On 10/27/22 at 01:50pm, Stephen Brennan wrote: > Though vmcoreinfo is intended to be small, at just one page, useful > information is still added to it, so we risk running out of space. > Currently there is no runtime check to see whether the vmcoreinfo buffer > has been exhausted. Add a warning for this case. > > Currently, my static checking tool[1] indicates that a good upper bound > for vmcoreinfo size is currently 3415 bytes, but the best time to add > warnings is before the risk becomes too high. > > [1] https://github.com/brenns10/kernel_stuff/blob/master/vmcoreinfosize/vmcoreinfosize.py > > Signed-off-by: Stephen Brennan <stephen.s.brennan@xxxxxxxxxx> > --- > kernel/crash_core.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/kernel/crash_core.c b/kernel/crash_core.c > index a0eb4d5cf557..87ef6096823f 100644 > --- a/kernel/crash_core.c > +++ b/kernel/crash_core.c > @@ -383,6 +383,9 @@ void vmcoreinfo_append_str(const char *fmt, ...) > memcpy(&vmcoreinfo_data[vmcoreinfo_size], buf, r); > > vmcoreinfo_size += r; > + > + WARN_ONCE(vmcoreinfo_size == VMCOREINFO_BYTES, > + "vmcoreinfo data exceeds allocated size, truncating"); > } Yeah, sounds like a good idea. Thanks. Acked-by: Baoquan He <bhe@xxxxxxxxxx> _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec
