> From: Kai Ji [mailto:[email protected]] > Sent: Friday, 26 September 2025 18.02 > > Bugzilla ID: 1773 > https://bugs.dpdk.org/show_bug.cgi?id=1773 > > Signed-off-by: Kai Ji <[email protected]> > --- > lib/eal/include/rte_common.h | 34 ++++++++++++++++++++++++++++++++++ > 1 file changed, 34 insertions(+) > > diff --git a/lib/eal/include/rte_common.h > b/lib/eal/include/rte_common.h > index 9e7d84f929..ddbba083be 100644 > --- a/lib/eal/include/rte_common.h > +++ b/lib/eal/include/rte_common.h > @@ -700,6 +700,40 @@ rte_is_aligned(const void * const __rte_restrict > ptr, const unsigned int align) > return ((uintptr_t)ptr & (align - 1)) == 0; > } > > +/** > + * Constant-time memory inequality comparison. > + * > + * This function compares two memory regions in constant time, making > it > + * resistant to timing side-channel attacks. The execution time > depends only > + * on the length parameter, not on the actual data values being > compared. > + * > + * This is particularly important for cryptographic operations where > timing > + * differences could leak information about secret keys, passwords, or > other > + * sensitive data. > + * > + * @param a > + * Pointer to the first memory region to compare > + * @param b > + * Pointer to the second memory region to compare > + * @param n > + * Number of bytes to compare > + * @return > + * false if the memory regions are identical, true if they differ > + */ > +static inline bool > +rte_consttime_memneq(const void *a, const void *b, size_t n) > +{ > + const volatile uint8_t *pa = (const volatile uint8_t *)a; > + const volatile uint8_t *pb = (const volatile uint8_t *)b; > + uint8_t result = 0; > + size_t i; > + > + for (i = 0; i < n; i++) > + result |= pa[i] ^ pb[i]; > + > + return result != 0; > +} > + > /*********** Macros for compile type checks ********/ > > /* Workaround for toolchain issues with missing C11 macro in FreeBSD > */ > -- > 2.34.1
My comments here still apply: https://inbox.dpdk.org/dev/[email protected]/ Also, this is certainly not a common function, so don't put it in rte_commo.h. Put it in rte_memory.h as suggested. -Morten
