On Thu, Aug 14, 2008 at 07:31:06PM +0100, Hugh Dickins wrote: > I got this oops below, after several hours of swap-heavy kernel builds > in tmpfs, on 2.6.27-rc1-mm1 a couple of weeks ago. Tried to reproduce > it without success, then got a very similar trace (not saved) from > 2.6.27-rc3 itself doing the same test yesterday: again oopsing in > proc_sys_compare on address -16, looks like it's trying for > PROC_I(dentry->d_inode)->sysctl but d_inode is NULL. > > I looked to see what's been going on in fs/proc recently, and your > [PATCH] sanitize proc_sysctl 9043476f726802f4b00c96d0c4f418dde48d1304 > does sound like it might be implicated. I've only seen this on > PowerPC G5, similar tests on x86_32 and _64 haven't shown it: > maybe a memory barrier needed somewhere? Bloody interesting. We never create negative hashed dentries in there and AFAICS we should never get d_delete() called on those... Missing barrier would mean serious trouble in dcache.c and not just for /proc/sys...
Are you sure about oops decoding? At least disassembly of proc_sys_compare() in the kernel image in question would be nice to see... _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev