From: Dave Martin Date: Thu, 5 Jan 2017 16:50:57 +0000 (+0000) Subject: powerpc/ptrace: Preserve previous fprs/vsrs on short regset write X-Git-Tag: v3.2.87~83 X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?p=pandora-kernel.git;a=commitdiff_plain;h=4a56059bf8e74e9efb3729bb70858d7b6393808c powerpc/ptrace: Preserve previous fprs/vsrs on short regset write commit 99dfe80a2a246c600440a815741fd2e74a8b4977 upstream. Ensure that if userspace supplies insufficient data to PTRACE_SETREGSET to fill all the registers, the thread's old registers are preserved. Fixes: c6e6771b87d4 ("powerpc: Introduce VSX thread_struct and CONFIG_VSX") Signed-off-by: Dave Martin Signed-off-by: Michael Ellerman [bwh: Backported to 3.2: - fpscr and fpr are direct members of struct thread_struct - Use memcpy() for fpscr, like the reverse copy below, to avoid type error - Adjust context] Signed-off-by: Ben Hutchings --- diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c index 5de73dbd15c7..b7ab4b483e65 100644 --- a/arch/powerpc/kernel/ptrace.c +++ b/arch/powerpc/kernel/ptrace.c @@ -359,6 +359,10 @@ static int fpr_set(struct task_struct *target, const struct user_regset *regset, flush_fp_to_thread(target); #ifdef CONFIG_VSX + for (i = 0; i < 32 ; i++) + buf[i] = target->thread.TS_FPR(i); + memcpy(&buf[32], &target->thread.fpscr, sizeof(double)); + /* copy to local buffer then write that out */ i = user_regset_copyin(&pos, &count, &kbuf, &ubuf, buf, 0, -1); if (i) @@ -501,6 +505,9 @@ static int vsr_set(struct task_struct *target, const struct user_regset *regset, flush_vsx_to_thread(target); + for (i = 0; i < 32 ; i++) + buf[i] = target->thread.fpr[i][TS_VSRLOWOFFSET]; + ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, buf, 0, 32 * sizeof(double)); for (i = 0; i < 32 ; i++)