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1/*
2 * Copyright (C) 1991, 1992 Linus Torvalds
3 * Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
4 */
5#include <linux/kallsyms.h>
6#include <linux/kprobes.h>
7#include <linux/uaccess.h>
8#include <linux/utsname.h>
9#include <linux/hardirq.h>
10#include <linux/kdebug.h>
11#include <linux/module.h>
12#include <linux/ptrace.h>
13#include <linux/sched/debug.h>
14#include <linux/sched/task_stack.h>
15#include <linux/ftrace.h>
16#include <linux/kexec.h>
17#include <linux/bug.h>
18#include <linux/nmi.h>
19#include <linux/sysfs.h>
20#include <linux/kasan.h>
21
22#include <asm/cpu_entry_area.h>
23#include <asm/stacktrace.h>
24#include <asm/unwind.h>
25
26int panic_on_unrecovered_nmi;
27int panic_on_io_nmi;
28static int die_counter;
29
30static struct pt_regs exec_summary_regs;
31
32bool in_task_stack(unsigned long *stack, struct task_struct *task,
33 struct stack_info *info)
34{
35 unsigned long *begin = task_stack_page(task);
36 unsigned long *end = task_stack_page(task) + THREAD_SIZE;
37
38 if (stack < begin || stack >= end)
39 return false;
40
41 info->type = STACK_TYPE_TASK;
42 info->begin = begin;
43 info->end = end;
44 info->next_sp = NULL;
45
46 return true;
47}
48
49bool in_entry_stack(unsigned long *stack, struct stack_info *info)
50{
51 struct entry_stack *ss = cpu_entry_stack(smp_processor_id());
52
53 void *begin = ss;
54 void *end = ss + 1;
55
56 if ((void *)stack < begin || (void *)stack >= end)
57 return false;
58
59 info->type = STACK_TYPE_ENTRY;
60 info->begin = begin;
61 info->end = end;
62 info->next_sp = NULL;
63
64 return true;
65}
66
67static void printk_stack_address(unsigned long address, int reliable,
68 char *log_lvl)
69{
70 touch_nmi_watchdog();
71 printk("%s %s%pB\n", log_lvl, reliable ? "" : "? ", (void *)address);
72}
73
74/*
75 * There are a couple of reasons for the 2/3rd prologue, courtesy of Linus:
76 *
77 * In case where we don't have the exact kernel image (which, if we did, we can
78 * simply disassemble and navigate to the RIP), the purpose of the bigger
79 * prologue is to have more context and to be able to correlate the code from
80 * the different toolchains better.
81 *
82 * In addition, it helps in recreating the register allocation of the failing
83 * kernel and thus make sense of the register dump.
84 *
85 * What is more, the additional complication of a variable length insn arch like
86 * x86 warrants having longer byte sequence before rIP so that the disassembler
87 * can "sync" up properly and find instruction boundaries when decoding the
88 * opcode bytes.
89 *
90 * Thus, the 2/3rds prologue and 64 byte OPCODE_BUFSIZE is just a random
91 * guesstimate in attempt to achieve all of the above.
92 */
93void show_opcodes(struct pt_regs *regs, const char *loglvl)
94{
95#define PROLOGUE_SIZE 42
96#define EPILOGUE_SIZE 21
97#define OPCODE_BUFSIZE (PROLOGUE_SIZE + 1 + EPILOGUE_SIZE)
98 u8 opcodes[OPCODE_BUFSIZE];
99 unsigned long prologue = regs->ip - PROLOGUE_SIZE;
100 bool bad_ip;
101
102 /*
103 * Make sure userspace isn't trying to trick us into dumping kernel
104 * memory by pointing the userspace instruction pointer at it.
