^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/sched.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) #include <linux/sched/task.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) #include <linux/sched/task_stack.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) #include <linux/interrupt.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) #include <asm/sections.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) #include <asm/ptrace.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) #include <asm/bitops.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) #include <asm/stacktrace.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <asm/unwind.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) unsigned long unwind_get_return_address(struct unwind_state *state)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) if (unwind_done(state))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) return __kernel_text_address(state->ip) ? state->ip : 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) EXPORT_SYMBOL_GPL(unwind_get_return_address);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) static bool outside_of_stack(struct unwind_state *state, unsigned long sp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) return (sp <= state->sp) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) (sp > state->stack_info.end - sizeof(struct stack_frame));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) static bool update_stack_info(struct unwind_state *state, unsigned long sp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) struct stack_info *info = &state->stack_info;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) unsigned long *mask = &state->stack_mask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) /* New stack pointer leaves the current stack */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) if (get_stack_info(sp, state->task, info, mask) != 0 ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) !on_stack(info, sp, sizeof(struct stack_frame)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) /* 'sp' does not point to a valid stack */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) return true;
^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 bool is_final_pt_regs(struct unwind_state *state,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) struct pt_regs *regs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) /* user mode or kernel thread pt_regs at the bottom of task stack */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) if (task_pt_regs(state->task) == regs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) /* user mode pt_regs at the bottom of irq stack */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) return state->stack_info.type == STACK_TYPE_IRQ &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) state->stack_info.end - sizeof(struct pt_regs) == (unsigned long)regs &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) READ_ONCE_NOCHECK(regs->psw.mask) & PSW_MASK_PSTATE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) bool unwind_next_frame(struct unwind_state *state)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) struct stack_info *info = &state->stack_info;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) struct stack_frame *sf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) struct pt_regs *regs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) unsigned long sp, ip;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) bool reliable;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) regs = state->regs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) if (unlikely(regs)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) sp = state->sp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) sf = (struct stack_frame *) sp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) ip = READ_ONCE_NOCHECK(sf->gprs[8]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) reliable = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) regs = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) if (!__kernel_text_address(ip)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) /* skip bogus %r14 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) state->regs = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) return unwind_next_frame(state);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) sf = (struct stack_frame *) state->sp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) sp = READ_ONCE_NOCHECK(sf->back_chain);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) if (likely(sp)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) /* Non-zero back-chain points to the previous frame */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) if (unlikely(outside_of_stack(state, sp))) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) if (!update_stack_info(state, sp))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) goto out_err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) sf = (struct stack_frame *) sp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) ip = READ_ONCE_NOCHECK(sf->gprs[8]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) reliable = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) /* No back-chain, look for a pt_regs structure */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) sp = state->sp + STACK_FRAME_OVERHEAD;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) if (!on_stack(info, sp, sizeof(struct pt_regs)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) goto out_err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) regs = (struct pt_regs *) sp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) if (is_final_pt_regs(state, regs))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) goto out_stop;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) ip = READ_ONCE_NOCHECK(regs->psw.addr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) sp = READ_ONCE_NOCHECK(regs->gprs[15]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) if (unlikely(outside_of_stack(state, sp))) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) if (!update_stack_info(state, sp))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) goto out_err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) reliable = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) /* Sanity check: ABI requires SP to be aligned 8 bytes. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) if (sp & 0x7)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) goto out_err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) ip = ftrace_graph_ret_addr(state->task, &state->graph_idx, ip, (void *) sp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) /* Update unwind state */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) state->sp = sp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) state->ip = ip;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) state->regs = regs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) state->reliable = reliable;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) out_err:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) state->error = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) out_stop:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) state->stack_info.type = STACK_TYPE_UNKNOWN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) EXPORT_SYMBOL_GPL(unwind_next_frame);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) void __unwind_start(struct unwind_state *state, struct task_struct *task,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) struct pt_regs *regs, unsigned long first_frame)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) struct stack_info *info = &state->stack_info;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) struct stack_frame *sf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) unsigned long ip, sp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) memset(state, 0, sizeof(*state));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) state->task = task;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) state->regs = regs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) /* Don't even attempt to start from user mode regs: */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) if (regs && user_mode(regs)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) info->type = STACK_TYPE_UNKNOWN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) /* Get the instruction pointer from pt_regs or the stack frame */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) if (regs) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) ip = regs->psw.addr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) sp = regs->gprs[15];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) } else if (task == current) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) sp = current_frame_address();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) sp = task->thread.ksp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) /* Get current stack pointer and initialize stack info */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) if (!update_stack_info(state, sp)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) /* Something is wrong with the stack pointer */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) info->type = STACK_TYPE_UNKNOWN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) state->error = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) if (!regs) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) /* Stack frame is within valid stack */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) sf = (struct stack_frame *)sp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) ip = READ_ONCE_NOCHECK(sf->gprs[8]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) ip = ftrace_graph_ret_addr(state->task, &state->graph_idx, ip, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) /* Update unwind state */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) state->sp = sp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) state->ip = ip;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) state->reliable = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) if (!first_frame)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) /* Skip through the call chain to the specified starting frame */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) while (!unwind_done(state)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) if (on_stack(&state->stack_info, first_frame, sizeof(struct stack_frame))) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) if (state->sp >= first_frame)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) unwind_next_frame(state);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) EXPORT_SYMBOL_GPL(__unwind_start);
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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