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Diffstat (limited to 'arch/x86_64/kernel/traps.c')
-rw-r--r--arch/x86_64/kernel/traps.c129
1 files changed, 90 insertions, 39 deletions
diff --git a/arch/x86_64/kernel/traps.c b/arch/x86_64/kernel/traps.c
index 5a5311d3de0..79d05c48207 100644
--- a/arch/x86_64/kernel/traps.c
+++ b/arch/x86_64/kernel/traps.c
@@ -110,28 +110,31 @@ static int kstack_depth_to_print = 12;
static int call_trace = 1;
#ifdef CONFIG_KALLSYMS
-#include <linux/kallsyms.h>
-int printk_address(unsigned long address)
-{
+# include <linux/kallsyms.h>
+void printk_address(unsigned long address)
+{
unsigned long offset = 0, symsize;
const char *symname;
char *modname;
- char *delim = ":";
+ char *delim = ":";
char namebuf[128];
- symname = kallsyms_lookup(address, &symsize, &offset, &modname, namebuf);
- if (!symname)
- return printk("[<%016lx>]", address);
- if (!modname)
+ symname = kallsyms_lookup(address, &symsize, &offset,
+ &modname, namebuf);
+ if (!symname) {
+ printk(" [<%016lx>]\n", address);
+ return;
+ }
+ if (!modname)
modname = delim = "";
- return printk("<%016lx>{%s%s%s%s%+ld}",
- address, delim, modname, delim, symname, offset);
-}
+ printk(" [<%016lx>] %s%s%s%s+0x%lx/0x%lx\n",
+ address, delim, modname, delim, symname, offset, symsize);
+}
#else
-int printk_address(unsigned long address)
-{
- return printk("[<%016lx>]", address);
-}
+void printk_address(unsigned long address)
+{
+ printk(" [<%016lx>]\n", address);
+}
#endif
static unsigned long *in_exception_stack(unsigned cpu, unsigned long stack,
@@ -149,10 +152,22 @@ static unsigned long *in_exception_stack(unsigned cpu, unsigned long stack,
};
unsigned k;
+ /*
+ * Iterate over all exception stacks, and figure out whether
+ * 'stack' is in one of them:
+ */
for (k = 0; k < N_EXCEPTION_STACKS; k++) {
unsigned long end;
+ /*
+ * set 'end' to the end of the exception stack.
+ */
switch (k + 1) {
+ /*
+ * TODO: this block is not needed i think, because
+ * setup64.c:cpu_init() sets up t->ist[DEBUG_STACK]
+ * properly too.
+ */
#if DEBUG_STKSZ > EXCEPTION_STKSZ
case DEBUG_STACK:
end = cpu_pda(cpu)->debugstack + DEBUG_STKSZ;
@@ -162,19 +177,43 @@ static unsigned long *in_exception_stack(unsigned cpu, unsigned long stack,
end = per_cpu(init_tss, cpu).ist[k];
break;
}
+ /*
+ * Is 'stack' above this exception frame's end?
+ * If yes then skip to the next frame.
+ */
if (stack >= end)
continue;
+ /*
+ * Is 'stack' above this exception frame's start address?
+ * If yes then we found the right frame.