105 */
106 bad_ip = user_mode(regs) &&
107 __chk_range_not_ok(prologue, OPCODE_BUFSIZE, TASK_SIZE_MAX);
108
109 if (bad_ip || probe_kernel_read(opcodes, (u8 *)prologue,
110 OPCODE_BUFSIZE)) {
111 printk("%sCode: Bad RIP value.\n", loglvl);
112 } else {
113 printk("%sCode: %" __stringify(PROLOGUE_SIZE) "ph <%02x> %"
114 __stringify(EPILOGUE_SIZE) "ph\n", loglvl, opcodes,
115 opcodes[PROLOGUE_SIZE], opcodes + PROLOGUE_SIZE + 1);
116 }
117}
118
119void show_ip(struct pt_regs *regs, const char *loglvl)
120{
121#ifdef CONFIG_X86_32
122 printk("%sEIP: %pS\n", loglvl, (void *)regs->ip);
123#else
124 printk("%sRIP: %04x:%pS\n", loglvl, (int)regs->cs, (void *)regs->ip);
125#endif
126 show_opcodes(regs, loglvl);
127}
128
129void show_iret_regs(struct pt_regs *regs)
130{
131 show_ip(regs, KERN_DEFAULT);
132 printk(KERN_DEFAULT "RSP: %04x:%016lx EFLAGS: %08lx", (int)regs->ss,
133 regs->sp, regs->flags);
134}
135
136static void show_regs_if_on_stack(struct stack_info *info, struct pt_regs *regs,
137 bool partial)
138{
139 /*
140 * These on_stack() checks aren't strictly necessary: the unwind code
141 * has already validated the 'regs' pointer. The checks are done for
142 * ordering reasons: if the registers are on the next stack, we don't
143 * want to print them out yet. Otherwise they'll be shown as part of
144 * the wrong stack. Later, when show_trace_log_lvl() switches to the
145 * next stack, this function will be called again with the same regs so
146 * they can be printed in the right context.
147 */
148 if (!partial && on_stack(info, regs, sizeof(*regs))) {
149 __show_regs(regs, SHOW_REGS_SHORT);
150
151 } else if (partial && on_stack(info, (void *)regs + IRET_FRAME_OFFSET,
152 IRET_FRAME_SIZE)) {
153 /*
154 * When an interrupt or exception occurs in entry code, the
155 * full pt_regs might not have been saved yet. In that case
156 * just print the iret frame.
157 */
158 show_iret_regs(regs);
159 }
160}
161
162void show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
163 unsigned long *stack, char *log_lvl)
164{
165 struct unwind_state state;
166 struct stack_info stack_info = {0};
167 unsigned long visit_mask = 0;
168 int graph_idx = 0;
169 bool partial = false;
170
171 printk("%sCall Trace:\n", log_lvl);
172
173 unwind_start(&state, task, regs, stack);
174 stack = stack ? : get_stack_pointer(task, regs);
175 regs = unwind_get_entry_regs(&state, &partial);
176
177 /*
178 * Iterate through the stacks, starting with the current stack pointer.
179 * Each stack has a pointer to the next one.
180 *
181 * x86-64 can have several stacks:
182 * - task stack
183 * - interrupt stack
184 * - HW exception stacks (double fault, nmi, debug, mce)
185 * - entry stack
186 *
187 * x86-32 can have up to four stacks:
188 * - task stack
189 * - softirq stack
190 * - hardirq stack
191 * - entry stack
192 */
193 for ( ; stack; stack = PTR_ALIGN(stack_info.next_sp, sizeof(long))) {
194 const char *stack_name;
195
196 if (get_stack_info(stack, task, &stack_info, &visit_mask)) {
197 /*
198 * We weren't on a valid stack. It's possible that
199 * we overflowed a valid stack into a guard page.
200 * See if the next page up is valid so that we can
201 * generate some kind of backtrace if this happens.
202 */
203 stack = (unsigned long *)PAGE_ALIGN((unsigned long)stack);
204 if (get_stack_info(stack, task, &stack_info, &visit_mask))
205 break;
206 }
207
208 stack_name = stack_type_name(stack_info.type);
209 if (stack_name)
210 printk("%s <%s>\n", log_lvl, stack_name);
211
212 if (regs)
213 show_regs_if_on_stack(&stack_info, regs, partial);
214
215 /*
216 * Scan the stack, printing any text addresses we find. At the
217 * same time, follow proper stack frames with the unwinder.
218 *
219 * Addresses found during the scan which are not reported by
220 * the unwinder are considered to be additional clues which are
221 * sometimes useful for debugging and are prefixed with '?'.
222 * This also serves as a failsafe option in case the unwinder
223 * goes off in the weeds.
