From 6f0aba63bfb3eb33b68cf746c44b6ab302599180 Mon Sep 17 00:00:00 2001
From: Paul Burton <paul.burton@imgtec.com>
Date: Mon, 27 Jul 2015 12:58:17 -0700
Subject: [PATCH] MIPS: Skip odd double FP registers when copying FP32
sigcontext
When a task uses 32 bit floating point, the odd indexed 32b register
values are stored in bits 63:32 of the preceding even indexed 64b
FP register field in saved context. Thus there is no point in
preserving the odd indexed 64b register fields since they hold no
valid context. This patch will cause them to be skipped, as is
already done in arch/mips/kernel/signal32.c.
[ralf@linux-mips.org: Fixed reject.]
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Matthew Fortune <matthew.fortune@imgtec.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linux-kernel@vger.kernel.org
Cc: Richard Weinberger <richard@nod.at>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Maciej W. Rozycki <macro@codesourcery.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Patchwork: https://patchwork.linux-mips.org/patch/10791/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
---
arch/mips/kernel/signal.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/arch/mips/kernel/signal.c b/arch/mips/kernel/signal.c
index 9c42c500134e..cc3a01f5c5af 100644
--- a/arch/mips/kernel/signal.c
+++ b/arch/mips/kernel/signal.c
@@ -69,8 +69,9 @@ static int copy_fp_to_sigcontext(void __user *sc)
uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
int i;
int err = 0;
+ int inc = test_thread_flag(TIF_32BIT_FPREGS) ? 2 : 1;
- for (i = 0; i < NUM_FPU_REGS; i++) {
+ for (i = 0; i < NUM_FPU_REGS; i += inc) {
err |=
__put_user(get_fpr64(¤t->thread.fpu.fpr[i], 0),
&fpregs[i]);
@@ -87,9 +88,10 @@ static int copy_fp_from_sigcontext(void __user *sc)
uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
int i;
int err = 0;
+ int inc = test_thread_flag(TIF_32BIT_FPREGS) ? 2 : 1;
u64 fpr_val;
- for (i = 0; i < NUM_FPU_REGS; i++) {
+ for (i = 0; i < NUM_FPU_REGS; i += inc) {
err |= __get_user(fpr_val, &fpregs[i]);
set_fpr64(¤t->thread.fpu.fpr[i], 0, fpr_val);
}