[compiler-rt] Sanitizer/MIPS: fix build fail on pre-R6 (PR #76894)
YunQiang Su via llvm-commits
llvm-commits at lists.llvm.org
Sat Jan 13 20:36:14 PST 2024
https://github.com/wzssyqa updated https://github.com/llvm/llvm-project/pull/76894
>From eff3c340eb154d5acc9bf99ec5e544fe4697a228 Mon Sep 17 00:00:00 2001
From: YunQiang Su <yunqiang.su at cipunited.com>
Date: Thu, 4 Jan 2024 13:07:41 +0800
Subject: [PATCH] Sanitizer/MIPS: Use $t9 for preemptible function call
Currently, almost all of the shared libraries of MIPS, rely on $t9
to get the address of current function, instead of PCREL instructions,
even on MIPSr6. So we have to set $t9 properly.
To get the address of preemptible function, we need the help of GOT.
MIPS/O32 has .cpload, which can help to generate 3 instructions to get GOT.
For __mips64, we can get GOT by:
lui $t8, %hi(%neg(%gp_rel(SANITIZER_STRINGIFY(TRAMPOLINE(func)))))
daddu $t8, $t8, $t9
daddiu $t8, $t8, %hi(%neg(%gp_rel(SANITIZER_STRINGIFY(TRAMPOLINE(func)))))
And then get the address of __interceptor_func, and jump to it
ld $t9, %got_disp(__interceptor_" SANITIZER_STRINGIFY(func) ")($t8)
jr $t9
---
compiler-rt/lib/interception/interception.h | 5 ++--
.../lib/sanitizer_common/sanitizer_asm.h | 23 +++++++++++++++++++
2 files changed, 26 insertions(+), 2 deletions(-)
diff --git a/compiler-rt/lib/interception/interception.h b/compiler-rt/lib/interception/interception.h
index 9d8b60b2eef58c2..58e969378a90822 100644
--- a/compiler-rt/lib/interception/interception.h
+++ b/compiler-rt/lib/interception/interception.h
@@ -205,8 +205,9 @@ const interpose_substitution substitution_##func_name[] \
ASM_TYPE_FUNCTION_STR "\n" \
SANITIZER_STRINGIFY(TRAMPOLINE(func)) ":\n" \
SANITIZER_STRINGIFY(CFI_STARTPROC) "\n" \
- SANITIZER_STRINGIFY(ASM_TAIL_CALL) " __interceptor_" \
- SANITIZER_STRINGIFY(ASM_PREEMPTIBLE_SYM(func)) "\n" \
+ C_ASM_TAIL_CALL(SANITIZER_STRINGIFY(TRAMPOLINE(func)), \
+ "__interceptor_" \
+ SANITIZER_STRINGIFY(ASM_PREEMPTIBLE_SYM(func))) "\n" \
SANITIZER_STRINGIFY(CFI_ENDPROC) "\n" \
".size " SANITIZER_STRINGIFY(TRAMPOLINE(func)) ", " \
".-" SANITIZER_STRINGIFY(TRAMPOLINE(func)) "\n" \
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_asm.h b/compiler-rt/lib/sanitizer_common/sanitizer_asm.h
index bbb18cfbdf15feb..3af66a4e4499882 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_asm.h
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_asm.h
@@ -53,6 +53,29 @@
# define ASM_TAIL_CALL tail
#endif
+// Currently, almost all of the shared libraries rely on the value of
+// $t9 to get the address of current function, instead of PCREL, even
+// on MIPSr6. To be compatiable with them, we have to set $t9 properly.
+// MIPS uses GOT to get the address of preemptible functions.
+#if defined(__mips64)
+# define C_ASM_TAIL_CALL(t_func, i_func) \
+ "lui $t8, %hi(%neg(%gp_rel(" t_func ")))\n" \
+ "daddu $t8, $t8, $t9\n" \
+ "daddiu $t8, $t8, %lo(%neg(%gp_rel(" t_func ")))\n" \
+ "ld $t9, %got_disp(" i_func ")($t8)\n" \
+ "jr $t9\n"
+#elif defined(__mips__)
+# define C_ASM_TAIL_CALL(t_func, i_func) \
+ ".set noreorder\n" \
+ ".cpload $t9\n" \
+ ".set reorder\n" \
+ "lw $t9, %got(" i_func ")($gp)\n" \
+ "jr $t9\n"
+#elif defined(ASM_TAIL_CALL)
+# define C_ASM_TAIL_CALL(t_func, i_func) \
+ SANITIZER_STRINGIFY(ASM_TAIL_CALL) " " i_func
+#endif
+
#if defined(__ELF__) && defined(__x86_64__) || defined(__i386__) || \
defined(__riscv)
# define ASM_PREEMPTIBLE_SYM(sym) sym at plt
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