Re: [PATCH v9 17/44] kasan, arm64: move initialization message
On Wed, Nov 11, 2020 at 7:50 PM Andrey Konovalov wrote: > > On Wed, Nov 11, 2020 at 4:04 PM Alexander Potapenko wrote: > > > > On Tue, Nov 10, 2020 at 11:11 PM Andrey Konovalov > > wrote: > > > > > > Software tag-based KASAN mode is fully initialized with kasan_init_tags(), > > > while the generic mode only requires kasan_init(). Move the > > > initialization message for tag-based mode into kasan_init_tags(). > > > > > > Also fix pr_fmt() usage for KASAN code: generic.c doesn't need it as it > > > doesn't use any printing functions; tag-based mode should use "kasan:" > > > instead of KBUILD_MODNAME (which stands for file name). > > > > > > Signed-off-by: Andrey Konovalov > > > Reviewed-by: Catalin Marinas Reviewed-by: Alexander Potapenko > > Cannot we have a single kasan_init() function that will call > > tool-specific initialization functions and print the message at the > > end? > > Unfortunately no. For different modes we need different functions that > are called in different places in the kernel. E.g. for generic KASAN > we only need kasan_init() to setup shadow pages; for SW tags we also > need kasan_init_sw_tags() which initializes per-cpu state and > finilizes initialization process. Ok, got it. -- Alexander Potapenko Software Engineer Google Germany GmbH Erika-Mann-Straße, 33 80636 München Geschäftsführer: Paul Manicle, Halimah DeLaine Prado Registergericht und -nummer: Hamburg, HRB 86891 Sitz der Gesellschaft: Hamburg
Re: [PATCH v9 17/44] kasan, arm64: move initialization message
On Wed, Nov 11, 2020 at 4:04 PM Alexander Potapenko wrote:
>
> On Tue, Nov 10, 2020 at 11:11 PM Andrey Konovalov
> wrote:
> >
> > Software tag-based KASAN mode is fully initialized with kasan_init_tags(),
> > while the generic mode only requires kasan_init(). Move the
> > initialization message for tag-based mode into kasan_init_tags().
> >
> > Also fix pr_fmt() usage for KASAN code: generic.c doesn't need it as it
> > doesn't use any printing functions; tag-based mode should use "kasan:"
> > instead of KBUILD_MODNAME (which stands for file name).
> >
> > Signed-off-by: Andrey Konovalov
> > Reviewed-by: Catalin Marinas
> > ---
> > Change-Id: Iddca9764b30ff0fab1922f26ca9d4f39b6f22673
> > ---
> > arch/arm64/include/asm/kasan.h | 9 +++--
> > arch/arm64/mm/kasan_init.c | 13 +
> > mm/kasan/generic.c | 2 --
> > mm/kasan/sw_tags.c | 4 +++-
> > 4 files changed, 11 insertions(+), 17 deletions(-)
> >
> > diff --git a/arch/arm64/include/asm/kasan.h b/arch/arm64/include/asm/kasan.h
> > index f7ea70d02cab..0aaf9044cd6a 100644
> > --- a/arch/arm64/include/asm/kasan.h
> > +++ b/arch/arm64/include/asm/kasan.h
> > @@ -12,14 +12,10 @@
> > #define arch_kasan_reset_tag(addr) __tag_reset(addr)
> > #define arch_kasan_get_tag(addr) __tag_get(addr)
> >
> > -#ifdef CONFIG_KASAN
> > -void kasan_init(void);
> > -#else
> > -static inline void kasan_init(void) { }
> > -#endif
> > -
> > #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
> >
> > +void kasan_init(void);
> > +
> > /*
> > * KASAN_SHADOW_START: beginning of the kernel virtual addresses.
> > * KASAN_SHADOW_END: KASAN_SHADOW_START + 1/N of kernel virtual addresses,
> > @@ -43,6 +39,7 @@ void kasan_copy_shadow(pgd_t *pgdir);
> > asmlinkage void kasan_early_init(void);
> >
> > #else
> > +static inline void kasan_init(void) { }
> > static inline void kasan_copy_shadow(pgd_t *pgdir) { }
> > #endif
> >
> > diff --git a/arch/arm64/mm/kasan_init.c b/arch/arm64/mm/kasan_init.c
> > index 5172799f831f..e35ce04beed1 100644
> > --- a/arch/arm64/mm/kasan_init.c
> > +++ b/arch/arm64/mm/kasan_init.c
> > @@ -278,17 +278,14 @@ static void __init kasan_init_depth(void)
> > init_task.kasan_depth = 0;
> > }
> >
> > -#else /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS) */
> > -
> > -static inline void __init kasan_init_shadow(void) { }
> > -
> > -static inline void __init kasan_init_depth(void) { }
> > -
> > -#endif /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */
> > -
> > void __init kasan_init(void)
> > {
> > kasan_init_shadow();
> > kasan_init_depth();
> > +#if defined(CONFIG_KASAN_GENERIC)
> > + /* CONFIG_KASAN_SW_TAGS also requires kasan_init_tags(). */
> > pr_info("KernelAddressSanitizer initialized\n");
> > +#endif
> > }
>
> Cannot we have a single kasan_init() function that will call
> tool-specific initialization functions and print the message at the
> end?
