1 files changed, 7 insertions, 0 deletions

diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index cf3a0b2d0059..25bb3f9b2552 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -667,6 +667,13 @@ END(stub_rt_sigreturn)
         SAVE_ARGS
         leaq -ARGOFFSET(%rsp),%rdi      # arg1 for handler
         pushq %rbp
+        /*
+         * Save rbp twice: One is for marking the stack frame, as usual, and the
+         * other, to fill pt_regs properly. This is because bx comes right
+         * before the last saved register in that structure, and not bp. If the
+         * base pointer were in the place bx is today, this would not be needed.
+         */
+        movq %rbp, -8(%rsp)
         CFI_ADJUST_CFA_OFFSET   8
         CFI_REL_OFFSET          rbp, 0
         movq %rsp,%rbp