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Catalin Marinas authored
The Undef abort handler in the kernel reads the undefined instruction from user space. If the page table was modified from another CPU, the user access could fail and do_page_fault() will be executed with interrupts disabled. This can potentially deadlock on ARM11MPCore or on Cortex-A15 with erratum 798181 workaround enabled (both implying IPI for TLB maintenance with page table lock held). This patch enables the IRQs in __und_usr before attempting to read the instruction from user space. Signed-off-by:
Catalin Marinas <catalin.marinas@arm.com> Tested-by:
Arun KS <getarunks@gmail.com> Cc: Hartley Sweeten <hsweeten@visionengravers.com> Cc: Ryan Mallon <rmallon@gmail.com> Signed-off-by:
Russell King <rmk+kernel@arm.linux.org.uk>
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