Date: Thu, 3 Mar 2005 17:35:05 +0000 (UTC) From: Bill Paul <wpaul@FreeBSD.org> To: src-committers@FreeBSD.org, cvs-src@FreeBSD.org, cvs-all@FreeBSD.org Subject: cvs commit: src/sys/net80211 ieee80211_ioctl.c Message-ID: <200503031735.j23HZ5hv094849@repoman.freebsd.org>
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wpaul 2005-03-03 17:35:05 UTC
FreeBSD src repository
Modified files:
sys/net80211 ieee80211_ioctl.c
Log:
Recently, it was reported to me that you could provoke a double fault
panic with the NDISulator if you did "ifconfig ndis0 10.0.0.1/24,"
whereas "ifconfig ndis0 10.0.0.1/24 up" worked fine. The double fault
was caused by the ifconfig thread running out of kernel stack space.
(This was partly due to the NDIsulator using a couple of big buffers on
the stack, but even after fixing that the double fault persisted.)
It turns out that ndis_init() is called in both cases, but in the first
case the code path passes through ieee80211_ioctl(), and it turns out
ieee80211_ioctl() consumes a whopping 2400 bytes of stack space.
Apparently, gcc -O2 causes the ieee80211_ioctl_get80211() routine to
be inlined into ieee80211_ioctl(), and for some reason which I do not
fully understand, this causes ieee80211_ioctl() to consume an extra 2K
of stack space.
To prevent this overly agressive optimization, ieee80211_ioctl_get80211()
is now declared with __attribute__ ((noinline)). With this change,
ieee80211_ioctl() now only reserves about 200 bytes of stack instead of 2400.
Revision Changes Path
1.19 +19 -0 src/sys/net80211/ieee80211_ioctl.c
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