ata: sata_sx4: fix pdc20621_get_from_dimm() on 64-bit
[ Upstream commit 52f80bb1 ] gcc warns about a memcpy() with overlapping pointers because of an incorrect size calculation: In file included from include/linux/string.h:369, from drivers/ata/sata_sx4.c:66: In function 'memcpy_fromio', inlined from 'pdc20621_get_from_dimm.constprop' at drivers/ata/sata_sx4.c:962:2: include/linux/fortify-string.h:97:33: error: '__builtin_memcpy' accessing 4294934464 bytes at offsets 0 and [16, 16400] overlaps 6442385281 bytes at offset -2147450817 [-Werror=restrict] 97 | #define __underlying_memcpy __builtin_memcpy | ^ include/linux/fortify-string.h:620:9: note: in expansion of macro '__underlying_memcpy' 620 | __underlying_##op(p, q, __fortify_size); \ | ^~~~~~~~~~~~~ include/linux/fortify-string.h:665:26: note: in expansion of macro '__fortify_memcpy_chk' 665 | #define memcpy(p, q, s) __fortify_memcpy_chk(p, q, s, \ | ^~~~~~~~~~~~~~~~~~~~ include/asm-generic/io.h:1184:9: note: in expansion of macro 'memcpy' 1184 | memcpy(buffer, __io_virt(addr), size); | ^~~~~~ The problem here is the overflow of an unsigned 32-bit number to a negative that gets converted into a signed 'long', keeping a large positive number. Replace the complex calculation with a more readable min() variant that avoids the warning. Fixes: 1da177e4 ("Linux-2.6.12-rc2") Signed-off-by:Arnd Bergmann <arnd@arndb.de> Signed-off-by:
Damien Le Moal <dlemoal@kernel.org> Signed-off-by:
Sasha Levin <sashal@kernel.org>
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