RISC-V: Use dynamic shadow offset

Switch to dynamic offset so that we can support Sv39, Sv48, and Sv57 at
the same time without building multiple libasan versions!

[1] https://github.com/llvm/llvm-project/commit/da0c8b275564f814a53a5c19497669ae2d99538d

gcc/ChangeLog:

	* config/riscv/riscv.cc (riscv_asan_shadow_offset): Use dynamic
	offset for RV64.
	(riscv_asan_dynamic_shadow_offset_p): New.
	(TARGET_ASAN_DYNAMIC_SHADOW_OFFSET_P): New.

gcc/testsuite/ChangeLog:

	* g++.dg/asan/asan_test.cc: Update the testcase for dynamic
	offset.

diff --git a/gcc/config/riscv/riscv.cc b/gcc/config/riscv/riscv.cc
index 8f5b43e2c245f21fed0e439f090fc161a859a39e..efdb1d332831b0069931b6f12e13892a0630eb4f 100644 (file)
--- a/gcc/config/riscv/riscv.cc
+++ b/gcc/config/riscv/riscv.cc
@@ -11226,11 +11226,18 @@ riscv_gpr_save_operation_p (rtx op)
 static unsigned HOST_WIDE_INT
 riscv_asan_shadow_offset (void)
 {
-  /* We only have libsanitizer support for RV64 at present.
+  /* This number must match ASAN_SHADOW_OFFSET_CONST in the file
+     libsanitizer/asan/asan_mapping.h, we use 0 here because RV64
+     using dynamic shadow offset, and RV32 isn't support yet.  */
+  return 0;
+}
+
+/* Implement TARGET_ASAN_DYNAMIC_SHADOW_OFFSET_P.  */
 
-     This number must match ASAN_SHADOW_OFFSET_CONST in the file
-     libsanitizer/asan/asan_mapping.h.  */
-  return TARGET_64BIT ? HOST_WIDE_INT_UC (0xd55550000) : 0;
+static bool
+riscv_asan_dynamic_shadow_offset_p (void)
+{
+  return TARGET_64BIT;
 }
 
 /* Implement TARGET_MANGLE_TYPE.  */
@@ -13764,6 +13771,9 @@ riscv_use_by_pieces_infrastructure_p (unsigned HOST_WIDE_INT size,
 #undef TARGET_ASAN_SHADOW_OFFSET
 #define TARGET_ASAN_SHADOW_OFFSET riscv_asan_shadow_offset
 
+#undef TARGET_ASAN_DYNAMIC_SHADOW_OFFSET_P
+#define TARGET_ASAN_DYNAMIC_SHADOW_OFFSET_P riscv_asan_dynamic_shadow_offset_p
+
 #ifdef TARGET_BIG_ENDIAN_DEFAULT
 #undef  TARGET_DEFAULT_TARGET_FLAGS
 #define TARGET_DEFAULT_TARGET_FLAGS (MASK_BIG_ENDIAN)

diff --git a/gcc/testsuite/g++.dg/asan/asan_test.cc b/gcc/testsuite/g++.dg/asan/asan_test.cc
index 0d976801cf195cbf7059adad52c74ce932428949..65580afd934b948ef9bb555d7dfeec4e0089c437 100644 (file)
--- a/gcc/testsuite/g++.dg/asan/asan_test.cc
+++ b/gcc/testsuite/g++.dg/asan/asan_test.cc
@@ -932,6 +932,9 @@ TEST(AddressSanitizer, ShadowGapTest) {
 #else
 # if defined(__powerpc64__)
   char *addr = (char*)0x024000800000;
+# elif defined(__riscv) && __riscv_xlen == 64
+  extern void *__asan_shadow_memory_dynamic_address;
+  char *addr = (char*)__asan_shadow_memory_dynamic_address + 0x1000;
 # else
   char *addr = (char*)0x0000100000080000;
 # endif