| Message ID | 20231222074605.452452-3-leobras@redhat.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Introduce & Optimize compat-mode helpers | expand |
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>
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 >
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>
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; \
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(-)