+ */
if (stack >= end - EXCEPTION_STKSZ) {
+ /*
+ * Make sure we only iterate through an exception
+ * stack once. If it comes up for the second time
+ * then there's something wrong going on - just
+ * break out and return NULL:
+ */
if (*usedp & (1U << k))
break;
*usedp |= 1U << k;
*idp = ids[k];
return (unsigned long *)end;
}
+ /*
+ * If this is a debug stack, and if it has a larger size than
+ * the usual exception stacks, then 'stack' might still
+ * be within the lower portion of the debug stack:
+ */
#if DEBUG_STKSZ > EXCEPTION_STKSZ
if (k == DEBUG_STACK - 1 && stack >= end - DEBUG_STKSZ) {
unsigned j = N_EXCEPTION_STACKS - 1;
+ /*
+ * Black magic. A large debug stack is composed of
+ * multiple exception stack entries, which we
+ * iterate through now. Dont look:
+ */
do {
++j;
end -= EXCEPTION_STKSZ;
@@ -193,20 +232,14 @@ static unsigned long *in_exception_stack(unsigned cpu, unsigned long stack,
static int show_trace_unwind(struct unwind_frame_info *info, void *context)
{
- int i = 11, n = 0;
+ int n = 0;
while (unwind(info) == 0 && UNW_PC(info)) {
- ++n;
- if (i > 50) {
- printk("\n ");
- i = 7;
- } else
- i += printk(" ");
- i += printk_address(UNW_PC(info));
+ n++;
+ printk_address(UNW_PC(info));
if (arch_unw_user_mode(info))
break;
}
- printk("\n");
return n;
}
@@ -224,7 +257,7 @@ void show_trace(struct task_struct *tsk, struct pt_regs *regs, unsigned long * s
int i = 11;
unsigned used = 0;
- printk("\nCall Trace:");
+ printk("\nCall Trace:\n");
if (!tsk)
tsk = current;
@@ -250,16 +283,15 @@ void show_trace(struct task_struct *tsk, struct pt_regs *regs, unsigned long * s
}
}
+ /*
+ * Print function call entries within a stack. 'cond' is the
+ * "end of stackframe" condition, that the 'stack++'
+ * iteration will eventually trigger.
+ */
#define HANDLE_STACK(cond) \
do while (cond) { \
unsigned long addr = *stack++; \
if (kernel_text_address(addr)) { \
- if (i > 50) { \
- printk("\n "); \
- i = 0; \
- } \
- else \
- i += printk(" "); \
/* \
* If the address is either in the text segment of the \
* kernel, or in the region which contains vmalloc'ed \
@@ -268,20 +300,30 @@ void show_trace(struct task_struct *tsk, struct pt_regs *regs, unsigned long * s
* down the cause of the crash will be able to figure \
* out the call path that was taken. \
*/ \
- i += printk_address(addr); \
+ printk_address(addr); \
} \
} while (0)
- for(; ; ) {
+ /*
+ * Print function call entries in all stacks, starting at the
+ * current stack address. If the stacks consist of nested
+ * exceptions
+ */
+ for ( ; ; ) {
const char *id;
unsigned long *estack_end;
estack_end = in_exception_stack(cpu, (unsigned long)stack,
&used, &id);
if (estack_end) {
- i += printk(" <%s>", id);
+ printk(" <%s>", id);
HANDLE_STACK (stack < estack_end);
- i += printk(" <EOE>");
+ printk(" <EOE>");
+ /*
+ * We link to the next stack via the
+ * second-to-last pointer (index -2 to end) in the
+ * exception stack:
+ */
stack = (unsigned long *) estack_end[-2];
continue;
}
@@ -291,19 +333,28 @@ void show_trace(struct task_struct *tsk, struct pt_regs *regs, unsigned long * s
(IRQSTACKSIZE - 64) / sizeof(*irqstack);
if (stack >= irqstack && stack < irqstack_end) {
- i += printk(" <IRQ>");
+ printk(" <IRQ>");
HANDLE_STACK (stack < irqstack_end);
+ /*
+ * We link to the next stack (which would be
+ * the process stack normally) the last
+ * pointer (index -1 to end) in the IRQ stack:
+ */
stack = (unsigned long *) (irqstack_end[-1]);
irqstack_end = NULL;
- i += printk(" <EOI>");
+ printk(" <EOI>");
continue;
}
}
break;
}
+ /*
+ * This prints the process stack:
+ */
HANDLE_STACK (((long) stack & (THREAD_SIZE-1)) != 0);
#undef HANDLE_STACK
+
printk("\n");
}
@@ -337,8 +388,8 @@ static void _show_stack(struct task_struct *tsk, struct pt_regs *regs, unsigned
break;
}
if (i && ((i % 4) == 0))
- printk("\n ");
- printk("%016lx ", *stack++);
+ printk("\n");
+ printk(" %016lx", *stack++);
touch_nmi_watchdog();
}
show_trace(tsk, regs, rsp);
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-27 22:56:25 +0000