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[RFC PATCH 2/4] riscv: add compile-time test into is_compat_task()

Leonardo Bras posted 4 patches 1 year, 12 months ago
[RFC PATCH 2/4] riscv: add compile-time test into is_compat_task()
Posted by Leonardo Bras 1 year, 12 months ago 
Currently several places will test for CONFIG_COMPAT before testing
is_compat_task(), probably in order to avoid a run-time test into the task
structure.

Since is_compat_task() is an inlined function, it would be helpful to add a
compile-time test of CONFIG_COMPAT, making sure it always returns zero when
the option is not enabled during the kernel build.

With this, the compiler is able to understand in build-time that
is_compat_task() will always return 0, and optimize-out some of the extra
code introduced by the option.

This will also allow removing a lot #ifdefs that were introduced, and make
the code more clean.

Signed-off-by: Leonardo Bras <leobras@redhat.com>
---
 arch/riscv/include/asm/compat.h    | 3 +++
 arch/riscv/include/asm/elf.h       | 4 ----
 arch/riscv/include/asm/pgtable.h   | 6 ------
 arch/riscv/include/asm/processor.h | 4 ++--
 4 files changed, 5 insertions(+), 12 deletions(-)

diff --git a/arch/riscv/include/asm/compat.h b/arch/riscv/include/asm/compat.h
index 2ac955b51148f..91517b51b8e27 100644
--- a/arch/riscv/include/asm/compat.h
+++ b/arch/riscv/include/asm/compat.h
@@ -14,6 +14,9 @@
 
 static inline int is_compat_task(void)
 {
+	if (!IS_ENABLED(CONFIG_COMPAT))
+		return 0;
+
 	return test_thread_flag(TIF_32BIT);
 }
 
diff --git a/arch/riscv/include/asm/elf.h b/arch/riscv/include/asm/elf.h
index 59a08367fddd7..2e88257cafaea 100644
--- a/arch/riscv/include/asm/elf.h
+++ b/arch/riscv/include/asm/elf.h
@@ -53,13 +53,9 @@ extern bool compat_elf_check_arch(Elf32_Ehdr *hdr);
 #define ELF_ET_DYN_BASE		((DEFAULT_MAP_WINDOW / 3) * 2)
 
 #ifdef CONFIG_64BIT
-#ifdef CONFIG_COMPAT
 #define STACK_RND_MASK		(is_compat_task() ? \
 				 0x7ff >> (PAGE_SHIFT - 12) : \
 				 0x3ffff >> (PAGE_SHIFT - 12))
-#else
-#define STACK_RND_MASK		(0x3ffff >> (PAGE_SHIFT - 12))
-#endif
 #endif
 
 /*
diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index 1d472b31e0cfe..ea5b269be223a 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -127,16 +127,10 @@
 #define VA_USER_SV48 (UL(1) << (VA_BITS_SV48 - 1))
 #define VA_USER_SV57 (UL(1) << (VA_BITS_SV57 - 1))
 
