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| author | Chris Metcalf <cmetcalf@tilera.com> | 2013-08-10 12:22:43 -0400 |
|---|---|---|
| committer | Chris Metcalf <cmetcalf@tilera.com> | 2013-08-30 11:56:54 -0400 |
| commit | 4036c7d3542ce82ea343bf95dd05ca46aefba9aa (patch) | |
| tree | d33fda13124e904569510e438ec4b525a31b8097 /arch/tile/kernel/process.c | |
| parent | 6fbeee29a2b87574527897c3ded1f92e236518c7 (diff) | |
| download | lwn-4036c7d3542ce82ea343bf95dd05ca46aefba9aa.tar.gz lwn-4036c7d3542ce82ea343bf95dd05ca46aefba9aa.zip | |
tile: don't call show_regs_print_info() with corrupt current
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>
Diffstat (limited to 'arch/tile/kernel/process.c')
| -rw-r--r-- | arch/tile/kernel/process.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/arch/tile/kernel/process.c b/arch/tile/kernel/process.c index 663289b803fc..44cdc4aa59e8 100644 --- a/arch/tile/kernel/process.c +++ b/arch/tile/kernel/process.c @@ -226,19 +226,20 @@ int get_unalign_ctl(struct task_struct *tsk, unsigned long 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. * This can be helpful if we are just trying to emit a clean panic. */ struct task_struct *validate_current(void) { - static struct task_struct corrupt = { .comm = "<corrupt>" }; struct task_struct *tsk = current; if (unlikely((unsigned long)tsk < PAGE_OFFSET || (high_memory && (void *)tsk > high_memory) || ((unsigned long)tsk & (__alignof__(*tsk) - 1)) != 0)) { pr_err("Corrupt 'current' %p (sp %#lx)\n", tsk, stack_pointer); - tsk = &corrupt; + tsk = &corrupt_current; } return tsk; } @@ -589,7 +590,8 @@ void show_regs(struct pt_regs *regs) int i; pr_err("\n"); - show_regs_print_info(KERN_ERR); + if (tsk != &corrupt_current) + show_regs_print_info(KERN_ERR); #ifdef __tilegx__ for (i = 0; i < 17; i++) pr_err(" r%-2d: "REGFMT" r%-2d: "REGFMT" r%-2d: "REGFMT"\n", |