| Message ID | 20200307093926.27145-1-tranmanphong@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: add check_wx_pages debugfs for CHECK_WX | expand |
On 07/03/2020 09:39, Phong Tran wrote: > follow the suggestion from > https://github.com/KSPP/linux/issues/35 > > Signed-off-by: Phong Tran <tranmanphong@gmail.com> > --- > arch/arm64/Kconfig.debug | 3 ++- > arch/arm64/include/asm/ptdump.h | 2 ++ > arch/arm64/mm/dump.c | 1 + > arch/arm64/mm/ptdump_debugfs.c | 18 ++++++++++++++++++ > 4 files changed, 23 insertions(+), 1 deletion(-) > > diff --git a/arch/arm64/Kconfig.debug b/arch/arm64/Kconfig.debug > index 1c906d932d6b..be552fa351e2 100644 > --- a/arch/arm64/Kconfig.debug > +++ b/arch/arm64/Kconfig.debug > @@ -48,7 +48,8 @@ config DEBUG_WX > of other unfixed kernel bugs easier. > > There is no runtime or memory usage effect of this option > - once the kernel has booted up - it's a one time check. > + once the kernel has booted up - it's a one time check and > + can be checked by echo "1" to "check_wx_pages" debugfs in runtime. I would suggest it may be better spelling this out a bit more, because at the moment it's a little confusing when the config option is "Warn on W+X mappings at boot", but your change makes it sound like it only happens when you do the echo. Perhaps something like: There is no runtime or memory usage effect of this option once the kernel has booted up - it's a one time check at boot, and can also be triggered at runtime by echo "1" to "check_wx_pages". > > If in doubt, say "Y". > > diff --git a/arch/arm64/include/asm/ptdump.h b/arch/arm64/include/asm/ptdump.h > index 38187f74e089..b80d6b4fc508 100644 > --- a/arch/arm64/include/asm/ptdump.h > +++ b/arch/arm64/include/asm/ptdump.h > @@ -24,9 +24,11 @@ struct ptdump_info { > void ptdump_walk(struct seq_file *s, struct ptdump_info *info); > #ifdef CONFIG_PTDUMP_DEBUGFS > void ptdump_debugfs_register(struct ptdump_info *info, const char *name); > +int ptdump_check_wx_init(void); > #else > static inline void ptdump_debugfs_register(struct ptdump_info *info, > const char *name) { } > +static inline int ptdump_check_wx_init(void) { return 0; } > #endif > void ptdump_check_wx(void); > #endif /* CONFIG_PTDUMP_CORE */ This is a confusing! Why have you made it dependent on CONFIG_PTDUMP_DEBUGFS? Well actually I can see why - it's because you've put the new functions in ptdump_debugfs.c which is (currently) only built when CONFIG_PTDUMP_DBEUGFS is enabled. So you need to either: a) Ensure the new code is built when CONFIG_PTDUMP_DEBUGFS isn't enabled. b) Update the Kconfig help text to say that the debugfs file for triggering a runtime W+X check is only available if CONFIG_PTDUMP_DEBUGFS is also enabled. Other than the confusion over config symbols this looks good. Thanks, Steve > diff --git a/arch/arm64/mm/dump.c b/arch/arm64/mm/dump.c > index 860c00ec8bd3..60c99a047763 100644 > --- a/arch/arm64/mm/dump.c > +++ b/arch/arm64/mm/dump.c > @@ -378,6 +378,7 @@ static int ptdump_init(void) > #endif > ptdump_initialize(); > ptdump_debugfs_register(&kernel_ptdump_info, "kernel_page_tables"); > + ptdump_check_wx_init(); > return 0; > } > device_initcall(ptdump_init); > diff --git a/arch/arm64/mm/ptdump_debugfs.c b/arch/arm64/mm/ptdump_debugfs.c > index 1f2eae3e988b..73cddc12c3c2 100644 > --- a/arch/arm64/mm/ptdump_debugfs.c > +++ b/arch/arm64/mm/ptdump_debugfs.c > @@ -16,3 +16,21 @@ void ptdump_debugfs_register(struct ptdump_info *info, const char *name) > { > debugfs_create_file(name, 0400, NULL, info, &ptdump_fops); > } > + > +static int check_wx_debugfs_set(void *data, u64 val) > +{ > + if (val != 1ULL) > + return -EINVAL; > + > + ptdump_check_wx(); > + > + return 0; > +} > + > +DEFINE_SIMPLE_ATTRIBUTE(check_wx_fops, NULL, check_wx_debugfs_set, "%llu\n"); > + > +int ptdump_check_wx_init(void) > +{ > + return debugfs_create_file("check_wx_pages", 0200, NULL, > + NULL, &check_wx_fops) ? 0 : -ENOMEM; > +} >
On Sat, Mar 07, 2020 at 04:39:26PM +0700, Phong Tran wrote: > follow the suggestion from > https://github.com/KSPP/linux/issues/35 That says: | This should be implemented for all architectures ... so surely this should be in generic code, rahter than being arm64-specific? Thanks, Mark. > > Signed-off-by: Phong Tran <tranmanphong@gmail.com> > --- > arch/arm64/Kconfig.debug | 3 ++- > arch/arm64/include/asm/ptdump.h | 2 ++ > arch/arm64/mm/dump.c | 1 + > arch/arm64/mm/ptdump_debugfs.c | 18 ++++++++++++++++++ > 4 files changed, 23 insertions(+), 1 deletion(-) > > diff --git a/arch/arm64/Kconfig.debug b/arch/arm64/Kconfig.debug > index 1c906d932d6b..be552fa351e2 100644 > --- a/arch/arm64/Kconfig.debug > +++ b/arch/arm64/Kconfig.debug > @@ -48,7 +48,8 @@ config DEBUG_WX > of other unfixed kernel bugs easier. > > There is no runtime or memory usage effect of this option > - once the kernel has booted up - it's a one time check. > + once the kernel has booted up - it's a one time check and > + can be checked by echo "1" to "check_wx_pages" debugfs in runtime. > > If in doubt, say "Y". > > diff --git a/arch/arm64/include/asm/ptdump.h b/arch/arm64/include/asm/ptdump.h > index 38187f74e089..b80d6b4fc508 100644 > --- a/arch/arm64/include/asm/ptdump.h > +++ b/arch/arm64/include/asm/ptdump.h > @@ -24,9 +24,11 @@ struct ptdump_info { > void ptdump_walk(struct seq_file *s, struct ptdump_info *info); > #ifdef CONFIG_PTDUMP_DEBUGFS > void ptdump_debugfs_register(struct ptdump_info *info, const char *name); > +int ptdump_check_wx_init(void); > #else > static inline void ptdump_debugfs_register(struct ptdump_info *info, > const char *name) { } > +static inline int ptdump_check_wx_init(void) { return 0; } > #endif > void ptdump_check_wx(void); > #endif /* CONFIG_PTDUMP_CORE */ > diff --git a/arch/arm64/mm/dump.c b/arch/arm64/mm/dump.c > index 860c00ec8bd3..60c99a047763 100644 > --- a/arch/arm64/mm/dump.c > +++ b/arch/arm64/mm/dump.c > @@ -378,6 +378,7 @@ static int ptdump_init(void) > #endif > ptdump_initialize(); > ptdump_debugfs_register(&kernel_ptdump_info, "kernel_page_tables"); > + ptdump_check_wx_init(); > return 0; > } > device_initcall(ptdump_init); > diff --git a/arch/arm64/mm/ptdump_debugfs.c b/arch/arm64/mm/ptdump_debugfs.c > index 1f2eae3e988b..73cddc12c3c2 100644 > --- a/arch/arm64/mm/ptdump_debugfs.c > +++ b/arch/arm64/mm/ptdump_debugfs.c > @@ -16,3 +16,21 @@ void ptdump_debugfs_register(struct ptdump_info *info, const char *name) > { > debugfs_create_file(name, 0400, NULL, info, &ptdump_fops); > } > + > +static int check_wx_debugfs_set(void *data, u64 val) > +{ > + if (val != 1ULL) > + return -EINVAL; > + > + ptdump_check_wx(); > + > + return 0; > +} > + > +DEFINE_SIMPLE_ATTRIBUTE(check_wx_fops, NULL, check_wx_debugfs_set, "%llu\n"); > + > +int ptdump_check_wx_init(void) > +{ > + return debugfs_create_file("check_wx_pages", 0200, NULL, > + NULL, &check_wx_fops) ? 0 : -ENOMEM; > +} > -- > 2.20.1 >
