Patchwork [04/39] powerpc: PTRACE_PEEKUSR/PTRACE_POKEUSER of FPR registers in little endian builds

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Submitter Anton Blanchard
Date Sept. 23, 2013, 2:04 a.m.
Message ID <1379901913-5945-5-git-send-email-anton@samba.org>
Download mbox | patch
Permalink /patch/277047/
State Accepted
Delegated to: Benjamin Herrenschmidt
Headers show

Comments

Anton Blanchard - Sept. 23, 2013, 2:04 a.m.
FPRs overlap the high 64bits of the first 32 VSX registers. The
ptrace FP read/write code assumes big endian ordering and grabs
the lowest 64 bits.

Fix this by using the TS_FPR macro which does the right thing.

Signed-off-by: Anton Blanchard <anton@samba.org>
---
 arch/powerpc/kernel/ptrace.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

Patch

diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c
index 9a0d24c..8d5d4e9 100644
--- a/arch/powerpc/kernel/ptrace.c
+++ b/arch/powerpc/kernel/ptrace.c
@@ -1554,8 +1554,8 @@  long arch_ptrace(struct task_struct *child, long request,
 
 			flush_fp_to_thread(child);
 			if (fpidx < (PT_FPSCR - PT_FPR0))
-				tmp = ((unsigned long *)child->thread.fpr)
-					[fpidx * TS_FPRWIDTH];
+				memcpy(&tmp, &child->thread.TS_FPR(fpidx),
+				       sizeof(long));
 			else
 				tmp = child->thread.fpscr.val;
 		}
@@ -1587,8 +1587,8 @@  long arch_ptrace(struct task_struct *child, long request,
 
 			flush_fp_to_thread(child);
 			if (fpidx < (PT_FPSCR - PT_FPR0))
-				((unsigned long *)child->thread.fpr)
-					[fpidx * TS_FPRWIDTH] = data;
+				memcpy(&child->thread.TS_FPR(fpidx), &data,
+				       sizeof(long));
 			else
 				child->thread.fpscr.val = data;
 			ret = 0;