Commit e2b85f70 authored Oct 31, 2018 by Florian Fainelli Committed by Russell King Nov 08, 2018

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>

parent b99afae1

arch/arm/mm/fault.c

+6 −0

Original line number	Diff line number	Diff line
		@@ -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;

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