Re: [Crash-utility] 32 bit linux-2.6.24-git8 user_regs_struct change breaks opening kdump crashfiles

Hello crash, The user_regs_struct was redefined in linux-2.6.24-git8/include/asm-x86/user_32.h. This results in the following error when opening 32 bit kdump crashfiles: ------------------------------------------------------------------------- please wait... (determining panic task) crash: invalid structure member offset: user_regs_struct_ebp FILE: netdump.c LINE: 687 FUNCTION: get_netdump_panic_task() [/sbin/crash] error trace: 80e09f4 => 8154159 => 814fc3f => 813ec75 813ec75: OFFSET_verify+126 814fc3f: get_netdump_panic_task+1196 8154159: get_kdump_panic_task+11 80e09f4: get_dumpfile_panic_task+153 -------------------------------------------------------------------- I've inserted a patch to crash-4.0-7.4/x86.c that fixes this for all linux-2.6.24-git8 and later kernels (2.6.25 -> 2.6.28-rc5). I've also inserted the kernel change that caused the breakage. The fix is bad because it breaks all kernels <= linux-2.6.24-git7. A better fix would be backward and forward compatible with all kernels, but since there was a lot of hardwired code revolving around the old 32 bit user_regs_struct I thought I would just submit this patch to expose the problem and maybe look for a better fix in the next crash update.

thx, joe --- crash-4.0-7.4.orig/x86.c 2008-10-14 09:35:40.000000000 -0400 +++ crash-4.0-7.4/x86.c 2008-11-17 13:37:40.000000000 -0500 @@ -1774,29 +1774,39 @@ machdep->flags |= OMIT_FRAME_PTR; STRUCT_SIZE_INIT(user_regs_struct, "user_regs_struct"); MEMBER_OFFSET_INIT(user_regs_struct_ebp, - "user_regs_struct", "ebp"); + "user_regs_struct", "bp"); MEMBER_OFFSET_INIT(user_regs_struct_esp, - "user_regs_struct", "esp"); + "user_regs_struct", "sp"); if (!VALID_STRUCT(user_regs_struct)) { /* Use this hardwired version -- sometimes the * debuginfo doesn't pick this up even though * it exists in the kernel; it shouldn't change. */ struct x86_user_regs_struct { - long ebx, ecx, edx, esi, edi, ebp, eax; - unsigned short ds, __ds, es, __es; - unsigned short fs, __fs, gs, __gs; - long orig_eax, eip; - unsigned short cs, __cs; - long eflags, esp; - unsigned short ss, __ss; + unsigned long bx; + unsigned long cx; + unsigned long dx; + unsigned long si; + unsigned long di; + unsigned long bp; + unsigned long ax; + unsigned long ds; + unsigned long es; + unsigned long fs; + unsigned long gs; + unsigned long orig_ax; + unsigned long ip; + unsigned long cs; + unsigned long flags; + unsigned long sp; + unsigned long ss; }; ASSIGN_SIZE(user_regs_struct) = sizeof(struct x86_user_regs_struct); ASSIGN_OFFSET(user_regs_struct_ebp) = - offsetof(struct x86_user_regs_struct, ebp); + offsetof(struct x86_user_regs_struct, bp); ASSIGN_OFFSET(user_regs_struct_esp) = - offsetof(struct x86_user_regs_struct, esp); + offsetof(struct x86_user_regs_struct, sp); } MEMBER_OFFSET_INIT(thread_struct_cr3, "thread_struct", "cr3"); STRUCT_SIZE_INIT(cpuinfo_x86, "cpuinfo_x86"); -------------------------------------------------------------------------------- --- linux-2.6.24-git7/include/asm-x86/user_32.h 2008-01-24 17:58:37.000000000 -0500 +++ linux-2.6.24-git8/include/asm-x86/user_32.h 2008-11-11 18:56:13.000000000 -0500 @@ -75,13 +75,23 @@ * doesn't use the extra segment registers) */ struct user_regs_struct { - long ebx, ecx, edx, esi, edi, ebp, eax; - unsigned short ds, __ds, es, __es; - unsigned short fs, __fs, gs, __gs; - long orig_eax, eip; - unsigned short cs, __cs; - long eflags, esp; - unsigned short ss, __ss; + unsigned long bx; + unsigned long cx; + unsigned long dx; + unsigned long si; + unsigned long di; + unsigned long bp; + unsigned long ax; + unsigned long ds; + unsigned long es; + unsigned long fs; + unsigned long gs; + unsigned long orig_ax; + unsigned long ip; + unsigned long cs; + unsigned long flags; + unsigned long sp; + unsigned long ss; }; /* When the kernel dumps core, it starts by dumping the user struct - -- Crash-utility mailing list Crash-utility(a)redhat.com https://www.redhat.com/mailman/listinfo/crash-utility