[tip:x86/vdso] x86, vdso: Clean up 32-bit vs 64-bit vdso params

tip-bot for Andy Lutomirski
2014-05-05T22:24:57Z

Commit-ID: 3d7ee969bffcc984c8aeaffc6ac6816fd929ace1
Gitweb: http://git.kernel.org/tip/3d7ee969bffcc984c8aeaffc6ac6816fd929ace1
Author: Andy Lutomirski <luto@amacapital.net>
AuthorDate: Mon, 5 May 2014 12:19:32 -0700
Committer: H. Peter Anvin <hpa@linux.intel.com>
CommitDate: Mon, 5 May 2014 13:18:40 -0700

x86, vdso: Clean up 32-bit vs 64-bit vdso params

Rather than using 'vdso_enabled' and an awful #define, just call the
parameters vdso32_enabled and vdso64_enabled.

Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/87913de56bdcbae3d93917938302fc369b05caee.1399317206.git.luto@amacapital.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
---
arch/x86/include/asm/elf.h | 20 +++++++++++++-------
arch/x86/um/vdso/vma.c | 2 +-
arch/x86/vdso/vdso32-setup.c | 19 ++++++++-----------
arch/x86/vdso/vma.c | 6 +++---
kernel/sysctl.c | 5 +++++
5 files changed, 30 insertions(+), 22 deletions(-)

diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h
index 2c71182..e96df2c 100644
--- a/arch/x86/include/asm/elf.h
+++ b/arch/x86/include/asm/elf.h
@@ -75,7 +75,12 @@ typedef struct user_fxsr_struct elf_fpxregset_t;

#include <asm/vdso.h>

-extern unsigned int vdso_enabled;
+#ifdef CONFIG_X86_64
+extern unsigned int vdso64_enabled;
+#endif
+#if defined(CONFIG_X86_32) || defined(CONFIG_COMPAT)
+extern unsigned int vdso32_enabled;
+#endif

/*
* This is used to ensure we don't load something for the wrong architecture.
@@ -269,9 +274,9 @@ extern int force_personality32;

struct task_struct;

-#define ARCH_DLINFO_IA32(vdso_enabled) \
+#define ARCH_DLINFO_IA32 \
do { \
- if (vdso_enabled) { \
+ if (vdso32_enabled) { \
NEW_AUX_ENT(AT_SYSINFO, VDSO_ENTRY); \
NEW_AUX_ENT(AT_SYSINFO_EHDR, VDSO_CURRENT_BASE); \
} \
@@ -281,7 +286,7 @@ do { \

#define STACK_RND_MASK (0x7ff)

-#define ARCH_DLINFO ARCH_DLINFO_IA32(vdso_enabled)
+#define ARCH_DLINFO ARCH_DLINFO_IA32

/* update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT entries changes */

@@ -292,14 +297,15 @@ do { \

#define ARCH_DLINFO \
do { \
- if (vdso_enabled) \
+ if (vdso64_enabled) \
NEW_AUX_ENT(AT_SYSINFO_EHDR, \
(unsigned long)current->mm->context.vdso); \
} while (0)

+/* As a historical oddity, the x32 and x86_64 vDSOs are controlled together. */
#define ARCH_DLINFO_X32 \
do { \
- if (vdso_enabled) \
+ if (vdso64_enabled) \
NEW_AUX_ENT(AT_SYSINFO_EHDR, \
(unsigned long)current->mm->context.vdso); \
} while (0)
@@ -310,7 +316,7 @@ do { \
if (test_thread_flag(TIF_X32)) \
ARCH_DLINFO_X32; \
else \
- ARCH_DLINFO_IA32(sysctl_vsyscall32)
+ ARCH_DLINFO_IA32

#define COMPAT_ELF_ET_DYN_BASE (TASK_UNMAPPED_BASE + 0x1000000)

diff --git a/arch/x86/um/vdso/vma.c b/arch/x86/um/vdso/vma.c
index af91901..916cda4 100644
--- a/arch/x86/um/vdso/vma.c
+++ b/arch/x86/um/vdso/vma.c
@@ -12,7 +12,7 @@
#include <asm/page.h>
#include <linux/init.h>

