From: Mukesh Kumar Chaurasiya Date: Mon, 27 Apr 2026 12:27:39 +0000 (+0530) Subject: powerpc: add exit_flags field in pt_regs X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d7a6797e0bc1ee7bddb8a298f2d1acddb300efb3;p=thirdparty%2Fkernel%2Flinux.git powerpc: add exit_flags field in pt_regs Add a new field `exit_flags` in the pt_regs structure. This field will hold the flags set during interrupt or syscall execution that are required during exit to user mode. Specifically, the `TIF_RESTOREALL` flag, stored in this field, helps the exit routine determine if any NVGPRs were modified and need to be restored before returning to userspace. This addition ensures a clean and architecture-specific mechanism to track per-syscall or per-interrupt state transitions related to register restore. Changes: - Add `exit_flags` and `__pt_regs_pad` to maintain 16-byte stack alignment - Update asm-offsets.c and ptrace.c for offset and validation - Update PT_* constants in uapi header to reflect the new layout Signed-off-by: Mukesh Kumar Chaurasiya Tested-by: Samir M Tested-by: David Gow Tested-by: Venkat Rao Bagalkote Reviewed-by: Shrikanth Hegde Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/20260427122742.210074-6-mkchauras@gmail.com --- diff --git a/arch/powerpc/include/asm/ptrace.h b/arch/powerpc/include/asm/ptrace.h index 94aa1de2b06e1..2e741ea57b807 100644 --- a/arch/powerpc/include/asm/ptrace.h +++ b/arch/powerpc/include/asm/ptrace.h @@ -53,6 +53,9 @@ struct pt_regs unsigned long esr; }; unsigned long result; + unsigned long exit_flags; + /* Maintain 16 byte interrupt stack alignment */ + unsigned long __pt_regs_pad[3]; }; }; #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 01e630149d48e..a393b7f2760a2 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[3]; /* Maintain 16 byte interrupt stack alignment */ }; #endif /* __ASSEMBLER__ */ @@ -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 47 /* 3 times */ +#define PT_DSCR 48 +#define PT_REGS_COUNT 48 -#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/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));