[Bug]: build with asan error in aarch64

[AeloriaDev]

Describe the bug

使能asan构建时，报错，信息如下
Use --sandbox_debug to see verbose messages from the sandbox and retain the sandbox build root for debugging
ld.lld: error: relocation refers to a discarded section: .note.GNU-stack

defined in bazel-out/aarch64-fastbuild/bin/external/brpc~/_objs/bthread/context.pic.o
referenced by context.cpp
bazel-out/aarch64-fastbuild/bin/external/brpc~/_objs/bthread/context.pic.o:(.init_array.00099+0x0)
collect2: error: ld returned 1 exit status

Steps To Reproduce

bazel build --config asan //...

Expected behavior

无错

Version

v0.6.0.dev260105

Operating system

devtools aarch64 ubuntu jammy

Hardware Resources

8c 32g

[peakshen]

看报错：LLD 链接器不认识 .note.GNU-stack 这个栈不可执行段，开启 ASAN 后被清理掉了，导致重定位失败。
有没有尝试过添加，-Wl,-z,nognustack 。

[AeloriaDev]

没有解决该问题, 我采用了以下方式,给brpc打了个patch

diff --git a/src/bthread/context.cpp b/src/bthread/context.cpp
index b7be731e..8692e68f 100644
--- a/src/bthread/context.cpp
+++ b/src/bthread/context.cpp
@@ -14,6 +14,12 @@
 
 */
 #include "bthread/context.h"
+
+// When building with ASan, skip the .note.GNU-stack section to avoid
+// link errors about discarded sections.
+#if defined(__SANITIZE_ADDRESS__)
+#define BTHREAD_SKIP_GNU_STACK_NOTE
+#endif
 #if defined(BTHREAD_CONTEXT_PLATFORM_windows_i386) && defined(BTHREAD_CONTEXT_COMPILER_gcc)
 __asm (
 ".text\n"
@@ -293,7 +299,9 @@ __asm (
 "    movl  %eax, 0x4(%esp)\n"
 "    jmp  *%edx\n"
 ".size bthread_jump_fcontext,.-bthread_jump_fcontext\n"
+#if !defined(BTHREAD_SKIP_GNU_STACK_NOTE)
 ".section .note.GNU-stack,\"\",%progbits\n"
+#endif
 ".previous\n"
 );
 
@@ -328,7 +336,9 @@ __asm (
 "    call  _exit@PLT\n"
 "    hlt\n"
 ".size bthread_make_fcontext,.-bthread_make_fcontext\n"
+#if !defined(BTHREAD_SKIP_GNU_STACK_NOTE)
 ".section .note.GNU-stack,\"\",%progbits\n"
+#endif
 ".previous\n"
 );
 
@@ -372,7 +382,9 @@ __asm (
 "    movq  %rdx, %rdi\n"
 "    jmp  *%r8\n"
 ".size bthread_jump_fcontext,.-bthread_jump_fcontext\n"
+#if !defined(BTHREAD_SKIP_GNU_STACK_NOTE)
 ".section .note.GNU-stack,\"\",%progbits\n"
+#endif
 ".previous\n"
 );
 
@@ -399,7 +411,9 @@ __asm (
 "    call  _exit@PLT\n"
 "    hlt\n"
 ".size bthread_make_fcontext,.-bthread_make_fcontext\n"
+#if !defined(BTHREAD_SKIP_GNU_STACK_NOTE)
 ".section .note.GNU-stack,\"\",%progbits\n"
+#endif
 ".previous\n"
 );
 
@@ -575,7 +589,9 @@ __asm (
 "    pop {pc}\n"
 ".size bthread_jump_fcontext,.-bthread_jump_fcontext\n"
 "@ Mark that we don't need executable stack.\n"
+#if !defined(BTHREAD_SKIP_GNU_STACK_NOTE)
 ".section .note.GNU-stack,\"\",%progbits\n"
+#endif
 );
 
 #endif
@@ -606,7 +622,9 @@ __asm (
 "    bl  _exit@PLT\n"
 ".size bthread_make_fcontext,.-bthread_make_fcontext\n"
 "@ Mark that we don't need executable stack.\n"
+#if !defined(BTHREAD_SKIP_GNU_STACK_NOTE)
 ".section .note.GNU-stack,\"\",%progbits\n"
+#endif
 );
 
