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| H A D | abort.c | 405c67d37d3d82d824f4bff042928219a45fa43e Fri Oct 05 16:43:48 UTC 2018 Jens Wiklander <jens.wiklander@linaro.org> abort.c: arm32: assume VFP instr if undef
If an undefined instruction exception is raised from user mode assume it
is a VFP instruction unless VFP already is enabled.
This avoids reading user mode memory while handling an abort which until
now has kept an undiscovered race where a page could become inaccessible
before the abort handler had the chance to read the instruction from the
page.
There is room for false positives. Those will be discovered the next
time the instruction is executed and still causes an undefined
instruction exception. Only this time VFP is already enabled so we know
it's not a VFP instruction. Enabling VFP in vain like this is harmless.
Reviewed-by: Jerome Forissier <jerome.forissier@linaro.org>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
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