On Fri, Sep 26, 2025 at 11:07:52AM -0700, Stephen Hemminger wrote: > On Fri, 26 Sep 2025 15:49:04 +0000 > Kai Ji <[email protected]> wrote: > > > Bugzilla ID: 1773 > > Cc: [email protected] > > > > [0] 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; > > +} > > New functions usually have to be marked experimental. > > Since DPDK adopts many things from FreeBSD, perhaps the function > should use the same naming conventions. That would mean > > int rte_consttime_memequal(void *, void *, size_t len); > > And will also need to update release notes.
+1 for removing the "not" from the name which avoids having double negatives in conditionals. Also agree with keeping consistency with BSD name. /Bruce
