Re: [PATCH v3 2/2] powerpc/ptrace: Hard wire PT_SOFTE value to 1 in gpr_get() too
From: Oleg Nesterov <oleg@redhat.com>
Date: 2020-11-19 22:44:06
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On 11/19, Christophe Leroy wrote:
quoted hunk ↗ jump to hunk
I think the following should work, and not require the first patch (compile tested only).--- a/arch/powerpc/kernel/ptrace/ptrace-view.c +++ b/arch/powerpc/kernel/ptrace/ptrace-view.c@@ -234,9 +234,21 @@ static int gpr_get(struct task_struct *target, conststruct user_regset *regset, BUILD_BUG_ON(offsetof(struct pt_regs, orig_gpr3) != offsetof(struct pt_regs, msr) + sizeof(long)); +#ifdef CONFIG_PPC64 + membuf_write(&to, &target->thread.regs->orig_gpr3, + offsetof(struct pt_regs, softe) - offsetof(struct pt_regs, orig_gpr3)); + membuf_store(&to, 1UL); + + BUILD_BUG_ON(offsetof(struct pt_regs, trap) != + offsetof(struct pt_regs, softe) + sizeof(long)); + + membuf_write(&to, &target->thread.regs->trap, + sizeof(struct user_pt_regs) - offsetof(struct pt_regs, trap)); +#else membuf_write(&to, &target->thread.regs->orig_gpr3, sizeof(struct user_pt_regs) - offsetof(struct pt_regs, orig_gpr3)); +#endif return membuf_zero(&to, ELF_NGREG * sizeof(unsigned long) - sizeof(struct user_pt_regs)); }
Probably yes. This mirrors the previous patch I sent (https://lore.kernel.org/lkml/20190917143753.GA12300@redhat.com/ (local)) and this is exactly what I tried to avoid, we can make a simpler fix now. But let me repeat, I agree with any fix even if imp my version simplifies the code, just commit this change and lets forget this problem. Oleg.