-#ifdef CONFIG_COMPAT
 #define MMAP_VA_BITS_64 ((VA_BITS >= VA_BITS_SV48) ? VA_BITS_SV48 : VA_BITS)
 #define MMAP_MIN_VA_BITS_64 (VA_BITS_SV39)
 #define MMAP_VA_BITS (is_compat_task() ? VA_BITS_SV32 : MMAP_VA_BITS_64)
 #define MMAP_MIN_VA_BITS (is_compat_task() ? VA_BITS_SV32 : MMAP_MIN_VA_BITS_64)
-#else
-#define MMAP_VA_BITS ((VA_BITS >= VA_BITS_SV48) ? VA_BITS_SV48 : VA_BITS)
-#define MMAP_MIN_VA_BITS (VA_BITS_SV39)
-#endif /* CONFIG_COMPAT */
-
 #else
 #include <asm/pgtable-32.h>
 #endif /* CONFIG_64BIT */
diff --git a/arch/riscv/include/asm/processor.h b/arch/riscv/include/asm/processor.h
index f19f861cda549..ed32e53e55999 100644
--- a/arch/riscv/include/asm/processor.h
+++ b/arch/riscv/include/asm/processor.h
@@ -22,7 +22,7 @@
 ({								\
 	unsigned long mmap_end;					\
 	typeof(addr) _addr = (addr);				\
-	if ((_addr) == 0 || (IS_ENABLED(CONFIG_COMPAT) && is_compat_task())) \
+	if ((_addr) == 0 || is_compat_task())			\
 		mmap_end = STACK_TOP_MAX;			\
 	else if ((_addr) >= VA_USER_SV57)			\
 		mmap_end = STACK_TOP_MAX;			\
@@ -39,7 +39,7 @@
 	typeof(addr) _addr = (addr);				\
 	typeof(base) _base = (base);				\
 	unsigned long rnd_gap = DEFAULT_MAP_WINDOW - (_base);	\
-	if ((_addr) == 0 || (IS_ENABLED(CONFIG_COMPAT) && is_compat_task())) \
+	if ((_addr) == 0 || is_compat_task())			\
 		mmap_base = (_base);				\
 	else if (((_addr) >= VA_USER_SV57) && (VA_BITS >= VA_BITS_SV57)) \
 		mmap_base = VA_USER_SV57 - rnd_gap;		\
-- 
2.43.0
Re: [RFC PATCH 2/4] riscv: add compile-time test into is_compat_task()
Posted by Guo Ren 1 year, 12 months ago 
On Fri, Dec 22, 2023 at 5:02 PM Leonardo Bras <leobras@redhat.com> wrote:
>
> Currently several places will test for CONFIG_COMPAT before testing
> is_compat_task(), probably in order to avoid a run-time test into the task
> structure.
>
> Since is_compat_task() is an inlined function, it would be helpful to add a
> compile-time test of CONFIG_COMPAT, making sure it always returns zero when
> the option is not enabled during the kernel build.
>
> With this, the compiler is able to understand in build-time that
> is_compat_task() will always return 0, and optimize-out some of the extra
> code introduced by the option.
>
> This will also allow removing a lot #ifdefs that were introduced, and make
> the code more clean.
>
> Signed-off-by: Leonardo Bras <leobras@redhat.com>
> ---
>  arch/riscv/include/asm/compat.h    | 3 +++
>  arch/riscv/include/asm/elf.h       | 4 ----
>  arch/riscv/include/asm/pgtable.h   | 6 ------
>  arch/riscv/include/asm/processor.h | 4 ++--
>  4 files changed, 5 insertions(+), 12 deletions(-)
>
> diff --git a/arch/riscv/include/asm/compat.h b/arch/riscv/include/asm/compat.h
> index 2ac955b51148f..91517b51b8e27 100644
> --- a/arch/riscv/include/asm/compat.h
> +++ b/arch/riscv/include/asm/compat.h
> @@ -14,6 +14,9 @@
>
>  static inline int is_compat_task(void)
>  {
> +       if (!IS_ENABLED(CONFIG_COMPAT))
> +               return 0;
> +
>         return test_thread_flag(TIF_32BIT);
>  }
>
> diff --git a/arch/riscv/include/asm/elf.h b/arch/riscv/include/asm/elf.h
> index 59a08367fddd7..2e88257cafaea 100644
> --- a/arch/riscv/include/asm/elf.h
> +++ b/arch/riscv/include/asm/elf.h
> @@ -53,13 +53,9 @@ extern bool compat_elf_check_arch(Elf32_Ehdr *hdr);
>  #define ELF_ET_DYN_BASE                ((DEFAULT_MAP_WINDOW / 3) * 2)
>
>  #ifdef CONFIG_64BIT
> -#ifdef CONFIG_COMPAT
>  #define STACK_RND_MASK         (is_compat_task() ? \
>                                  0x7ff >> (PAGE_SHIFT - 12) : \
>                                  0x3ffff >> (PAGE_SHIFT - 12))
> -#else
> -#define STACK_RND_MASK         (0x3ffff >> (PAGE_SHIFT - 12))
> -#endif
>  #endif
>
>  /*
> diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
> index 1d472b31e0cfe..ea5b269be223a 100644
> --- a/arch/riscv/include/asm/pgtable.h
> +++ b/arch/riscv/include/asm/pgtable.h
> @@ -127,16 +127,10 @@
>  #define VA_USER_SV48 (UL(1) << (VA_BITS_SV48 - 1))
>  #define VA_USER_SV57 (UL(1) << (VA_BITS_SV57 - 1))
>
> -#ifdef CONFIG_COMPAT
>  #define MMAP_VA_BITS_64 ((VA_BITS >= VA_BITS_SV48) ? VA_BITS_SV48 : VA_BITS)
>  #define MMAP_MIN_VA_BITS_64 (VA_BITS_SV39)
>  #define MMAP_VA_BITS (is_compat_task() ? VA_BITS_SV32 : MMAP_VA_BITS_64)
>  #define MMAP_MIN_VA_BITS (is_compat_task() ? VA_BITS_SV32 : MMAP_MIN_VA_BITS_64)
> -#else
> -#define MMAP_VA_BITS ((VA_BITS >= VA_BITS_SV48) ? VA_BITS_SV48 : VA_BITS)
> -#define MMAP_MIN_VA_BITS (VA_BITS_SV39)
> -#endif /* CONFIG_COMPAT */
> -
>  #else
>  #include <asm/pgtable-32.h>
>  #endif /* CONFIG_64BIT */
> diff --git a/arch/riscv/include/asm/processor.h b/arch/riscv/include/asm/processor.h
> index f19f861cda549..ed32e53e55999 100644
> --- a/arch/riscv/include/asm/processor.h
> +++ b/arch/riscv/include/asm/processor.h
> @@ -22,7 +22,7 @@
>  ({                                                             \
>         unsigned long mmap_end;                                 \
>         typeof(addr) _addr = (addr);                            \
> -       if ((_addr) == 0 || (IS_ENABLED(CONFIG_COMPAT) && is_compat_task())) \
> +       if ((_addr) == 0 || is_compat_task())                   \
>                 mmap_end = STACK_TOP_MAX;                       \
>         else if ((_addr) >= VA_USER_SV57)                       \
>                 mmap_end = STACK_TOP_MAX;                       \
> @@ -39,7 +39,7 @@
>         typeof(addr) _addr = (addr);                            \
>         typeof(base) _base = (base);                            \
>         unsigned long rnd_gap = DEFAULT_MAP_WINDOW - (_base);   \
> -       if ((_addr) == 0 || (IS_ENABLED(CONFIG_COMPAT) && is_compat_task())) \
> +       if ((_addr) == 0 || is_compat_task())                   \
>                 mmap_base = (_base);                            \
>         else if (((_addr) >= VA_USER_SV57) && (VA_BITS >= VA_BITS_SV57)) \
>                 mmap_base = VA_USER_SV57 - rnd_gap;             \
> --
> 2.43.0
>
Reviewed-by: Guo Ren <guoren@kernel.org>