 #endif
@@ -677,7 +695,9 @@ __asm (
 "    ret x4\n"
 ".size   bthread_jump_fcontext,.-bthread_jump_fcontext\n"
 "# Mark that we don't need executable stack.\n"
+#if !defined(BTHREAD_SKIP_GNU_STACK_NOTE)
 ".section .note.GNU-stack,\"\",%progbits\n"
+#endif
 );
 
 #endif
@@ -709,7 +729,9 @@ __asm (
 "    bl  _exit\n"
 ".size   bthread_make_fcontext,.-bthread_make_fcontext\n"
 "# Mark that we don't need executable stack.\n"
+#if !defined(BTHREAD_SKIP_GNU_STACK_NOTE)
 ".section .note.GNU-stack,\"\",%progbits\n"
+#endif
 );
 
 #endif

[peakshen]

没有解决该问题, 我采用了以下方式,给brpc打了个patch

diff --git a/src/bthread/context.cpp b/src/bthread/context.cpp
index b7be731e..8692e68f 100644
--- a/src/bthread/context.cpp
+++ b/src/bthread/context.cpp
@@ -14,6 +14,12 @@

*/
#include "bthread/context.h"
+
+// When building with ASan, skip the .note.GNU-stack section to avoid
+// link errors about discarded sections.
+#if defined(SANITIZE_ADDRESS)
+#define BTHREAD_SKIP_GNU_STACK_NOTE
+#endif
#if defined(BTHREAD_CONTEXT_PLATFORM_windows_i386) && defined(BTHREAD_CONTEXT_COMPILER_gcc)
__asm (
".text\n"
@@ -293,7 +299,9 @@ __asm (
" movl %eax, 0x4(%esp)\n"
" jmp *%edx\n"
".size bthread_jump_fcontext,.-bthread_jump_fcontext\n"
+#if !defined(BTHREAD_SKIP_GNU_STACK_NOTE)
".section .note.GNU-stack,"",%progbits\n"
+#endif
".previous\n"
);

@@ -328,7 +336,9 @@ __asm (
" call _exit@PLT\n"
" hlt\n"
".size bthread_make_fcontext,.-bthread_make_fcontext\n"
+#if !defined(BTHREAD_SKIP_GNU_STACK_NOTE)
".section .note.GNU-stack,"",%progbits\n"
+#endif
".previous\n"
);

@@ -372,7 +382,9 @@ __asm (
" movq %rdx, %rdi\n"
" jmp *%r8\n"
".size bthread_jump_fcontext,.-bthread_jump_fcontext\n"
+#if !defined(BTHREAD_SKIP_GNU_STACK_NOTE)
".section .note.GNU-stack,"",%progbits\n"
+#endif
".previous\n"
);

@@ -399,7 +411,9 @@ __asm (
" call _exit@PLT\n"
" hlt\n"
".size bthread_make_fcontext,.-bthread_make_fcontext\n"
+#if !defined(BTHREAD_SKIP_GNU_STACK_NOTE)
".section .note.GNU-stack,"",%progbits\n"
+#endif
".previous\n"
);

@@ -575,7 +589,9 @@ __asm (
" pop {pc}\n"
".size bthread_jump_fcontext,.-bthread_jump_fcontext\n"
"@ Mark that we don't need executable stack.\n"
+#if !defined(BTHREAD_SKIP_GNU_STACK_NOTE)
".section .note.GNU-stack,"",%progbits\n"
+#endif
);

#endif
@@ -606,7 +622,9 @@ __asm (
" bl _exit@PLT\n"
".size bthread_make_fcontext,.-bthread_make_fcontext\n"
"@ Mark that we don't need executable stack.\n"
+#if !defined(BTHREAD_SKIP_GNU_STACK_NOTE)
".section .note.GNU-stack,"",%progbits\n"
+#endif
);

#endif
@@ -677,7 +695,9 @@ __asm (
" ret x4\n"
".size bthread_jump_fcontext,.-bthread_jump_fcontext\n"
"# Mark that we don't need executable stack.\n"
+#if !defined(BTHREAD_SKIP_GNU_STACK_NOTE)
".section .note.GNU-stack,"",%progbits\n"
+#endif
);

#endif
@@ -709,7 +729,9 @@ __asm (
" bl _exit\n"
".size bthread_make_fcontext,.-bthread_make_fcontext\n"
"# Mark that we don't need executable stack.\n"
+#if !defined(BTHREAD_SKIP_GNU_STACK_NOTE)
".section .note.GNU-stack,"",%progbits\n"
+#endif
);

#endif

ok 这也是一种问题解决方式。
针对编译问题，我们在研发环境视频排查下。