* [PATCH] drivers: lkdtm: fix clang -Wformat warning
@ 2022-07-21 21:20 Justin Stitt
2022-07-21 21:34 ` Nathan Chancellor
2022-07-21 21:42 ` Nick Desaulniers
0 siblings, 2 replies; 6+ messages in thread
From: Justin Stitt @ 2022-07-21 21:20 UTC (permalink / raw)
To: Kees Cook
Cc: Arnd Bergmann, Greg Kroah-Hartman, Nathan Chancellor,
Nick Desaulniers, Tom Rix, linux-kernel, llvm, Justin Stitt
When building with Clang we encounter the following warning
(ARCH=hexagon + CONFIG_FRAME_WARN=0):
| ../drivers/misc/lkdtm/bugs.c:107:3: error: format specifies type
| 'unsigned long' but the argument has type 'int' [-Werror,-Wformat]
| REC_STACK_SIZE, recur_count);
| ^~~~~~~~~~~~~~
Cast REC_STACK_SIZE to `unsigned long` to match format specifier `%lu`.
Link: https://github.com/ClangBuiltLinux/linux/issues/378
Reported-by: Nathan Chancellor <nathan@kernel.org>
Suggested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Justin Stitt <justinstitt@google.com>
---
Reported by Nathan here:
https://lore.kernel.org/all/YtmrCJjQrSbv8Aj1@dev-arch.thelio-3990X/
drivers/misc/lkdtm/bugs.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/misc/lkdtm/bugs.c b/drivers/misc/lkdtm/bugs.c
index 009239ad1d8a..6381255aaecc 100644
--- a/drivers/misc/lkdtm/bugs.c
+++ b/drivers/misc/lkdtm/bugs.c
@@ -29,7 +29,7 @@ struct lkdtm_list {
#if defined(CONFIG_FRAME_WARN) && (CONFIG_FRAME_WARN > 0)
#define REC_STACK_SIZE (_AC(CONFIG_FRAME_WARN, UL) / 2)
#else
-#define REC_STACK_SIZE (THREAD_SIZE / 8)
+#define REC_STACK_SIZE ((unsigned long)(THREAD_SIZE / 8))
#endif
#define REC_NUM_DEFAULT ((THREAD_SIZE / REC_STACK_SIZE) * 2)
--
2.37.1.359.gd136c6c3e2-goog
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH] drivers: lkdtm: fix clang -Wformat warning
2022-07-21 21:20 [PATCH] drivers: lkdtm: fix clang -Wformat warning Justin Stitt
@ 2022-07-21 21:34 ` Nathan Chancellor
2022-07-21 21:42 ` Nick Desaulniers
1 sibling, 0 replies; 6+ messages in thread
From: Nathan Chancellor @ 2022-07-21 21:34 UTC (permalink / raw)
To: Justin Stitt
Cc: Kees Cook, Arnd Bergmann, Greg Kroah-Hartman, Nick Desaulniers,
Tom Rix, linux-kernel, llvm
On Thu, Jul 21, 2022 at 02:20:12PM -0700, Justin Stitt wrote:
> When building with Clang we encounter the following warning
> (ARCH=hexagon + CONFIG_FRAME_WARN=0):
> | ../drivers/misc/lkdtm/bugs.c:107:3: error: format specifies type
> | 'unsigned long' but the argument has type 'int' [-Werror,-Wformat]
> | REC_STACK_SIZE, recur_count);
> | ^~~~~~~~~~~~~~
>
> Cast REC_STACK_SIZE to `unsigned long` to match format specifier `%lu`.
>
> Link: https://github.com/ClangBuiltLinux/linux/issues/378
> Reported-by: Nathan Chancellor <nathan@kernel.org>
> Suggested-by: Nathan Chancellor <nathan@kernel.org>
> Signed-off-by: Justin Stitt <justinstitt@google.com>
I think this is the right fix, as REC_STACK_SIZE will be 'unsigned long'
when CONFIG_FRAME_WARN is greater than 0 due to the _AC(..., UL) macro,
so the other one should match too. THREAD_SIZE might not be an unsigned
long; I see at least hexagon, microblaze, m68k, powerpc, and sh that
define it as either a regular integer literal with no suffix or
'1 << THREAD_SHIFT', which will both be of type 'int'.
