AcoSail/kernel_optimize_test
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tile: don't call show_regs_print_info() with corrupt current

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We use the validate_current() API to make sure that "current" seems
plausible before using it.  With the new show_regs_print_info()
API, we want to check that current is OK before calling it, since
otherwise we will end up in a recursive panic.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
This commit is contained in:
Chris Metcalf 2013-08-10 12:22:43 -04:00
parent 6fbeee29a2
commit 4036c7d354
1 changed files with 5 additions and 3 deletions
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8
arch/tile/kernel/process.c
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@ -226,19 +226,20 @@ int get_unalign_ctl(struct task_struct *tsk, unsigned long adr)
(unsigned int __user *)adr); (unsigned int __user *)adr);
} }
static struct task_struct corrupt_current = { .comm = "<corrupt>" };
/* /*
* Return "current" if it looks plausible, or else a pointer to a dummy. * Return "current" if it looks plausible, or else a pointer to a dummy.
* This can be helpful if we are just trying to emit a clean panic. * This can be helpful if we are just trying to emit a clean panic.
*/ */
struct task_struct *validate_current(void) struct task_struct *validate_current(void)
{ {
static struct task_struct corrupt = { .comm = "<corrupt>" };
struct task_struct *tsk = current; struct task_struct *tsk = current;
if (unlikely((unsigned long)tsk < PAGE_OFFSET || if (unlikely((unsigned long)tsk < PAGE_OFFSET ||
(high_memory && (void *)tsk > high_memory) || (high_memory && (void *)tsk > high_memory) ||
((unsigned long)tsk & (__alignof__(*tsk) - 1)) != 0)) { ((unsigned long)tsk & (__alignof__(*tsk) - 1)) != 0)) {
pr_err("Corrupt 'current' %p (sp %#lx)\n", tsk, stack_pointer); pr_err("Corrupt 'current' %p (sp %#lx)\n", tsk, stack_pointer);
tsk = &corrupt; tsk = &corrupt_current;
} }
return tsk; return tsk;
} }
@ -589,7 +590,8 @@ void show_regs(struct pt_regs *regs)
int i; int i;
pr_err("\n"); pr_err("\n");
show_regs_print_info(KERN_ERR); if (tsk != &corrupt_current)
show_regs_print_info(KERN_ERR);
#ifdef __tilegx__ #ifdef __tilegx__
for (i = 0; i < 17; i++) for (i = 0; i < 17; i++)
pr_err(" r%-2d: "REGFMT" r%-2d: "REGFMT" r%-2d: "REGFMT"\n", pr_err(" r%-2d: "REGFMT" r%-2d: "REGFMT" r%-2d: "REGFMT"\n",