| Message ID | 20221204174632.3677-11-jszhang@kernel.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | riscv: improve boot time isa extensions handling | expand |
Are there any patches that depend on it? Any existing utilization? My first idea is to let __vdso_flush_icache use it, the standard implementation is so heavy for user space JIT scenario, maybe vendors could give a custom one. On Mon, Dec 5, 2022 at 1:57 AM Jisheng Zhang <jszhang@kernel.org> wrote: > > 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> > --- > arch/riscv/include/asm/vdso.h | 4 ++++ > arch/riscv/kernel/alternative.c | 25 +++++++++++++++++++++++++ > arch/riscv/kernel/vdso.c | 5 ----- > arch/riscv/kernel/vdso/vdso.lds.S | 7 +++++++ > 4 files changed, 36 insertions(+), 5 deletions(-) > > diff --git a/arch/riscv/include/asm/vdso.h b/arch/riscv/include/asm/vdso.h > index af981426fe0f..b6ff7473fb8a 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 9d88375624b5..eaf7ddaba54c 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> > @@ -187,6 +189,27 @@ static void __init_or_module _apply_alternatives(struct alt_entry *begin, > stage); > } > > +static void __init apply_vdso_alternatives(void) > +{ > + const struct elf64_hdr *hdr; > + const struct elf64_shdr *shdr; > + const struct elf64_shdr *alt; > + struct alt_entry *begin, *end; > + > + hdr = (struct elf64_hdr *)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); > +} > + > void __init apply_boot_alternatives(void) > { > /* If called on non-boot cpu things could go wrong */ > @@ -195,6 +218,8 @@ 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 123d05255fcf..1f47bc6566cf 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.*) > -- > 2.37.2 >
On Mon, Dec 05, 2022 at 09:56:37AM +0800, Guo Ren wrote: > Are there any patches that depend on it? Any existing utilization? My > first idea is to let __vdso_flush_icache use it, the standard > implementation is so heavy for user space JIT scenario, maybe vendors > could give a custom one. Hi Guo, the 11th patch of swtiching cpu_relax() to riscv_has_extension_likely() depends on this patch, the gettimeofday implementation calls cpu_relax() which may use ZIHINTPAUSE extension, so we need to patch vDSO. Thanks > > On Mon, Dec 5, 2022 at 1:57 AM Jisheng Zhang <jszhang@kernel.org> wrote: > > > > 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> > > --- > > arch/riscv/include/asm/vdso.h | 4 ++++ > > arch/riscv/kernel/alternative.c | 25 +++++++++++++++++++++++++ > > arch/riscv/kernel/vdso.c | 5 ----- > > arch/riscv/kernel/vdso/vdso.lds.S | 7 +++++++ > > 4 files changed, 36 insertions(+), 5 deletions(-) > > > > diff --git a/arch/riscv/include/asm/vdso.h b/arch/riscv/include/asm/vdso.h > > index af981426fe0f..b6ff7473fb8a 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 9d88375624b5..eaf7ddaba54c 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> > > @@ -187,6 +189,27 @@ static void __init_or_module _apply_alternatives(struct alt_entry *begin, > > stage); > > } > > > > +static void __init apply_vdso_alternatives(void) > > +{ > > + const struct elf64_hdr *hdr; > > + const struct elf64_shdr *shdr; > > + const struct elf64_shdr *alt; > > + struct alt_entry *begin, *end; > > + > > + hdr = (struct elf64_hdr *)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); > > +} > > + > > void __init apply_boot_alternatives(void) > > { > > /* If called on non-boot cpu things could go wrong */ > > @@ -195,6 +218,8 @@ 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 123d05255fcf..1f47bc6566cf 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.*) > > -- > > 2.37.2 > > > > > -- > Best Regards > Guo Ren