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
> ---
> Reported by Nathan here:
> https://lore.kernel.org/all/YtmrCJjQrSbv8Aj1@dev-arch.thelio-3990X/
>
> drivers/misc/lkdtm/bugs.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/misc/lkdtm/bugs.c b/drivers/misc/lkdtm/bugs.c
> index 009239ad1d8a..6381255aaecc 100644
> --- a/drivers/misc/lkdtm/bugs.c
> +++ b/drivers/misc/lkdtm/bugs.c
> @@ -29,7 +29,7 @@ struct lkdtm_list {
> #if defined(CONFIG_FRAME_WARN) && (CONFIG_FRAME_WARN > 0)
> #define REC_STACK_SIZE (_AC(CONFIG_FRAME_WARN, UL) / 2)
> #else
> -#define REC_STACK_SIZE (THREAD_SIZE / 8)
> +#define REC_STACK_SIZE ((unsigned long)(THREAD_SIZE / 8))
> #endif
> #define REC_NUM_DEFAULT ((THREAD_SIZE / REC_STACK_SIZE) * 2)
>
> --
> 2.37.1.359.gd136c6c3e2-goog
>
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] drivers: lkdtm: fix clang -Wformat warning
2022-07-21 21:20 [PATCH] drivers: lkdtm: fix clang -Wformat warning Justin Stitt
2022-07-21 21:34 ` Nathan Chancellor
@ 2022-07-21 21:42 ` Nick Desaulniers
2022-07-21 21:57 ` [PATCH v2] " Justin Stitt
1 sibling, 1 reply; 6+ messages in thread
From: Nick Desaulniers @ 2022-07-21 21:42 UTC (permalink / raw)
To: Justin Stitt
Cc: Kees Cook, Arnd Bergmann, Greg Kroah-Hartman, Nathan Chancellor,
Tom Rix, linux-kernel, llvm
On Thu, Jul 21, 2022 at 2:20 PM Justin Stitt <justinstitt@google.com> wrote:
>
> When building with Clang we encounter the following warning
> (ARCH=hexagon + CONFIG_FRAME_WARN=0):
> | ../drivers/misc/lkdtm/bugs.c:107:3: error: format specifies type
> | 'unsigned long' but the argument has type 'int' [-Werror,-Wformat]
> | REC_STACK_SIZE, recur_count);
> | ^~~~~~~~~~~~~~
>
> Cast REC_STACK_SIZE to `unsigned long` to match format specifier `%lu`.
>
> Link: https://github.com/ClangBuiltLinux/linux/issues/378
> Reported-by: Nathan Chancellor <nathan@kernel.org>
> Suggested-by: Nathan Chancellor <nathan@kernel.org>
> Signed-off-by: Justin Stitt <justinstitt@google.com>
> ---
> Reported by Nathan here:
> https://lore.kernel.org/all/YtmrCJjQrSbv8Aj1@dev-arch.thelio-3990X/
>
> drivers/misc/lkdtm/bugs.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/misc/lkdtm/bugs.c b/drivers/misc/lkdtm/bugs.c
> index 009239ad1d8a..6381255aaecc 100644
> --- a/drivers/misc/lkdtm/bugs.c
> +++ b/drivers/misc/lkdtm/bugs.c
> @@ -29,7 +29,7 @@ struct lkdtm_list {
> #if defined(CONFIG_FRAME_WARN) && (CONFIG_FRAME_WARN > 0)
> #define REC_STACK_SIZE (_AC(CONFIG_FRAME_WARN, UL) / 2)
> #else
> -#define REC_STACK_SIZE (THREAD_SIZE / 8)
> +#define REC_STACK_SIZE ((unsigned long)(THREAD_SIZE / 8))
`THREAD_SIZE / 8UL` might be more concise.
