Merge branch 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 vdso updates from Ingo Molnar:
 "Further simplifications and improvements to the VDSO code, by Andy
  Lutomirski"

* 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86_64/vsyscall: Fix warn_bad_vsyscall log output
  x86/vdso: Set VM_MAYREAD for the vvar vma
  x86, vdso: Get rid of the fake section mechanism
  x86, vdso: Move the vvar area before the vdso text

8 files changed, 193 insertions, 291 deletions

diff --git a/arch/x86/include/asm/vdso.h b/arch/x86/include/asm/vdso.h
index 30be253dd283..8021bd28c0f1 100644
--- a/arch/x86/include/asm/vdso.h
+++ b/arch/x86/include/asm/vdso.h
@@ -18,15 +18,15 @@ struct vdso_image {
 
         unsigned long alt, alt_len;
 
-        unsigned long sym_end_mapping;  /* Total size of the mapping */
-
-        unsigned long sym_vvar_page;
-        unsigned long sym_hpet_page;
-        unsigned long sym_VDSO32_NOTE_MASK;
-        unsigned long sym___kernel_sigreturn;
-        unsigned long sym___kernel_rt_sigreturn;
-        unsigned long sym___kernel_vsyscall;
-        unsigned long sym_VDSO32_SYSENTER_RETURN;
+        long sym_vvar_start;  /* Negative offset to the vvar area */
+
+        long sym_vvar_page;
+        long sym_hpet_page;
+        long sym_VDSO32_NOTE_MASK;
+        long sym___kernel_sigreturn;
+        long sym___kernel_rt_sigreturn;
+        long sym___kernel_vsyscall;
+        long sym_VDSO32_SYSENTER_RETURN;
 };
 
 #ifdef CONFIG_X86_64
diff --git a/arch/x86/kernel/vsyscall_64.c b/arch/x86/kernel/vsyscall_64.c
index ea5b5709aa76..e1e1e80fc6a6 100644
--- a/arch/x86/kernel/vsyscall_64.c
+++ b/arch/x86/kernel/vsyscall_64.c
@@ -81,10 +81,10 @@ static void warn_bad_vsyscall(const char *level, struct pt_regs *regs,
         if (!show_unhandled_signals)
                 return;
 
-        pr_notice_ratelimited("%s%s[%d] %s ip:%lx cs:%lx sp:%lx ax:%lx si:%lx di:%lx\n",
-                              level, current->comm, task_pid_nr(current),
-                              message, regs->ip, regs->cs,
-                              regs->sp, regs->ax, regs->si, regs->di);
+        printk_ratelimited("%s%s[%d] %s ip:%lx cs:%lx sp:%lx ax:%lx si:%lx di:%lx\n",
+                           level, current->comm, task_pid_nr(current),
+                           message, regs->ip, regs->cs,
+                           regs->sp, regs->ax, regs->si, regs->di);
 }
 
 static int addr_to_vsyscall_nr(unsigned long addr)
diff --git a/arch/x86/vdso/Makefile b/arch/x86/vdso/Makefile
index 61b04fe36e66..5a4affe025e8 100644
--- a/arch/x86/vdso/Makefile
+++ b/arch/x86/vdso/Makefile
@@ -10,7 +10,7 @@ VDSO32-$(CONFIG_X86_32)		:= y
 VDSO32-$(CONFIG_COMPAT)         := y
 
 # files to link into the vdso
-vobjs-y := vdso-note.o vclock_gettime.o vgetcpu.o vdso-fakesections.o
+vobjs-y := vdso-note.o vclock_gettime.o vgetcpu.o
 
 # files to link into kernel
 obj-y                           += vma.o
@@ -37,7 +37,8 @@ vdso_img_sodbg := $(vdso_img-y:%=vdso%.so.dbg)
 obj-y += $(vdso_img_objs)
 targets += $(vdso_img_cfiles)
 targets += $(vdso_img_sodbg)
-.SECONDARY: $(vdso_img-y:%=$(obj)/vdso-image-%.c)
+.SECONDARY: $(vdso_img-y:%=$(obj)/vdso-image-%.c) \
+        $(vdso_img-y:%=$(obj)/vdso%.so)
 
 export CPPFLAGS_vdso.lds += -P -C
 
@@ -54,10 +55,10 @@ hostprogs-y			+= vdso2c
 
 quiet_cmd_vdso2c = VDSO2C  $@
 define cmd_vdso2c
-        $(obj)/vdso2c $< $@
+        $(obj)/vdso2c $< $(<:%.dbg=%) $@
 endef
 
-$(obj)/vdso-image-%.c: $(obj)/vdso%.so.dbg $(obj)/vdso2c FORCE
+$(obj)/vdso-image-%.c: $(obj)/vdso%.so.dbg $(obj)/vdso%.so $(obj)/vdso2c FORCE
         $(call if_changed,vdso2c)
 
 #
@@ -113,6 +114,10 @@ $(obj)/%-x32.o: $(obj)/%.o FORCE
 
 targets += vdsox32.lds $(vobjx32s-y)
 
+$(obj)/%.so: OBJCOPYFLAGS := -S
+$(obj)/%.so: $(obj)/%.so.dbg
+        $(call if_changed,objcopy)
+
 $(obj)/vdsox32.so.dbg: $(src)/vdsox32.lds $(vobjx32s) FORCE
         $(call if_changed,vdso)
 
@@ -134,7 +139,7 @@ override obj-dirs = $(dir $(obj)) $(obj)/vdso32/
 
 targets += vdso32/vdso32.lds
 targets += vdso32/note.o vdso32/vclock_gettime.o $(vdso32.so-y:%=vdso32/%.o)
-targets += vdso32/vclock_gettime.o vdso32/vdso-fakesections.o
+targets += vdso32/vclock_gettime.o
 
 $(obj)/vdso32.o: $(vdso32-images:%=$(obj)/%)
 
@@ -156,7 +161,6 @@ $(vdso32-images:%=$(obj)/%.dbg): KBUILD_CFLAGS = $(KBUILD_CFLAGS_32)
 $(vdso32-images:%=$(obj)/%.dbg): $(obj)/vdso32-%.so.dbg: FORCE \
                                  $(obj)/vdso32/vdso32.lds \
                                  $(obj)/vdso32/vclock_gettime.o \
-                                 $(obj)/vdso32/vdso-fakesections.o \
                                  $(obj)/vdso32/note.o \
                                  $(obj)/vdso32/%.o
         $(call if_changed,vdso)
diff --git a/arch/x86/vdso/vdso-fakesections.c b/arch/x86/vdso/vdso-fakesections.c
deleted file mode 100644
index aa5fbfab20a5..000000000000
--- a/arch/x86/vdso/vdso-fakesections.c
+++ /dev/null
@@ -1,21 +0,0 @@
-/*
- * Copyright 2014 Andy Lutomirski
- * Subject to the GNU Public License, v.2
- *
- * String table for loadable section headers.  See vdso2c.h for why
- * this exists.
- */
-
-const char fake_shstrtab[] __attribute__((section(".fake_shstrtab"))) =
-        ".hash\0"
-        ".dynsym\0"
-        ".dynstr\0"
-        ".gnu.version\0"
-        ".gnu.version_d\0"
-        ".dynamic\0"
-        ".rodata\0"
-        ".fake_shstrtab\0"  /* Yay, self-referential code. */
-        ".note\0"
-        ".eh_frame_hdr\0"
-        ".eh_frame\0"
-        ".text";
diff --git a/arch/x86/vdso/vdso-layout.lds.S b/arch/x86/vdso/vdso-layout.lds.S
index 9197544eea9a..de2c921025f5 100644
--- a/arch/x86/vdso/vdso-layout.lds.S
+++ b/arch/x86/vdso/vdso-layout.lds.S
@@ -18,6 +18,25 @@
 
 SECTIONS
 {
+        /*
+         * User/kernel shared data is before the vDSO.  This may be a little
+         * uglier than putting it after the vDSO, but it avoids issues with
+         * non-allocatable things that dangle past the end of the PT_LOAD
+         * segment.
+         */
+
+        vvar_start = . - 2 * PAGE_SIZE;
+        vvar_page = vvar_start;
+
+        /* Place all vvars at the offsets in asm/vvar.h. */
+#define EMIT_VVAR(name, offset) vvar_ ## name = vvar_page + offset;
+#define __VVAR_KERNEL_LDS
+#include <asm/vvar.h>
+#undef __VVAR_KERNEL_LDS
+#undef EMIT_VVAR
+
+        hpet_page = vvar_start + PAGE_SIZE;
+
         . = SIZEOF_HEADERS;
 
         .hash           : { *(.hash) }                  :text
@@ -74,31 +93,6 @@ SECTIONS
         .altinstructions        : { *(.altinstructions) }       :text
         .altinstr_replacement   : { *(.altinstr_replacement) }  :text
 
-        /*
-         * The remainder of the vDSO consists of special pages that are
-         * shared between the kernel and userspace.  It needs to be at the
-         * end so that it doesn't overlap the mapping of the actual
-         * vDSO image.
-         */
-
-        . = ALIGN(PAGE_SIZE);
-        vvar_page = .;
-
-        /* Place all vvars at the offsets in asm/vvar.h. */
-#define EMIT_VVAR(name, offset) vvar_ ## name = vvar_page + offset;
-#define __VVAR_KERNEL_LDS
-#include <asm/vvar.h>
-#undef __VVAR_KERNEL_LDS
-#undef EMIT_VVAR