From 4c0b5a451675e9a95be98a16ddb889bb0486d2ad Mon Sep 17 00:00:00 2001 From: Leonardo Bras Date: Wed, 3 Jan 2024 13:00:21 -0300 Subject: [PATCH] riscv: add compile-time test into is_compat_task() 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 Reviewed-by: Guo Ren Reviewed-by: Andy Chiu Link: https://lore.kernel.org/r/20240103160024.70305-5-leobras@redhat.com Signed-off-by: Palmer Dabbelt --- 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 2ac955b51148..91517b51b8e2 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 59a08367fddd..2e88257cafae 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 9a7a92edcb46..f5b504265d76 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 #endif /* CONFIG_64BIT */ diff --git a/arch/riscv/include/asm/processor.h b/arch/riscv/include/asm/processor.h index 2278e2a8362a..d2d7ce30baf3 100644 --- a/arch/riscv/include/asm/processor.h +++ b/arch/riscv/include/asm/processor.h @@ -28,7 +28,7 @@ ({ \ 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) && (VA_BITS >= VA_BITS_SV57)) \ mmap_end = VA_USER_SV57; \ @@ -45,7 +45,7 @@ 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; \