[IA64] page_not_present fault in region 5 is normal (63028aa7) · Commits · 戴 / test

When copying data from user-space to kernel-space by __copy_user(), a page_not_present fault sometimes occurs at vmalloced kernel address because of VHPT pre-fetching. Ignore the page_not_present fault in ia64_do_page_fault() before jumping into exception handlers. Signed-off-by:

Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by:

Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by:

Tony Luck <tony.luck@intel.com>

arch/ia64/mm/fault.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -229,9 +229,6 @@ ia64_do_page_fault (unsigned long address, unsigned long isr, struct pt_regs *re
		return;
		}

		if (ia64_done_with_exception(regs))
		return;

		/*
		* Since we have no vma's for region 5, we might get here even if the address is
		* valid, due to the VHPT walker inserting a non present translation that becomes
		@@ -242,6 +239,9 @@ ia64_do_page_fault (unsigned long address, unsigned long isr, struct pt_regs *re
		if (REGION_NUMBER(address) == 5 && mapped_kernel_page_is_present(address))
		return;

		if (ia64_done_with_exception(regs))
		return;

		/*
		* Oops. The kernel tried to access some bad page. We'll have to terminate things
		* with extreme prejudice.

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