[libc-commits] [libc] c1bb710 - [libc] Special case sniffing of thread start args for riscv.

[Siva Chandra via libc-commits]

Author: Siva Chandra
Date: 2023-03-13T07:29:35Z
New Revision: c1bb7108a2ffe7e6c95224c17b0ff62ccb2639f8

URL: https://github.com/llvm/llvm-project/commit/c1bb7108a2ffe7e6c95224c17b0ff62ccb2639f8
DIFF: https://github.com/llvm/llvm-project/commit/c1bb7108a2ffe7e6c95224c17b0ff62ccb2639f8.diff

LOG: [libc] Special case sniffing of thread start args for riscv.

Added: 
    

Modified: 
    libc/src/__support/threads/linux/thread.cpp

Removed: 
    


################################################################################
diff  --git a/libc/src/__support/threads/linux/thread.cpp b/libc/src/__support/threads/linux/thread.cpp
index c0bbd3d77e885..e9b95eed99a58 100644
--- a/libc/src/__support/threads/linux/thread.cpp
+++ b/libc/src/__support/threads/linux/thread.cpp
@@ -116,12 +116,15 @@ __attribute__((always_inline)) inline uintptr_t get_start_args_addr() {
          // on to the stack. So, we have to step past two 64-bit values to get
          // to the start args.
          + sizeof(uintptr_t) * 2;
-#elif defined(LIBC_TARGET_ARCH_IS_AARCH64) ||                                  \
-    defined(LIBC_TARGET_ARCH_IS_RISCV64)
+#elif defined(LIBC_TARGET_ARCH_IS_AARCH64)
   // The frame pointer after cloning the new thread in the Thread::run method
   // is set to the stack pointer where start args are stored. So, we fetch
   // from there.
   return reinterpret_cast<uintptr_t>(__builtin_frame_address(1));
+#elif defined(LIBC_TARGET_ARCH_IS_RISCV64)
+  // The current frame pointer is the previous stack pointer where the start
+  // args are stored.
+  return reinterpret_cast<uintptr_t>(__builtin_frame_address(0));
 #endif
 }