Re: [PATCH v2] [PR corefiles/32441] Fix segfault if target_fileio_read_alloc fails

[Andrew Burgess <aburgess@redhat.com>]

Brandon Belew <brandon.belew@zetier.com> writes:

> Check for target_fileio_read_alloc failure in linux_fill_prpsinfo
> before dereferencing buffer. This fixes a segfault in the 'gcore'
> command when attached to certain remote targets.

LGTM.

Approved-By: Andrew Burgess <aburgess@redhat.com>

Thanks,
Andrew


> ---
>  gdb/linux-tdep.c | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/gdb/linux-tdep.c b/gdb/linux-tdep.c
> index d3ab02d03e0..735d20dc050 100644
> --- a/gdb/linux-tdep.c
> +++ b/gdb/linux-tdep.c
> @@ -854,7 +854,7 @@ linux_info_proc (struct gdbarch *gdbarch, const char *args,
>      {
>        xsnprintf (filename, sizeof filename, "/proc/%ld/cmdline", pid);
>        gdb_byte *buffer;
> -      ssize_t len = target_fileio_read_alloc (NULL, filename, &buffer);
> +      LONGEST len = target_fileio_read_alloc (nullptr, filename, &buffer);
>
>        if (len > 0)
>  	{
> @@ -2180,17 +2180,17 @@ linux_fill_prpsinfo (struct elf_internal_linux_prpsinfo *p)
>    /* The number of fields read by `sscanf'.  */
>    int n_fields = 0;
>
> -  gdb_assert (p != NULL);
> +  gdb_assert (p != nullptr);
>
>    /* Obtaining PID and filename.  */
>    pid = inferior_ptid.pid ();
>    xsnprintf (filename, sizeof (filename), "/proc/%d/cmdline", (int) pid);
>    /* The full name of the program which generated the corefile.  */
> -  gdb_byte *buf = NULL;
> -  size_t buf_len = target_fileio_read_alloc (NULL, filename, &buf);
> +  gdb_byte *buf = nullptr;
> +  LONGEST buf_len = target_fileio_read_alloc (nullptr, filename, &buf);
>    gdb::unique_xmalloc_ptr<char> fname ((char *)buf);
>
> -  if (buf_len < 1 || fname.get ()[0] == '\0')
> +  if (buf_len < 1 || fname.get () == nullptr || fname.get ()[0] == '\0')
>      {
>        /* No program name was read, so we won't be able to retrieve more
>  	 information about the process.  */
> --
> 2.47.1