[PATCH] D63944: [TSan] Improve handling of stack pointer mangling in {set,long}jmp, pt.3

[Julian Lettner via Phabricator via llvm-commits]

yln created this revision.
Herald added subscribers: llvm-commits, Sanitizers, krytarowski, kubamracek.
Herald added projects: Sanitizers, LLVM.

Remove unnecessary computation of mangled SP for x86_64 architecture.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D63944

Files:
  compiler-rt/lib/tsan/rtl/tsan_interceptors.cc
  compiler-rt/lib/tsan/rtl/tsan_rtl_amd64.S


Index: compiler-rt/lib/tsan/rtl/tsan_rtl_amd64.S
===================================================================
--- compiler-rt/lib/tsan/rtl/tsan_rtl_amd64.S
+++ compiler-rt/lib/tsan/rtl/tsan_rtl_amd64.S
@@ -189,19 +189,11 @@
   push %rdi
   CFI_ADJUST_CFA_OFFSET(8)
   CFI_REL_OFFSET(%rdi, 0)
-  // obtain %rsp
+  // obtain SP, store in %rdi, first argument to `void __tsan_setjmp(uptr sp)`
 #if defined(__FreeBSD__) || defined(__NetBSD__)
   lea 8(%rsp), %rdi
-  mov %rdi, %rsi
-#elif defined(__APPLE__)
+#elif defined(__linux__) || defined(__APPLE__)
   lea 16(%rsp), %rdi
-  mov %rdi, %rsi
-  xorq ___tsan_darwin_setjmp_xor_key(%rip), %rsi
-#elif defined(__linux__)
-  lea 16(%rsp), %rdi
-  mov %rdi, %rsi
-  xor %fs:0x30, %rsi  // magic mangling of rsp (see libc setjmp)
-  rol $0x11, %rsi
 #else
 # error "Unknown platform"
 #endif
@@ -238,19 +230,11 @@
   push %rdi
   CFI_ADJUST_CFA_OFFSET(8)
   CFI_REL_OFFSET(%rdi, 0)
-  // obtain %rsp
+  // obtain SP, store in %rdi, first argument to `void __tsan_setjmp(uptr sp)`
 #if defined(__FreeBSD__) || defined(__NetBSD__)
   lea 8(%rsp), %rdi
-  mov %rdi, %rsi
-#elif defined(__APPLE__)
-  lea 16(%rsp), %rdi
-  mov %rdi, %rsi
-  xorq ___tsan_darwin_setjmp_xor_key(%rip), %rsi
-#elif defined(__linux__)
+#elif defined(__linux__) || defined(__APPLE__)
   lea 16(%rsp), %rdi
-  mov %rdi, %rsi
-  xor %fs:0x30, %rsi  // magic mangling of rsp (see libc setjmp)
-  rol $0x11, %rsi
 #else
 # error "Unknown platform"
 #endif
@@ -294,19 +278,11 @@
   // align stack frame
   sub $8, %rsp
   CFI_ADJUST_CFA_OFFSET(8)
-  // obtain %rsp
+  // obtain SP, store in %rdi, first argument to `void __tsan_setjmp(uptr sp)`
 #if defined(__FreeBSD__) || defined(__NetBSD__)
   lea 24(%rsp), %rdi
-  mov %rdi, %rsi
-#elif defined(__APPLE__)
-  lea 32(%rsp), %rdi
-  mov %rdi, %rsi
-  xorq ___tsan_darwin_setjmp_xor_key(%rip), %rsi
-#elif defined(__linux__)
+#elif defined(__linux__) || defined(__APPLE__)
   lea 32(%rsp), %rdi
-  mov %rdi, %rsi
-  xor %fs:0x30, %rsi  // magic mangling of rsp (see libc setjmp)
-  rol $0x11, %rsi
 #else
 # error "Unknown platform"
 #endif
@@ -358,15 +334,11 @@
   // align stack frame
   sub $8, %rsp
   CFI_ADJUST_CFA_OFFSET(8)
-  // obtain %rsp
+  // obtain SP, store in %rdi, first argument to `void __tsan_setjmp(uptr sp)`
 #if defined(__FreeBSD__)
   lea 24(%rsp), %rdi
-  mov %rdi, %rsi
 #else
   lea 32(%rsp), %rdi
-  mov %rdi, %rsi
-  xor %fs:0x30, %rsi  // magic mangling of rsp (see libc setjmp)
-  rol $0x11, %rsi
 #endif
   // call tsan interceptor
   call ASM_SYMBOL(__tsan_setjmp)
Index: compiler-rt/lib/tsan/rtl/tsan_interceptors.cc
===================================================================
--- compiler-rt/lib/tsan/rtl/tsan_interceptors.cc
+++ compiler-rt/lib/tsan/rtl/tsan_interceptors.cc
@@ -553,7 +553,7 @@
 }
 
 // FIXME: put everything below into a common extern "C" block?
-extern "C" void __tsan_setjmp(uptr sp, uptr mangled_sp) {
+extern "C" void __tsan_setjmp(uptr sp) {
   cur_thread_init();
   SetJmp(cur_thread(), sp);
 }


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D63944.207106.patch
Type: text/x-patch
Size: 3033 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20190628/049ab61a/attachment.bin>