Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
ARM: ensure interrupts are enabled in __do_user_fault()
__do_user_fault() may be called from fault handling paths where the
interrupts are enabled or disabled. E.g. do_page_fault() calls this
with interrupts enabled, whereas do_sect_fault()->do_bad_area()
will call this with interrupts disabled. Since this is a userspace
fault, we know that interrupts were enabled in the parent context,
so call local_irq_enable() here to give a consistent interrupt state.
This is necessary for force_sig_info() when PREEMPT_RT is enabled.
Reported-by: Yadi.hu <yadi.hu@windriver.com>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
+5
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arch/arm/mm/fault.c
+5
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arch/arm/mm/fault.c
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/*
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* Something tried to access memory that isn't in our memory map..
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* User mode accesses just cause a SIGSEGV
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* User mode accesses just cause a SIGSEGV. Ensure interrupts are enabled
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* for preempt RT.
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*/
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static void
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__do_user_fault(unsigned long addr, unsigned int fsr, unsigned int sig,
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int code, struct pt_regs *regs)
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{
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struct task_struct *tsk = current;
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local_irq_enable();
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#ifdef CONFIG_DEBUG_USER
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if (((user_debug & UDBG_SEGV) && (sig == SIGSEGV)) ||
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* should not be faulting in kernel space, which includes the
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* vector/khelper page. Handle the branch predictor hardening
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* while interrupts are still disabled, then send a SIGSEGV.
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* Note that __do_user_fault() will enable interrupts.
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*/
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harden_branch_predictor();
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__do_user_fault(addr, fsr, SIGSEGV, SEGV_MAPERR, regs);