-- 
Best Regards
 Guo Ren
Re: [RFC PATCH 2/4] riscv: add compile-time test into is_compat_task()
Posted by Leonardo Bras 1 year, 12 months ago 
On Fri, Dec 22, 2023 at 05:35:20PM +0800, Guo Ren wrote:
> On Fri, Dec 22, 2023 at 5:02 PM Leonardo Bras <leobras@redhat.com> wrote:
> >
> > Currently several places will test for CONFIG_COMPAT before testing
> > is_compat_task(), probably in order to avoid a run-time test into the task
> > structure.
> >
> > Since is_compat_task() is an inlined function, it would be helpful to add a
> > compile-time test of CONFIG_COMPAT, making sure it always returns zero when
> > the option is not enabled during the kernel build.
> >
> > With this, the compiler is able to understand in build-time that
> > is_compat_task() will always return 0, and optimize-out some of the extra
> > code introduced by the option.
> >
> > This will also allow removing a lot #ifdefs that were introduced, and make
> > the code more clean.
> >
> > Signed-off-by: Leonardo Bras <leobras@redhat.com>
> > ---
> >  arch/riscv/include/asm/compat.h    | 3 +++
> >  arch/riscv/include/asm/elf.h       | 4 ----
> >  arch/riscv/include/asm/pgtable.h   | 6 ------
> >  arch/riscv/include/asm/processor.h | 4 ++--
> >  4 files changed, 5 insertions(+), 12 deletions(-)
> >
> > diff --git a/arch/riscv/include/asm/compat.h b/arch/riscv/include/asm/compat.h
> > index 2ac955b51148f..91517b51b8e27 100644
> > --- a/arch/riscv/include/asm/compat.h
> > +++ b/arch/riscv/include/asm/compat.h
> > @@ -14,6 +14,9 @@
> >
> >  static inline int is_compat_task(void)
> >  {
> > +       if (!IS_ENABLED(CONFIG_COMPAT))
> > +               return 0;
> > +
> >         return test_thread_flag(TIF_32BIT);
> >  }
> >
> > diff --git a/arch/riscv/include/asm/elf.h b/arch/riscv/include/asm/elf.h
> > index 59a08367fddd7..2e88257cafaea 100644
> > --- a/arch/riscv/include/asm/elf.h
> > +++ b/arch/riscv/include/asm/elf.h
> > @@ -53,13 +53,9 @@ extern bool compat_elf_check_arch(Elf32_Ehdr *hdr);
> >  #define ELF_ET_DYN_BASE                ((DEFAULT_MAP_WINDOW / 3) * 2)
> >
> >  #ifdef CONFIG_64BIT
> > -#ifdef CONFIG_COMPAT
> >  #define STACK_RND_MASK         (is_compat_task() ? \
> >                                  0x7ff >> (PAGE_SHIFT - 12) : \
> >                                  0x3ffff >> (PAGE_SHIFT - 12))
> > -#else
> > -#define STACK_RND_MASK         (0x3ffff >> (PAGE_SHIFT - 12))
> > -#endif
> >  #endif
> >
> >  /*
> > diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
> > index 1d472b31e0cfe..ea5b269be223a 100644
> > --- a/arch/riscv/include/asm/pgtable.h
> > +++ b/arch/riscv/include/asm/pgtable.h
> > @@ -127,16 +127,10 @@
> >  #define VA_USER_SV48 (UL(1) << (VA_BITS_SV48 - 1))
> >  #define VA_USER_SV57 (UL(1) << (VA_BITS_SV57 - 1))
> >
> > -#ifdef CONFIG_COMPAT
> >  #define MMAP_VA_BITS_64 ((VA_BITS >= VA_BITS_SV48) ? VA_BITS_SV48 : VA_BITS)
> >  #define MMAP_MIN_VA_BITS_64 (VA_BITS_SV39)
> >  #define MMAP_VA_BITS (is_compat_task() ? VA_BITS_SV32 : MMAP_VA_BITS_64)
> >  #define MMAP_MIN_VA_BITS (is_compat_task() ? VA_BITS_SV32 : MMAP_MIN_VA_BITS_64)
> > -#else
> > -#define MMAP_VA_BITS ((VA_BITS >= VA_BITS_SV48) ? VA_BITS_SV48 : VA_BITS)
> > -#define MMAP_MIN_VA_BITS (VA_BITS_SV39)
> > -#endif /* CONFIG_COMPAT */
> > -
> >  #else
> >  #include <asm/pgtable-32.h>
> >  #endif /* CONFIG_64BIT */
> > diff --git a/arch/riscv/include/asm/processor.h b/arch/riscv/include/asm/processor.h
> > index f19f861cda549..ed32e53e55999 100644
> > --- a/arch/riscv/include/asm/processor.h
> > +++ b/arch/riscv/include/asm/processor.h
> > @@ -22,7 +22,7 @@
> >  ({                                                             \
> >         unsigned long mmap_end;                                 \
> >         typeof(addr) _addr = (addr);                            \
> > -       if ((_addr) == 0 || (IS_ENABLED(CONFIG_COMPAT) && is_compat_task())) \
> > +       if ((_addr) == 0 || is_compat_task())                   \
> >                 mmap_end = STACK_TOP_MAX;                       \
> >         else if ((_addr) >= VA_USER_SV57)                       \
> >                 mmap_end = STACK_TOP_MAX;                       \
> > @@ -39,7 +39,7 @@
> >         typeof(addr) _addr = (addr);                            \
> >         typeof(base) _base = (base);                            \
> >         unsigned long rnd_gap = DEFAULT_MAP_WINDOW - (_base);   \
> > -       if ((_addr) == 0 || (IS_ENABLED(CONFIG_COMPAT) && is_compat_task())) \
> > +       if ((_addr) == 0 || is_compat_task())                   \
> >                 mmap_base = (_base);                            \
> >         else if (((_addr) >= VA_USER_SV57) && (VA_BITS >= VA_BITS_SV57)) \
> >                 mmap_base = VA_USER_SV57 - rnd_gap;             \
> > --
> > 2.43.0
> >
> Reviewed-by: Guo Ren <guoren@kernel.org>

