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[1/3] fault-inject: improve build for CONFIG_FAULT_INJECTION=n

Message ID 20240813121237.2382534-1-jani.nikula@intel.com
State New
Headers show
Series [1/3] fault-inject: improve build for CONFIG_FAULT_INJECTION=n | expand

Commit Message

Jani Nikula Aug. 13, 2024, 12:12 p.m. UTC
The fault-inject.h users across the kernel need to add a lot of #ifdef
CONFIG_FAULT_INJECTION to cater for shortcomings in the header. Make
fault-inject.h self-contained for CONFIG_FAULT_INJECTION=n, and add
stubs for DECLARE_FAULT_ATTR(), setup_fault_attr(), should_fail_ex(),
and should_fail() to allow removal of conditional compilation.

Cc: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
---
 include/linux/fault-inject.h | 36 +++++++++++++++++++++++++++++-------
 1 file changed, 29 insertions(+), 7 deletions(-)

Comments

Ghimiray, Himal Prasad Aug. 13, 2024, 12:55 p.m. UTC | #1
On 13-08-2024 17:42, Jani Nikula wrote:
> The fault-inject.h users across the kernel need to add a lot of #ifdef
> CONFIG_FAULT_INJECTION to cater for shortcomings in the header. Make
> fault-inject.h self-contained for CONFIG_FAULT_INJECTION=n, and add
> stubs for DECLARE_FAULT_ATTR(), setup_fault_attr(), should_fail_ex(),
> and should_fail() to allow removal of conditional compilation.

Would a "Fixes" tag be appropriate here?
Fixes: 6ff1cb355e62 ("[PATCH] fault-injection capabilities infrastructure")

> 
> Cc: Akinobu Mita <akinobu.mita@gmail.com>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
> ---
>   include/linux/fault-inject.h | 36 +++++++++++++++++++++++++++++-------
>   1 file changed, 29 insertions(+), 7 deletions(-)
> 
> diff --git a/include/linux/fault-inject.h b/include/linux/fault-inject.h
> index 354413950d34..8c829d28dcf3 100644
> --- a/include/linux/fault-inject.h
> +++ b/include/linux/fault-inject.h
> @@ -2,13 +2,17 @@
>   #ifndef _LINUX_FAULT_INJECT_H
>   #define _LINUX_FAULT_INJECT_H
>   
> +#include <linux/err.h>
> +#include <linux/types.h>
> +
> +struct dentry;
> +struct kmem_cache;
> +
>   #ifdef CONFIG_FAULT_INJECTION
>   
> -#include <linux/types.h>
> -#include <linux/debugfs.h>
> +#include <linux/atomic.h>
>   #include <linux/configfs.h>
>   #include <linux/ratelimit.h>
> -#include <linux/atomic.h>
>   
>   /*
>    * For explanation of the elements of this struct, see
> @@ -51,6 +55,28 @@ int setup_fault_attr(struct fault_attr *attr, char *str);
>   bool should_fail_ex(struct fault_attr *attr, ssize_t size, int flags);
>   bool should_fail(struct fault_attr *attr, ssize_t size);
>   
> +#else /* CONFIG_FAULT_INJECTION */
> +
> +struct fault_attr {
> +};
> +
> +#define DECLARE_FAULT_ATTR(name) struct fault_attr name = {}
> +
> +static inline int setup_fault_attr(struct fault_attr *attr, char *str)
> +{
> +	return 0; /* Note: 0 means error for __setup() handlers! */
> +}
> +static inline bool should_fail_ex(struct fault_attr *attr, ssize_t size, int flags)
> +{
> +	return false;
> +}
> +static inline bool should_fail(struct fault_attr *attr, ssize_t size)
> +{
> +	return false;
> +}
> +
> +#endif /* CONFIG_FAULT_INJECTION */
> +
>   #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
>   
>   struct dentry *fault_create_debugfs_attr(const char *name,
> @@ -87,10 +113,6 @@ static inline void fault_config_init(struct fault_config *config,
>   
>   #endif /* CONFIG_FAULT_INJECTION_CONFIGFS */
>   
> -#endif /* CONFIG_FAULT_INJECTION */
> -
> -struct kmem_cache;
> -
>   #ifdef CONFIG_FAIL_PAGE_ALLOC
>   bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order);
>   #else
Andrew Morton Aug. 14, 2024, 2:24 a.m. UTC | #2
On Tue, 13 Aug 2024 15:12:35 +0300 Jani Nikula <jani.nikula@intel.com> wrote:

> The fault-inject.h users across the kernel need to add a lot of #ifdef
> CONFIG_FAULT_INJECTION to cater for shortcomings in the header. Make
> fault-inject.h self-contained for CONFIG_FAULT_INJECTION=n, and add
> stubs for DECLARE_FAULT_ATTR(), setup_fault_attr(), should_fail_ex(),
> and should_fail() to allow removal of conditional compilation.
> 
> --- a/include/linux/fault-inject.h
> +++ b/include/linux/fault-inject.h
>  
> -#include <linux/types.h>
> -#include <linux/debugfs.h>

Removing a nested include exposes all those sites which were
erroneously depending upon that nested include.  Here's what I have
found so far, there will be more.

--- a/mm/failslab.c~fault-inject-improve-build-for-config_fault_injection=n-fix
+++ a/mm/failslab.c
@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0
 #include <linux/fault-inject.h>
 #include <linux/error-injection.h>
+#include <linux/debugfs.h>
 #include <linux/slab.h>
 #include <linux/mm.h>
 #include "slab.h"
--- a/lib/fault-inject.c~fault-inject-improve-build-for-config_fault_injection=n-fix
+++ a/lib/fault-inject.c
@@ -2,6 +2,7 @@
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/random.h>
+#include <linux/debugfs.h>
 #include <linux/sched.h>
 #include <linux/stat.h>
 #include <linux/types.h>
--- a/kernel/futex/core.c~fault-inject-improve-build-for-config_fault_injection=n-fix
+++ a/kernel/futex/core.c
@@ -34,6 +34,7 @@
 #include <linux/compat.h>
 #include <linux/jhash.h>
 #include <linux/pagemap.h>
+#include <linux/debugfs.h>
 #include <linux/plist.h>
 #include <linux/memblock.h>
 #include <linux/fault-inject.h>
Jani Nikula Aug. 14, 2024, 6:57 a.m. UTC | #3
On Tue, 13 Aug 2024, Andrew Morton <akpm@linux-foundation.org> wrote:
> On Tue, 13 Aug 2024 15:12:35 +0300 Jani Nikula <jani.nikula@intel.com> wrote:
>
>> The fault-inject.h users across the kernel need to add a lot of #ifdef
>> CONFIG_FAULT_INJECTION to cater for shortcomings in the header. Make
>> fault-inject.h self-contained for CONFIG_FAULT_INJECTION=n, and add
>> stubs for DECLARE_FAULT_ATTR(), setup_fault_attr(), should_fail_ex(),
>> and should_fail() to allow removal of conditional compilation.
>> 
>> --- a/include/linux/fault-inject.h
>> +++ b/include/linux/fault-inject.h
>>  
>> -#include <linux/types.h>
>> -#include <linux/debugfs.h>
>
> Removing a nested include exposes all those sites which were
> erroneously depending upon that nested include.  Here's what I have
> found so far, there will be more.

Right. I didn't hit them with the configs I tried... though I wonder why
not, especially lib/fault-inject.c puzzles me.

How do you want to proceed? Arguably uncovering and fixing those places
is good, but that's kind of an unintended consequence here.

BR,
Jani.


>
> --- a/mm/failslab.c~fault-inject-improve-build-for-config_fault_injection=n-fix
> +++ a/mm/failslab.c
> @@ -1,6 +1,7 @@
>  // SPDX-License-Identifier: GPL-2.0
>  #include <linux/fault-inject.h>
>  #include <linux/error-injection.h>
> +#include <linux/debugfs.h>
>  #include <linux/slab.h>
>  #include <linux/mm.h>
>  #include "slab.h"
> --- a/lib/fault-inject.c~fault-inject-improve-build-for-config_fault_injection=n-fix
> +++ a/lib/fault-inject.c
> @@ -2,6 +2,7 @@
>  #include <linux/kernel.h>
>  #include <linux/init.h>
>  #include <linux/random.h>
> +#include <linux/debugfs.h>
>  #include <linux/sched.h>
>  #include <linux/stat.h>
>  #include <linux/types.h>
> --- a/kernel/futex/core.c~fault-inject-improve-build-for-config_fault_injection=n-fix
> +++ a/kernel/futex/core.c
> @@ -34,6 +34,7 @@
>  #include <linux/compat.h>
>  #include <linux/jhash.h>
>  #include <linux/pagemap.h>
> +#include <linux/debugfs.h>
>  #include <linux/plist.h>
>  #include <linux/memblock.h>
>  #include <linux/fault-inject.h>
> _
>
Andrew Morton Aug. 14, 2024, 7:12 p.m. UTC | #4
On Wed, 14 Aug 2024 09:57:31 +0300 Jani Nikula <jani.nikula@intel.com> wrote:

