From: Martin Schwidefsky Date: Tue, 27 Oct 2015 12:13:38 +0000 (+0100) Subject: s390/kernel: fix ptrace peek/poke for floating point registers X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=55a423b6f105fa323168f15f4bb67f23b21da44e;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git s390/kernel: fix ptrace peek/poke for floating point registers git commit 155e839a814834a3b4b31e729f4716e59d3d2dd4 "s390/kernel: dynamically allocate FP register save area" introduced a regression in regard to ptrace. If the vector register extension is not present or unused the ptrace peek of a floating pointer register return incorrect data and the ptrace poke to a floating pointer register overwrites the task structure starting at task->thread.fpu.fprs. Cc: stable@kernel.org # v4.3 Signed-off-by: Martin Schwidefsky --- diff --git a/arch/s390/kernel/ptrace.c b/arch/s390/kernel/ptrace.c index 3ccd9008a4dc..01c37b36caf9 100644 --- a/arch/s390/kernel/ptrace.c +++ b/arch/s390/kernel/ptrace.c @@ -244,7 +244,7 @@ static unsigned long __peek_user(struct task_struct *child, addr_t addr) ((addr_t) child->thread.fpu.vxrs + 2*offset); else tmp = *(addr_t *) - ((addr_t) &child->thread.fpu.fprs + offset); + ((addr_t) child->thread.fpu.fprs + offset); } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) { /* @@ -388,7 +388,7 @@ static int __poke_user(struct task_struct *child, addr_t addr, addr_t data) child->thread.fpu.vxrs + 2*offset) = data; else *(addr_t *)((addr_t) - &child->thread.fpu.fprs + offset) = data; + child->thread.fpu.fprs + offset) = data; } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) { /* @@ -622,7 +622,7 @@ static u32 __peek_user_compat(struct task_struct *child, addr_t addr) ((addr_t) child->thread.fpu.vxrs + 2*offset); else tmp = *(__u32 *) - ((addr_t) &child->thread.fpu.fprs + offset); + ((addr_t) child->thread.fpu.fprs + offset); } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) { /* @@ -747,7 +747,7 @@ static int __poke_user_compat(struct task_struct *child, child->thread.fpu.vxrs + 2*offset) = tmp; else *(__u32 *)((addr_t) - &child->thread.fpu.fprs + offset) = tmp; + child->thread.fpu.fprs + offset) = tmp; } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) { /*