Thanks!
Leo

> 
> -- 
> Best Regards
>  Guo Ren
>
Re: [RFC PATCH 2/4] riscv: add compile-time test into is_compat_task()
Posted by Andy Chiu 1 year, 12 months ago 
On Sat, Dec 23, 2023 at 1:12 AM Leonardo Bras <leobras@redhat.com> wrote:
>
> On Fri, Dec 22, 2023 at 05:35:20PM +0800, Guo Ren wrote:
> > On Fri, Dec 22, 2023 at 5:02 PM Leonardo Bras <leobras@redhat.com> wrote:
> > >
> > > Currently several places will test for CONFIG_COMPAT before testing
> > > is_compat_task(), probably in order to avoid a run-time test into the task
> > > structure.
> > >
> > > Since is_compat_task() is an inlined function, it would be helpful to add a
> > > compile-time test of CONFIG_COMPAT, making sure it always returns zero when
> > > the option is not enabled during the kernel build.
> > >
> > > With this, the compiler is able to understand in build-time that
> > > is_compat_task() will always return 0, and optimize-out some of the extra
> > > code introduced by the option.
> > >
> > > This will also allow removing a lot #ifdefs that were introduced, and make
> > > the code more clean.
> > >
> > > Signed-off-by: Leonardo Bras <leobras@redhat.com>
> > > ---
> > >  arch/riscv/include/asm/compat.h    | 3 +++
> > >  arch/riscv/include/asm/elf.h       | 4 ----
> > >  arch/riscv/include/asm/pgtable.h   | 6 ------
> > >  arch/riscv/include/asm/processor.h | 4 ++--
> > >  4 files changed, 5 insertions(+), 12 deletions(-)
> > >
> > > diff --git a/arch/riscv/include/asm/compat.h b/arch/riscv/include/asm/compat.h
> > > index 2ac955b51148f..91517b51b8e27 100644
> > > --- a/arch/riscv/include/asm/compat.h
> > > +++ b/arch/riscv/include/asm/compat.h
> > > @@ -14,6 +14,9 @@
> > >
> > >  static inline int is_compat_task(void)
> > >  {
> > > +       if (!IS_ENABLED(CONFIG_COMPAT))
> > > +               return 0;
> > > +
> > >         return test_thread_flag(TIF_32BIT);
> > >  }
> > >
> > > diff --git a/arch/riscv/include/asm/elf.h b/arch/riscv/include/asm/elf.h
> > > index 59a08367fddd7..2e88257cafaea 100644
> > > --- a/arch/riscv/include/asm/elf.h
> > > +++ b/arch/riscv/include/asm/elf.h
> > > @@ -53,13 +53,9 @@ extern bool compat_elf_check_arch(Elf32_Ehdr *hdr);
> > >  #define ELF_ET_DYN_BASE                ((DEFAULT_MAP_WINDOW / 3) * 2)
> > >
> > >  #ifdef CONFIG_64BIT
> > > -#ifdef CONFIG_COMPAT
> > >  #define STACK_RND_MASK         (is_compat_task() ? \
> > >                                  0x7ff >> (PAGE_SHIFT - 12) : \
> > >                                  0x3ffff >> (PAGE_SHIFT - 12))
> > > -#else
> > > -#define STACK_RND_MASK         (0x3ffff >> (PAGE_SHIFT - 12))