> > Removing a nested include exposes all those sites which were
> > erroneously depending upon that nested include.  Here's what I have
> > found so far, there will be more.
> 
> Right. I didn't hit them with the configs I tried... though I wonder why
> not, especially lib/fault-inject.c puzzles me.
> 
> How do you want to proceed? Arguably uncovering and fixing those places
> is good, but that's kind of an unintended consequence here.

Is OK, it's a good change.  I fixed everything which my usual build
testing covers.  Other things will be reported and I'll fix those also.
If you have time to eyeball the 36 files which include fault-inject.h
then that would help things along.
Abhinav Kumar Aug. 14, 2024, 11:38 p.m. UTC | #5
On 8/13/2024 5:12 AM, Jani Nikula wrote:
> With the proper stubs in place in linux/fault-inject.h, we can remove a
> bunch of conditional compilation for CONFIG_FAULT_INJECTION=n.
> 
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Akinobu Mita <akinobu.mita@gmail.com>
> Cc: Rob Clark <robdclark@gmail.com>
> Cc: Abhinav Kumar <quic_abhinavk@quicinc.com>
> Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
> ---
>   drivers/gpu/drm/msm/msm_debugfs.c | 2 --
>   drivers/gpu/drm/msm/msm_drv.c     | 2 --
>   drivers/gpu/drm/msm/msm_drv.h     | 4 ----
>   3 files changed, 8 deletions(-)
> 

Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
diff mbox series

Patch

diff --git a/include/linux/fault-inject.h b/include/linux/fault-inject.h
index 354413950d34..8c829d28dcf3 100644
--- a/include/linux/fault-inject.h
+++ b/include/linux/fault-inject.h
@@ -2,13 +2,17 @@ 
 #ifndef _LINUX_FAULT_INJECT_H
 #define _LINUX_FAULT_INJECT_H
 
+#include <linux/err.h>
+#include <linux/types.h>
+
+struct dentry;
+struct kmem_cache;
+
 #ifdef CONFIG_FAULT_INJECTION
 
-#include <linux/types.h>
-#include <linux/debugfs.h>
+#include <linux/atomic.h>
 #include <linux/configfs.h>
 #include <linux/ratelimit.h>
-#include <linux/atomic.h>
 
 /*
  * For explanation of the elements of this struct, see
@@ -51,6 +55,28 @@  int setup_fault_attr(struct fault_attr *attr, char *str);
 bool should_fail_ex(struct fault_attr *attr, ssize_t size, int flags);
 bool should_fail(struct fault_attr *attr, ssize_t size);
 
+#else /* CONFIG_FAULT_INJECTION */
+
+struct fault_attr {
+};
+
+#define DECLARE_FAULT_ATTR(name) struct fault_attr name = {}
+
+static inline int setup_fault_attr(struct fault_attr *attr, char *str)
+{
+	return 0; /* Note: 0 means error for __setup() handlers! */
+}
+static inline bool should_fail_ex(struct fault_attr *attr, ssize_t size, int flags)
+{
+	return false;
+}
+static inline bool should_fail(struct fault_attr *attr, ssize_t size)
+{
+	return false;
+}
+
+#endif /* CONFIG_FAULT_INJECTION */
+
 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
 
 struct dentry *fault_create_debugfs_attr(const char *name,
@@ -87,10 +113,6 @@  static inline void fault_config_init(struct fault_config *config,
 
 #endif /* CONFIG_FAULT_INJECTION_CONFIGFS */
 
-#endif /* CONFIG_FAULT_INJECTION */
-
-struct kmem_cache;
-
 #ifdef CONFIG_FAIL_PAGE_ALLOC
 bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order);
 #else