[Crash-utility] Re: [RFC] Patch to fix broken net command

[Dave Anderson]

Rachita Kothiyal wrote:

> Hi Dave
>
> Following changes in the 2.6.14 kernel in the files_struct,
> the 'net' command was broken. The following patch fixes it.
> I have done basic testing on kernels before and after 2.6.14
> to ensure that backward compatibility is maintained.
>
> Kindly review and provide your comments.
>
> Thanks
> Rachita
>
>  o From 2.6.14 kernel onwards, there were changes introduced
>    in the files_struct. This patch accomodates those kernel
>    changes in crash to keep the 'net' command working.
>
> Signed-off-by: Rachita Kothiyal <rachita at in.ibm.com>

Hi Rachita,

The patch works for me -- thanks again for your help.
I've marked the bug as "fixed in next release" in the
crash TODO file.

Thanks,
   Dave


>
> ---
>
>  net.c |   57 ++++++++++++++++++++++++++++++++++++++-------------------
>  1 files changed, 38 insertions(+), 19 deletions(-)
>
> diff -puN net.c~fix-net-command net.c
> --- crash-4.0-2.23/net.c~fix-net-command        2006-04-17 19:16:18.000000000 +0530
> +++ crash-4.0-2.23-rachita/net.c        2006-04-17 20:41:16.000000000 +0530
> @@ -1082,7 +1082,7 @@ dump_sockets(ulong flag, struct referenc
>  void
>  dump_sockets_workhorse(ulong task, ulong flag, struct reference *ref)
>  {
> -       ulong files_struct_addr = 0;
> +       ulong files_struct_addr = 0, fdtable_addr = 0;
>         int max_fdset = 0;
>         int max_fds = 0;
>         ulong open_fds_addr = 0;
> @@ -1114,32 +1114,51 @@ dump_sockets_workhorse(ulong task, ulong
>              sizeof(void *), "task files contents", FAULT_ON_ERROR);
>
>          if (files_struct_addr) {
> -               readmem(files_struct_addr + OFFSET(files_struct_max_fdset),
> -                       KVADDR, &max_fdset, sizeof(int),
> -                       "files_struct max_fdset", FAULT_ON_ERROR);
> -
> -               readmem(files_struct_addr + OFFSET(files_struct_max_fds),
> -                       KVADDR, &max_fds, sizeof(int), "files_struct max_fds",
> -                       FAULT_ON_ERROR);
> -       }
> +                if (VALID_MEMBER(files_struct_max_fdset)) {
> +                       readmem(files_struct_addr + OFFSET(files_struct_max_fdset),
> +                               KVADDR, &max_fdset, sizeof(int),
> +                               "files_struct max_fdset", FAULT_ON_ERROR);
> +                       readmem(files_struct_addr + OFFSET(files_struct_max_fds),
> +                               KVADDR, &max_fds, sizeof(int), "files_struct max_fds",
> +                               FAULT_ON_ERROR);
> +                }
> +               else if (VALID_MEMBER(files_struct_fdt)) {
> +                       readmem(files_struct_addr + OFFSET(files_struct_fdt), KVADDR,
> +                               &fdtable_addr, sizeof(void *), "fdtable buffer",
> +                               FAULT_ON_ERROR);
> +                       readmem(fdtable_addr + OFFSET(fdtable_max_fdset),
> +                               KVADDR, &max_fdset, sizeof(int),
> +                               "fdtable_struct max_fdset", FAULT_ON_ERROR);
> +                       readmem(fdtable_addr + OFFSET(fdtable_max_fds),
> +                               KVADDR, &max_fds, sizeof(int), "fdtable_struct max_fds",
> +                               FAULT_ON_ERROR);
> +               }
> +       }
>
> -       if (!files_struct_addr || (max_fdset == 0) || (max_fds == 0)) {
> +       if ((VALID_MEMBER(files_struct_fdt) && !fdtable_addr) ||
> +           !files_struct_addr || (max_fdset == 0) || (max_fds == 0)) {
>                 if (!NET_REFERENCE_CHECK(ref))
>                         fprintf(fp, "No open sockets.\n");
>                 return;
>         }
>
> -       readmem(files_struct_addr + OFFSET(files_struct_open_fds), KVADDR,
> -               &open_fds_addr, sizeof(void *), "files_struct open_fds addr",
> -               FAULT_ON_ERROR);
> +       if (VALID_MEMBER(fdtable_open_fds)){
> +               readmem(fdtable_addr + OFFSET(fdtable_open_fds), KVADDR,
> +                       &open_fds_addr, sizeof(void *), "files_struct open_fds addr",
> +                       FAULT_ON_ERROR);
> +               readmem(fdtable_addr + OFFSET(fdtable_fd), KVADDR, &fd,
> +                       sizeof(void *), "files_struct fd addr", FAULT_ON_ERROR);
> +       } else {
> +               readmem(files_struct_addr + OFFSET(files_struct_open_fds), KVADDR,
> +                       &open_fds_addr, sizeof(void *), "files_struct open_fds addr",
> +                       FAULT_ON_ERROR);
> +               readmem(files_struct_addr + OFFSET(files_struct_fd), KVADDR, &fd,
> +                       sizeof(void *), "files_struct fd addr", FAULT_ON_ERROR);
> +       }
>
>         if (open_fds_addr)
> -               readmem(open_fds_addr, KVADDR, &open_fds, sizeof(fd_set),
> -                       "files_struct open_fds", FAULT_ON_ERROR);
> -
> -       readmem(files_struct_addr + OFFSET(files_struct_fd), KVADDR, &fd,
> -               sizeof(void *), "files_struct fd addr", FAULT_ON_ERROR);
> -
> +               readmem(open_fds_addr, KVADDR, &open_fds, sizeof(fd_set),
> +                       "files_struct open_fds", FAULT_ON_ERROR);
>         if (!open_fds_addr || !fd) {
>                 if (!NET_REFERENCE_CHECK(ref))
>                         fprintf(fp, "No open sockets.\n");
> _