, 0)
 
   // tail jump to libc setjmp
@@ -208,11 +210,9 @@
   add     x29, sp, 0
   CFI_DEF_CFA_REGISTER (29)
 
-  // Save jmp_buf and savesigs
-  stp     x19, x20, [sp, 16]
+  // Save jmp_buf
+  str     x19, [sp, 16]
   CFI_OFFSET (19, -16)
-  CFI_OFFSET (20, -8)
-  mov     w20, w1
   mov     x19, x0
 
   // Obtain SP, first argument to `void __tsan_setjmp(uptr sp)`
@@ -222,14 +222,12 @@
   bl      ASM_SYMBOL(__tsan_setjmp)
 
   // restore env parameter
-  mov     w1, w20
   mov     x0, x19
-  ldp     x19, x20, [sp, 16]
+  ldr     x19, [sp, 16]
   ldp     x29, x30, [sp], 32
-  CFI_RESTORE (30)
-  CFI_RESTORE (29)
   CFI_RESTORE (19)
-  CFI_RESTORE (20)
+  CFI_RESTORE (29)
+  CFI_RESTORE (30)
   CFI_DEF_CFA (31, 0)
 
   // tail jump to libc sigsetjmp
@@ -263,11 +261,9 @@
   add     x29, sp, 0
   CFI_DEF_CFA_REGISTER (29)
 
-  // Save jmp_buf and savesigs
-  stp     x19, x20, [sp, 16]
+  // Save jmp_buf
+  str     x19, [sp, 16]
   CFI_OFFSET (19, -16)
-  CFI_OFFSET (20, -8)
-  mov     w20, w1
   mov     x19, x0
 
   // Obtain SP, first argument to `void __tsan_setjmp(uptr sp)`
@@ -276,14 +272,13 @@
   // call tsan interceptor
   bl      ASM_SYMBOL(__tsan_setjmp)
 
-  mov     w1, w20
+  // restore env parameter
   mov     x0, x19
-  ldp     x19, x20, [sp, 16]
+  ldr     x19, [sp, 16]
   ldp     x29, x30, [sp], 32
-  CFI_RESTORE (30)
-  CFI_RESTORE (29)
   CFI_RESTORE (19)
-  CFI_RESTORE (20)
+  CFI_RESTORE (29)
+  CFI_RESTORE (30)
   CFI_DEF_CFA (31, 0)
 
   // tail jump to libc __sigsetjmp


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