[RFC V2 5/8] powerpc: add exit_flags field in pt_regs

Mukesh Kumar Chaurasiya
2025-09-08T21:05:32Z

Add field exit_flags in the pt_regs. This will hold the flags while
executing interrupt or syscall which is required during exit to user.

Signed-off-by: Mukesh Kumar Chaurasiya <mchauras@linux.ibm.com>
---
arch/powerpc/include/asm/ptrace.h | 2 ++
arch/powerpc/include/uapi/asm/ptrace.h | 14 +++++++++-----
arch/powerpc/kernel/asm-offsets.c | 1 +
arch/powerpc/kernel/ptrace/ptrace.c | 1 +
4 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/arch/powerpc/include/asm/ptrace.h b/arch/powerpc/include/asm/ptrace.h
index 7b9350756875a..1b0ad5088f60d 100644
--- a/arch/powerpc/include/asm/ptrace.h
+++ b/arch/powerpc/include/asm/ptrace.h
@@ -53,6 +53,8 @@ struct pt_regs
unsigned long esr;
};
unsigned long result;
+ unsigned long exit_flags;
+ unsigned long __pt_regs_pad[1]; /* Maintain 16 byte interrupt stack alignment */
};
};
#if defined(CONFIG_PPC64) || defined(CONFIG_PPC_KUAP)
diff --git a/arch/powerpc/include/uapi/asm/ptrace.h b/arch/powerpc/include/uapi/asm/ptrace.h
index 7004cfea3f5ff..4de612e2e40ac 100644
--- a/arch/powerpc/include/uapi/asm/ptrace.h
+++ b/arch/powerpc/include/uapi/asm/ptrace.h
@@ -55,6 +55,8 @@ struct pt_regs
unsigned long dar; /* Fault registers */
unsigned long dsisr; /* on 4xx/Book-E used for ESR */
unsigned long result; /* Result of a system call */
+ unsigned long exit_flags; /* System call exit flags */
+ unsigned long __pt_regs_pad[1]; /* Maintain 16 byte interrupt stack alignment */
};

#endif /* __ASSEMBLY__ */
@@ -114,10 +116,12 @@ struct pt_regs
#define PT_DAR 41
#define PT_DSISR 42
#define PT_RESULT 43
-#define PT_DSCR 44
-#define PT_REGS_COUNT 44
+#define PT_EXIT_FLAGS 44
+#define PT_PAD 45
+#define PT_DSCR 46
+#define PT_REGS_COUNT 46

-#define PT_FPR0 48 /* each FP reg occupies 2 slots in this space */
+#define PT_FPR0 (PT_REGS_COUNT + 4) /* each FP reg occupies 2 slots in this space */

#ifndef __powerpc64__

@@ -129,7 +133,7 @@ struct pt_regs
#define PT_FPSCR (PT_FPR0 + 32) /* each FP reg occupies 1 slot in 64-bit space */

-#define PT_VR0 82 /* each Vector reg occupies 2 slots in 64-bit */
+#define PT_VR0 (PT_FPSCR + 2) /* <82> each Vector reg occupies 2 slots in 64-bit */
#define PT_VSCR (PT_VR0 + 32*2 + 1)
#define PT_VRSAVE (PT_VR0 + 33*2)

@@ -137,7 +141,7 @@ struct pt_regs
/*
* Only store first 32 VSRs here. The second 32 VSRs in VR0-31
*/
-#define PT_VSR0 150 /* each VSR reg occupies 2 slots in 64-bit */
+#define PT_VSR0 (PT_VRSAVE + 2) /* each VSR reg occupies 2 slots in 64-bit */
#define PT_VSR31 (PT_VSR0 + 2*31)
#endif /* __powerpc64__ */

diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index b3048f6d3822c..4d4e880e3c616 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -291,6 +291,7 @@ int main(void)
STACK_PT_REGS_OFFSET(_ESR, esr);
STACK_PT_REGS_OFFSET(ORIG_GPR3, orig_gpr3);
STACK_PT_REGS_OFFSET(RESULT, result);
+ STACK_PT_REGS_OFFSET(EXIT_FLAGS, exit_flags);
STACK_PT_REGS_OFFSET(_TRAP, trap);
#ifdef CONFIG_PPC64
STACK_PT_REGS_OFFSET(SOFTE, softe);
diff --git a/arch/powerpc/kernel/ptrace/ptrace.c b/arch/powerpc/kernel/ptrace/ptrace.c
index c6997df632873..2134b6d155ff6 100644
--- a/arch/powerpc/kernel/ptrace/ptrace.c
+++ b/arch/powerpc/kernel/ptrace/ptrace.c
@@ -432,6 +432,7 @@ void __init pt_regs_check(void)
CHECK_REG(PT_DAR, dar);
CHECK_REG(PT_DSISR, dsisr);
CHECK_REG(PT_RESULT, result);
+ CHECK_REG(PT_EXIT_FLAGS, exit_flags);
#undef CHECK_REG

BUILD_BUG_ON(PT_REGS_COUNT != sizeof(struct user_pt_regs) / sizeof(unsigned long));
--
2.51.0