This patch enables 32 bit vDSO which are larger than a page. Currently two pages are reserved, this should be enough for future improvements.
Signed-off-by: Stefani Seibold <[email protected]> --- arch/x86/include/asm/fixmap.h | 4 +++- arch/x86/vdso/vdso32-setup.c | 29 +++++++++++++++++++---------- 2 files changed, 22 insertions(+), 11 deletions(-) diff --git a/arch/x86/include/asm/fixmap.h b/arch/x86/include/asm/fixmap.h index 094d0cc..f513f14 100644 --- a/arch/x86/include/asm/fixmap.h +++ b/arch/x86/include/asm/fixmap.h @@ -43,6 +43,8 @@ extern unsigned long __FIXADDR_TOP; #define FIXADDR_USER_START __fix_to_virt(FIX_VDSO) #define FIXADDR_USER_END __fix_to_virt(FIX_VDSO - 1) + +#define MAX_VDSO_PAGES 2 #else #define FIXADDR_TOP (VSYSCALL_END-PAGE_SIZE) @@ -74,7 +76,7 @@ extern unsigned long __FIXADDR_TOP; enum fixed_addresses { #ifdef CONFIG_X86_32 FIX_HOLE, - FIX_VDSO, + FIX_VDSO = MAX_VDSO_PAGES, VVAR_PAGE, VSYSCALL_HPET, #else diff --git a/arch/x86/vdso/vdso32-setup.c b/arch/x86/vdso/vdso32-setup.c index 1a9f8c3..aa785f0 100644 --- a/arch/x86/vdso/vdso32-setup.c +++ b/arch/x86/vdso/vdso32-setup.c @@ -16,6 +16,7 @@ #include <linux/mm.h> #include <linux/err.h> #include <linux/module.h> +#include <linux/slab.h> #include <asm/cpufeature.h> #include <asm/msr.h> @@ -190,7 +191,8 @@ static __init void relocate_vdso(Elf32_Ehdr *ehdr) } } -static struct page *vdso32_pages[VDSO_PAGES]; +static struct page *vdso32_pages[MAX_VDSO_PAGES]; +static unsigned int vdso32_size; #ifdef CONFIG_X86_64 @@ -256,6 +258,7 @@ static int __init gate_vma_init(void) static void map_compat_vdso(int map) { static int vdso_mapped; + unsigned int i; if (map == vdso_mapped) return; @@ -267,7 +270,8 @@ static void map_compat_vdso(int map) __set_fixmap(VVAR_PAGE, __pa_symbol(&__vvar_page), PAGE_KERNEL_VVAR); - __set_fixmap(FIX_VDSO, page_to_pfn(vdso32_pages[0]) << PAGE_SHIFT, + for(i = 0; i != vdso32_size; ++i) + __set_fixmap(FIX_VDSO, page_to_pfn(vdso32_pages[i]) << PAGE_SHIFT, map ? PAGE_READONLY_EXEC : PAGE_NONE); /* flush stray tlbs */ @@ -278,11 +282,10 @@ static void map_compat_vdso(int map) int __init sysenter_setup(void) { - void *vdso_page = (void *)get_zeroed_page(GFP_ATOMIC); + void *vdso_pages; const void *vdso; size_t vdso_len; - - vdso32_pages[0] = virt_to_page(vdso_page); + unsigned int i; #ifdef CONFIG_X86_32 gate_vma_init(); @@ -299,9 +302,15 @@ int __init sysenter_setup(void) vdso_len = &vdso32_int80_end - &vdso32_int80_start; } - memcpy(vdso_page, vdso, vdso_len); - patch_vdso32(vdso_page, vdso_len); - relocate_vdso(vdso_page); + vdso32_size = (vdso_len + PAGE_SIZE - 1) / PAGE_SIZE; + vdso_pages = kmalloc(VDSO_OFFSET(vdso32_size), GFP_ATOMIC); + + for(i = 0; i != vdso32_size; ++i) + vdso32_pages[i] = virt_to_page(vdso_pages + VDSO_OFFSET(i)); + + memcpy(vdso_pages, vdso, vdso_len); + patch_vdso32(vdso_pages, vdso_len); + relocate_vdso(vdso_pages); return 0; } @@ -334,7 +343,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) if (compat) addr = VDSO_HIGH_BASE; else { - addr = get_unmapped_area(NULL, 0, VDSO_OFFSET(VDSO_PAGES), 0, 0); + addr = get_unmapped_area(NULL, 0, VDSO_OFFSET(VDSO_PREV_PAGES + vdso32_size), 0, 0); if (IS_ERR_VALUE(addr)) { ret = addr; goto up_fail; @@ -351,7 +360,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) */ ret = install_special_mapping(mm, addr, - VDSO_OFFSET(VDSO_PAGES - VDSO_PREV_PAGES), + VDSO_OFFSET(vdso32_size), VM_READ|VM_EXEC| VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC, vdso32_pages); -- 1.9.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