> #endif
> #define REC_NUM_DEFAULT ((THREAD_SIZE / REC_STACK_SIZE) * 2)
>
> --
> 2.37.1.359.gd136c6c3e2-goog
>
--
Thanks,
~Nick Desaulniers
^ permalink raw reply [flat|nested] 6+ messages in thread* [PATCH v2] drivers: lkdtm: fix clang -Wformat warning
2022-07-21 21:42 ` Nick Desaulniers
@ 2022-07-21 21:57 ` Justin Stitt
2022-07-21 22:05 ` Nathan Chancellor
2022-07-23 13:42 ` Kees Cook
0 siblings, 2 replies; 6+ messages in thread
From: Justin Stitt @ 2022-07-21 21:57 UTC (permalink / raw)
To: ndesaulniers
Cc: arnd, gregkh, justinstitt, keescook, linux-kernel, llvm, nathan,
trix
When building with Clang we encounter the following warning
(ARCH=hexagon + CONFIG_FRAME_WARN=0):
| ../drivers/misc/lkdtm/bugs.c:107:3: error: format specifies type
| 'unsigned long' but the argument has type 'int' [-Werror,-Wformat]
| REC_STACK_SIZE, recur_count);
| ^~~~~~~~~~~~~~
Cast REC_STACK_SIZE to `unsigned long` to match format specifier `%lu`
as well as maintain symmetry with `#define REC_STACK_SIZE
(_AC(CONFIG_FRAME_WARN, UL) / 2)`.
Link: https://github.com/ClangBuiltLinux/linux/issues/378
Reported-by: Nathan Chancellor <nathan@kernel.org>
Suggested-by: Nathan Chancellor <nathan@kernel.org>
Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Justin Stitt <justinstitt@google.com>
---
Reported by Nathan here:
https://lore.kernel.org/all/YtmrCJjQrSbv8Aj1@dev-arch.thelio-3990X/
changes from v1 -> v2:
* Use implicit division conversion with `/ nUL` instead of verbose
`(unsigned long)` ~ Thanks Nick
drivers/misc/lkdtm/bugs.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/misc/lkdtm/bugs.c b/drivers/misc/lkdtm/bugs.c
index 009239ad1d8a..48821f4c2b21 100644
--- a/drivers/misc/lkdtm/bugs.c
+++ b/drivers/misc/lkdtm/bugs.c
@@ -29,7 +29,7 @@ struct lkdtm_list {
#if defined(CONFIG_FRAME_WARN) && (CONFIG_FRAME_WARN > 0)
#define REC_STACK_SIZE (_AC(CONFIG_FRAME_WARN, UL) / 2)
#else
-#define REC_STACK_SIZE (THREAD_SIZE / 8)
+#define REC_STACK_SIZE (THREAD_SIZE / 8UL)
#endif
#define REC_NUM_DEFAULT ((THREAD_SIZE / REC_STACK_SIZE) * 2)
--
2.37.1.359.gd136c6c3e2-goog
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH v2] drivers: lkdtm: fix clang -Wformat warning
2022-07-21 21:57 ` [PATCH v2] " Justin Stitt
@ 2022-07-21 22:05 ` Nathan Chancellor
2022-07-23 13:42 ` Kees Cook
1 sibling, 0 replies; 6+ messages in thread
From: Nathan Chancellor @ 2022-07-21 22:05 UTC (permalink / raw)
To: Justin Stitt
Cc: ndesaulniers, arnd, gregkh, keescook, linux-kernel, llvm, trix
On Thu, Jul 21, 2022 at 02:57:06PM -0700, Justin Stitt wrote:
> When building with Clang we encounter the following warning
> (ARCH=hexagon + CONFIG_FRAME_WARN=0):
> | ../drivers/misc/lkdtm/bugs.c:107:3: error: format specifies type
> | 'unsigned long' but the argument has type 'int' [-Werror,-Wformat]
> | REC_STACK_SIZE, recur_count);
> | ^~~~~~~~~~~~~~
>
> Cast REC_STACK_SIZE to `unsigned long` to match format specifier `%lu`
> as well as maintain symmetry with `#define REC_STACK_SIZE
> (_AC(CONFIG_FRAME_WARN, UL) / 2)`.
