diff options
| author | Mukesh Kumar Chaurasiya (IBM) <mkchauras@gmail.com> | 2026-07-24 01:18:09 +0530 |
|---|---|---|
| committer | Madhavan Srinivasan <maddy@linux.ibm.com> | 2026-07-28 10:23:31 +0530 |
| commit | 263e5159e00aa46bf26f3496ff7aae1fc9a6c826 (patch) | |
| tree | f1633364afd97b9cc15185c24f697ddc89f0b516 /arch/powerpc/include | |
| parent | bddf7540099bf653eaea339e886add6f62555cf3 (diff) | |
powerpc: Fix exit_flags field placement in pt_regs for ptrace
Commit d7a6797e0bc1 ("powerpc: add exit_flags field in pt_regs") added
the exit_flags field to struct pt_regs to pass internal exit control
flags (e.g. _TIF_RESTOREALL) from syscall_exit_prepare() to the
low-level assembly exit path.
However, the field was placed in a way that was visible to userspace
tools such as strace via PTRACE_GETREGS, or caused a struct layout or
size regression observable through ptrace. The field is purely
kernel-internal and must not be exposed beyond the user_pt_regs
boundary.
Move exit_flags into struct thread_info where it is only accessible to
the kernel, and keep it out of the ptrace-visible register window
entirely.
Fixes: d7a6797e0bc1 ("powerpc: add exit_flags field in pt_regs")
Reported-by: Dmitry V. Levin <ldv@strace.io>
Closes: https://lore.kernel.org/all/20260722070155.GA11808@strace.io/
Signed-off-by: Mukesh Kumar Chaurasiya (IBM) <mkchauras@gmail.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260723194809.4046600-1-mkchauras@gmail.com
Diffstat (limited to 'arch/powerpc/include')
| -rw-r--r-- | arch/powerpc/include/asm/ptrace.h | 3 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/thread_info.h | 1 | ||||
| -rw-r--r-- | arch/powerpc/include/uapi/asm/ptrace.h | 14 |
3 files changed, 6 insertions, 12 deletions
diff --git a/arch/powerpc/include/asm/ptrace.h b/arch/powerpc/include/asm/ptrace.h index fdeb97421785..d53c4dd4d8b6 100644 --- a/arch/powerpc/include/asm/ptrace.h +++ b/arch/powerpc/include/asm/ptrace.h @@ -53,9 +53,6 @@ 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/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h index ee3b9adb5b67..0487e94d3416 100644 --- a/arch/powerpc/include/asm/thread_info.h +++ b/arch/powerpc/include/asm/thread_info.h @@ -57,6 +57,7 @@ struct thread_info { #ifdef CONFIG_SMP unsigned int cpu; #endif + unsigned long exit_flags; /* Exit Flags for entry/exit */ unsigned long syscall_work; /* SYSCALL_WORK_ flags */ unsigned long local_flags; /* private flags for thread */ #ifdef CONFIG_LIVEPATCH_64 diff --git a/arch/powerpc/include/uapi/asm/ptrace.h b/arch/powerpc/include/uapi/asm/ptrace.h index a393b7f2760a..01e630149d48 100644 --- a/arch/powerpc/include/uapi/asm/ptrace.h +++ b/arch/powerpc/include/uapi/asm/ptrace.h @@ -55,8 +55,6 @@ 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__ */ @@ -116,12 +114,10 @@ struct pt_regs #define PT_DAR 41 #define PT_DSISR 42 #define PT_RESULT 43 -#define PT_EXIT_FLAGS 44 -#define PT_PAD 47 /* 3 times */ -#define PT_DSCR 48 -#define PT_REGS_COUNT 48 +#define PT_DSCR 44 +#define PT_REGS_COUNT 44 -#define PT_FPR0 (PT_REGS_COUNT + 4) /* each FP reg occupies 2 slots in this space */ +#define PT_FPR0 48 /* each FP reg occupies 2 slots in this space */ #ifndef __powerpc64__ @@ -133,7 +129,7 @@ struct pt_regs #define PT_FPSCR (PT_FPR0 + 32) /* each FP reg occupies 1 slot in 64-bit space */ -#define PT_VR0 (PT_FPSCR + 2) /* <82> each Vector reg occupies 2 slots in 64-bit */ +#define PT_VR0 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) @@ -141,7 +137,7 @@ struct pt_regs /* * Only store first 32 VSRs here. The second 32 VSRs in VR0-31 */ -#define PT_VSR0 (PT_VRSAVE + 2) /* each VSR reg occupies 2 slots in 64-bit */ +#define PT_VSR0 150 /* each VSR reg occupies 2 slots in 64-bit */ #define PT_VSR31 (PT_VSR0 + 2*31) #endif /* __powerpc64__ */ |