Re: [PATCH RFC v2 67/70] MIPS: kernel: process: Do not allow FR=0 on MIPS R6
From: Paul Burton <hidden>
Date: 2015-01-29 23:13:51
On Fri, Jan 16, 2015 at 10:49:46AM +0000, Markos Chandras wrote:
quoted hunk ↗ jump to hunk
A prctl() call to set FR=0 for MIPS R6 should not be allowed since FR=1 is the only option for R6 cores. Cc: Paul Burton <redacted> Cc: Matthew Fortune <redacted> Signed-off-by: Markos Chandras <redacted> --- arch/mips/include/asm/fpu.h | 3 ++- arch/mips/kernel/process.c | 4 ++++ 2 files changed, 6 insertions(+), 1 deletion(-)diff --git a/arch/mips/include/asm/fpu.h b/arch/mips/include/asm/fpu.h index 994d21939676..b96d9d327626 100644 --- a/arch/mips/include/asm/fpu.h +++ b/arch/mips/include/asm/fpu.h@@ -68,7 +68,8 @@ static inline int __enable_fpu(enum fpu_mode mode) goto fr_common; case FPU_64BIT: -#if !(defined(CONFIG_CPU_MIPS32_R2) || defined(CONFIG_64BIT)) +#if !(defined(CONFIG_CPU_MIPS32_R2) || defined(CONFIG_CPU_MIPS32_R6) \ + || defined(CONFIG_64BIT))
Hi Markos,
This change really seems like a separate one, since it has nothing to do
with the prctl or disallowing FR=1, but rather with allowing FR=1 on r6.
Thanks,
Paul
quoted hunk ↗ jump to hunk
/* we only have a 32-bit FPU */ return SIGFPE; #endifdiff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c index b732c0ce2e56..41ebd5d0ac30 100644 --- a/arch/mips/kernel/process.c +++ b/arch/mips/kernel/process.c@@ -581,6 +581,10 @@ int mips_set_process_fp_mode(struct task_struct *task, unsigned int value) if ((value & PR_FP_MODE_FRE) && !cpu_has_fre) return -EOPNOTSUPP; + /* FR = 0 not supported in MIPS R6 */ + if (!(value & PR_FP_MODE_FR) && cpu_has_fpu && cpu_has_mips_r6) + return -EOPNOTSUPP; + /* Save FP & vector context, then disable FPU & MSA */ if (task->signal == current->signal) lose_fpu(1);-- 2.2.1