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| author | Arnd Bergmann <arnd@arndb.de> | 2024-03-26 15:53:37 +0100 |
|---|---|---|
| committer | Damien Le Moal <dlemoal@kernel.org> | 2024-04-01 00:52:17 +0200 |
| commit | 52f80bb181a9a1530ade30bc18991900bbb9697f (patch) | |
| tree | a7c5ec691f5db1fcd04f5a1d9efc70cfef4917ae | |
| parent | Linux 6.9-rc2 (diff) | |
| download | linux-52f80bb181a9a1530ade30bc18991900bbb9697f.tar.xz linux-52f80bb181a9a1530ade30bc18991900bbb9697f.zip | |
ata: sata_sx4: fix pdc20621_get_from_dimm() on 64-bit
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: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
| -rw-r--r-- | drivers/ata/sata_sx4.c | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/drivers/ata/sata_sx4.c b/drivers/ata/sata_sx4.c index b51d7a9d0d90..a482741eb181 100644 --- a/drivers/ata/sata_sx4.c +++ b/drivers/ata/sata_sx4.c @@ -957,8 +957,7 @@ static void pdc20621_get_from_dimm(struct ata_host *host, void *psource, offset -= (idx * window_size); idx++; - dist = ((long) (window_size - (offset + size))) >= 0 ? size : - (long) (window_size - offset); + dist = min(size, window_size - offset); memcpy_fromio(psource, dimm_mmio + offset / 4, dist); psource += dist; @@ -1005,8 +1004,7 @@ static void pdc20621_put_to_dimm(struct ata_host *host, void *psource, readl(mmio + PDC_DIMM_WINDOW_CTLR); offset -= (idx * window_size); idx++; - dist = ((long)(s32)(window_size - (offset + size))) >= 0 ? size : - (long) (window_size - offset); + dist = min(size, window_size - offset); memcpy_toio(dimm_mmio + offset / 4, psource, dist); writel(0x01, mmio + PDC_GENERAL_CTLR); readl(mmio + PDC_GENERAL_CTLR); |