> > > -#endif
> > >  #endif
> > >
> > >  /*
> > > diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
> > > index 1d472b31e0cfe..ea5b269be223a 100644
> > > --- a/arch/riscv/include/asm/pgtable.h
> > > +++ b/arch/riscv/include/asm/pgtable.h
> > > @@ -127,16 +127,10 @@
> > >  #define VA_USER_SV48 (UL(1) << (VA_BITS_SV48 - 1))
> > >  #define VA_USER_SV57 (UL(1) << (VA_BITS_SV57 - 1))
> > >
> > > -#ifdef CONFIG_COMPAT
> > >  #define MMAP_VA_BITS_64 ((VA_BITS >= VA_BITS_SV48) ? VA_BITS_SV48 : VA_BITS)
> > >  #define MMAP_MIN_VA_BITS_64 (VA_BITS_SV39)
> > >  #define MMAP_VA_BITS (is_compat_task() ? VA_BITS_SV32 : MMAP_VA_BITS_64)
> > >  #define MMAP_MIN_VA_BITS (is_compat_task() ? VA_BITS_SV32 : MMAP_MIN_VA_BITS_64)
> > > -#else
> > > -#define MMAP_VA_BITS ((VA_BITS >= VA_BITS_SV48) ? VA_BITS_SV48 : VA_BITS)
> > > -#define MMAP_MIN_VA_BITS (VA_BITS_SV39)
> > > -#endif /* CONFIG_COMPAT */
> > > -
> > >  #else
> > >  #include <asm/pgtable-32.h>
> > >  #endif /* CONFIG_64BIT */
> > > diff --git a/arch/riscv/include/asm/processor.h b/arch/riscv/include/asm/processor.h
> > > index f19f861cda549..ed32e53e55999 100644
> > > --- a/arch/riscv/include/asm/processor.h
> > > +++ b/arch/riscv/include/asm/processor.h
> > > @@ -22,7 +22,7 @@
> > >  ({                                                             \
> > >         unsigned long mmap_end;                                 \
> > >         typeof(addr) _addr = (addr);                            \
> > > -       if ((_addr) == 0 || (IS_ENABLED(CONFIG_COMPAT) && is_compat_task())) \
> > > +       if ((_addr) == 0 || is_compat_task())                   \
> > >                 mmap_end = STACK_TOP_MAX;                       \
> > >         else if ((_addr) >= VA_USER_SV57)                       \
> > >                 mmap_end = STACK_TOP_MAX;                       \
> > > @@ -39,7 +39,7 @@
> > >         typeof(addr) _addr = (addr);                            \
> > >         typeof(base) _base = (base);                            \
> > >         unsigned long rnd_gap = DEFAULT_MAP_WINDOW - (_base);   \
> > > -       if ((_addr) == 0 || (IS_ENABLED(CONFIG_COMPAT) && is_compat_task())) \
> > > +       if ((_addr) == 0 || is_compat_task())                   \
> > >                 mmap_base = (_base);                            \
> > >         else if (((_addr) >= VA_USER_SV57) && (VA_BITS >= VA_BITS_SV57)) \
> > >                 mmap_base = VA_USER_SV57 - rnd_gap;             \
> > > --
> > > 2.43.0
> > >
> > Reviewed-by: Guo Ren <guoren@kernel.org>
>
> Thanks!
> Leo
>
> >
> > --
> > Best Regards
> >  Guo Ren
> >
>

