x86, vdso: Patch alternatives in the 32-bit VDSO

We need the alternatives mechanism for rdtsc_barrier() to work.

Signed-off-by: Stefani Seibold <stefani@seibold.net>
Link: http://lkml.kernel.org/r/1395094933-14252-9-git-send-email-stefani@seibold.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

3 files changed, 24 insertions, 15 deletions

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 <asm/vdso.h>
 #include <asm/page.h>
 
+#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