| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | #include <linux/kernel.h> |
| 2 | #include <asm/system.h> |
| 3 | |
| 4 | typedef unsigned int instr; |
| 5 | |
| 6 | #define MAJOR_OP 0xfc000000 |
| 7 | #define LDA_OP 0x20000000 |
| 8 | #define STQ_OP 0xb4000000 |
| 9 | #define BR_OP 0xc0000000 |
| 10 | |
| 11 | #define STK_ALLOC_1 0x23de8000 /* lda $30,-X($30) */ |
| 12 | #define STK_ALLOC_1M 0xffff8000 |
| 13 | #define STK_ALLOC_2 0x43c0153e /* subq $30,X,$30 */ |
| 14 | #define STK_ALLOC_2M 0xffe01fff |
| 15 | |
| 16 | #define MEM_REG 0x03e00000 |
| 17 | #define MEM_BASE 0x001f0000 |
| 18 | #define MEM_OFF 0x0000ffff |
| 19 | #define MEM_OFF_SIGN 0x00008000 |
| 20 | #define BASE_SP 0x001e0000 |
| 21 | |
| 22 | #define STK_ALLOC_MATCH(INSTR) \ |
| 23 | (((INSTR) & STK_ALLOC_1M) == STK_ALLOC_1 \ |
| 24 | || ((INSTR) & STK_ALLOC_2M) == STK_ALLOC_2) |
| 25 | #define STK_PUSH_MATCH(INSTR) \ |
| 26 | (((INSTR) & (MAJOR_OP | MEM_BASE | MEM_OFF_SIGN)) == (STQ_OP | BASE_SP)) |
| 27 | #define MEM_OP_OFFSET(INSTR) \ |
| 28 | (((long)((INSTR) & MEM_OFF) << 48) >> 48) |
| 29 | #define MEM_OP_REG(INSTR) \ |
| 30 | (((INSTR) & MEM_REG) >> 22) |
| 31 | |
| 32 | /* Branches, jumps, PAL calls, and illegal opcodes end a basic block. */ |
| 33 | #define BB_END(INSTR) \ |
| 34 | (((instr)(INSTR) >= BR_OP) | ((instr)(INSTR) < LDA_OP) | \ |
| 35 | ((((instr)(INSTR) ^ 0x60000000) < 0x20000000) & \ |
| 36 | (((instr)(INSTR) & 0x0c000000) != 0))) |
| 37 | |
| 38 | #define IS_KERNEL_TEXT(PC) ((unsigned long)(PC) > START_ADDR) |
| 39 | |
| 40 | static char reg_name[][4] = { |
| 41 | "v0 ", "t0 ", "t1 ", "t2 ", "t3 ", "t4 ", "t5 ", "t6 ", "t7 ", |
| 42 | "s0 ", "s1 ", "s2 ", "s3 ", "s4 ", "s5 ", "s6 ", "a0 ", "a1 ", |
| 43 | "a2 ", "a3 ", "a4 ", "a5 ", "t8 ", "t9 ", "t10", "t11", "ra ", |
| 44 | "pv ", "at ", "gp ", "sp ", "0" |
| 45 | }; |
| 46 | |
| 47 | |
| 48 | static instr * |
| 49 | display_stored_regs(instr * pro_pc, unsigned char * sp) |
| 50 | { |
| 51 | instr * ret_pc = 0; |
| 52 | int reg; |
| 53 | unsigned long value; |
| 54 | |
| 55 | printk("Prologue [<%p>], Frame %p:\n", pro_pc, sp); |
| 56 | while (!BB_END(*pro_pc)) |
| 57 | if (STK_PUSH_MATCH(*pro_pc)) { |
| 58 | reg = (*pro_pc & MEM_REG) >> 21; |
| 59 | value = *(unsigned long *)(sp + (*pro_pc & MEM_OFF)); |
| 60 | if (reg == 26) |
| 61 | ret_pc = (instr *)value; |
| 62 | printk("\t\t%s / 0x%016lx\n", reg_name[reg], value); |
| 63 | } |
| 64 | return ret_pc; |
| 65 | } |
| 66 | |
| 67 | static instr * |
| 68 | seek_prologue(instr * pc) |
| 69 | { |
| 70 | while (!STK_ALLOC_MATCH(*pc)) |
| 71 | --pc; |
| 72 | while (!BB_END(*(pc - 1))) |
| 73 | --pc; |
| 74 | return pc; |
| 75 | } |
| 76 | |
| 77 | static long |
| 78 | stack_increment(instr * prologue_pc) |
| 79 | { |
| 80 | while (!STK_ALLOC_MATCH(*prologue_pc)) |
| 81 | ++prologue_pc; |
| 82 | |
| 83 | /* Count the bytes allocated. */ |
| 84 | if ((*prologue_pc & STK_ALLOC_1M) == STK_ALLOC_1M) |
| 85 | return -(((long)(*prologue_pc) << 48) >> 48); |
| 86 | else |
| 87 | return (*prologue_pc >> 13) & 0xff; |
| 88 | } |
| 89 | |
| 90 | void |
| 91 | stacktrace(void) |
| 92 | { |
| 93 | instr * ret_pc; |
| 94 | instr * prologue = (instr *)stacktrace; |
| 95 | register unsigned char * sp __asm__ ("$30"); |
| 96 | |
| 97 | printk("\tstack trace:\n"); |
| 98 | do { |
| 99 | ret_pc = display_stored_regs(prologue, sp); |
| 100 | sp += stack_increment(prologue); |
| 101 | prologue = seek_prologue(ret_pc); |
| 102 | } while (IS_KERNEL_TEXT(ret_pc)); |
| 103 | } |