[Crash-utility] [PATCH] Fix module init for initcall crash

[Dave Anderson]

----- Original Message -----
> From: Rabin Vincent <rabinv at axis.com>
> 
> If the kernel crashed while running a module's initcall, then the
> mod->init_size is not zero and in this case crash fails while gathering
> module symbol data with:
> 
>  crash: store_module_symbols_v2: total: 7 mcnt: 8
> 
> This seems to be because store_module_symbols_v2 will add pseudo-symbols
> for MODULE_INIT_START and MODULE_INIT_END, while the "total" calculation
> in module_init() doesn't account for this.

Hi Rabin,

Queued for crash-7.1.8:

  https://github.com/crash-utility/crash/commit/3d41b666a51619523b2d545f431901f4f52055e7

Thanks,
  Dave
 
  
> 
> For reference, a log with -d8:
> 
>  please wait... (gathering module symbol data)module: c00fc5c0
>  <readmem: c00fc5c0, KVADDR, "module struct", 384, (ROE|Q), 8701800>
>  <readmem: 80540000, KVADDR, "pgd page", 16384, (FOE), a0c3ec8>
>  <read_ramdump: addr: 80540000 paddr: 540000 cnt: 16384>
>  read_ramdump: addr: 80540000 paddr: 540000 cnt: 16384 offset: 540000
>  <readmem: 72b0000, PHYSADDR, "page table", 16384, (FOE), a0c7ed0>
>  <read_ramdump: addr: 72b0000 paddr: 72b0000 cnt: 16384>
>  read_ramdump: addr: 0 paddr: 72b0000 cnt: 16384 offset: 72b0000
>  <read_ramdump: addr: c00fc5c0 paddr: 722c5c0 cnt: 384>
>  read_ramdump: addr: c00fc5c0 paddr: 722c5c0 cnt: 384 offset: 722c5c0
>  FREEBUF(0)
>  GETBUF(384 -> 0)
>  <readmem: c00fc5c0, KVADDR, "module buffer", 384, (FOE), 8701800>
>  <read_ramdump: addr: c00fc5c0 paddr: 722c5c0 cnt: 384>
>  read_ramdump: addr: c00fc5c0 paddr: 722c5c0 cnt: 384 offset: 722c5c0
>  c00fc5c0 (c00fc000): null_blk syms: 0 gplsyms: 0 ksyms: 5
>    GETBUF(2031 -> 1)
>  <readmem: c00fc000, KVADDR, "module (kallsyms)", 2031, (ROE|Q), 8704000>
>  <read_ramdump: addr: c00fc000 paddr: 722c000 cnt: 2031>
>  read_ramdump: addr: c00fc000 paddr: 722c000 cnt: 2031 offset: 722c000
>      GETBUF(4140 -> 2)
>  <readmem: c0104000, KVADDR, "module init (kallsyms)", 4140, (ROE|Q),
>  870e000>
>  <read_ramdump: addr: c0104000 paddr: 7154000 cnt: 4140>
>  read_ramdump: addr: c0104000 paddr: 7154000 cnt: 4140 offset: 7154000
>  null_set_queue_mode: st_name: 1 st_value: c00fc000 st_shndx: 2 st_info: t
>  null_set_irqmode: st_name: 21 st_value: c00fc048 st_shndx: 2 st_info: t
>  null_exit: st_name: 38 st_value: c00fc090 st_shndx: 6 st_info: t
>  cleanup_module: st_name: 48 st_value: c00fc090 st_shndx: 6 st_info: t
>      FREEBUF(2)
>    FREEBUF(1)
>  FREEBUF(0)
> 
>  crash: store_module_symbols_v2: total: 7 mcnt: 8
> ---
>  kernel.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/kernel.c b/kernel.c
> index 9019cf5..bdd0d05 100644
> --- a/kernel.c
> +++ b/kernel.c
> @@ -3475,6 +3475,7 @@ module_init(void)
>  
>  		total += nsyms;
>  		total += 2;  /* store the module's start/ending addresses */
> +		total += 2;  /* and the init start/ending addresses */
>  
>  		/*
>  		 *  If the module has kallsyms, set up to grab them as well.
> --
> 2.1.4
> 
>