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pci: Sanity check mask argument to pci_set_*_by_mask()

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Coverity complains that in functions like pci_set_word_by_mask()
we might end up shifting by more than 31 bits. This is true,
but only if the caller passes in a zero mask. Help Coverity out
by asserting that the mask argument is valid.

Fixes: CID 1487168

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20220818135421.2515257-3-peter.maydell@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Peter Maydell 2022-08-18 14:54:21 +01:00 committed by Michael S. Tsirkin
parent 31e039e76d
commit 775cc426a9
1 changed files with 16 additions and 4 deletions
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20
include/hw/pci/pci.h
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@ -688,7 +688,10 @@ static inline void
pci_set_byte_by_mask(uint8_t *config, uint8_t mask, uint8_t reg)
{
uint8_t val = pci_get_byte(config);
uint8_t rval = reg << ctz32(mask);
uint8_t rval;
assert(mask);
rval = reg << ctz32(mask);
pci_set_byte(config, (~mask & val) | (mask & rval));
}
@ -696,7 +699,10 @@ static inline void
pci_set_word_by_mask(uint8_t *config, uint16_t mask, uint16_t reg)
{
uint16_t val = pci_get_word(config);
uint16_t rval = reg << ctz32(mask);
uint16_t rval;
assert(mask);
rval = reg << ctz32(mask);
pci_set_word(config, (~mask & val) | (mask & rval));
}
@ -704,7 +710,10 @@ static inline void
pci_set_long_by_mask(uint8_t *config, uint32_t mask, uint32_t reg)
{
uint32_t val = pci_get_long(config);
uint32_t rval = reg << ctz32(mask);
uint32_t rval;
assert(mask);
rval = reg << ctz32(mask);
pci_set_long(config, (~mask & val) | (mask & rval));
}
@ -712,7 +721,10 @@ static inline void
pci_set_quad_by_mask(uint8_t *config, uint64_t mask, uint64_t reg)
{
uint64_t val = pci_get_quad(config);
uint64_t rval = reg << ctz32(mask);
uint64_t rval;
assert(mask);
rval = reg << ctz32(mask);
pci_set_quad(config, (~mask & val) | (mask & rval));
}