diff options
| author | Jisheng Zhang <jszhang@kernel.org> | 2023-01-29 01:28:53 +0800 |
|---|---|---|
| committer | Palmer Dabbelt <palmer@rivosinc.com> | 2023-01-31 23:29:42 -0800 |
| commit | cabfd146b371462ed480a968f98eb0c2c80e3c8a (patch) | |
| tree | 38df344a6023b4f31d3b03877eb0b550b7d0a820 | |
| parent | 8d23e94a443388e81c42ea7e476a5d79c1c795c9 (diff) | |
riscv: alternative: patch alternatives in the vDSO
Make it possible to use alternatives in the vDSO, so that better
implementations can be used if possible.
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20230128172856.3814-11-jszhang@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
| -rw-r--r-- | arch/riscv/include/asm/vdso.h | 4 | ||||
| -rw-r--r-- | arch/riscv/kernel/alternative.c | 29 | ||||
| -rw-r--r-- | arch/riscv/kernel/vdso.c | 5 | ||||
| -rw-r--r-- | arch/riscv/kernel/vdso/vdso.lds.S | 7 |
4 files changed, 40 insertions, 5 deletions
diff --git a/arch/riscv/include/asm/vdso.h b/arch/riscv/include/asm/vdso.h index a7644f46d0e5..f891478829a5 100644 --- a/arch/riscv/include/asm/vdso.h +++ b/arch/riscv/include/asm/vdso.h @@ -28,8 +28,12 @@ #define COMPAT_VDSO_SYMBOL(base, name) \ (void __user *)((unsigned long)(base) + compat__vdso_##name##_offset) +extern char compat_vdso_start[], compat_vdso_end[]; + #endif /* CONFIG_COMPAT */ +extern char vdso_start[], vdso_end[]; + #endif /* !__ASSEMBLY__ */ #endif /* CONFIG_MMU */ diff --git a/arch/riscv/kernel/alternative.c b/arch/riscv/kernel/alternative.c index 3d4f1f32c7f6..fc341b69bf62 100644 --- a/arch/riscv/kernel/alternative.c +++ b/arch/riscv/kernel/alternative.c @@ -11,7 +11,9 @@ #include <linux/cpu.h> #include <linux/uaccess.h> #include <asm/alternative.h> +#include <asm/module.h> #include <asm/sections.h> +#include <asm/vdso.h> #include <asm/vendorid_list.h> #include <asm/sbi.h> #include <asm/csr.h> @@ -160,6 +162,31 @@ static void __init_or_module _apply_alternatives(struct alt_entry *begin, stage); } +#ifdef CONFIG_MMU +static void __init apply_vdso_alternatives(void) +{ + const Elf_Ehdr *hdr; + const Elf_Shdr *shdr; + const Elf_Shdr *alt; + struct alt_entry *begin, *end; + + hdr = (Elf_Ehdr *)vdso_start; + shdr = (void *)hdr + hdr->e_shoff; + alt = find_section(hdr, shdr, ".alternative"); + if (!alt) + return; + + begin = (void *)hdr + alt->sh_offset, + end = (void *)hdr + alt->sh_offset + alt->sh_size, + + _apply_alternatives((struct alt_entry *)begin, + (struct alt_entry *)end, + RISCV_ALTERNATIVES_BOOT); +} +#else +static void __init apply_vdso_alternatives(void) { } +#endif + void __init apply_boot_alternatives(void) { /* If called on non-boot cpu things could go wrong */ @@ -168,6 +195,8 @@ void __init apply_boot_alternatives(void) _apply_alternatives((struct alt_entry *)__alt_start, (struct alt_entry *)__alt_end, RISCV_ALTERNATIVES_BOOT); + + apply_vdso_alternatives(); } /* diff --git a/arch/riscv/kernel/vdso.c b/arch/riscv/kernel/vdso.c index e410275918ac..4e631c098f4d 100644 --- a/arch/riscv/kernel/vdso.c +++ b/arch/riscv/kernel/vdso.c @@ -22,11 +22,6 @@ struct vdso_data { }; #endif -extern char vdso_start[], vdso_end[]; -#ifdef CONFIG_COMPAT -extern char compat_vdso_start[], compat_vdso_end[]; -#endif - enum vvar_pages { VVAR_DATA_PAGE_OFFSET, VVAR_TIMENS_PAGE_OFFSET, diff --git a/arch/riscv/kernel/vdso/vdso.lds.S b/arch/riscv/kernel/vdso/vdso.lds.S index 150b1a572e61..4a0606633290 100644 --- a/arch/riscv/kernel/vdso/vdso.lds.S +++ b/arch/riscv/kernel/vdso/vdso.lds.S @@ -40,6 +40,13 @@ SECTIONS . = 0x800; .text : { *(.text .text.*) } :text + . = ALIGN(4); + .alternative : { + __alt_start = .; + *(.alternative) + __alt_end = .; + } + .data : { *(.got.plt) *(.got) *(.data .data.* .gnu.linkonce.d.*) |