224 */
225 for (; stack < stack_info.end; stack++) {
226 unsigned long real_addr;
227 int reliable = 0;
228 unsigned long addr = READ_ONCE_NOCHECK(*stack);
229 unsigned long *ret_addr_p =
230 unwind_get_return_address_ptr(&state);
231
232 if (!__kernel_text_address(addr))
233 continue;
234
235 /*
236 * Don't print regs->ip again if it was already printed
237 * by show_regs_if_on_stack().
238 */
239 if (regs && stack == ®s->ip)
240 goto next;
241
242 if (stack == ret_addr_p)
243 reliable = 1;
244
245 /*
246 * When function graph tracing is enabled for a
247 * function, its return address on the stack is
248 * replaced with the address of an ftrace handler
249 * (return_to_handler). In that case, before printing
250 * the "real" address, we want to print the handler
251 * address as an "unreliable" hint that function graph
252 * tracing was involved.
253 */
254 real_addr = ftrace_graph_ret_addr(task, &graph_idx,
255 addr, stack);
256 if (real_addr != addr)
257 printk_stack_address(addr, 0, log_lvl);
258 printk_stack_address(real_addr, reliable, log_lvl);
259
260 if (!reliable)
261 continue;
262
263next:
264 /*
265 * Get the next frame from the unwinder. No need to
266 * check for an error: if anything goes wrong, the rest
267 * of the addresses will just be printed as unreliable.
268 */
269 unwind_next_frame(&state);
270
271 /* if the frame has entry regs, print them */
272 regs = unwind_get_entry_regs(&state, &partial);
273 if (regs)
274 show_regs_if_on_stack(&stack_info, regs, partial);
275 }
276
277 if (stack_name)
278 printk("%s </%s>\n", log_lvl, stack_name);
279 }
280}
281
282void show_stack(struct task_struct *task, unsigned long *sp)
283{
284 task = task ? : current;
285
286 /*
287 * Stack frames below this one aren't interesting. Don't show them
288 * if we're printing for %current.
289 */
290 if (!sp && task == current)
291 sp = get_stack_pointer(current, NULL);
292
293 show_trace_log_lvl(task, NULL, sp, KERN_DEFAULT);
294}
295
296void show_stack_regs(struct pt_regs *regs)
297{
298 show_trace_log_lvl(current, regs, NULL, KERN_DEFAULT);
299}
300
301static arch_spinlock_t die_lock = __ARCH_SPIN_LOCK_UNLOCKED;
302static int die_owner = -1;
303static unsigned int die_nest_count;
304
305unsigned long oops_begin(void)
306{
307 int cpu;
308 unsigned long flags;
309
310 oops_enter();
311
312 /* racy, but better than risking deadlock. */
313 raw_local_irq_save(flags);
314 cpu = smp_processor_id();
315 if (!arch_spin_trylock(&die_lock)) {
316 if (cpu == die_owner)
317 /* nested oops. should stop eventually */;
318 else
319 arch_spin_lock(&die_lock);
320 }
321 die_nest_count++;
322 die_owner = cpu;
323 console_verbose();
324 bust_spinlocks(1);
325 return flags;
326}
327NOKPROBE_SYMBOL(oops_begin);
328
329void __noreturn rewind_stack_do_exit(int signr);
330
331void oops_end(unsigned long flags, struct pt_regs *regs, int signr)
332{
333 if (regs && kexec_should_crash(current))
334 crash_kexec(regs);
335
336 bust_spinlocks(0);
337 die_owner = -1;
338 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
339 die_nest_count--;
340 if (!die_nest_count)
341 /* Nest count reaches zero, release the lock. */
342 arch_spin_unlock(&die_lock);
343 raw_local_irq_restore(flags);
344 oops_exit();
345
346 /* Executive summary in case the oops scrolled away */
347 __show_regs(&exec_summary_regs, SHOW_REGS_ALL);
348
349 if (!signr)
350 return;
351 if (in_interrupt())
352 panic("Fatal exception in interrupt");
353 if (panic_on_oops)
354 panic("Fatal exception");
355
356 /*
357 * We're not going to return, but we might be on an IST stack or
358 * have very little stack space left. Rewind the stack and kill
359 * the task.
360 * Before we rewind the stack, we have to tell KASAN that we're going to
361 * reuse the task stack and that existing poisons are invalid.
