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ARM: 8807/1: mm: Facilitate debugging CONFIG_KUSER_HELPERS disabled 

Some software such as perf makes unconditional use of the special
[vectors] page which is only provided when CONFIG_KUSER_HELPERS is
enabled in the kernel.

Facilitate the debugging of such situations by printing a debug message
to the kernel log showing the task name and the faulting address.

Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Suggested-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
This commit is contained in:
Florian Fainelli 2018-10-31 23:53:12 +01:00 committed by Russell King
parent b99afae139
commit e2b85f709a
1 changed files with 6 additions and 0 deletions
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6
arch/arm/mm/fault.c
View File

@ -173,6 +173,12 @@ __do_user_fault(struct task_struct *tsk, unsigned long addr,
show_regs(regs);
}
#endif
#ifndef CONFIG_KUSER_HELPERS
if ((sig == SIGSEGV) && ((addr & PAGE_MASK) == 0xffff0000))
printk_ratelimited(KERN_DEBUG
"%s: CONFIG_KUSER_HELPERS disabled at 0x%08lx\n",
tsk->comm, addr);
#endif
tsk->thread.address = addr;
tsk->thread.error_code = fsr;