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