(2014/10/28 3:15), Prarit Bhargava wrote: > > > On 10/27/2014 02:05 PM, Jason Baron wrote: >> Hi Prarit, >> >> On 10/24/2014 08:53 AM, Prarit Bhargava wrote: >>> There have been several times where I have had to rebuild a kernel to >>> cause a panic when hitting a WARN() in the code in order to get a crash >>> dump from a system. Sometimes this is easy to do, other times (such as >>> in the case of a remote admin) it is not trivial to send new images to the >>> user.panic_on_stackoverflow >>> >>> A much easier method would be a switch to change the WARN() over to a >>> BUG(). This makes debugging easier in that I can now test the actual >>> image the WARN() was seen on and I do not have to engage in remote >>> debugging. >>> >>> This patch adds a bug_on_warn kernel parameter and >>> /proc/sys/kernel/bug_on_warn calls BUG() in the warn_slowpath_common() >>> path. The function will still print out the location of the warning. >>> >>> An example of the bug_on_warn output: >>> >>> The first line below is from the WARN_ON() to output the WARN_ON()'s location. >>> After that the new BUG() call is displayed. >>> >>> WARNING: CPU: 27 PID: 3204 at >>> /home/rhel7/redhat/debug/dummy-module/dummy-module.c:25 init_dummy+0x28/0x30 >>> [dummy_module]() >>> bug_on_warn set, calling BUG()... >>> ------------[ cut here ]------------ >>> kernel BUG at kernel/panic.c:434! >> >> Seems reasonable-I'm wondering why you just don't call panic() in this >> case. The BUG() call at line '434' doesn't at anything since its just being >> called from panic.c. +1, I like calling panic() instead of BUG() :) Thank you, > > Hmm ... I didn't even think about that. > >> >> So something like 'panic_on_warn' would seem to be more appropriate >> in keeping with things like 'panic_on_oops' or 'panic_on_stackoverflow'. > > I like it a lot better that way too :) I'm changing it to panic_on_warn unless > anyone has any strenuous objections. > > P. > >> >> Thanks, >> >> -Jason >> > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo at vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > -- Masami HIRAMATSU Software Platform Research Dept. Linux Technology Research Center Hitachi, Ltd., Yokohama Research Laboratory E-mail: masami.hiramatsu.pt at hitachi.com
