Re: [Freeipmi-devel] [PATCH] Using DMI firmware in sysfs if exists

[Albert Chu]

It seems important, so I'll put a release on my todo queue.

Al

On Wed, 2017-06-28 at 11:16 +0800, Ike Panhc wrote:
> Hi Albert,
> 
> Thanks for feedback.
> 
> You are the one to make the call. and I believe it
> is good to have a new release so every distro can
> have this fix especially they have arm64 release.
> 
> --
> Ike Panhc
> 
> 
> On 06/28/2017 07:42 AM, Albert Chu wrote:
> > LGTM, thanks!  This seems important/serious enough that it would affect
> > current users.  Do you think a new release is warranted?
> > 
> > Al
> > 
> > On Tue, 2017-06-27 at 16:07 +0800, Ike Panhc wrote:
> >> On arm64 system scanning /dev/mem for SMBIOS tables might fail and
> >> stopped with SIGBUS. Kernel version > 4.2 provides DMI tables in
> >> /sys/firmware/dmi/tables and it is much safer for ipmi-locate to
> >> read. If it exists, reading from it instead of /dev/mem fix
> >> ipmi-locate crash on several arm64 system.
> >>
> >> Unfortunately mmap() does not work on DMI tables so also fallback to
> >> read if mmap() failed.
> >>
> >> Signed-off-by: Ike Panhc <address@hidden>
> >> ---
> >>  libfreeipmi/locate/ipmi-locate-dmidecode.c | 28 
> >> +++++++++++++++++++++++-----
> >>  1 file changed, 23 insertions(+), 5 deletions(-)
> >>
> >> diff --git a/libfreeipmi/locate/ipmi-locate-dmidecode.c 
> >> b/libfreeipmi/locate/ipmi-locate-dmidecode.c
> >> index 8a89fc0..db1c473 100644
> >> --- a/libfreeipmi/locate/ipmi-locate-dmidecode.c
> >> +++ b/libfreeipmi/locate/ipmi-locate-dmidecode.c
> >> @@ -115,7 +115,6 @@ struct dmi_header
> >>    fipmiu16 handle;
> >>  };
> >>  
> >> -#ifndef HAVE_MMAP
> >>  static int
> >>  _myread (ipmi_locate_ctx_t ctx,
> >>           int fd,
> >> @@ -155,7 +154,6 @@ _myread (ipmi_locate_ctx_t ctx,
> >>  
> >>    return (0);
> >>  }
> >> -#endif
> >>  
> >>  static int
> >>  _checksum (const fipmiu8 *buf, size_t len)
> >> @@ -233,14 +231,16 @@ _mem_chunk (ipmi_locate_ctx_t ctx,
> >>                     base - mmoffset)) == MAP_FAILED)
> >>      {
> >>        LOCATE_ERRNO_TO_LOCATE_ERRNUM (ctx, errno);
> >> -      goto cleanup;
> >> +      goto try_read;
> >>      }
> >>  
> >>    memcpy (p, (fipmiu8 *) mmp + mmoffset, len);
> >>    rv = p;
> >>    /* ignore potential error, just return result */
> >>    munmap (mmp, mmoffset + len);
> >> -#else /* HAVE_MMAP */
> >> +  goto cleanup;
> >> + try_read:
> >> +#endif /* HAVE_MMAP */
> >>  
> >>    if (lseek (fd, base, SEEK_SET) < 0)
> >>      {
> >> @@ -252,7 +252,6 @@ _mem_chunk (ipmi_locate_ctx_t ctx,
> >>      goto cleanup;
> >>  
> >>    rv = p;
> >> -#endif /* HAVE_MMAP */
> >>  
> >>   cleanup:
> >>    /* ignore potential error, cleanup path */
> >> @@ -457,6 +456,8 @@ ipmi_locate_dmidecode_get_device_info 
> >> (ipmi_locate_ctx_t ctx,
> >>    char linebuf[64];
> >>    fipmiu8 *buf = NULL;
> >>    int rv = -1;
> >> +  static char const sys_fw_dmi_tables[] = "/sys/firmware/dmi/tables/DMI";
> >> +  struct stat st;
> >>  
> >>    if (!ctx || ctx->magic != IPMI_LOCATE_CTX_MAGIC)
> >>      {
> >> @@ -471,6 +472,23 @@ ipmi_locate_dmidecode_get_device_info 
> >> (ipmi_locate_ctx_t ctx,
> >>      }
> >>  
> >>    memset (&locate_info, '\0', sizeof (struct ipmi_locate_info));
> >> +
> >> +  /* if DMI firmware exist, use it and do not dig into /dev/mem */
> >> +  if (!(stat (sys_fw_dmi_tables, &st)))
> >> +    {
> >> +      rv = _dmi_table (ctx,
> >> +                        0,
> >> +                        st.st_size,
> >> +                        st.st_size / 4,
> >> +                        0,
> >> +                        sys_fw_dmi_tables,
> >> +                        type,
> >> +                        &locate_info);
> >> +      if (!(rv))
> >> +        memcpy (info, &locate_info, sizeof (struct ipmi_locate_info));
> >> +      return (rv);
> >> +    }
> >> +
> >>    /*
> >>     * Linux up to 2.6.6-rc2: /proc/efi/systab
> >>     * Linux 2.6.6-rc3 and up: /sys/firmware/efi/systab
> > 
> 

-- 
Albert Chu
address@hidden
Computer Scientist
High Performance Systems Division
Lawrence Livermore National Laboratory