diff options
Diffstat (limited to 'arch/sparc64/lib/mcount.S')
| -rw-r--r-- | arch/sparc64/lib/mcount.S | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/arch/sparc64/lib/mcount.S b/arch/sparc64/lib/mcount.S new file mode 100644 index 000000000000..2ef2e268bdcf --- /dev/null +++ b/arch/sparc64/lib/mcount.S @@ -0,0 +1,61 @@ +/* + * Copyright (C) 2000 Anton Blanchard (anton@linuxcare.com) + * + * This file implements mcount(), which is used to collect profiling data. + * This can also be tweaked for kernel stack overflow detection. + */ + +#include <linux/config.h> +#include <linux/linkage.h> + +#include <asm/ptrace.h> +#include <asm/thread_info.h> + +/* + * This is the main variant and is called by C code. GCC's -pg option + * automatically instruments every C function with a call to this. + */ + +#ifdef CONFIG_STACK_DEBUG + +#define OVSTACKSIZE 4096 /* lets hope this is enough */ + + .data + .align 8 +panicstring: + .asciz "Stack overflow\n" + .align 8 +ovstack: + .skip OVSTACKSIZE +#endif + .text + .align 32 + .globl mcount, _mcount +mcount: +_mcount: +#ifdef CONFIG_STACK_DEBUG + /* + * Check whether %sp is dangerously low. + */ + ldub [%g6 + TI_FPDEPTH], %g1 + srl %g1, 1, %g3 + add %g3, 1, %g3 + sllx %g3, 8, %g3 ! each fpregs frame is 256b + add %g3, 192, %g3 + add %g6, %g3, %g3 ! where does task_struct+frame end? + sub %g3, STACK_BIAS, %g3 + cmp %sp, %g3 + bg,pt %xcc, 1f + sethi %hi(panicstring), %g3 + sethi %hi(ovstack), %g7 ! cant move to panic stack fast enough + or %g7, %lo(ovstack), %g7 + add %g7, OVSTACKSIZE, %g7 + sub %g7, STACK_BIAS, %g7 + mov %g7, %sp + call prom_printf + or %g3, %lo(panicstring), %o0 + call prom_halt + nop +#endif +1: retl + nop |