4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Maciej W. Rozycki <macro@xxxxxxxx> commit c7e814628df65f424fe197dde73bfc67e4a244d7 upstream. Use 64-bit accesses for 64-bit floating-point general registers with PTRACE_PEEKUSR, removing the truncation of their upper halves in the FR=1 mode, caused by commit bbd426f542cb ("MIPS: Simplify FP context access"), which inadvertently switched them to using 32-bit accesses. The PTRACE_POKEUSR side is fine as it's never been broken and continues using 64-bit accesses. Fixes: bbd426f542cb ("MIPS: Simplify FP context access") Signed-off-by: Maciej W. Rozycki <macro@xxxxxxxx> Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx> Cc: linux-mips@xxxxxxxxxxxxxx Cc: <stable@xxxxxxxxxxxxxxx> # 3.15+ Patchwork: https://patchwork.linux-mips.org/patch/19334/ Signed-off-by: James Hogan <jhogan@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/mips/kernel/ptrace.c | 2 +- arch/mips/kernel/ptrace32.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) --- a/arch/mips/kernel/ptrace.c +++ b/arch/mips/kernel/ptrace.c @@ -838,7 +838,7 @@ long arch_ptrace(struct task_struct *chi break; } #endif - tmp = get_fpr32(&fregs[addr - FPR_BASE], 0); + tmp = get_fpr64(&fregs[addr - FPR_BASE], 0); break; case PC: tmp = regs->cp0_epc; --- a/arch/mips/kernel/ptrace32.c +++ b/arch/mips/kernel/ptrace32.c @@ -107,7 +107,7 @@ long compat_arch_ptrace(struct task_stru addr & 1); break; } - tmp = get_fpr32(&fregs[addr - FPR_BASE], 0); + tmp = get_fpr64(&fregs[addr - FPR_BASE], 0); break; case PC: tmp = regs->cp0_epc;