Hi Qiwu, The patch to setup_ikconfig() has been queued for crash-7.2.7: https://github.com/crash-utility/crash/commit/70e794c10f30e29a636967bbdacdf3068bfc4897 Thanks, Dave ----- Original Message ----- > > Hi Anderson, > I want to introduce a patch to your crash tool project. It’s a bugfix for a > segfault in setup_ikconfig. > We add an ikconfig entry only if ent[0] != '#', it is not an advisable > condition because there is a potential segfault risk if ent is gibberish. > I explain the reproducing steps about this segfault case: > I try to apply the following patch to crash 7.2.6++ code for a test. > --- a/arm64.c > +++ b/arm64.c > @@ -32,6 +32,7 @@ static int verify_kimage_voffset(void); > static void arm64_calc_kimage_voffset(void); > static void arm64_calc_phys_offset(void); > static void arm64_calc_virtual_memory_ranges(void); > +static void arm64_get_section_size_bits(void); > static int arm64_kdump_phys_base(ulong *); > static ulong arm64_processor_speed(void); > static void arm64_init_kernel_pgd(void); > @@ -375,7 +376,11 @@ arm64_init(int when) > > case POST_GDB: > arm64_calc_virtual_memory_ranges(); > - machdep->section_size_bits = _SECTION_SIZE_BITS; > + arm64_get_section_size_bits(); > + if (CRASHDEBUG(1)) { > + fprintf(fp, "SECTION_SIZE_BITS: %ld\n", > machdep->section_size_bits); > + } > + > if (!machdep->max_physmem_bits) { > if ((string = > pc->read_vmcoreinfo("NUMBER(MAX_PHYSMEM_BITS)"))) { > machdep->max_physmem_bits = atol(string); > @@ -1055,6 +1060,32 @@ arm64_calc_phys_offset(void) > fprintf(fp, "using %lx as phys_offset\n", ms->phys_offset); > } > > +/* > + * Determine SECTION_SIZE_BITS either by reading VMCOREINFO or the kernel > + * config, otherwise borrow the 64-bit ARM default definiton. > + */ > +static void > +arm64_get_section_size_bits(void) > +{ > + int ret; > + char *string; > + > + if ((string = pc->read_vmcoreinfo("NUMBER(SECTION_SIZE_BITS)"))) { > + machdep->section_size_bits = atol(string); > + free(string); > + return; > + } > + > + if ((ret = get_kernel_config("CONFIG_MEMORY_HOTPLUG", NULL)) == > IKCONFIG_Y) { > + if ((ret = get_kernel_config("CONFIG_HOTPLUG_SIZE_BITS", > &string)) == IKCONFIG_STR) { > + machdep->section_size_bits = atol(string); > + free(string); > + return; > + } > + } else { > + machdep->section_size_bits = _SECTION_SIZE_BITS; > + } > +} > > Then I make and load the dumpfiles by crash, it occurs a segment fault as > below: > crash[31000]: segfault at 0 ip 00007f0fb24d98d1 sp 00007fff1703f7e8 error 4 > in libc-2.26.so[7f0fb235b000+1d6000] > > So I add debug to find out the segfault reason, It occurred in > setup_ikconfig-> add_ikconfig_entry. > add_ikconfig_entry: ▒▒▒U //The last ent is a gibberish, lead > to segfault > > I think the most advisable judgement is if an ikconfig entry start with > "CONFIG_". I debug by the following patch and never reproduce segfault > again. > diff --git a/kernel.c b/kernel.c > index 7804aef..d023c87 100644 > --- a/kernel.c > +++ b/kernel.c > @@ -10144,7 +10144,7 @@ static int setup_ikconfig(char *config) > while (whitespace(*ent)) > ent++; > > - if (ent[0] != '#') { > + if (!strncmp(ent, "CONFIG_", strlen("CONFIG_"))) { > add_ikconfig_entry(ent, > &ikconfig_all[kt->ikconfig_ents++]); > if (kt->ikconfig_ents == IKCONFIG_MAX) { > > Thanks for your review. I’m looking forward to your favourable reply! > > Best regards, > > > > > > #/******本邮件及其附件含有小米公司的保密信息，仅限于发送给上面地址中列出的个人或群组。禁止任何其他人以任何形式使用（包括但不限于全部或部分地泄露、复制、或散发）本邮件中的信息。如果您错收了本邮件，请您立即电话或邮件通知发件人并删除本邮件！ > This e-mail and its attachments contain confidential information from > XIAOMI, which is intended only for the person or entity whose address is > listed above. Any use of the information contained herein in any way > (including, but not limited to, total or partial disclosure, reproduction, > or dissemination) by persons other than the intended recipient(s) is > prohibited. If you receive this e-mail in error, please notify the sender by > phone or email immediately and delete it!******/# > -- Crash-utility mailing list Crash-utility@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/crash-utility