On Mon, Mar 09, 2020 at 12:17:14PM +0000, Mark Rutland wrote: > On Sat, Mar 07, 2020 at 04:39:26PM +0700, Phong Tran wrote: > > follow the suggestion from > > https://github.com/KSPP/linux/issues/35 > > That says: > > | This should be implemented for all architectures > > ... so surely this should be in generic code, rahter than being > arm64-specific? > > Thanks, > Mark. > > > > > Signed-off-by: Phong Tran <tranmanphong@gmail.com> > > --- > > arch/arm64/Kconfig.debug | 3 ++- > > arch/arm64/include/asm/ptdump.h | 2 ++ > > arch/arm64/mm/dump.c | 1 + > > arch/arm64/mm/ptdump_debugfs.c | 18 ++++++++++++++++++ > > 4 files changed, 23 insertions(+), 1 deletion(-) > > > > diff --git a/arch/arm64/Kconfig.debug b/arch/arm64/Kconfig.debug > > index 1c906d932d6b..be552fa351e2 100644 > > --- a/arch/arm64/Kconfig.debug > > +++ b/arch/arm64/Kconfig.debug > > @@ -48,7 +48,8 @@ config DEBUG_WX > > of other unfixed kernel bugs easier. > > > > There is no runtime or memory usage effect of this option > > - once the kernel has booted up - it's a one time check. > > + once the kernel has booted up - it's a one time check and > > + can be checked by echo "1" to "check_wx_pages" debugfs in runtime. > > > > If in doubt, say "Y". > > > > diff --git a/arch/arm64/include/asm/ptdump.h b/arch/arm64/include/asm/ptdump.h > > index 38187f74e089..b80d6b4fc508 100644 > > --- a/arch/arm64/include/asm/ptdump.h > > +++ b/arch/arm64/include/asm/ptdump.h > > @@ -24,9 +24,11 @@ struct ptdump_info { > > void ptdump_walk(struct seq_file *s, struct ptdump_info *info); > > #ifdef CONFIG_PTDUMP_DEBUGFS > > void ptdump_debugfs_register(struct ptdump_info *info, const char *name); > > +int ptdump_check_wx_init(void); > > #else > > static inline void ptdump_debugfs_register(struct ptdump_info *info, > > const char *name) { } > > +static inline int ptdump_check_wx_init(void) { return 0; } > > #endif > > void ptdump_check_wx(void); > > #endif /* CONFIG_PTDUMP_CORE */ > > diff --git a/arch/arm64/mm/dump.c b/arch/arm64/mm/dump.c > > index 860c00ec8bd3..60c99a047763 100644 > > --- a/arch/arm64/mm/dump.c > > +++ b/arch/arm64/mm/dump.c > > @@ -378,6 +378,7 @@ static int ptdump_init(void) > > #endif > > ptdump_initialize(); > > ptdump_debugfs_register(&kernel_ptdump_info, "kernel_page_tables"); > > + ptdump_check_wx_init(); > > return 0; > > } > > device_initcall(ptdump_init); > > diff --git a/arch/arm64/mm/ptdump_debugfs.c b/arch/arm64/mm/ptdump_debugfs.c > > index 1f2eae3e988b..73cddc12c3c2 100644 > > --- a/arch/arm64/mm/ptdump_debugfs.c > > +++ b/arch/arm64/mm/ptdump_debugfs.c > > @@ -16,3 +16,21 @@ void ptdump_debugfs_register(struct ptdump_info *info, const char *name) > > { > > debugfs_create_file(name, 0400, NULL, info, &ptdump_fops); > > } > > + > > +static int check_wx_debugfs_set(void *data, u64 val) > > +{ > > + if (val != 1ULL) > > + return -EINVAL; > > + > > + ptdump_check_wx(); > > + > > + return 0; > > +} > > + > > +DEFINE_SIMPLE_ATTRIBUTE(check_wx_fops, NULL, check_wx_debugfs_set, "%llu\n"); > > + > > +int ptdump_check_wx_init(void) > > +{ > > + return debugfs_create_file("check_wx_pages", 0200, NULL, > > + NULL, &check_wx_fops) ? 0 : -ENOMEM; Do not check the return value of this function, especially as it is returning a pointer, not an int! Just call the function and move on, you should not do anything different if it returns an error or not. thanks, greg k-h
