On Wed, 2024-03-13 at 09:34 -0400, Steven Rostedt wrote:
> From: "Steven Rostedt (Google)" <rost...@goodmis.org>
>
> [
> Note, I need to take this patch through my tree, so I'm looking for acks.
Note that this device driver is changing quite rapidly, so I expect
some conflicts here later. I guess Liuns will have to handle them ;)
> This causes the build to fail when I add the __assign_str() check, which
> I was about to push to Linus, but it breaks allmodconfig due to this error.
> ]
>
> The __string() and __assign_str() helper macros of the TRACE_EVENT() macro
> are going through some optimizations where only the source string of
> __string() will be used and the __assign_str() source will be ignored and
> later removed.
>
> To make sure that there's no issues, a new check is added between the
> __string() src argument and the __assign_str() src argument that does a
> strcmp() to make sure they are the same string.
>
> The hclgevf trace events have:
>
> __assign_str(devname, &hdev->nic.kinfo.netdev->name);
>
> Which triggers the warning:
>
> hclgevf_trace.h:34:39: error: passing argument 1 of ‘strcmp’ from
> incompatible pointer type [-Werror=incompatible-pointer-types]
> 34 | __assign_str(devname, &hdev->nic.kinfo.netdev->name);
> [..]
> arch/x86/include/asm/string_64.h:75:24: note: expected ‘const char *’ but
> argument is of type ‘char (*)[16]’
> 75 | int strcmp(const char *cs, const char *ct);
> | ~~~~~~~~~~~~^~
>
>
> Because __assign_str() now has:
>
> WARN_ON_ONCE(__builtin_constant_p(src) ? \
> strcmp((src), __data_offsets.dst##_ptr_) : \
> (src) != __data_offsets.dst##_ptr_); \
>
> The problem is the '&' on hdev->nic.kinfo.netdev->name. That's because
> that name is:
>
> char name[IFNAMSIZ]
>
> Where passing an address '&' of a char array is not compatible with strcmp().
>
> The '&' is not necessary, remove it.
>
> Fixes: d8355240cf8fb ("net: hns3: add trace event support for PF/VF mailbox")
checkpactch in strict mode complains the hash is not 12 char long.
> Signed-off-by: Steven Rostedt (Google) <rost...@goodmis.org>
FWIW
Acked-by: Paolo Abeni <pab...@redhat.com>