362 */
363 kasan_unpoison_task_stack(current);
364 rewind_stack_do_exit(signr);
365}
366NOKPROBE_SYMBOL(oops_end);
367
368int __die(const char *str, struct pt_regs *regs, long err)
369{
370 const char *pr = "";
371
372 /* Save the regs of the first oops for the executive summary later. */
373 if (!die_counter)
374 exec_summary_regs = *regs;
375
376 if (IS_ENABLED(CONFIG_PREEMPTION))
377 pr = IS_ENABLED(CONFIG_PREEMPT_RT) ? " PREEMPT_RT" : " PREEMPT";
378
379 printk(KERN_DEFAULT
380 "%s: %04lx [#%d]%s%s%s%s%s\n", str, err & 0xffff, ++die_counter,
381 pr,
382 IS_ENABLED(CONFIG_SMP) ? " SMP" : "",
383 debug_pagealloc_enabled() ? " DEBUG_PAGEALLOC" : "",
384 IS_ENABLED(CONFIG_KASAN) ? " KASAN" : "",
385 IS_ENABLED(CONFIG_PAGE_TABLE_ISOLATION) ?
386 (boot_cpu_has(X86_FEATURE_PTI) ? " PTI" : " NOPTI") : "");
387
388 show_regs(regs);
389 print_modules();
390
391 if (notify_die(DIE_OOPS, str, regs, err,
392 current->thread.trap_nr, SIGSEGV) == NOTIFY_STOP)
393 return 1;
394
395 return 0;
396}
397NOKPROBE_SYMBOL(__die);
398
399/*
400 * This is gone through when something in the kernel has done something bad
401 * and is about to be terminated:
402 */
403void die(const char *str, struct pt_regs *regs, long err)
404{
405 unsigned long flags = oops_begin();
406 int sig = SIGSEGV;
407
408 if (__die(str, regs, err))
409 sig = 0;
410 oops_end(flags, regs, sig);
411}
412
413void show_regs(struct pt_regs *regs)
414{
415 show_regs_print_info(KERN_DEFAULT);
416
417 __show_regs(regs, user_mode(regs) ? SHOW_REGS_USER : SHOW_REGS_ALL);
418
419 /*
420 * When in-kernel, we also print out the stack at the time of the fault..
421 */
422 if (!user_mode(regs))
423 show_trace_log_lvl(current, regs, NULL, KERN_DEFAULT);
424}
1/*
2 * Copyright (C) 1991, 1992 Linus Torvalds
3 * Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
4 */
5#include <linux/kallsyms.h>
6#include <linux/kprobes.h>
7#include <linux/uaccess.h>
8#include <linux/utsname.h>
9#include <linux/hardirq.h>
10#include <linux/kdebug.h>
11#include <linux/module.h>
12#include <linux/ptrace.h>
13#include <linux/ftrace.h>
14#include <linux/kexec.h>
15#include <linux/bug.h>
16#include <linux/nmi.h>
17#include <linux/sysfs.h>
18
19#include <asm/stacktrace.h>
20
21
22int panic_on_unrecovered_nmi;
23int panic_on_io_nmi;
24unsigned int code_bytes = 64;
25int kstack_depth_to_print = 3 * STACKSLOTS_PER_LINE;
26static int die_counter;
27
28static void printk_stack_address(unsigned long address, int reliable,
29 void *data)
30{
31 printk("%s [<%p>] %s%pB\n",
32 (char *)data, (void *)address, reliable ? "" : "? ",
33 (void *)address);
34}
35
36void printk_address(unsigned long address)
37{
38 pr_cont(" [<%p>] %pS\n", (void *)address, (void *)address);
39}
40
41#ifdef CONFIG_FUNCTION_GRAPH_TRACER
42static void
43print_ftrace_graph_addr(unsigned long addr, void *data,
44 const struct stacktrace_ops *ops,
45 struct thread_info *tinfo, int *graph)
46{
47 struct task_struct *task;
48 unsigned long ret_addr;
49 int index;
50
51 if (addr != (unsigned long)return_to_handler)
52 return;
53
54 task = tinfo->task;
55 index = task->curr_ret_stack;
56
57 if (!task->ret_stack || index < *graph)
58 return;
59
60 index -= *graph;
61 ret_addr = task->ret_stack[index].ret;
62
63 ops->address(data, ret_addr, 1);
64
65 (*graph)++;
66}
67#else
68static inline void