Reviewed-by: Andy Chiu <andy.chiu@sifive.com>
Re: [RFC PATCH 2/4] riscv: add compile-time test into is_compat_task()
Posted by Leonardo Bras Soares Passos 1 year, 11 months ago 
On Sat, Dec 23, 2023 at 1:15 AM Andy Chiu <andy.chiu@sifive.com> wrote:
>
> On Sat, Dec 23, 2023 at 1:12 AM Leonardo Bras <leobras@redhat.com> wrote:
> >
> > On Fri, Dec 22, 2023 at 05:35:20PM +0800, Guo Ren wrote:
> > > On Fri, Dec 22, 2023 at 5:02 PM Leonardo Bras <leobras@redhat.com> wrote:
> > > >
> > > > Currently several places will test for CONFIG_COMPAT before testing
> > > > is_compat_task(), probably in order to avoid a run-time test into the task
> > > > structure.
> > > >
> > > > Since is_compat_task() is an inlined function, it would be helpful to add a
> > > > compile-time test of CONFIG_COMPAT, making sure it always returns zero when
> > > > the option is not enabled during the kernel build.
> > > >
> > > > With this, the compiler is able to understand in build-time that
> > > > is_compat_task() will always return 0, and optimize-out some of the extra
> > > > code introduced by the option.
> > > >
> > > > This will also allow removing a lot #ifdefs that were introduced, and make
> > > > the code more clean.
> > > >
> > > > Signed-off-by: Leonardo Bras <leobras@redhat.com>
> > > > ---
> > > >  arch/riscv/include/asm/compat.h    | 3 +++
> > > >  arch/riscv/include/asm/elf.h       | 4 ----
> > > >  arch/riscv/include/asm/pgtable.h   | 6 ------
> > > >  arch/riscv/include/asm/processor.h | 4 ++--
> > > >  4 files changed, 5 insertions(+), 12 deletions(-)
> > > >
> > > > diff --git a/arch/riscv/include/asm/compat.h b/arch/riscv/include/asm/compat.h
> > > > index 2ac955b51148f..91517b51b8e27 100644
> > > > --- a/arch/riscv/include/asm/compat.h
> > > > +++ b/arch/riscv/include/asm/compat.h
> > > > @@ -14,6 +14,9 @@
> > > >
> > > >  static inline int is_compat_task(void)
> > > >  {
> > > > +       if (!IS_ENABLED(CONFIG_COMPAT))
> > > > +               return 0;
> > > > +
> > > >         return test_thread_flag(TIF_32BIT);
> > > >  }
> > > >
> > > > diff --git a/arch/riscv/include/asm/elf.h b/arch/riscv/include/asm/elf.h
> > > > index 59a08367fddd7..2e88257cafaea 100644
> > > > --- a/arch/riscv/include/asm/elf.h
> > > > +++ b/arch/riscv/include/asm/elf.h
> > > > @@ -53,13 +53,9 @@ extern bool compat_elf_check_arch(Elf32_Ehdr *hdr);
> > > >  #define ELF_ET_DYN_BASE                ((DEFAULT_MAP_WINDOW / 3) * 2)
> > > >
> > > >  #ifdef CONFIG_64BIT
> > > > -#ifdef CONFIG_COMPAT
> > > >  #define STACK_RND_MASK         (is_compat_task() ? \
> > > >                                  0x7ff >> (PAGE_SHIFT - 12) : \
> > > >                                  0x3ffff >> (PAGE_SHIFT - 12))
> > > > -#else
> > > > -#define STACK_RND_MASK         (0x3ffff >> (PAGE_SHIFT - 12))
> > > > -#endif
> > > >  #endif
> > > >
