On Thu, Jul 23, 2026 at 03:02:38PM +0530, Mukesh Kumar Chaurasiya wrote: > On Wed, Jul 22, 2026 at 10:01:55AM +0300, Dmitry V. Levin wrote: > > On Fri, Jan 23, 2026 at 01:09:13PM +0530, Mukesh Kumar Chaurasiya wrote: > > > From: Mukesh Kumar Chaurasiya <[email protected]> > > > > > > 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. > > > > Apparently, this change breaks PTRACE_GETREGS as the latter has no means > > to communicate the size of struct pt_regs being written to userspace. > > > > As result, the kernel with this patch will write to userpsace 32 more > > bytes than before, and unless the userspace is re-compiled with the latest > > ptrace.h, 32 bytes of userspace memory after struct pt_regs will be > > overwritten. > > > > This issue was detected by strace test suite, specifically, the test that > > checks whether the actual number of bytes written by > > ptrace(PTRACE_GETREGS) matches sizeof(struct pt_regs), and that test failed > > with runtime version v7.1 and headers version v7.2-rc1. > > > [...] > > Hey, > > Can you try this fix? This should fix the ABI breakage. [...] > 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__ */ >
As this patch essentially reverts the uapi header to its v7.1 state, the uapi part of the patch is definitely fine. -- ldv