>
> Link: https://github.com/ClangBuiltLinux/linux/issues/378
> Reported-by: Nathan Chancellor <nathan@kernel.org>
> Suggested-by: Nathan Chancellor <nathan@kernel.org>
Personally, I would drop this; my suggestion was the cast, which we are
not going with anymore. Not worth a v3 unless there are other changes
requested.
> Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
> Signed-off-by: Justin Stitt <justinstitt@google.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
> ---
> Reported by Nathan here:
> https://lore.kernel.org/all/YtmrCJjQrSbv8Aj1@dev-arch.thelio-3990X/
>
> changes from v1 -> v2:
> * Use implicit division conversion with `/ nUL` instead of verbose
> `(unsigned long)` ~ Thanks Nick
>
> drivers/misc/lkdtm/bugs.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/misc/lkdtm/bugs.c b/drivers/misc/lkdtm/bugs.c
> index 009239ad1d8a..48821f4c2b21 100644
> --- a/drivers/misc/lkdtm/bugs.c
> +++ b/drivers/misc/lkdtm/bugs.c
> @@ -29,7 +29,7 @@ struct lkdtm_list {
> #if defined(CONFIG_FRAME_WARN) && (CONFIG_FRAME_WARN > 0)
> #define REC_STACK_SIZE (_AC(CONFIG_FRAME_WARN, UL) / 2)
> #else
> -#define REC_STACK_SIZE (THREAD_SIZE / 8)
> +#define REC_STACK_SIZE (THREAD_SIZE / 8UL)
> #endif
> #define REC_NUM_DEFAULT ((THREAD_SIZE / REC_STACK_SIZE) * 2)
>
> --
> 2.37.1.359.gd136c6c3e2-goog
>
>
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH v2] drivers: lkdtm: fix clang -Wformat warning
2022-07-21 21:57 ` [PATCH v2] " Justin Stitt
2022-07-21 22:05 ` Nathan Chancellor
@ 2022-07-23 13:42 ` Kees Cook
1 sibling, 0 replies; 6+ messages in thread
From: Kees Cook @ 2022-07-23 13:42 UTC (permalink / raw)
To: Justin Stitt, ndesaulniers
Cc: arnd, gregkh, justinstitt, linux-kernel, llvm, nathan, trix
On July 21, 2022 2:57:06 PM PDT, Justin Stitt <justinstitt@google.com> wrote:
>When building with Clang we encounter the following warning
>(ARCH=hexagon + CONFIG_FRAME_WARN=0):
>| ../drivers/misc/lkdtm/bugs.c:107:3: error: format specifies type
>| 'unsigned long' but the argument has type 'int' [-Werror,-Wformat]
>| REC_STACK_SIZE, recur_count);
>| ^~~~~~~~~~~~~~
>
>Cast REC_STACK_SIZE to `unsigned long` to match format specifier `%lu`
>as well as maintain symmetry with `#define REC_STACK_SIZE
>(_AC(CONFIG_FRAME_WARN, UL) / 2)`.
>
>Link: https://github.com/ClangBuiltLinux/linux/issues/378
>Reported-by: Nathan Chancellor <nathan@kernel.org>
>Suggested-by: Nathan Chancellor <nathan@kernel.org>
>Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
>Signed-off-by: Justin Stitt <justinstitt@google.com>
Thanks!
Acked-by: Kees Cook <keescook@chromium.org>
Fixes: 24cccab42c419 ("lkdtm/bugs: Adjust recursion test to avoid elision")
--
Kees Cook
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2022-07-23 13:43 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
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2022-07-21 21:20 [PATCH] drivers: lkdtm: fix clang -Wformat warning Justin Stitt
2022-07-21 21:34 ` Nathan Chancellor
2022-07-21 21:42 ` Nick Desaulniers
2022-07-21 21:57 ` [PATCH v2] " Justin Stitt
2022-07-21 22:05 ` Nathan Chancellor
2022-07-23 13:42 ` Kees Cook
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