tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
arm64: Fix __range_ok macro
Without this, the following scenario is incorrectly determined
to be invalid.
addr 0x7f_ffffe000 size 8192 addr_limit 0x80_00000000
This behavior was observed while trying to vmsplice the stack
as part of a CRIU dump of a process on a system started with the
norandmaps kernel parameter.
Signed-off-by: Christopher Covington <cov@codeaurora.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
authored by
Christopher Covington
and committed by
Catalin Marinas
31b1e940
74397174
+2
-2
+2
-2
arch/arm64/include/asm/uaccess.h
+2
-2
arch/arm64/include/asm/uaccess.h
···
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* Returns 1 if the range is valid, 0 otherwise.
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*
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* This is equivalent to the following test:
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* (u65)addr + (u65)size < (u65)current->addr_limit
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* (u65)addr + (u65)size <= current->addr_limit
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*
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* This needs 65-bit arithmetic.
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*/
···
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({ \
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unsigned long flag, roksum; \
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__chk_user_ptr(addr); \
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asm("adds %1, %1, %3; ccmp %1, %4, #2, cc; cset %0, cc" \
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asm("adds %1, %1, %3; ccmp %1, %4, #2, cc; cset %0, ls" \
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: "=&r" (flag), "=&r" (roksum) \
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: "1" (addr), "Ir" (size), \
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"r" (current_thread_info()->addr_limit) \