Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 4.9 28/66] s390/ptrace: Preserve previous registers for short regset write | Date | Tue, 31 Jan 2017 06:36:32 +0100 |
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4.9-stable review patch. If anyone has any objections, please let me know.
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From: Martin Schwidefsky <schwidefsky@de.ibm.com>
commit 9dce990d2cf57b5ed4e71a9cdbd7eae4335111ff upstream.
Ensure that if userspace supplies insufficient data to PTRACE_SETREGSET to fill all the registers, the thread's old registers are preserved.
convert_vx_to_fp() is adapted to handle only a specified number of registers rather than unconditionally handling all of them: other callers of this function are adapted appropriately.
Based on an initial patch by Dave Martin.
Reported-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- arch/s390/kernel/ptrace.c | 8 ++++++++ 1 file changed, 8 insertions(+)
--- a/arch/s390/kernel/ptrace.c +++ b/arch/s390/kernel/ptrace.c @@ -963,6 +963,11 @@ static int s390_fpregs_set(struct task_s if (target == current) save_fpu_regs(); + if (MACHINE_HAS_VX) + convert_vx_to_fp(fprs, target->thread.fpu.vxrs); + else + memcpy(&fprs, target->thread.fpu.fprs, sizeof(fprs)); + /* If setting FPC, must validate it first. */ if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) { u32 ufpc[2] = { target->thread.fpu.fpc, 0 }; @@ -1067,6 +1072,9 @@ static int s390_vxrs_low_set(struct task if (target == current) save_fpu_regs(); + for (i = 0; i < __NUM_VXRS_LOW; i++) + vxrs[i] = *((__u64 *)(target->thread.fpu.vxrs + i) + 1); + rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1); if (rc == 0) for (i = 0; i < __NUM_VXRS_LOW; i++)
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