From: Dave Martin Dave.Martin@arm.com
[ Upstream commit 5fbd5fc49fc39ac8433da62d16682a1d0217ea4f ]
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 Dave.Martin@arm.com Signed-off-by: Will Deacon will.deacon@arm.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com --- 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 b81fa63bc834..f67bb64d2640 100644 --- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -822,18 +822,20 @@ 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;
if (pos + count > VFP_STATE_SIZE) return -EIO;
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;