On Mon, Dec 5, 2022 at 11:33 PM Jisheng Zhang <jszhang@kernel.org> wrote: > > On Mon, Dec 05, 2022 at 09:56:37AM +0800, Guo Ren wrote: > > Are there any patches that depend on it? Any existing utilization? My > > first idea is to let __vdso_flush_icache use it, the standard > > implementation is so heavy for user space JIT scenario, maybe vendors > > could give a custom one. > > Hi Guo, > > the 11th patch of swtiching cpu_relax() to riscv_has_extension_likely() > depends on this patch, the gettimeofday implementation calls cpu_relax() > which may use ZIHINTPAUSE extension, so we need to patch vDSO. Oh, I missed that. Thx. Reviewed-by: Guo Ren <guoren@kernel.org> > > Thanks > > > > > On Mon, Dec 5, 2022 at 1:57 AM Jisheng Zhang <jszhang@kernel.org> wrote: > > > > > > 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> > > > --- > > > arch/riscv/include/asm/vdso.h | 4 ++++ > > > arch/riscv/kernel/alternative.c | 25 +++++++++++++++++++++++++ > > > arch/riscv/kernel/vdso.c | 5 ----- > > > arch/riscv/kernel/vdso/vdso.lds.S | 7 +++++++ > > > 4 files changed, 36 insertions(+), 5 deletions(-) > > > > > > diff --git a/arch/riscv/include/asm/vdso.h b/arch/riscv/include/asm/vdso.h > > > index af981426fe0f..b6ff7473fb8a 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 9d88375624b5..eaf7ddaba54c 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> > > > @@ -187,6 +189,27 @@ static void __init_or_module _apply_alternatives(struct alt_entry *begin, > > > stage); > > > } > > > > > > +static void __init apply_vdso_alternatives(void) > > > +{ > > > + const struct elf64_hdr *hdr; > > > + const struct elf64_shdr *shdr; > > > + const struct elf64_shdr *alt; > > > + struct alt_entry *begin, *end; > > > + > > > + hdr = (struct elf64_hdr *)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); > > > +} > > > + > > > void __init apply_boot_alternatives(void) > > > { > > > /* If called on non-boot cpu things could go wrong */ > > > @@ -195,6 +218,8 @@ 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 123d05255fcf..1f47bc6566cf 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.*) > > > -- > > > 2.37.2 > > > > > > > > > -- > > Best Regards > > Guo Ren
On Mon, Dec 05, 2022 at 01:46:29AM +0800, Jisheng Zhang wrote: > 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> > --- > arch/riscv/include/asm/vdso.h | 4 ++++ > arch/riscv/kernel/alternative.c | 25 +++++++++++++++++++++++++ > arch/riscv/kernel/vdso.c | 5 ----- > arch/riscv/kernel/vdso/vdso.lds.S | 7 +++++++ > 4 files changed, 36 insertions(+), 5 deletions(-) > Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
diff --git a/arch/riscv/include/asm/vdso.h b/arch/riscv/include/asm/vdso.h index af981426fe0f..b6ff7473fb8a 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 9d88375624b5..eaf7ddaba54c 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> @@ -187,6 +189,27 @@ static void __init_or_module _apply_alternatives(struct alt_entry *begin, stage); } +static void __init apply_vdso_alternatives(void) +{ + const struct elf64_hdr *hdr; + const struct elf64_shdr *shdr; + const struct elf64_shdr *alt; + struct alt_entry *begin, *end; + + hdr = (struct elf64_hdr *)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); +} + void __init apply_boot_alternatives(void) { /* If called on non-boot cpu things could go wrong */ @@ -195,6 +218,8 @@ 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 123d05255fcf..1f47bc6566cf 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.*)
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> --- arch/riscv/include/asm/vdso.h | 4 ++++ arch/riscv/kernel/alternative.c | 25 +++++++++++++++++++++++++ arch/riscv/kernel/vdso.c | 5 ----- arch/riscv/kernel/vdso/vdso.lds.S | 7 +++++++ 4 files changed, 36 insertions(+), 5 deletions(-)