^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) #include <linux/oprofile.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) #include <linux/sched.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) #include <linux/mm.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) #include <linux/uaccess.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) #include <asm/ptrace.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) #include <asm/stacktrace.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) #include <linux/stacktrace.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <asm/sections.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <asm/inst.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) struct stackframe {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) unsigned long sp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) unsigned long pc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) unsigned long ra;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) static inline int get_mem(unsigned long addr, unsigned long *result)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) unsigned long *address = (unsigned long *) addr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) if (!access_ok(address, sizeof(unsigned long)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) return -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) if (__copy_from_user_inatomic(result, address, sizeof(unsigned long)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) return -3;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) * These two instruction helpers were taken from process.c
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) static inline int is_ra_save_ins(union mips_instruction *ip)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) /* sw / sd $ra, offset($sp) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) return (ip->i_format.opcode == sw_op || ip->i_format.opcode == sd_op)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) && ip->i_format.rs == 29 && ip->i_format.rt == 31;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) static inline int is_sp_move_ins(union mips_instruction *ip)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) /* addiu/daddiu sp,sp,-imm */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) if (ip->i_format.rs != 29 || ip->i_format.rt != 29)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) if (ip->i_format.opcode == addiu_op || ip->i_format.opcode == daddiu_op)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) * Looks for specific instructions that mark the end of a function.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) * This usually means we ran into the code area of the previous function.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) static inline int is_end_of_function_marker(union mips_instruction *ip)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) /* jr ra */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) if (ip->r_format.func == jr_op && ip->r_format.rs == 31)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) /* lui gp */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) if (ip->i_format.opcode == lui_op && ip->i_format.rt == 28)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) * TODO for userspace stack unwinding:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) * - handle cases where the stack is adjusted inside a function
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) * (generally doesn't happen)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) * - find optimal value for max_instr_check
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) * - try to find a better way to handle leaf functions
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) static inline int unwind_user_frame(struct stackframe *old_frame,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) const unsigned int max_instr_check)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) struct stackframe new_frame = *old_frame;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) off_t ra_offset = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) size_t stack_size = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) unsigned long addr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) if (old_frame->pc == 0 || old_frame->sp == 0 || old_frame->ra == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) return -9;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) for (addr = new_frame.pc; (addr + max_instr_check > new_frame.pc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) && (!ra_offset || !stack_size); --addr) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) union mips_instruction ip;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) if (get_mem(addr, (unsigned long *) &ip))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) return -11;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) if (is_sp_move_ins(&ip)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) int stack_adjustment = ip.i_format.simmediate;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) if (stack_adjustment > 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) /* This marks the end of the previous function,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) which means we overran. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) stack_size = (unsigned long) stack_adjustment;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) } else if (is_ra_save_ins(&ip)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) int ra_slot = ip.i_format.simmediate;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) if (ra_slot < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) /* This shouldn't happen. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) ra_offset = ra_slot;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) } else if (is_end_of_function_marker(&ip))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) if (!ra_offset || !stack_size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) goto done;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) if (ra_offset) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) new_frame.ra = old_frame->sp + ra_offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) if (get_mem(new_frame.ra, &(new_frame.ra)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) return -13;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) if (stack_size) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) new_frame.sp = old_frame->sp + stack_size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) if (get_mem(new_frame.sp, &(new_frame.sp)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) return -14;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) if (new_frame.sp > old_frame->sp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) return -2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) done:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) new_frame.pc = old_frame->ra;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) *old_frame = new_frame;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) static inline void do_user_backtrace(unsigned long low_addr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) struct stackframe *frame,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) unsigned int depth)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) const unsigned int max_instr_check = 512;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) const unsigned long high_addr = low_addr + THREAD_SIZE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) while (depth-- && !unwind_user_frame(frame, max_instr_check)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) oprofile_add_trace(frame->ra);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) if (frame->sp < low_addr || frame->sp > high_addr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) #ifndef CONFIG_KALLSYMS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) static inline void do_kernel_backtrace(unsigned long low_addr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) struct stackframe *frame,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) unsigned int depth) { }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) #else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) static inline void do_kernel_backtrace(unsigned long low_addr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) struct stackframe *frame,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) unsigned int depth)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) while (depth-- && frame->pc) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) frame->pc = unwind_stack_by_address(low_addr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) &(frame->sp),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) frame->pc,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) &(frame->ra));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) oprofile_add_trace(frame->ra);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) void notrace op_mips_backtrace(struct pt_regs *const regs, unsigned int depth)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) struct stackframe frame = { .sp = regs->regs[29],
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) .pc = regs->cp0_epc,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) .ra = regs->regs[31] };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) const int userspace = user_mode(regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) const unsigned long low_addr = ALIGN(frame.sp, THREAD_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) if (userspace)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) do_user_backtrace(low_addr, &frame, depth);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) do_kernel_backtrace(low_addr, &frame, depth);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) }
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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