Date: Tue, 30 Sep 2008 13:15:59 +0300 From: Jaakko Heinonen <jh@saunalahti.fi> To: jb@FreeBSD.org Cc: mgass@unix.csbsju.edu, stable@FreeBSD.org Subject: DTrace MFC broke kldstat(2) on RELENG_7 Message-ID: <20080930101559.GA810@a91-153-122-179.elisa-laajakaista.fi>
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Hi, I recently noticed that kldstat(8) started to dump core for me on RELENG_7. I traced the problem down to kldstat(2). r182231 (DTrace MFC) introduced a new version of kld_file_stat struct and added some code to support the old version of the structure in kldstat(). In the new code the old structure is known as kld_file_stat_1. Unfortunately there's a bug in this code: kldstat() copies always sizeof(struct kld_file_stat) of data to user space while it should copy sizeof(struct kld_file_stat_1) when the old struct is used. This guy is probably suffering from this problem too: http://lists.freebsd.org/pipermail/freebsd-questions/2008-September/182896.html I used this patch to fix the problem: %%% Index: sys/kern/kern_linker.c =================================================================== --- sys/kern/kern_linker.c (revision 183486) +++ sys/kern/kern_linker.c (working copy) @@ -1199,7 +1199,12 @@ kldstat(struct thread *td, struct kldsta td->td_retval[0] = 0; - return (copyout(&stat, uap->stat, sizeof(struct kld_file_stat))); + if (version_num == 1) + return (copyout(&stat, uap->stat, + sizeof(struct kld_file_stat_1))); + else + return (copyout(&stat, uap->stat, + sizeof(struct kld_file_stat))); } int %%% -- Jaakko
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