> > > >  /*
> > > > diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
> > > > index 1d472b31e0cfe..ea5b269be223a 100644
> > > > --- a/arch/riscv/include/asm/pgtable.h
> > > > +++ b/arch/riscv/include/asm/pgtable.h
> > > > @@ -127,16 +127,10 @@
> > > >  #define VA_USER_SV48 (UL(1) << (VA_BITS_SV48 - 1))
> > > >  #define VA_USER_SV57 (UL(1) << (VA_BITS_SV57 - 1))
> > > >
> > > > -#ifdef CONFIG_COMPAT
> > > >  #define MMAP_VA_BITS_64 ((VA_BITS >= VA_BITS_SV48) ? VA_BITS_SV48 : VA_BITS)
> > > >  #define MMAP_MIN_VA_BITS_64 (VA_BITS_SV39)
> > > >  #define MMAP_VA_BITS (is_compat_task() ? VA_BITS_SV32 : MMAP_VA_BITS_64)
> > > >  #define MMAP_MIN_VA_BITS (is_compat_task() ? VA_BITS_SV32 : MMAP_MIN_VA_BITS_64)
> > > > -#else
> > > > -#define MMAP_VA_BITS ((VA_BITS >= VA_BITS_SV48) ? VA_BITS_SV48 : VA_BITS)
> > > > -#define MMAP_MIN_VA_BITS (VA_BITS_SV39)
> > > > -#endif /* CONFIG_COMPAT */
> > > > -
> > > >  #else
> > > >  #include <asm/pgtable-32.h>
> > > >  #endif /* CONFIG_64BIT */
> > > > diff --git a/arch/riscv/include/asm/processor.h b/arch/riscv/include/asm/processor.h
> > > > index f19f861cda549..ed32e53e55999 100644
> > > > --- a/arch/riscv/include/asm/processor.h
> > > > +++ b/arch/riscv/include/asm/processor.h
> > > > @@ -22,7 +22,7 @@
> > > >  ({                                                             \
> > > >         unsigned long mmap_end;                                 \
> > > >         typeof(addr) _addr = (addr);                            \
> > > > -       if ((_addr) == 0 || (IS_ENABLED(CONFIG_COMPAT) && is_compat_task())) \
> > > > +       if ((_addr) == 0 || is_compat_task())                   \
> > > >                 mmap_end = STACK_TOP_MAX;                       \
> > > >         else if ((_addr) >= VA_USER_SV57)                       \
> > > >                 mmap_end = STACK_TOP_MAX;                       \
> > > > @@ -39,7 +39,7 @@
> > > >         typeof(addr) _addr = (addr);                            \
> > > >         typeof(base) _base = (base);                            \
> > > >         unsigned long rnd_gap = DEFAULT_MAP_WINDOW - (_base);   \
> > > > -       if ((_addr) == 0 || (IS_ENABLED(CONFIG_COMPAT) && is_compat_task())) \
> > > > +       if ((_addr) == 0 || is_compat_task())                   \
> > > >                 mmap_base = (_base);                            \
> > > >         else if (((_addr) >= VA_USER_SV57) && (VA_BITS >= VA_BITS_SV57)) \
> > > >                 mmap_base = VA_USER_SV57 - rnd_gap;             \
> > > > --
> > > > 2.43.0
> > > >
> > > Reviewed-by: Guo Ren <guoren@kernel.org>
> >
> > Thanks!
> > Leo
> >
> > >
> > > --
> > > Best Regards
> > >  Guo Ren
> > >
> >
>
> Reviewed-by: Andy Chiu <andy.chiu@sifive.com>
>

Thanks Andy!

Patchew 2.1-devel-b67e4c2

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