----- "ville mattila" <ville.mattila@xxxxxxxxxxxxx> wrote: > > > > > Hello, > > > > > > I get segementation fault from our 64-bit kernel crash > > > This crash is caused by "echo c > /proc/sys-trigger". > > > The reason seems to be that the x86_64_cpu_pda_init is > > > not called at least gdb do not break there. ... [ snip ] ... A patch for your initialization-time segmentation violation is attached. ... [ snip ] ... But as for this one: > > Btw, the "struct" command caused another segementation fault. > Here is gdb bt: > > (gdb) bt > #0 0x00007f74b3524a92 in strcmp () from /lib/libc.so.6 > #1 0x0000000000534284 in lookup_partial_symtab (name=0x120e3c0 "x8664_pda") at symtab.c:276 > #2 0x00000000005344ed in lookup_symtab (name=0x120e3c0 "x8664_pda") at symtab.c:228 > #3 0x000000000060019d in c_lex () at c-exp.y:2149 > #4 0x00000000006008f5 in c_parse_internal () at c-exp.c.tmp:1468 > #5 0x00000000006022dd in c_parse () at c-exp.y:2225 > #6 0x000000000055f614 in parse_exp_in_context (stringptr=0x7fffbc2f2260, block=<value optimized out>, comma=<value optimized out>, void_context_p=0, out_subexp=0x0) at parse.c:1094 > #7 0x000000000055f924 in parse_expression (string=0x7fffbc2f2950 "x8664_pda") at parse.c:1144 > #8 0x000000000053291b in gdb_command_funnel (req=0xca2c00) at symtab.c:4992 > #9 0x00000000004c1740 in gdb_interface (req=0xca2c00) at gdb_interface.c:407 > #10 0x00000000004e9dca in datatype_info (name=0xb618a7 "x8664_pda", member=0x0, dm=0x7fffbc2f3620) at symbols.c:4146 > #11 0x00000000004eb1ee in arg_to_datatype (s=0xb618a7 "x8664_pda", dm=0x7fffbc2f3620, flags=524290) at symbols.c:4867 > #12 0x00000000004efa1b in cmd_datatype_common (flags=2048) at symbols.c:4664 > #13 0x000000000045efd9 in exec_command () at main.c:644 > #14 0x000000000045f1fa in main_loop () at main.c:603 > #15 0x00000000005452a9 in captured_command_loop (data=0x120e3c0) at ./main.c:226 > #16 0x00000000005434e4 in catch_errors (func=0x5452a0 <captured_command_loop>, func_args=0x0, errstring=0x7f9d7c "", mask=<value optimized out>) at exceptions.c:520 > #17 0x0000000000544d36 in captured_main (data=<value optimized out>) at ./main.c:924 > #18 0x00000000005434e4 in catch_errors (func=0x544340 <captured_main>, func_args=0x7fffbc2f38b0, errstring=0x7f9d7c "", mask=<value optimized out>) at exceptions.c:520 > #19 0x000000000054412f in gdb_main_entry (argc=<value optimized out>, argv=<value optimized out>) at ./main.c:939 > #20 0x000000000045fece in main (argc=3, argv=0x7fffbc2f3a08) at main.c:517 > (gdb) frame 1 > #1 0x0000000000534284 in lookup_partial_symtab (name=0x120e3c0 "x8664_pda") at symtab.c:276 > 276 if (FILENAME_CMP (name, pst->filename) == 0) > (gdb) p name > $4 = 0x120e3c0 "x8664_pda" > (gdb) p pst > $5 = (struct partial_symtab *) 0x14d6040 > (gdb) p pst->filename > $6 = 0x0 > (gdb) p *pst > $7 = {next = 0x0, filename = 0x0, fullname = 0x0, dirname = 0x0, > objfile = 0x0, section_offsets = 0x0, textlow = 0, texthigh = 0, > dependencies = 0x0, number_of_dependencies = 0, globals_offset = 0, > n_global_syms = 0, statics_offset = 0, n_static_syms = 0, symtab = 0x0, > read_symtab = 0, read_symtab_private = 0x0, readin = 0 '\0'} > (gdb) I cannot reproduce it, even with your supplied kernel/dumpfile pair: # crash vmlinux-2.6.31.7+up-syms kerneldump-20100114-091104 ... [ snip ] ... crash> struct x8664_pda struct: invalid data structure reference: x8664_pda crash> While walking through the "ALL_PSYMTABS" list of partial_symtabs in lookup_partial_symtab(), I never see a NULL-filled partial_symtab structure as you show above. What I do see is 13434 partial_symtab structures, with pst->filenames starting from: /workarea5/work/fw/mulperi/ararat/kernel/sg-kernel.git/arch/x86/lib/csum-copy_64.S until the last one: /workarea5/work/fw/mulperi/ararat/kernel/sg-kernel.git/arch/x86/kernel/head_64.S So I don't know what the deal is with that one. Dave
Index: x86_64.c =================================================================== RCS file: /nfs/projects/cvs/crash/x86_64.c,v retrieving revision 1.136 diff -u -p -r1.136 x86_64.c --- x86_64.c 21 Dec 2009 16:21:11 -0000 1.136 +++ x86_64.c 19 Jan 2010 19:43:30 -0000 @@ -794,15 +794,36 @@ x86_64_per_cpu_init(void) int i, cpus, cpunumber; struct machine_specific *ms; - if (!(kt->flags & PER_CPU_OFF)) + ms = machdep->machspec; + + if (!(kt->flags & PER_CPU_OFF)) { + /* + * Presume kernel is !CONFIG_SMP. + */ + if (symbol_exists("per_cpu__irq_stack_union")) { + ms->stkinfo.ibase[0] = + symbol_value("per_cpu__irq_stack_union"); + if ((ms->stkinfo.isize = + MEMBER_SIZE("irq_stack_union", "irq_stack")) <= 0) + ms->stkinfo.isize = 16384; + } + if (DUMPFILE() && symbol_exists("per_cpu__current_task")) { + if (!(ms->current = calloc(kt->cpus, sizeof(ulong)))) + error(FATAL, + "cannot calloc" + " %d x86_64 current pointers!\n", + kt->cpus); + get_symbol_data("per_cpu__current_task", sizeof(ulong), + &ms->current[0]); + } + return; + } if (!symbol_exists("per_cpu__cpu_number") || !symbol_exists("per_cpu__irq_stack_union")) return; - ms = machdep->machspec; - for (i = cpus = 0; i < NR_CPUS; i++) { if (!readmem(symbol_value("per_cpu__cpu_number") + kt->__per_cpu_offset[i],
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