From 5fbd5fc49fc39ac8433da62d16682a1d0217ea4f Mon Sep 17 00:00:00 2001 From: Dave Martin Date: Thu, 29 Jun 2017 15:25:49 +0100 Subject: [PATCH] arm64: ptrace: Fix incorrect get_user() use in compat_vfp_set() Now that compat_vfp_get() uses the regset API to copy the FPSCR value out to userspace, compat_vfp_set() looks inconsistent. In particular, compat_vfp_set() will fail if called with kbuf != NULL && ubuf == NULL (which is valid usage according to the regset API). This patch fixes compat_vfp_set() to use user_regset_copyin(), similarly to compat_vfp_get(). This also squashes a sparse warning triggered by the cast that drops __user when calling get_user(). Signed-off-by: Dave Martin Signed-off-by: Will Deacon --- arch/arm64/kernel/ptrace.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c index 949ab6bdfbad..1b38c0150aec 100644 --- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -935,15 +935,17 @@ static int compat_vfp_set(struct task_struct *target, { struct user_fpsimd_state *uregs; compat_ulong_t fpscr; - int ret; + int ret, vregs_end_pos; uregs = &target->thread.fpsimd_state.user_fpsimd; + vregs_end_pos = VFP_STATE_SIZE - sizeof(compat_ulong_t); ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, uregs, 0, - VFP_STATE_SIZE - sizeof(compat_ulong_t)); + vregs_end_pos); if (count && !ret) { - ret = get_user(fpscr, (compat_ulong_t *)ubuf); + ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &fpscr, + vregs_end_pos, VFP_STATE_SIZE); if (!ret) { uregs->fpsr = fpscr & VFP_FPSCR_STAT_MASK; uregs->fpcr = fpscr & VFP_FPSCR_CTRL_MASK; -- 2.39.5