69print_ftrace_graph_addr(unsigned long addr, void *data,
70 const struct stacktrace_ops *ops,
71 struct thread_info *tinfo, int *graph)
72{ }
73#endif
74
75/*
76 * x86-64 can have up to three kernel stacks:
77 * process stack
78 * interrupt stack
79 * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
80 */
81
82static inline int valid_stack_ptr(struct thread_info *tinfo,
83 void *p, unsigned int size, void *end)
84{
85 void *t = tinfo;
86 if (end) {
87 if (p < end && p >= (end-THREAD_SIZE))
88 return 1;
89 else
90 return 0;
91 }
92 return p > t && p < t + THREAD_SIZE - size;
93}
94
95unsigned long
96print_context_stack(struct thread_info *tinfo,
97 unsigned long *stack, unsigned long bp,
98 const struct stacktrace_ops *ops, void *data,
99 unsigned long *end, int *graph)
100{
101 struct stack_frame *frame = (struct stack_frame *)bp;
102
103 while (valid_stack_ptr(tinfo, stack, sizeof(*stack), end)) {
104 unsigned long addr;
105
106 addr = *stack;
107 if (__kernel_text_address(addr)) {
108 if ((unsigned long) stack == bp + sizeof(long)) {
109 ops->address(data, addr, 1);
110 frame = frame->next_frame;
111 bp = (unsigned long) frame;
112 } else {
113 ops->address(data, addr, 0);
114 }
115 print_ftrace_graph_addr(addr, data, ops, tinfo, graph);
116 }
117 stack++;
118 }
119 return bp;
120}
121EXPORT_SYMBOL_GPL(print_context_stack);
122
123unsigned long
124print_context_stack_bp(struct thread_info *tinfo,
125 unsigned long *stack, unsigned long bp,
126 const struct stacktrace_ops *ops, void *data,
127 unsigned long *end, int *graph)
128{
129 struct stack_frame *frame = (struct stack_frame *)bp;
130 unsigned long *ret_addr = &frame->return_address;
131
132 while (valid_stack_ptr(tinfo, ret_addr, sizeof(*ret_addr), end)) {
133 unsigned long addr = *ret_addr;
134
135 if (!__kernel_text_address(addr))
136 break;
137
138 if (ops->address(data, addr, 1))
139 break;
140 frame = frame->next_frame;
141 ret_addr = &frame->return_address;
142 print_ftrace_graph_addr(addr, data, ops, tinfo, graph);
143 }
144
145 return (unsigned long)frame;
146}
147EXPORT_SYMBOL_GPL(print_context_stack_bp);
148
149static int print_trace_stack(void *data, char *name)
150{
151 printk("%s <%s> ", (char *)data, name);
152 return 0;
153}
154
155/*
156 * Print one address/symbol entries per line.
157 */
158static int print_trace_address(void *data, unsigned long addr, int reliable)
159{
160 touch_nmi_watchdog();
161 printk_stack_address(addr, reliable, data);
162 return 0;
163}
164
165static const struct stacktrace_ops print_trace_ops = {
166 .stack = print_trace_stack,
167 .address = print_trace_address,
168 .walk_stack = print_context_stack,
169};
170
171void
172show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
173 unsigned long *stack, unsigned long bp, char *log_lvl)
174{
175 printk("%sCall Trace:\n", log_lvl);
176 dump_trace(task, regs, stack, bp, &print_trace_ops, log_lvl);
177}
178
179void show_trace(struct task_struct *task, struct pt_regs *regs,
180 unsigned long *stack, unsigned long bp)
181{
182 show_trace_log_lvl(task, regs, stack, bp, "");
183}
184
185void show_stack(struct task_struct *task, unsigned long *sp)
186{
187 unsigned long bp = 0;
188 unsigned long stack;
189
190 /*
191 * Stack frames below this one aren't interesting. Don't show them
192 * if we're printing for %current.
