[PATCH] emulex/benet: Annotate flash_cookie as nonstring

[PATCH] emulex/benet: Annotate flash_cookie as nonstring

[Kees Cook]

GCC 15's new -Wunterminated-string-initialization notices that the 32
character "flash_cookie" (which is not used as a C-String)
needs to be marked as "nonstring":

drivers/net/ethernet/emulex/benet/be_cmds.c:2618:51: warning: initializer-string for array of 'char' truncates NUL terminator but destination lacks 'nonstring' attribute (17 chars into 16 available) [-Wunterminated-string-initialization]
 2618 | static char flash_cookie[2][16] = {"*** SE FLAS", "H DIRECTORY *** "};
      |                                                   ^~~~~~~~~~~~~~~~~~

Add this annotation, avoid using a multidimensional array, but keep the
string split (with a comment about why). Additionally mark it const
and annotate the "cookie" member that is being memcmp()ed against as
nonstring too.

Signed-off-by: Kees Cook <kees@kernel.org>
---
Cc: Ajit Khaparde <ajit.khaparde@broadcom.com>
Cc: Sriharsha Basavapatna <sriharsha.basavapatna@broadcom.com>
Cc: Somnath Kotur <somnath.kotur@broadcom.com>
Cc: Andrew Lunn <andrew+netdev@lunn.ch>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: netdev@vger.kernel.org
---
 drivers/net/ethernet/emulex/benet/be_cmds.c | 6 +++++-
 drivers/net/ethernet/emulex/benet/be_cmds.h | 2 +-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/emulex/benet/be_cmds.c b/drivers/net/ethernet/emulex/benet/be_cmds.c
index 51b8377edd1d..adb441b36581 100644
--- a/drivers/net/ethernet/emulex/benet/be_cmds.c
+++ b/drivers/net/ethernet/emulex/benet/be_cmds.c
@@ -2615,7 +2615,11 @@ static int be_cmd_get_flash_crc(struct be_adapter *adapter, u8 *flashed_crc,
 	return status;
 }
 
-static char flash_cookie[2][16] = {"*** SE FLAS", "H DIRECTORY *** "};
+/*
+ * Since the cookie is text, add a parsing-skipped space to keep it from
+ * ever being matched on storage holding this source file.
+ */
+static const char flash_cookie[32] __nonstring = "*** SE FLAS" "H DIRECTORY *** ";
 
 static bool phy_flashing_required(struct be_adapter *adapter)
 {
diff --git a/drivers/net/ethernet/emulex/benet/be_cmds.h b/drivers/net/ethernet/emulex/benet/be_cmds.h
index d70818f06be7..5e2d3ddb5d43 100644
--- a/drivers/net/ethernet/emulex/benet/be_cmds.h
+++ b/drivers/net/ethernet/emulex/benet/be_cmds.h
@@ -1415,7 +1415,7 @@ struct flash_section_entry {
 } __packed;
 
 struct flash_section_info {
-	u8 cookie[32];
+	u8 cookie[32] __nonstring;
 	struct flash_section_hdr fsec_hdr;
 	struct flash_section_entry fsec_entry[32];
 } __packed;
-- 
2.34.1

Re: [PATCH] emulex/benet: Annotate flash_cookie as nonstring

[Simon Horman]

On Wed, Apr 16, 2025 at 03:10:29PM -0700, Kees Cook wrote:
> GCC 15's new -Wunterminated-string-initialization notices that the 32
> character "flash_cookie" (which is not used as a C-String)
> needs to be marked as "nonstring":
> 
> drivers/net/ethernet/emulex/benet/be_cmds.c:2618:51: warning: initializer-string for array of 'char' truncates NUL terminator but destination lacks 'nonstring' attribute (17 chars into 16 available) [-Wunterminated-string-initialization]
>  2618 | static char flash_cookie[2][16] = {"*** SE FLAS", "H DIRECTORY *** "};
>       |                                                   ^~~~~~~~~~~~~~~~~~
> 
> Add this annotation, avoid using a multidimensional array, but keep the
> string split (with a comment about why). Additionally mark it const
> and annotate the "cookie" member that is being memcmp()ed against as
> nonstring too.
> 
> Signed-off-by: Kees Cook <kees@kernel.org>

I am assuming this is for net-next.

Reviewed-by: Simon Horman <horms@kernel.org>

Re: [PATCH] emulex/benet: Annotate flash_cookie as nonstring

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net-next.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Wed, 16 Apr 2025 15:10:29 -0700 you wrote:
> GCC 15's new -Wunterminated-string-initialization notices that the 32
> character "flash_cookie" (which is not used as a C-String)
> needs to be marked as "nonstring":
> 
> drivers/net/ethernet/emulex/benet/be_cmds.c:2618:51: warning: initializer-string for array of 'char' truncates NUL terminator but destination lacks 'nonstring' attribute (17 chars into 16 available) [-Wunterminated-string-initialization]
>  2618 | static char flash_cookie[2][16] = {"*** SE FLAS", "H DIRECTORY *** "};
>       |                                                   ^~~~~~~~~~~~~~~~~~
> 
> [...]

Here is the summary with links:
  - emulex/benet: Annotate flash_cookie as nonstring
    https://git.kernel.org/netdev/net-next/c/f0f149d9747f

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html