do_ade may be invoked with preempt enabled. do_cpu will be invoked with
preempt enabled. When it's preempted(in do_ade/do_cpu), TIF_USEDFPU will be
cleared, when it returns to do_ade/do_cpu, the fpu is actually disabled.
e.g.
In do_ade()
emulate_load_store_insn():
BUG_ON(!is_fpu_owner()); <-- This assertion may be breaked.
In do_cpu()
enable_restore_fp_context():
was_fpu_owner = is_fpu_owner();
This patch simply disables interrupts in related handlers, and
disable preempt/enable interrupts in do_ade/do_cpu.
---
arch/mips/kernel/genex.S | 4 ++--
arch/mips/kernel/traps.c | 4 ++++
2 files changed, 6 insertions(+), 2 deletions(-)
diff --git a/arch/mips/kernel/genex.S b/arch/mips/kernel/genex.S
index ac35e12..a5c6931 100644
--- a/arch/mips/kernel/genex.S
+++ b/arch/mips/kernel/genex.S
@@ -370,7 +370,7 @@ NESTED(nmi_handler, PT_SIZE, sp)
.macro __build_clear_ade
MFC0 t0, CP0_BADVADDR
PTR_S t0, PT_BVADDR(sp)
- KMODE
+ CLI
.endm
.macro __BUILD_silent exception
@@ -422,7 +422,7 @@ NESTED(nmi_handler, PT_SIZE, sp)
BUILD_HANDLER dbe be cli silent /* #7 */
BUILD_HANDLER bp bp sti silent /* #9 */
BUILD_HANDLER ri ri sti silent /* #10 */
- BUILD_HANDLER cpu cpu sti silent /* #11 */
+ BUILD_HANDLER cpu cpu cli silent /* #11 */
BUILD_HANDLER ov ov sti silent /* #12 */
BUILD_HANDLER tr tr sti silent /* #13 */
BUILD_HANDLER msa_fpe msa_fpe sti silent /* #14 */
diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index 51706d6..0e0f7de 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -1166,6 +1166,9 @@ asmlinkage void do_cpu(struct pt_regs *regs)
int status, err;
unsigned long __maybe_unused flags;
+ preempt_disable();
+ local_irq_enable();
+
prev_state = exception_enter();
cpid = (regs->cp0_cause >> CAUSEB_CE) & 3;
@@ -1258,6 +1261,7 @@ asmlinkage void do_cpu(struct pt_regs *regs)
out:
exception_exit(prev_state);
+ preempt_enable();
}
asmlinkage void do_msa_fpe(struct pt_regs *regs)
--
1.9.0
