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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
commit | ace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch) | |
tree | b2d64bc10158fdd5497876388cd68142ca374ed3 /arch/s390/include/asm/unwind.h | |
parent | Initial commit. (diff) | |
download | linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip |
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | arch/s390/include/asm/unwind.h | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/arch/s390/include/asm/unwind.h b/arch/s390/include/asm/unwind.h new file mode 100644 index 0000000000..b8ecf04e34 --- /dev/null +++ b/arch/s390/include/asm/unwind.h @@ -0,0 +1,98 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_S390_UNWIND_H +#define _ASM_S390_UNWIND_H + +#include <linux/sched.h> +#include <linux/ftrace.h> +#include <linux/rethook.h> +#include <linux/llist.h> +#include <asm/ptrace.h> +#include <asm/stacktrace.h> + +/* + * To use the stack unwinder it has to be initialized with unwind_start. + * There four combinations for task and regs: + * 1) task==NULL, regs==NULL: the unwind starts for the task that is currently + * running, sp/ip picked up from the CPU registers + * 2) task==NULL, regs!=NULL: the unwind starts from the sp/ip found in + * the struct pt_regs of an interrupt frame for the current task + * 3) task!=NULL, regs==NULL: the unwind starts for an inactive task with + * the sp picked up from task->thread.ksp and the ip picked up from the + * return address stored by __switch_to + * 4) task!=NULL, regs!=NULL: the sp/ip are picked up from the interrupt + * frame 'regs' of a inactive task + * If 'first_frame' is not zero unwind_start skips unwind frames until it + * reaches the specified stack pointer. + * The end of the unwinding is indicated with unwind_done, this can be true + * right after unwind_start, e.g. with first_frame!=0 that can not be found. + * unwind_next_frame skips to the next frame. + * Once the unwind is completed unwind_error() can be used to check if there + * has been a situation where the unwinder could not correctly understand + * the tasks call chain. + */ + +struct unwind_state { + struct stack_info stack_info; + unsigned long stack_mask; + struct task_struct *task; + struct pt_regs *regs; + unsigned long sp, ip; + int graph_idx; + struct llist_node *kr_cur; + bool reliable; + bool error; +}; + +/* Recover the return address modified by rethook and ftrace_graph. */ +static inline unsigned long unwind_recover_ret_addr(struct unwind_state *state, + unsigned long ip) +{ + ip = ftrace_graph_ret_addr(state->task, &state->graph_idx, ip, (void *)state->sp); +#ifdef CONFIG_RETHOOK + if (is_rethook_trampoline(ip)) + ip = rethook_find_ret_addr(state->task, state->sp, &state->kr_cur); +#endif + return ip; +} + +void __unwind_start(struct unwind_state *state, struct task_struct *task, + struct pt_regs *regs, unsigned long first_frame); +bool unwind_next_frame(struct unwind_state *state); +unsigned long unwind_get_return_address(struct unwind_state *state); + +static inline bool unwind_done(struct unwind_state *state) +{ + return state->stack_info.type == STACK_TYPE_UNKNOWN; +} + +static inline bool unwind_error(struct unwind_state *state) +{ + return state->error; +} + +static __always_inline void unwind_start(struct unwind_state *state, + struct task_struct *task, + struct pt_regs *regs, + unsigned long first_frame) +{ + task = task ?: current; + first_frame = first_frame ?: get_stack_pointer(task, regs); + __unwind_start(state, task, regs, first_frame); +} + +static inline struct pt_regs *unwind_get_entry_regs(struct unwind_state *state) +{ + return unwind_done(state) ? NULL : state->regs; +} + +#define unwind_for_each_frame(state, task, regs, first_frame) \ + for (unwind_start(state, task, regs, first_frame); \ + !unwind_done(state); \ + unwind_next_frame(state)) + +static inline void unwind_init(void) {} +static inline void unwind_module_init(struct module *mod, void *orc_ip, + size_t orc_ip_size, void *orc, + size_t orc_size) {} + +#endif /* _ASM_S390_UNWIND_H */ |