193 */
194 if (!sp && (!task || task == current)) {
195 sp = &stack;
196 bp = stack_frame(current, NULL);
197 }
198
199 show_stack_log_lvl(task, NULL, sp, bp, "");
200}
201
202static arch_spinlock_t die_lock = __ARCH_SPIN_LOCK_UNLOCKED;
203static int die_owner = -1;
204static unsigned int die_nest_count;
205
206unsigned long oops_begin(void)
207{
208 int cpu;
209 unsigned long flags;
210
211 oops_enter();
212
213 /* racy, but better than risking deadlock. */
214 raw_local_irq_save(flags);
215 cpu = smp_processor_id();
216 if (!arch_spin_trylock(&die_lock)) {
217 if (cpu == die_owner)
218 /* nested oops. should stop eventually */;
219 else
220 arch_spin_lock(&die_lock);
221 }
222 die_nest_count++;
223 die_owner = cpu;
224 console_verbose();
225 bust_spinlocks(1);
226 return flags;
227}
228EXPORT_SYMBOL_GPL(oops_begin);
229NOKPROBE_SYMBOL(oops_begin);
230
231void oops_end(unsigned long flags, struct pt_regs *regs, int signr)
232{
233 if (regs && kexec_should_crash(current))
234 crash_kexec(regs);
235
236 bust_spinlocks(0);
237 die_owner = -1;
238 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
239 die_nest_count--;
240 if (!die_nest_count)
241 /* Nest count reaches zero, release the lock. */
242 arch_spin_unlock(&die_lock);
243 raw_local_irq_restore(flags);
244 oops_exit();
245
246 if (!signr)
247 return;
248 if (in_interrupt())
249 panic("Fatal exception in interrupt");
250 if (panic_on_oops)
251 panic("Fatal exception");
252 do_exit(signr);
253}
254NOKPROBE_SYMBOL(oops_end);
255
256int __die(const char *str, struct pt_regs *regs, long err)
257{
258#ifdef CONFIG_X86_32
259 unsigned short ss;
260 unsigned long sp;
261#endif
262 printk(KERN_DEFAULT
263 "%s: %04lx [#%d] ", str, err & 0xffff, ++die_counter);
264#ifdef CONFIG_PREEMPT
265 printk("PREEMPT ");
266#endif
267#ifdef CONFIG_SMP
268 printk("SMP ");
269#endif
270 if (debug_pagealloc_enabled())
271 printk("DEBUG_PAGEALLOC ");
272#ifdef CONFIG_KASAN
273 printk("KASAN");
274#endif
275 printk("\n");
276 if (notify_die(DIE_OOPS, str, regs, err,
277 current->thread.trap_nr, SIGSEGV) == NOTIFY_STOP)
278 return 1;
279
280 print_modules();
281 show_regs(regs);
282#ifdef CONFIG_X86_32
283 if (user_mode(regs)) {
284 sp = regs->sp;
285 ss = regs->ss & 0xffff;
286 } else {
287 sp = kernel_stack_pointer(regs);
288 savesegment(ss, ss);
289 }
290 printk(KERN_EMERG "EIP: [<%08lx>] ", regs->ip);
291 print_symbol("%s", regs->ip);
292 printk(" SS:ESP %04x:%08lx\n", ss, sp);
293#else
294 /* Executive summary in case the oops scrolled away */
295 printk(KERN_ALERT "RIP ");
296 printk_address(regs->ip);
297 printk(" RSP <%016lx>\n", regs->sp);
298#endif
299 return 0;
300}
301NOKPROBE_SYMBOL(__die);
302
303/*
304 * This is gone through when something in the kernel has done something bad
305 * and is about to be terminated:
306 */
307void die(const char *str, struct pt_regs *regs, long err)
308{
309 unsigned long flags = oops_begin();
310 int sig = SIGSEGV;
311
312 if (!user_mode(regs))
313 report_bug(regs->ip, regs);
314
315 if (__die(str, regs, err))
316 sig = 0;
317 oops_end(flags, regs, sig);
318}
319
320static int __init kstack_setup(char *s)
321{
322 ssize_t ret;
323 unsigned long val;
324
325 if (!s)
326 return -EINVAL;
327
328 ret = kstrtoul(s, 0, &val);
329 if (ret)
330 return ret;
331 kstack_depth_to_print = val;
332 return 0;
333}
334early_param("kstack", kstack_setup);
335
336static int __init code_bytes_setup(char *s)
337{
338 ssize_t ret;
339 unsigned long val;
340
341 if (!s)
342 return -EINVAL;
343
344 ret = kstrtoul(s, 0, &val);
345 if (ret)
346 return ret;
347
348 code_bytes = val;
349 if (code_bytes > 8192)
350 code_bytes = 8192;
351
352 return 1;
353}
354__setup("code_bytes=", code_bytes_setup);