diff options
Diffstat (limited to 'arch/alpha/kernel/traps.c')
| -rw-r--r-- | arch/alpha/kernel/traps.c | 31 |
1 files changed, 16 insertions, 15 deletions
diff --git a/arch/alpha/kernel/traps.c b/arch/alpha/kernel/traps.c index 8a66fe544c69..7fc72aeb7398 100644 --- a/arch/alpha/kernel/traps.c +++ b/arch/alpha/kernel/traps.c @@ -9,6 +9,7 @@ * This file initializes the trap entry points */ +#include <linux/cpu.h> #include <linux/jiffies.h> #include <linux/mm.h> #include <linux/sched/signal.h> @@ -233,7 +234,21 @@ do_entIF(unsigned long type, struct pt_regs *regs) { int signo, code; - if ((regs->ps & ~IPL_MAX) == 0) { + if (type == 3) { /* FEN fault */ + /* Irritating users can call PAL_clrfen to disable the + FPU for the process. The kernel will then trap in + do_switch_stack and undo_switch_stack when we try + to save and restore the FP registers. + + Given that GCC by default generates code that uses the + FP registers, PAL_clrfen is not useful except for DoS + attacks. So turn the bleeding FPU back on and be done + with it. */ + current_thread_info()->pcb.flags |= 1; + __reload_thread(¤t_thread_info()->pcb); + return; + } + if (!user_mode(regs)) { if (type == 1) { const unsigned int *data = (const unsigned int *) regs->pc; @@ -366,20 +381,6 @@ do_entIF(unsigned long type, struct pt_regs *regs) } break; - case 3: /* FEN fault */ - /* Irritating users can call PAL_clrfen to disable the - FPU for the process. The kernel will then trap in - do_switch_stack and undo_switch_stack when we try - to save and restore the FP registers. - - Given that GCC by default generates code that uses the - FP registers, PAL_clrfen is not useful except for DoS - attacks. So turn the bleeding FPU back on and be done - with it. */ - current_thread_info()->pcb.flags |= 1; - __reload_thread(¤t_thread_info()->pcb); - return; - case 5: /* illoc */ default: /* unexpected instruction-fault type */ ; |