projects / mirror_ubuntu-zesty-kernel.git / blame
| Commit | Line | Data |
|---|---|---|
| 1da177e4 LT |
1 | /* |
| 2 | * Copyright (C) 2000 Anton Blanchard (anton@linuxcare.com) | |
| 3 | * | |
| 4 | * This file implements mcount(), which is used to collect profiling data. | |
| 5 | * This can also be tweaked for kernel stack overflow detection. | |
| 6 | */ | |
| 7 | ||
| 8 | #include <linux/config.h> | |
| 9 | #include <linux/linkage.h> | |
| 10 | ||
| 11 | #include <asm/ptrace.h> | |
| 12 | #include <asm/thread_info.h> | |
| 13 | ||
| 14 | /* | |
| 15 | * This is the main variant and is called by C code. GCC's -pg option | |
| 16 | * automatically instruments every C function with a call to this. | |
| 17 | */ | |
| 18 | ||
| 19 | #ifdef CONFIG_STACK_DEBUG | |
| 20 | ||
| 21 | #define OVSTACKSIZE 4096 /* lets hope this is enough */ | |
| 22 | ||
| 23 | .data | |
| 24 | .align 8 | |
| 25 | panicstring: | |
| 26 | .asciz "Stack overflow\n" | |
| 27 | .align 8 | |
| 28 | ovstack: | |
| 29 | .skip OVSTACKSIZE | |
| 30 | #endif | |
| 31 | .text | |
| 32 | .align 32 | |
| 33 | .globl mcount, _mcount | |
| 34 | mcount: | |
| 35 | _mcount: | |
| 36 | #ifdef CONFIG_STACK_DEBUG | |
| 37 | /* | |
| 38 | * Check whether %sp is dangerously low. | |
| 39 | */ | |
| 40 | ldub [%g6 + TI_FPDEPTH], %g1 | |
| 41 | srl %g1, 1, %g3 | |
| 42 | add %g3, 1, %g3 | |
| 43 | sllx %g3, 8, %g3 ! each fpregs frame is 256b | |
| 44 | add %g3, 192, %g3 | |
| 45 | add %g6, %g3, %g3 ! where does task_struct+frame end? | |
| 46 | sub %g3, STACK_BIAS, %g3 | |
| 47 | cmp %sp, %g3 | |
| 48 | bg,pt %xcc, 1f | |
| 49 | sethi %hi(panicstring), %g3 | |
| 50 | sethi %hi(ovstack), %g7 ! cant move to panic stack fast enough | |
| 51 | or %g7, %lo(ovstack), %g7 | |
| 52 | add %g7, OVSTACKSIZE, %g7 | |
| 53 | sub %g7, STACK_BIAS, %g7 | |
| 54 | mov %g7, %sp | |
| 55 | call prom_printf | |
| 56 | or %g3, %lo(panicstring), %o0 | |
| 57 | call prom_halt | |
| 58 | nop | |
| 59 | #endif | |
| 60 | 1: retl | |
| 61 | nop |