On Fri, Sep 17, 2021 at 02:58:09PM +0200, Tim Wiederhake wrote:
This helps to bring down the frame size of virNWFilterRuleDefFixup, as it exceeds 8192 bytes when libvirt is build with sanitizers enabled, in debug mode, on clang.
Signed-off-by: Tim Wiederhake <twiederh@redhat.com> --- src/conf/nwfilter_conf.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-)
diff --git a/src/conf/nwfilter_conf.c b/src/conf/nwfilter_conf.c index a3109962af..62334edeec 100644 --- a/src/conf/nwfilter_conf.c +++ b/src/conf/nwfilter_conf.c @@ -2189,23 +2189,23 @@ virNWFilterRuleValidate(virNWFilterRuleDef *rule) static void virNWFilterRuleDefFixup(virNWFilterRuleDef *rule) { + ethHdrDataDef *ethHdr; + #define COPY_NEG_SIGN(A, B) \ (A).flags = ((A).flags & ~NWFILTER_ENTRY_ITEM_FLAG_IS_NEG) | \ ((B).flags & NWFILTER_ENTRY_ITEM_FLAG_IS_NEG);
switch (rule->prtclType) { case VIR_NWFILTER_RULE_PROTOCOL_MAC: - COPY_NEG_SIGN(rule->p.ethHdrFilter.ethHdr.dataSrcMACMask, - rule->p.ethHdrFilter.ethHdr.dataSrcMACAddr); - COPY_NEG_SIGN(rule->p.ethHdrFilter.ethHdr.dataDstMACMask, - rule->p.ethHdrFilter.ethHdr.dataDstMACAddr); + ethHdr = &rule->p.ethHdrFilter.ethHdr; + COPY_NEG_SIGN(ethHdr->dataSrcMACMask, ethHdr->dataSrcMACAddr); + COPY_NEG_SIGN(ethHdr->dataDstMACMask, ethHdr->dataDstMACAddr);
I don't get why this reduces stack size at all ? COPY_NEG_SIGN is just doing a bitwise and + or + assignment which doesn't require any intermediate variables. Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|