On 31.01.24 18:15, Matthias Brugger wrote:
On Mon, Jan 29, 2024 at 10:04:50PM +0100, Heinrich Schuchardt wrote:
The string section of the different SMBIOS structures is always terminated
by two NUL bytes even if there is no string at all. This is described in
section 6.1.3 "Text string" of the SMBIOS 3.7.0 specification.
Signed-off-by: Heinrich Schuchardt <heinrich.schucha...@canonical.com>
I send the very same patch some years ago [1], unfortunately it got
somehow lost. Happy to see you trying to fix the same problem, so:
Reviewed-by: Matthias Brugger <mbrug...@suse.com>
[1]
https://patchwork.ozlabs.org/project/uboot/patch/20210406090435.19357-1-matthias....@kernel.org/
Thanks for the pointer. I assume not answering Simon's question lead to
your patch not being merged.
To answer it:
>> But where are the \0 bytes
>> actually written? Perhaps that should be in smbios_set_eos()?
We have defined SMBIOS_STRUCT_EOS_BYTES as 2 and we have an array
char eos[SMBIOS_STRUCT_EOS_BYTES];
at the end of each SMBIOS structure.
We call memset(t, 0, sizeof(struct smbios_typeX)); for each table.
This is enough to ensure two zero bytes exist if there are no strings.
Best regards
Heinrich
---
lib/smbios.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/lib/smbios.c b/lib/smbios.c
index 7bd9805fec0..81908e89610 100644
--- a/lib/smbios.c
+++ b/lib/smbios.c
@@ -311,6 +311,9 @@ int smbios_update_version(const char *version)
*/
static int smbios_string_table_len(const struct smbios_ctx *ctx)
{
+ /* If the structure contains no string it is followed by two NUL bytes
*/
+ if (ctx->next_ptr == ctx->eos)
+ return 2;
/* Allow for the final \0 after all strings */
return (ctx->next_ptr + 1) - ctx->eos;
}
--
2.43.0
