Date: Sat, 12 Aug 2017 15:42:21 -0400 From: Farhan Khan <khanzf@gmail.com> To: freebsd-hackers@freebsd.org Subject: Monitor kernel variable with ddb(4) Message-ID: <CAFd4kYCrRgdhc76peh3-vGcS1CQ9RJUWAPJX5_hR7hMNkqiQeQ@mail.gmail.com>
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Hi all, I am trying to figure out where a net80211's vap flags are modified. I see that memory is originally allocated here: http://src.illumos.org/source/xref/freebsd-head/sys/net/if.c#445. However, I cannot figure out where the ifp->if_flags and if->if_drv_flags are ever modified in the kernel. Someone suggested using ddb(4), so I entered the live debugger using sysctl debug.kdb.enter=1 I then set a breakpoint at if_alloc. However, I cannot seem to figure out the next steps to monitor where the ifp->if_flags or if->if_drv_flags are updated. Full explanation - My kernel module is immediately unloading, but I am not certain why. I traced it back in the ieee80211 code to those flags, but not sure where they are updated. Any ideas? Thank you! -- Farhan Khan PGP Fingerprint: 782F 342B 5B08 0D2F F4E8 82C3 FFA1 CAE1 6536 51CA
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