On Mon, Mar 09, 2020 at 12:17:14PM +0000, Mark Rutland wrote: > On Sat, Mar 07, 2020 at 04:39:26PM +0700, Phong Tran wrote: > > follow the suggestion from > > https://github.com/KSPP/linux/issues/35 > > That says: > > | This should be implemented for all architectures > > ... so surely this should be in generic code, rahter than being > arm64-specific? Not all architectures have implemented CONFIG_DEBUG_WX... -Kees > > Thanks, > Mark. > > > > > Signed-off-by: Phong Tran <tranmanphong@gmail.com> > > --- > > arch/arm64/Kconfig.debug | 3 ++- > > arch/arm64/include/asm/ptdump.h | 2 ++ > > arch/arm64/mm/dump.c | 1 + > > arch/arm64/mm/ptdump_debugfs.c | 18 ++++++++++++++++++ > > 4 files changed, 23 insertions(+), 1 deletion(-) > > > > diff --git a/arch/arm64/Kconfig.debug b/arch/arm64/Kconfig.debug > > index 1c906d932d6b..be552fa351e2 100644 > > --- a/arch/arm64/Kconfig.debug > > +++ b/arch/arm64/Kconfig.debug > > @@ -48,7 +48,8 @@ config DEBUG_WX > > of other unfixed kernel bugs easier. > > > > There is no runtime or memory usage effect of this option > > - once the kernel has booted up - it's a one time check. > > + once the kernel has booted up - it's a one time check and > > + can be checked by echo "1" to "check_wx_pages" debugfs in runtime. > > > > If in doubt, say "Y". > > > > diff --git a/arch/arm64/include/asm/ptdump.h b/arch/arm64/include/asm/ptdump.h > > index 38187f74e089..b80d6b4fc508 100644 > > --- a/arch/arm64/include/asm/ptdump.h > > +++ b/arch/arm64/include/asm/ptdump.h > > @@ -24,9 +24,11 @@ struct ptdump_info { > > void ptdump_walk(struct seq_file *s, struct ptdump_info *info); > > #ifdef CONFIG_PTDUMP_DEBUGFS > > void ptdump_debugfs_register(struct ptdump_info *info, const char *name); > > +int ptdump_check_wx_init(void); > > #else > > static inline void ptdump_debugfs_register(struct ptdump_info *info, > > const char *name) { } > > +static inline int ptdump_check_wx_init(void) { return 0; } > > #endif > > void ptdump_check_wx(void); > > #endif /* CONFIG_PTDUMP_CORE */ > > diff --git a/arch/arm64/mm/dump.c b/arch/arm64/mm/dump.c > > index 860c00ec8bd3..60c99a047763 100644 > > --- a/arch/arm64/mm/dump.c > > +++ b/arch/arm64/mm/dump.c > > @@ -378,6 +378,7 @@ static int ptdump_init(void) > > #endif > > ptdump_initialize(); > > ptdump_debugfs_register(&kernel_ptdump_info, "kernel_page_tables"); > > + ptdump_check_wx_init(); > > return 0; > > } > > device_initcall(ptdump_init); > > diff --git a/arch/arm64/mm/ptdump_debugfs.c b/arch/arm64/mm/ptdump_debugfs.c > > index 1f2eae3e988b..73cddc12c3c2 100644 > > --- a/arch/arm64/mm/ptdump_debugfs.c > > +++ b/arch/arm64/mm/ptdump_debugfs.c > > @@ -16,3 +16,21 @@ void ptdump_debugfs_register(struct ptdump_info *info, const char *name) > > { > > debugfs_create_file(name, 0400, NULL, info, &ptdump_fops); > > } > > + > > +static int check_wx_debugfs_set(void *data, u64 val) > > +{ > > + if (val != 1ULL) > > + return -EINVAL; > > + > > + ptdump_check_wx(); > > + > > + return 0; > > +} > > + > > +DEFINE_SIMPLE_ATTRIBUTE(check_wx_fops, NULL, check_wx_debugfs_set, "%llu\n"); > > + > > +int ptdump_check_wx_init(void) > > +{ > > + return debugfs_create_file("check_wx_pages", 0200, NULL, > > + NULL, &check_wx_fops) ? 0 : -ENOMEM; > > +} > > -- > > 2.20.1 > >
