[Crash-utility] Re: [Crash-Utility][PATCH] symbols.c: skip non-exist module memory type

Thanks Tao, On a funny side, though I didn't understand this area of code much, but I ironically made the exact same fix to avoid problem for time being on my side, thinking there might be a different fix coming 🙂. Glad its now taken care. Thanks 🙂 Regards, Naveen ________________________________ From: Tao Liu <ltao(a)redhat.com&gt; Sent: Tuesday, April 2, 2024 12:15 PM To: devel(a)lists.crash-utility.osci.io <devel(a)lists.crash-utility.osci.io&gt; Cc: Tao Liu <ltao(a)redhat.com>; Naveen Chaudhary <naveenchaudhary2010(a)hotmail.com&gt; Subject: [Crash-Utility][PATCH] symbols.c: skip non-exist module memory type Not all mod_mem_type will be included for kernel modules. E.g. in the following module case: (gdb) p lm->symtable[0] $1 = (struct syment *) 0x4dcbad0 (gdb) p lm->symtable[1] $2 = (struct syment *) 0x4dcbb70 (gdb) p lm->symtable[2] $3 = (struct syment *) 0x4dcbc10 (gdb) p lm->symtable[3] $4 = (struct syment *) 0x0 (gdb) p lm->symtable[4] $5 = (struct syment *) 0x4dcbcb0 (gdb) p lm->symtable[5] $6 = (struct syment *) 0x4dcbd00 (gdb) p lm->symtable[6] $7 = (struct syment *) 0x0 (gdb) p lm->symtable[7] $8 = (struct syment *) 0x4dcbb48 mod_mem MOD_RO_AFTER_INIT(3) and MOD_INIT_RODATA(6) is not exist, which should be skipped, otherwise a segfault will happen. Fixes: 7750e61fdb2a ("Support module memory layout change on Linux 6.4") Signed-off-by: Tao Liu <ltao(a)redhat.com&gt; Reported-by: Naveen Chaudhary <naveenchaudhary2010(a)hotmail.com&gt; --- symbols.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/symbols.c b/symbols.c index cbc9ed1..27e55c6 100644 --- a/symbols.c +++ b/symbols.c @@ -5580,7 +5580,7 @@ value_search_module_6_4(ulong value, ulong *offset) sp = lm->symtable[t]; sp_end = lm->symend[t]; - if (value < sp->value || value > sp_end->value) + if (!sp || value < sp->value || value > sp_end->value) continue; splast = NULL; -- 2.40.1