[gcc(refs/users/xry111/heads/loongarch-sanitizer-test)] cherry-pick https://reviews.llvm.org/D129418

[gcc(refs/users/xry111/heads/loongarch-sanitizer-test)] cherry-pick https://reviews.llvm.org/D129418

[Xi Ruoyao]

https://gcc.gnu.org/g:7d4d249bdb128761dac4a232c2ae45737b5ff57d

commit 7d4d249bdb128761dac4a232c2ae45737b5ff57d
Author: Xi Ruoyao <xry111@xry111.site>
Date:   Mon Jul 11 18:21:01 2022 +0800

    cherry-pick https://reviews.llvm.org/D129418

Diff:
---
 libsanitizer/asan/asan_interceptors_vfork.S        |  1 +
 libsanitizer/asan/asan_mapping.h                   |  9 ++++
 ...zer_common_interceptors_vfork_loongarch64.inc.S | 57 ++++++++++++++++++++++
 .../sanitizer_common/sanitizer_stacktrace.cpp      |  4 +-
 4 files changed, 69 insertions(+), 2 deletions(-)

diff --git a/libsanitizer/asan/asan_interceptors_vfork.S b/libsanitizer/asan/asan_interceptors_vfork.S
index 3ae5503e83c..ec29adc7b13 100644
--- a/libsanitizer/asan/asan_interceptors_vfork.S
+++ b/libsanitizer/asan/asan_interceptors_vfork.S
@@ -6,6 +6,7 @@
 #include "sanitizer_common/sanitizer_common_interceptors_vfork_aarch64.inc.S"
 #include "sanitizer_common/sanitizer_common_interceptors_vfork_arm.inc.S"
 #include "sanitizer_common/sanitizer_common_interceptors_vfork_i386.inc.S"
+#include "sanitizer_common/sanitizer_common_interceptors_vfork_loongarch64.inc.S"
 #include "sanitizer_common/sanitizer_common_interceptors_vfork_riscv64.inc.S"
 #include "sanitizer_common/sanitizer_common_interceptors_vfork_x86_64.inc.S"
 #endif
diff --git a/libsanitizer/asan/asan_mapping.h b/libsanitizer/asan/asan_mapping.h
index 1b6669e1270..463a3259e24 100644
--- a/libsanitizer/asan/asan_mapping.h
+++ b/libsanitizer/asan/asan_mapping.h
@@ -114,6 +114,13 @@
 // || `[0x0080000000000, 0x008ffffffffff]` || LowShadow  ||
 // || `[0x0000000000000, 0x007ffffffffff]` || LowMem     ||
 //
+// Default Linux/LoongArch64 (47-bit VMA) mapping:
+// || `[0x500000000000, 0x7fffffffffff]` || HighMem    ||
+// || `[0x4a0000000000, 0x4fffffffffff]` || HighShadow ||
+// || `[0x480000000000, 0x49ffffffffff]` || ShadowGap  ||
+// || `[0x400000000000, 0x47ffffffffff]` || LowShadow  ||
+// || `[0x000000000000, 0x3fffffffffff]` || LowMem     ||
+//
 // Shadow mapping on FreeBSD/x86-64 with SHADOW_OFFSET == 0x400000000000:
 // || `[0x500000000000, 0x7fffffffffff]` || HighMem    ||
 // || `[0x4a0000000000, 0x4fffffffffff]` || HighShadow ||
@@ -194,6 +201,8 @@
 #    define ASAN_SHADOW_OFFSET_CONST 0x0000002000000000
 #  elif defined(__sparc__)
 #    define ASAN_SHADOW_OFFSET_CONST 0x0000080000000000
+#  elif SANITIZER_LOONGARCH64
+#    define ASAN_SHADOW_OFFSET_CONST 0x0000400000000000
 #  elif SANITIZER_WINDOWS64
 #    define ASAN_SHADOW_OFFSET_DYNAMIC
 #  else
diff --git a/libsanitizer/sanitizer_common/sanitizer_common_interceptors_vfork_loongarch64.inc.S b/libsanitizer/sanitizer_common/sanitizer_common_interceptors_vfork_loongarch64.inc.S
new file mode 100644
