Messages in this thread Patch in this message | | | From | Shaohua Li <> | Subject | [PATCH v2 1/3] X86: make VDSO data support multiple pages | Date | Wed, 17 Dec 2014 15:12:24 -0800 |
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Currently vdso data is one page. Next patches will add per-cpu data to vdso, which requires several pages if CPU number is big. This makes VDSO data support multiple pages.
Cc: Andy Lutomirski <luto@amacapital.net> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Signed-off-by: Shaohua Li <shli@fb.com> --- arch/x86/include/asm/vdso.h | 2 +- arch/x86/include/asm/vvar.h | 8 ++++++-- arch/x86/kernel/asm-offsets.c | 5 +++++ arch/x86/kernel/vmlinux.lds.S | 6 +++--- arch/x86/tools/relocs.c | 2 +- arch/x86/vdso/vdso-layout.lds.S | 9 +++++---- arch/x86/vdso/vdso2c.c | 6 +++--- arch/x86/vdso/vma.c | 9 +++++---- 8 files changed, 29 insertions(+), 18 deletions(-)
diff --git a/arch/x86/include/asm/vdso.h b/arch/x86/include/asm/vdso.h index 8021bd2..35ca749 100644 --- a/arch/x86/include/asm/vdso.h +++ b/arch/x86/include/asm/vdso.h @@ -20,7 +20,7 @@ struct vdso_image { long sym_vvar_start; /* Negative offset to the vvar area */ - long sym_vvar_page; + long sym_vvar_pages; long sym_hpet_page; long sym_VDSO32_NOTE_MASK; long sym___kernel_sigreturn; diff --git a/arch/x86/include/asm/vvar.h b/arch/x86/include/asm/vvar.h index 3f32dfc..62bc6f8 100644 --- a/arch/x86/include/asm/vvar.h +++ b/arch/x86/include/asm/vvar.h @@ -29,7 +29,7 @@ #else -extern char __vvar_page; +extern char __vvar_pages; #define DECLARE_VVAR(offset, type, name) \ extern type vvar_ ## name __attribute__((visibility("hidden"))); @@ -45,7 +45,11 @@ extern char __vvar_page; /* DECLARE_VVAR(offset, type, name) */ DECLARE_VVAR(128, struct vsyscall_gtod_data, vsyscall_gtod_data) - +/* + * you must update VVAR_TOTAL_SIZE to reflect all of the variables we're + * stuffing into the vvar area. Don't change any of the above without + * also changing this math of VVAR_TOTAL_SIZE + */ #undef DECLARE_VVAR #endif diff --git a/arch/x86/kernel/asm-offsets.c b/arch/x86/kernel/asm-offsets.c index 9f6b934..0ab31a9 100644 --- a/arch/x86/kernel/asm-offsets.c +++ b/arch/x86/kernel/asm-offsets.c @@ -16,6 +16,7 @@ #include <asm/sigframe.h> #include <asm/bootparam.h> #include <asm/suspend.h> +#include <asm/vgtod.h> #ifdef CONFIG_XEN #include <xen/interface/xen.h> @@ -71,4 +72,8 @@ void common(void) { BLANK(); DEFINE(PTREGS_SIZE, sizeof(struct pt_regs)); + + BLANK(); + DEFINE(VVAR_TOTAL_SIZE, + ALIGN(128 + sizeof(struct vsyscall_gtod_data), PAGE_SIZE)); } diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S index 00bf300..2efeee9 100644 --- a/arch/x86/kernel/vmlinux.lds.S +++ b/arch/x86/kernel/vmlinux.lds.S @@ -149,7 +149,7 @@ SECTIONS . = ALIGN(PAGE_SIZE); - __vvar_page = .; + __vvar_pages = .; .vvar : AT(ADDR(.vvar) - LOAD_OFFSET) { /* work around gold bug 13023 */ @@ -168,10 +168,10 @@ SECTIONS * Pad the rest of the page with zeros. Otherwise the loader * can leave garbage here. */ - . = __vvar_beginning_hack + PAGE_SIZE; + . = __vvar_beginning_hack + VVAR_TOTAL_SIZE; } :data - . = ALIGN(__vvar_page + PAGE_SIZE, PAGE_SIZE); + . = ALIGN(__vvar_pages + VVAR_TOTAL_SIZE, PAGE_SIZE); /* Init code and data - will be freed after init */ . = ALIGN(PAGE_SIZE); diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c index 0c2fae8..ea01c48 100644 --- a/arch/x86/tools/relocs.c +++ b/arch/x86/tools/relocs.c @@ -73,7 +73,7 @@ static const char * const sym_regex_kernel[S_NSYMTYPES] = { "init_per_cpu__.*|" "__end_rodata_hpage_align|" #endif - "__vvar_page|" + "__vvar_pages|" "_end)$" }; diff --git a/arch/x86/vdso/vdso-layout.lds.S b/arch/x86/vdso/vdso-layout.lds.S index de2c921..413c739 100644 --- a/arch/x86/vdso/vdso-layout.lds.S +++ b/arch/x86/vdso/vdso-layout.lds.S @@ -1,4 +1,5 @@ #include <asm/vdso.h> +#include <asm/asm-offsets.h> /* * Linker script for vDSO. This is an ELF shared object prelinked to @@ -25,17 +26,17 @@ SECTIONS * segment. */ - vvar_start = . - 2 * PAGE_SIZE; - vvar_page = vvar_start; + vvar_start = . - (VVAR_TOTAL_SIZE + PAGE_SIZE); + vvar_pages = vvar_start; /* Place all vvars at the offsets in asm/vvar.h. */ -#define EMIT_VVAR(name, offset) vvar_ ## name = vvar_page + offset; +#define EMIT_VVAR(name, offset) vvar_ ## name = vvar_pages + offset; #define __VVAR_KERNEL_LDS #include <asm/vvar.h> #undef __VVAR_KERNEL_LDS #undef EMIT_VVAR - hpet_page = vvar_start + PAGE_SIZE; + hpet_page = vvar_start + VVAR_TOTAL_SIZE; . = SIZEOF_HEADERS; diff --git a/arch/x86/vdso/vdso2c.c b/arch/x86/vdso/vdso2c.c index 8627db2..95eda74 100644 --- a/arch/x86/vdso/vdso2c.c +++ b/arch/x86/vdso/vdso2c.c @@ -71,14 +71,14 @@ const char *outfilename; /* Symbols that we need in vdso2c. */ enum { sym_vvar_start, - sym_vvar_page, + sym_vvar_pages, sym_hpet_page, sym_VDSO_FAKE_SECTION_TABLE_START, sym_VDSO_FAKE_SECTION_TABLE_END, }; const int special_pages[] = { - sym_vvar_page, + sym_vvar_pages, sym_hpet_page, }; @@ -89,7 +89,7 @@ struct vdso_sym { struct vdso_sym required_syms[] = { [sym_vvar_start] = {"vvar_start", true}, - [sym_vvar_page] = {"vvar_page", true}, + [sym_vvar_pages] = {"vvar_pages", true}, [sym_hpet_page] = {"hpet_page", true}, [sym_VDSO_FAKE_SECTION_TABLE_START] = { "VDSO_FAKE_SECTION_TABLE_START", false diff --git a/arch/x86/vdso/vma.c b/arch/x86/vdso/vma.c index 009495b..6496c65 100644 --- a/arch/x86/vdso/vma.c +++ b/arch/x86/vdso/vma.c @@ -19,6 +19,7 @@ #include <asm/page.h> #include <asm/hpet.h> #include <asm/desc.h> +#include <asm/asm-offsets.h> #if defined(CONFIG_X86_64) unsigned int __read_mostly vdso64_enabled = 1; @@ -133,11 +134,11 @@ static int map_vdso(const struct vdso_image *image, bool calculate_addr) goto up_fail; } - if (image->sym_vvar_page) + if (image->sym_vvar_pages) ret = remap_pfn_range(vma, - text_start + image->sym_vvar_page, - __pa_symbol(&__vvar_page) >> PAGE_SHIFT, - PAGE_SIZE, + text_start + image->sym_vvar_pages, + __pa_symbol(&__vvar_pages) >> PAGE_SHIFT, + VVAR_TOTAL_SIZE, PAGE_READONLY); if (ret) -- 1.8.1
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