On Mon, Mar 09, 2020 at 09:15:10AM -0700, Kees Cook wrote: > On Mon, Mar 09, 2020 at 12:17:14PM +0000, Mark Rutland wrote: > > On Sat, Mar 07, 2020 at 04:39:26PM +0700, Phong Tran wrote: > > > follow the suggestion from > > > https://github.com/KSPP/linux/issues/35 > > > > That says: > > > > | This should be implemented for all architectures > > > > ... so surely this should be in generic code, rahter than being > > arm64-specific? > > Not all architectures have implemented CONFIG_DEBUG_WX... Sure; I assumed the generic code could be gated with: #ifdef CONFIG_DEBUG_WX debug_checkwx() #endif ... or something to that effect, so that the common code could handle all the sysfs bits and ensure that part was consistent. Thanksm Mark. > > -Kees > > > > > Thanks, > > Mark. > > > > > > > > Signed-off-by: Phong Tran <tranmanphong@gmail.com> > > > --- > > > arch/arm64/Kconfig.debug | 3 ++- > > > arch/arm64/include/asm/ptdump.h | 2 ++ > > > arch/arm64/mm/dump.c | 1 + > > > arch/arm64/mm/ptdump_debugfs.c | 18 ++++++++++++++++++ > > > 4 files changed, 23 insertions(+), 1 deletion(-) > > > > > > diff --git a/arch/arm64/Kconfig.debug b/arch/arm64/Kconfig.debug > > > index 1c906d932d6b..be552fa351e2 100644 > > > --- a/arch/arm64/Kconfig.debug > > > +++ b/arch/arm64/Kconfig.debug > > > @@ -48,7 +48,8 @@ config DEBUG_WX > > > of other unfixed kernel bugs easier. > > > > > > There is no runtime or memory usage effect of this option > > > - once the kernel has booted up - it's a one time check. > > > + once the kernel has booted up - it's a one time check and > > > + can be checked by echo "1" to "check_wx_pages" debugfs in runtime. > > > > > > If in doubt, say "Y". > > > > > > diff --git a/arch/arm64/include/asm/ptdump.h b/arch/arm64/include/asm/ptdump.h > > > index 38187f74e089..b80d6b4fc508 100644 > > > --- a/arch/arm64/include/asm/ptdump.h > > > +++ b/arch/arm64/include/asm/ptdump.h > > > @@ -24,9 +24,11 @@ struct ptdump_info { > > > void ptdump_walk(struct seq_file *s, struct ptdump_info *info); > > > #ifdef CONFIG_PTDUMP_DEBUGFS > > > void ptdump_debugfs_register(struct ptdump_info *info, const char *name); > > > +int ptdump_check_wx_init(void); > > > #else > > > static inline void ptdump_debugfs_register(struct ptdump_info *info, > > > const char *name) { } > > > +static inline int ptdump_check_wx_init(void) { return 0; } > > > #endif > > > void ptdump_check_wx(void); > > > #endif /* CONFIG_PTDUMP_CORE */ > > > diff --git a/arch/arm64/mm/dump.c b/arch/arm64/mm/dump.c > > > index 860c00ec8bd3..60c99a047763 100644 > > > --- a/arch/arm64/mm/dump.c > > > +++ b/arch/arm64/mm/dump.c > > > @@ -378,6 +378,7 @@ static int ptdump_init(void) > > > #endif > > > ptdump_initialize(); > > > ptdump_debugfs_register(&kernel_ptdump_info, "kernel_page_tables"); > > > + ptdump_check_wx_init(); > > > return 0; > > > } > > > device_initcall(ptdump_init); > > > diff --git a/arch/arm64/mm/ptdump_debugfs.c b/arch/arm64/mm/ptdump_debugfs.c > > > index 1f2eae3e988b..73cddc12c3c2 100644 > > > --- a/arch/arm64/mm/ptdump_debugfs.c > > > +++ b/arch/arm64/mm/ptdump_debugfs.c > > > @@ -16,3 +16,21 @@ void ptdump_debugfs_register(struct ptdump_info *info, const char *name) > > > { > > > debugfs_create_file(name, 0400, NULL, info, &ptdump_fops); > > > } > > > + > > > +static int check_wx_debugfs_set(void *data, u64 val) > > > +{ > > > + if (val != 1ULL) > > > + return -EINVAL; > > > + > > > + ptdump_check_wx(); > > > + > > > + return 0; > > > +} > > > + > > > +DEFINE_SIMPLE_ATTRIBUTE(check_wx_fops, NULL, check_wx_debugfs_set, "%llu\n"); > > > + > > > +int ptdump_check_wx_init(void) > > > +{ > > > + return debugfs_create_file("check_wx_pages", 0200, NULL, > > > + NULL, &check_wx_fops) ? 0 : -ENOMEM; > > > +} > > > -- > > > 2.20.1 > > > > > -- > Kees Cook