Unfortunately no. For different modes we need different functions that
are called in different places in the kernel. E.g. for generic KASAN
we only need kasan_init() to setup shadow pages; for SW tags we also
need kasan_init_sw_tags() which initializes per-cpu state and
finilizes initialization process.
Re: [PATCH v9 17/44] kasan, arm64: move initialization message
On Tue, Nov 10, 2020 at 11:11 PM Andrey Konovalov wrote:
>
> Software tag-based KASAN mode is fully initialized with kasan_init_tags(),
> while the generic mode only requires kasan_init(). Move the
> initialization message for tag-based mode into kasan_init_tags().
>
> Also fix pr_fmt() usage for KASAN code: generic.c doesn't need it as it
> doesn't use any printing functions; tag-based mode should use "kasan:"
> instead of KBUILD_MODNAME (which stands for file name).
>
> Signed-off-by: Andrey Konovalov
> Reviewed-by: Catalin Marinas
> ---
> Change-Id: Iddca9764b30ff0fab1922f26ca9d4f39b6f22673
> ---
> arch/arm64/include/asm/kasan.h | 9 +++--
> arch/arm64/mm/kasan_init.c | 13 +
> mm/kasan/generic.c | 2 --
> mm/kasan/sw_tags.c | 4 +++-
> 4 files changed, 11 insertions(+), 17 deletions(-)
>
> diff --git a/arch/arm64/include/asm/kasan.h b/arch/arm64/include/asm/kasan.h
> index f7ea70d02cab..0aaf9044cd6a 100644
> --- a/arch/arm64/include/asm/kasan.h
> +++ b/arch/arm64/include/asm/kasan.h
> @@ -12,14 +12,10 @@
> #define arch_kasan_reset_tag(addr) __tag_reset(addr)
> #define arch_kasan_get_tag(addr) __tag_get(addr)
>
> -#ifdef CONFIG_KASAN
> -void kasan_init(void);
> -#else
> -static inline void kasan_init(void) { }
> -#endif
> -
> #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
>
> +void kasan_init(void);
> +
> /*
> * KASAN_SHADOW_START: beginning of the kernel virtual addresses.
> * KASAN_SHADOW_END: KASAN_SHADOW_START + 1/N of kernel virtual addresses,
> @@ -43,6 +39,7 @@ void kasan_copy_shadow(pgd_t *pgdir);
> asmlinkage void kasan_early_init(void);
>
> #else
> +static inline void kasan_init(void) { }
> static inline void kasan_copy_shadow(pgd_t *pgdir) { }
> #endif
>
> diff --git a/arch/arm64/mm/kasan_init.c b/arch/arm64/mm/kasan_init.c
> index 5172799f831f..e35ce04beed1 100644
> --- a/arch/arm64/mm/kasan_init.c
> +++ b/arch/arm64/mm/kasan_init.c
> @@ -278,17 +278,14 @@ static void __init kasan_init_depth(void)
> init_task.kasan_depth = 0;
> }
>
> -#else /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS) */
> -
> -static inline void __init kasan_init_shadow(void) { }
> -
> -static inline void __init kasan_init_depth(void) { }
> -
> -#endif /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */
> -
> void __init kasan_init(void)
> {
> kasan_init_shadow();
> kasan_init_depth();
> +#if defined(CONFIG_KASAN_GENERIC)
> + /* CONFIG_KASAN_SW_TAGS also requires kasan_init_tags(). */
> pr_info("KernelAddressSanitizer initialized\n");
> +#endif
> }
Cannot we have a single kasan_init() function that will call
tool-specific initialization functions and print the message at the
end?
> +
> +#endif /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */
> diff --git a/mm/kasan/generic.c b/mm/kasan/generic.c
> index e1af3b6c53b8..adb254df1b1d 100644
> --- a/mm/kasan/generic.c
> +++ b/mm/kasan/generic.c
> @@ -9,8 +9,6 @@
> *Andrey Konovalov
> */
>
> -#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> -
> #include
> #include
> #include
> diff --git a/mm/kasan/sw_tags.c b/mm/kasan/sw_tags.c
> index b2638c2cd58a..d25f8641b7cd 100644
> --- a/mm/kasan/sw_tags.c
> +++ b/mm/kasan/sw_tags.c
> @@ -6,7 +6,7 @@
> * Author: Andrey Konovalov
> */
>
> -#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> +#define pr_fmt(fmt) "kasan: " fmt
>
> #include
> #include
> @@ -41,6 +41,8 @@ void kasan_init_tags(void)
>
> for_each_possible_cpu(cpu)
> per_cpu(prng_state, cpu) = (u32)get_cycles();
> +
> + pr_info("KernelAddressSanitizer initialized\n");
> }
>
> /*
> --
> 2.29.2.222.g5d2a92d10f8-goog
>
--
Alexander Potapenko
Software Engineer
Google Germany GmbH
Erika-Mann-Straße, 33
80636 München
Geschäftsführer: Paul Manicle, Halimah DeLaine Prado
Registergericht und -nummer: Hamburg, HRB 86891
Sitz der Gesellschaft: Hamburg
