[PATCH 4.9 003/329] MIPS: Fix ptrace(2) PTRACE_PEEKUSR and PTRACE_POKEUSR accesses to o32 FGRs

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Maciej W. Rozycki <macro@xxxxxxxx>

commit 9a3a92ccfe3620743d4ae57c987dc8e9c5f88996 upstream.

Check the TIF_32BIT_FPREGS task setting of the tracee rather than the
tracer in determining the layout of floating-point general registers in
the floating-point context, correcting access to odd-numbered registers
for o32 tracees where the setting disagrees between the two processes.

Fixes: 597ce1723e0f ("MIPS: Support for 64-bit FP with O32 binaries")
Signed-off-by: Maciej W. Rozycki <macro@xxxxxxxx>
Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Cc: linux-mips@xxxxxxxxxxxxxx
Cc: <stable@xxxxxxxxxxxxxxx> # 3.14+
Signed-off-by: James Hogan <jhogan@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 arch/mips/kernel/ptrace.c   |    4 ++--
 arch/mips/kernel/ptrace32.c |    4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

--- a/arch/mips/kernel/ptrace.c
+++ b/arch/mips/kernel/ptrace.c
@@ -827,7 +827,7 @@ long arch_ptrace(struct task_struct *chi
 			fregs = get_fpu_regs(child);
 
 #ifdef CONFIG_32BIT
-			if (test_thread_flag(TIF_32BIT_FPREGS)) {
+			if (test_tsk_thread_flag(child, TIF_32BIT_FPREGS)) {
 				/*
 				 * The odd registers are actually the high
 				 * order bits of the values stored in the even
@@ -916,7 +916,7 @@ long arch_ptrace(struct task_struct *chi
 
 			init_fp_ctx(child);
 #ifdef CONFIG_32BIT
-			if (test_thread_flag(TIF_32BIT_FPREGS)) {
+			if (test_tsk_thread_flag(child, TIF_32BIT_FPREGS)) {
 				/*
 				 * The odd registers are actually the high
 				 * order bits of the values stored in the even
--- a/arch/mips/kernel/ptrace32.c
+++ b/arch/mips/kernel/ptrace32.c
@@ -97,7 +97,7 @@ long compat_arch_ptrace(struct task_stru
 				break;
 			}
 			fregs = get_fpu_regs(child);
-			if (test_thread_flag(TIF_32BIT_FPREGS)) {
+			if (test_tsk_thread_flag(child, TIF_32BIT_FPREGS)) {
 				/*
 				 * The odd registers are actually the high
 				 * order bits of the values stored in the even
@@ -204,7 +204,7 @@ long compat_arch_ptrace(struct task_stru
 				       sizeof(child->thread.fpu));
 				child->thread.fpu.fcr31 = 0;
 			}
-			if (test_thread_flag(TIF_32BIT_FPREGS)) {
+			if (test_tsk_thread_flag(child, TIF_32BIT_FPREGS)) {
 				/*
 				 * The odd registers are actually the high
 				 * order bits of the values stored in the even