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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222// SPDX-License-Identifier: GPL-2.0/* * Copyright (C) 1991, 1992 Linus Torvalds * Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs */#include <linux/sched/debug.h>#include <linux/kallsyms.h>#include <linux/kprobes.h>#include <linux/uaccess.h>#include <linux/hardirq.h>#include <linux/kdebug.h>#include <linux/export.h>#include <linux/ptrace.h>#include <linux/kexec.h>#include <linux/sysfs.h>#include <linux/bug.h>#include <linux/nmi.h>
#include <asm/cpu_entry_area.h>#include <asm/stacktrace.h>
static const char * const exception_stack_names[] = { [ ESTACK_DF ] = "#DF", [ ESTACK_NMI ] = "NMI", [ ESTACK_DB ] = "#DB", [ ESTACK_MCE ] = "#MC", [ ESTACK_VC ] = "#VC", [ ESTACK_VC2 ] = "#VC2",};
const char *stack_type_name(enum stack_type type){ BUILD_BUG_ON(N_EXCEPTION_STACKS != 6);
if (type == STACK_TYPE_TASK) return "TASK";
if (type == STACK_TYPE_IRQ) return "IRQ";
if (type == STACK_TYPE_SOFTIRQ) return "SOFTIRQ";
if (type == STACK_TYPE_ENTRY) { /* * On 64-bit, we have a generic entry stack that we * use for all the kernel entry points, including * SYSENTER. */ return "ENTRY_TRAMPOLINE"; }
if (type >= STACK_TYPE_EXCEPTION && type <= STACK_TYPE_EXCEPTION_LAST) return exception_stack_names[type - STACK_TYPE_EXCEPTION];
return NULL;}
/** * struct estack_pages - Page descriptor for exception stacks * @offs: Offset from the start of the exception stack area * @size: Size of the exception stack * @type: Type to store in the stack_info struct */struct estack_pages { u32 offs; u16 size; u16 type;};
#define EPAGERANGE(st) \ [PFN_DOWN(CEA_ESTACK_OFFS(st)) ... \ PFN_DOWN(CEA_ESTACK_OFFS(st) + CEA_ESTACK_SIZE(st) - 1)] = { \ .offs = CEA_ESTACK_OFFS(st), \ .size = CEA_ESTACK_SIZE(st), \ .type = STACK_TYPE_EXCEPTION + ESTACK_ ##st, }
/* * Array of exception stack page descriptors. If the stack is larger than * PAGE_SIZE, all pages covering a particular stack will have the same * info. The guard pages including the not mapped DB2 stack are zeroed * out. */static conststruct estack_pages estack_pages[CEA_ESTACK_PAGES] ____cacheline_aligned = { EPAGERANGE(DF), EPAGERANGE(NMI), EPAGERANGE(DB), EPAGERANGE(MCE), EPAGERANGE(VC), EPAGERANGE(VC2),};
static __always_inline bool in_exception_stack(unsigned long *stack, struct stack_info *info){ unsigned long begin, end, stk = (unsigned long)stack; const struct estack_pages *ep; struct pt_regs *regs; unsigned int k;
BUILD_BUG_ON(N_EXCEPTION_STACKS != 6);
begin = (unsigned long)__this_cpu_read(cea_exception_stacks); /* * Handle the case where stack trace is collected _before_ * cea_exception_stacks had been initialized. */ if (!begin) return false;
end = begin + sizeof(struct cea_exception_stacks); /* Bail if @stack is outside the exception stack area. */ if (stk < begin || stk >= end) return false;
/* Calc page offset from start of exception stacks */ k = (stk - begin) >> PAGE_SHIFT; /* Lookup the page descriptor */ ep = &estack_pages[k]; /* Guard page? */ if (!ep->size) return false;
begin += (unsigned long)ep->offs; end = begin + (unsigned long)ep->size; regs = (struct pt_regs *)end - 1;
info->type = ep->type; info->begin = (unsigned long *)begin; info->end = (unsigned long *)end; info->next_sp = (unsigned long *)regs->sp; return true;}
static __always_inline bool in_irq_stack(unsigned long *stack, struct stack_info *info){ unsigned long *end = (unsigned long *)this_cpu_read(hardirq_stack_ptr); unsigned long *begin;
/* * @end points directly to the top most stack entry to avoid a -8 * adjustment in the stack switch hotpath. Adjust it back before * calculating @begin. */ end++; begin = end - (IRQ_STACK_SIZE / sizeof(long));
/* * Due to the switching logic RSP can never be == @end because the * final operation is 'popq %rsp' which means after that RSP points * to the original stack and not to @end. */ if (stack < begin || stack >= end) return false;
info->type = STACK_TYPE_IRQ; info->begin = begin; info->end = end;
/* * The next stack pointer is stored at the top of the irq stack * before switching to the irq stack. Actual stack entries are all * below that. */ info->next_sp = (unsigned long *)*(end - 1);
return true;}
bool noinstr get_stack_info_noinstr(unsigned long *stack, struct task_struct *task, struct stack_info *info){ if (in_task_stack(stack, task, info)) return true;
if (task != current) return false;
if (in_exception_stack(stack, info)) return true;
if (in_irq_stack(stack, info)) return true;
if (in_entry_stack(stack, info)) return true;
return false;}
int get_stack_info(unsigned long *stack, struct task_struct *task, struct stack_info *info, unsigned long *visit_mask){ task = task ? : current;
if (!stack) goto unknown;
if (!get_stack_info_noinstr(stack, task, info)) goto unknown;
/* * Make sure we don't iterate through any given stack more than once. * If it comes up a second time then there's something wrong going on: * just break out and report an unknown stack type. */ if (visit_mask) { if (*visit_mask & (1UL << info->type)) { if (task == current) printk_deferred_once(KERN_WARNING "WARNING: stack recursion on stack type %d\n", info->type); goto unknown; } *visit_mask |= 1UL << info->type; }
return 0;
unknown: info->type = STACK_TYPE_UNKNOWN; return -EINVAL;}