On Sat, Mar 07, 2020 at 04:39:26PM +0700, Phong Tran wrote: > follow the suggestion from > https://github.com/KSPP/linux/issues/35 > > Signed-off-by: Phong Tran <tranmanphong@gmail.com> > --- > arch/arm64/Kconfig.debug | 3 ++- > arch/arm64/include/asm/ptdump.h | 2 ++ > arch/arm64/mm/dump.c | 1 + > arch/arm64/mm/ptdump_debugfs.c | 18 ++++++++++++++++++ > 4 files changed, 23 insertions(+), 1 deletion(-) Any plans to spin an updated version of this? The review feedback all seemed reasonable to me. Thanks, Will
diff --git a/arch/arm64/Kconfig.debug b/arch/arm64/Kconfig.debug index 1c906d932d6b..be552fa351e2 100644 --- a/arch/arm64/Kconfig.debug +++ b/arch/arm64/Kconfig.debug @@ -48,7 +48,8 @@ config DEBUG_WX of other unfixed kernel bugs easier. There is no runtime or memory usage effect of this option - once the kernel has booted up - it's a one time check. + once the kernel has booted up - it's a one time check and + can be checked by echo "1" to "check_wx_pages" debugfs in runtime. If in doubt, say "Y". diff --git a/arch/arm64/include/asm/ptdump.h b/arch/arm64/include/asm/ptdump.h index 38187f74e089..b80d6b4fc508 100644 --- a/arch/arm64/include/asm/ptdump.h +++ b/arch/arm64/include/asm/ptdump.h @@ -24,9 +24,11 @@ struct ptdump_info { void ptdump_walk(struct seq_file *s, struct ptdump_info *info); #ifdef CONFIG_PTDUMP_DEBUGFS void ptdump_debugfs_register(struct ptdump_info *info, const char *name); +int ptdump_check_wx_init(void); #else static inline void ptdump_debugfs_register(struct ptdump_info *info, const char *name) { } +static inline int ptdump_check_wx_init(void) { return 0; } #endif void ptdump_check_wx(void); #endif /* CONFIG_PTDUMP_CORE */ diff --git a/arch/arm64/mm/dump.c b/arch/arm64/mm/dump.c index 860c00ec8bd3..60c99a047763 100644 --- a/arch/arm64/mm/dump.c +++ b/arch/arm64/mm/dump.c @@ -378,6 +378,7 @@ static int ptdump_init(void) #endif ptdump_initialize(); ptdump_debugfs_register(&kernel_ptdump_info, "kernel_page_tables"); + ptdump_check_wx_init(); return 0; } device_initcall(ptdump_init); diff --git a/arch/arm64/mm/ptdump_debugfs.c b/arch/arm64/mm/ptdump_debugfs.c index 1f2eae3e988b..73cddc12c3c2 100644 --- a/arch/arm64/mm/ptdump_debugfs.c +++ b/arch/arm64/mm/ptdump_debugfs.c @@ -16,3 +16,21 @@ void ptdump_debugfs_register(struct ptdump_info *info, const char *name) { debugfs_create_file(name, 0400, NULL, info, &ptdump_fops); } + +static int check_wx_debugfs_set(void *data, u64 val) +{ + if (val != 1ULL) + return -EINVAL; + + ptdump_check_wx(); + + return 0; +} + +DEFINE_SIMPLE_ATTRIBUTE(check_wx_fops, NULL, check_wx_debugfs_set, "%llu\n"); + +int ptdump_check_wx_init(void) +{ + return debugfs_create_file("check_wx_pages", 0200, NULL, + NULL, &check_wx_fops) ? 0 : -ENOMEM; +}
follow the suggestion from https://github.com/KSPP/linux/issues/35 Signed-off-by: Phong Tran <tranmanphong@gmail.com> --- arch/arm64/Kconfig.debug | 3 ++- arch/arm64/include/asm/ptdump.h | 2 ++ arch/arm64/mm/dump.c | 1 + arch/arm64/mm/ptdump_debugfs.c | 18 ++++++++++++++++++ 4 files changed, 23 insertions(+), 1 deletion(-)