[PATCH v4 08/12] s390/ptrace: Provide frame_pointer()
From: Jens Remus
Date: Tue Jan 27 2026 - 10:44:46 EST
On s390 64-bit the s390x ELF ABI [1] designates register 11 as the
"preferred" frame pointer (FP) register in user space.
[1]: s390x ELF ABI, https://github.com/IBM/s390x-abi/releases
Signed-off-by: Jens Remus <jremus@xxxxxxxxxxxxx>
---
Notes (jremus):
Changes in v4:
- Split out "while at it" changes into separate commit that can go
upstream independently. (Heiko)
Changes in RFC v2:
- Separate provide frame_pointer() into this new commit.
arch/s390/include/asm/ptrace.h | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/arch/s390/include/asm/ptrace.h b/arch/s390/include/asm/ptrace.h
index e6ec0ccf3d73..8f18d00b5fdb 100644
--- a/arch/s390/include/asm/ptrace.h
+++ b/arch/s390/include/asm/ptrace.h
@@ -250,6 +250,12 @@ static __always_inline unsigned long user_stack_pointer(const struct pt_regs *re
return regs->gprs[15];
}
+static __always_inline unsigned long frame_pointer(const struct pt_regs *regs)
+{
+ /* Return ABI-designated "preferred" frame-pointer register value. */
+ return regs->gprs[11];
+}
+
static __always_inline unsigned long regs_get_register(const struct pt_regs *regs,
unsigned int offset)
{
--
2.51.0