>On Tuesday 23 May 2017 08:22 AM, Hatayama, Daisuke wrote: >> Currently, makedumpfile results in Segmentation fault on sadump dump >> files as follows: >> >> # LANG=C makedumpfile -f --message-level=31 -ld31 -x vmlinux ./sadump_vmcore sadump_vmcore-ld31 >> sadump: read dump device as single partition >> sadump: single partition configuration >> page_size : 4096 >> sadump: timezone information is missing >> Segmentation fault >> >> By bisect, I found that this issue is caused by the following commit >> that moves invocation of cache_init() in initial() a bit early: >> >> # git bisect bad >> 8e2834bac4f62da3894da297f083068431be6d80 is the first bad commit >> commit 8e2834bac4f62da3894da297f083068431be6d80 >> Author: Pratyush Anand <panand at redhat.com> >> Date: Thu Mar 2 17:37:11 2017 +0900 >> >> [PATCH v3 2/7] initial(): call cache_init() a bit early >> >> Call cache_init() before get_kcore_dump_loads(), because latter uses >> cache_search(). >> >> Call path is like this : >> get_kcore_dump_loads() -> process_dump_load() -> vaddr_to_paddr() -> >> vtop4_x86_64() -> readmem() -> cache_search() >> >> Signed-off-by: Pratyush Anand <panand at redhat.com> >> >> :100644 100644 6942047199deb09dd1fff2121e264584dbb05587 3b8e9810468de26b0d8b73d456f0bd4f3d3aa2fe M >makedumpfile.c >> >> In this timing, on sadump vmcores, info->page_size has not been >> initialized yet so has 0. So, malloc() in cache_init() returns a chunk >> of 0 size. A bit later, info->page_size is initialized with 4096. >> Later processing on cache.c behaves assuming the chunk size is 8 * >> 4096. This destroys objects allocated after the chunk, resulting in >> the above Segmentation fault. >> >> To fix this issue, this commit moves setting info->page_size before >> cache_init(). >> >> Signed-off-by: HATAYAMA Daisuke <d.hatayama at jp.fujitsu.com> >> Cc: Pratyush Anand <panand at redhat.com> > >For 1/2 >Reviewed-by: Pratyush Anand <panand at redhat.com> Thanks for your work, I'll merge this patch into v1.6.2. Regards, Atsushi Kumagai >> --- >> makedumpfile.c | 6 +++--- >> 1 file changed, 3 insertions(+), 3 deletions(-) >> >> diff --git a/makedumpfile.c b/makedumpfile.c >> index 301772a..f300b19 100644 >> --- a/makedumpfile.c >> +++ b/makedumpfile.c >> @@ -3878,6 +3878,9 @@ initial(void) >> if (!get_value_for_old_linux()) >> return FALSE; >> >> + if (info->flag_sadump && !set_page_size(sadump_page_size())) >> + return FALSE; >> + >> if (!is_xen_memory() && !cache_init()) >> return FALSE; >> >> @@ -3906,9 +3909,6 @@ initial(void) >> return FALSE; >> } >> >> - if (!set_page_size(sadump_page_size())) >> - return FALSE; >> - >> if (!sadump_initialize_bitmap_memory()) >> return FALSE; >> >> > >_______________________________________________ >kexec mailing list >kexec at lists.infradead.org >http://lists.infradead.org/mailman/listinfo/kexec