index 00000000000..08d30a5e3ee
--- /dev/null
+++ b/libsanitizer/sanitizer_common/sanitizer_common_interceptors_vfork_loongarch64.inc.S
@@ -0,0 +1,57 @@
+#if defined(__loongarch__) && defined(__loongarch_lp64) && defined(__linux__)
+
+#include "sanitizer_common/sanitizer_asm.h"
+
+ASM_HIDDEN(COMMON_INTERCEPTOR_SPILL_AREA)
+ASM_HIDDEN(_ZN14__interception10real_vforkE)
+
+.comm _ZN14__interception10real_vforkE,8,8
+.globl ASM_WRAPPER_NAME(vfork)
+ASM_TYPE_FUNCTION(ASM_WRAPPER_NAME(vfork))
+ASM_WRAPPER_NAME(vfork):
+        // Save ra in the off-stack spill area.
+        // allocate space on stack
+        addi.d    $sp, $sp, -16
+        // store $ra value
+        st.d      $ra, $sp, 8
+        bl        COMMON_INTERCEPTOR_SPILL_AREA
+        // restore previous values from stack
+        ld.d      $ra, $sp, 8
+        // adjust stack
+        addi.d    $sp, $sp, 16
+        // store $ra by $a0
+        st.d      $ra, $a0, 0
+
+        // Call real vfork. This may return twice. User code that runs between the first and the second return
+        // may clobber the stack frame of the interceptor; that's why it does not have a frame.
+        la.local  $a0, _ZN14__interception10real_vforkE
+        ld.d      $a0, $a0, 0
+        jirl      $ra, $a0, 0
+
+        // adjust stack
+        addi.d    $sp, $sp, -16
+        // store $a0 by adjusted stack
+        st.d      $a0, $sp, 8
+        // jump to exit label if $a0 is 0
+        beqz      $a0, .L_exit
+
+        // $a0 != 0 => parent process. Clear stack shadow.
+        // put old $sp to $a0
+        addi.d    $a0, $sp, 16
+        bl        %plt(COMMON_INTERCEPTOR_HANDLE_VFORK)
+
+.L_exit:
+        // Restore $ra
+        bl        COMMON_INTERCEPTOR_SPILL_AREA
+        ld.d      $ra, $a0, 0
+        // load value by stack
+        ld.d      $a0, $sp, 8
+        // adjust stack
+        addi.d    $sp, $sp, 16
+        jr        $ra
+ASM_SIZE(vfork)
+
+.weak vfork
+.set vfork, ASM_WRAPPER_NAME(vfork)
+
+#endif
diff --git a/libsanitizer/sanitizer_common/sanitizer_stacktrace.cpp b/libsanitizer/sanitizer_common/sanitizer_stacktrace.cpp
index 7386285f34b..661495e2340 100644
--- a/libsanitizer/sanitizer_common/sanitizer_stacktrace.cpp
+++ b/libsanitizer/sanitizer_common/sanitizer_stacktrace.cpp
@@ -128,7 +128,7 @@ void BufferedStackTrace::UnwindFast(uptr pc, uptr bp, uptr stack_top,
 #endif
 #elif defined(__s390__)
     uhwptr pc1 = frame[14];
-#elif defined(__riscv)
+#elif defined(__loongarch__) || defined(__riscv)
     // frame[-1] contains the return address
     uhwptr pc1 = frame[-1];
 #else
@@ -143,7 +143,7 @@ void BufferedStackTrace::UnwindFast(uptr pc, uptr bp, uptr stack_top,
       trace_buffer[size++] = (uptr) pc1;
     }
     bottom = (uptr)frame;
-#if defined(__riscv)
+#if defined(__loongarch__) || defined(__riscv)
     // frame[-2] contain fp of the previous frame
     uptr new_bp = (uptr)frame[-2];
 #else