From b4b541a610c4db8643b36030ee5012203ca65778 Mon Sep 17 00:00:00 2001 From: Andy Lutomirski Date: Mon, 17 Mar 2014 23:22:08 +0100 Subject: [PATCH] x86, vdso: Patch alternatives in the 32-bit VDSO We need the alternatives mechanism for rdtsc_barrier() to work. Signed-off-by: Stefani Seibold Link: http://lkml.kernel.org/r/1395094933-14252-9-git-send-email-stefani@seibold.net Signed-off-by: H. Peter Anvin --- arch/x86/include/asm/vdso.h | 2 ++ arch/x86/vdso/Makefile | 3 ++- arch/x86/vdso/vdso32-setup.c | 23 ++++++++++++----------- arch/x86/vdso/vma.c | 13 ++++++++++--- 4 files changed, 26 insertions(+), 15 deletions(-) diff --git a/arch/x86/include/asm/vdso.h b/arch/x86/include/asm/vdso.h index 5594e84d65d9..f8605e61b0c5 100644 --- a/arch/x86/include/asm/vdso.h +++ b/arch/x86/include/asm/vdso.h @@ -28,4 +28,6 @@ extern const char vdso32_int80_start, vdso32_int80_end; extern const char vdso32_syscall_start, vdso32_syscall_end; extern const char vdso32_sysenter_start, vdso32_sysenter_end; +void __init patch_vdso32(void *vdso, size_t len); + #endif /* _ASM_X86_VDSO_H */ diff --git a/arch/x86/vdso/Makefile b/arch/x86/vdso/Makefile index fd14be1d1472..7a3d13e23f25 100644 --- a/arch/x86/vdso/Makefile +++ b/arch/x86/vdso/Makefile @@ -21,7 +21,8 @@ vobjs-$(VDSOX32-y) += $(vobjx32s-compat) vobj64s := $(filter-out $(vobjx32s-compat),$(vobjs-y)) # files to link into kernel -obj-$(VDSO64-y) += vma.o vdso.o +obj-y += vma.o +obj-$(VDSO64-y) += vdso.o obj-$(VDSOX32-y) += vdsox32.o obj-$(VDSO32-y) += vdso32.o vdso32-setup.o diff --git a/arch/x86/vdso/vdso32-setup.c b/arch/x86/vdso/vdso32-setup.c index ab20c04b688a..e0fc767bcad3 100644 --- a/arch/x86/vdso/vdso32-setup.c +++ b/arch/x86/vdso/vdso32-setup.c @@ -112,24 +112,25 @@ void enable_sep_cpu(void) int __init sysenter_setup(void) { - void *syscall_page = (void *)get_zeroed_page(GFP_ATOMIC); - const void *vsyscall; - size_t vsyscall_len; + void *vdso_page = (void *)get_zeroed_page(GFP_ATOMIC); + const void *vdso; + size_t vdso_len; - vdso32_pages[0] = virt_to_page(syscall_page); + vdso32_pages[0] = virt_to_page(vdso_page); if (vdso32_syscall()) { - vsyscall = &vdso32_syscall_start; - vsyscall_len = &vdso32_syscall_end - &vdso32_syscall_start; + vdso = &vdso32_syscall_start; + vdso_len = &vdso32_syscall_end - &vdso32_syscall_start; } else if (vdso32_sysenter()){ - vsyscall = &vdso32_sysenter_start; - vsyscall_len = &vdso32_sysenter_end - &vdso32_sysenter_start; + vdso = &vdso32_sysenter_start; + vdso_len = &vdso32_sysenter_end - &vdso32_sysenter_start; } else { - vsyscall = &vdso32_int80_start; - vsyscall_len = &vdso32_int80_end - &vdso32_int80_start; + vdso = &vdso32_int80_start; + vdso_len = &vdso32_int80_end - &vdso32_int80_start; } - memcpy(syscall_page, vsyscall, vsyscall_len); + memcpy(vdso_page, vdso, vdso_len); + patch_vdso32(vdso_page, vdso_len); return 0; } diff --git a/arch/x86/vdso/vma.c b/arch/x86/vdso/vma.c index 431e87544411..7345bc9a1af6 100644 --- a/arch/x86/vdso/vma.c +++ b/arch/x86/vdso/vma.c @@ -16,6 +16,7 @@ #include #include +#if defined(CONFIG_X86_64) unsigned int __read_mostly vdso_enabled = 1; extern char vdso_start[], vdso_end[]; @@ -28,8 +29,12 @@ static unsigned vdso_size; extern char vdsox32_start[], vdsox32_end[]; extern struct page *vdsox32_pages[]; static unsigned vdsox32_size; +#endif +#endif -static void __init patch_vdsox32(void *vdso, size_t len) +#if defined(CONFIG_X86_32) || defined(CONFIG_X86_X32_ABI) || \ + defined(CONFIG_COMPAT) +void __init patch_vdso32(void *vdso, size_t len) { Elf32_Ehdr *hdr = vdso; Elf32_Shdr *sechdrs, *alt_sec = 0; @@ -52,7 +57,7 @@ static void __init patch_vdsox32(void *vdso, size_t len) } /* If we get here, it's probably a bug. */ - pr_warning("patch_vdsox32: .altinstructions not found\n"); + pr_warning("patch_vdso32: .altinstructions not found\n"); return; /* nothing to patch */ found: @@ -61,6 +66,7 @@ found: } #endif +#if defined(CONFIG_X86_64) static void __init patch_vdso64(void *vdso, size_t len) { Elf64_Ehdr *hdr = vdso; @@ -104,7 +110,7 @@ static int __init init_vdso(void) vdso_pages[i] = virt_to_page(vdso_start + i*PAGE_SIZE); #ifdef CONFIG_X86_X32_ABI - patch_vdsox32(vdsox32_start, vdsox32_end - vdsox32_start); + patch_vdso32(vdsox32_start, vdsox32_end - vdsox32_start); npages = (vdsox32_end - vdsox32_start + PAGE_SIZE - 1) / PAGE_SIZE; vdsox32_size = npages << PAGE_SHIFT; for (i = 0; i < npages; i++) @@ -204,3 +210,4 @@ static __init int vdso_setup(char *s) return 0; } __setup("vdso=", vdso_setup); +#endif -- 2.34.1