-unsigned int __read_mostly vdso_enabled = 1;
+static unsigned int __read_mostly vdso_enabled = 1;
unsigned long um_vdso_addr;

extern unsigned long task_size;
diff --git a/arch/x86/vdso/vdso32-setup.c b/arch/x86/vdso/vdso32-setup.c
index 0034898..5a657d9 100644
--- a/arch/x86/vdso/vdso32-setup.c
+++ b/arch/x86/vdso/vdso32-setup.c
@@ -37,7 +37,6 @@
#endif

#ifdef CONFIG_X86_64
-#define vdso_enabled sysctl_vsyscall32
#define arch_setup_additional_pages syscall32_setup_pages
#endif

@@ -45,13 +44,13 @@
* Should the kernel map a VDSO page into processes and pass its
* address down to glibc upon exec()?
*/
-unsigned int __read_mostly vdso_enabled = VDSO_DEFAULT;
+unsigned int __read_mostly vdso32_enabled = VDSO_DEFAULT;

-static int __init vdso_setup(char *s)
+static int __init vdso32_setup(char *s)
{
- vdso_enabled = simple_strtoul(s, NULL, 0);
+ vdso32_enabled = simple_strtoul(s, NULL, 0);

- if (vdso_enabled > 1)
+ if (vdso32_enabled > 1)
pr_warn("vdso32 values other than 0 and 1 are no longer allowed; vdso disabled\n");

return 1;
@@ -62,12 +61,10 @@ static int __init vdso_setup(char *s)
* behavior on both 64-bit and 32-bit kernels.
* On 32-bit kernels, vdso=[012] means the same thing.
*/
-__setup("vdso32=", vdso_setup);
+__setup("vdso32=", vdso32_setup);

#ifdef CONFIG_X86_32
-__setup_param("vdso=", vdso32_setup, vdso_setup, 0);
-
-EXPORT_SYMBOL_GPL(vdso_enabled);
+__setup_param("vdso=", vdso_setup, vdso32_setup, 0);
#endif

static struct page **vdso32_pages;
@@ -160,7 +157,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
return x32_setup_additional_pages(bprm, uses_interp);
#endif

- if (vdso_enabled != 1) /* Other values all mean "disabled" */
+ if (vdso32_enabled != 1) /* Other values all mean "disabled" */
return 0;

down_write(&mm->mmap_sem);
@@ -244,7 +241,7 @@ subsys_initcall(sysenter_setup);
static struct ctl_table abi_table2[] = {
{
.procname = "vsyscall32",
- .data = &sysctl_vsyscall32,
+ .data = &vdso32_enabled,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec
diff --git a/arch/x86/vdso/vma.c b/arch/x86/vdso/vma.c
index 1ad1026..8b79039 100644
--- a/arch/x86/vdso/vma.c
+++ b/arch/x86/vdso/vma.c
@@ -17,7 +17,7 @@
#include <asm/page.h>

#if defined(CONFIG_X86_64)
-unsigned int __read_mostly vdso_enabled = 1;
+unsigned int __read_mostly vdso64_enabled = 1;

DECLARE_VDSO_IMAGE(vdso);
extern unsigned short vdso_sync_cpuid;
@@ -160,7 +160,7 @@ static int setup_additional_pages(struct linux_binprm *bprm,
unsigned long addr;
int ret;

- if (!vdso_enabled)
+ if (!vdso64_enabled)
return 0;

down_write(&mm->mmap_sem);
@@ -203,7 +203,7 @@ int x32_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)

static __init int vdso_setup(char *s)
{
- vdso_enabled = simple_strtoul(s, NULL, 0);
+ vdso64_enabled = simple_strtoul(s, NULL, 0);
return 0;
}
__setup("vdso=", vdso_setup);
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 74f5b58..420d77a 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -1418,8 +1418,13 @@ static struct ctl_table vm_table[] = {
(defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
{
.procname = "vdso_enabled",
+#ifdef CONFIG_X86_32
+ .data = &vdso32_enabled,
+ .maxlen = sizeof(vdso32_enabled),
+#else
.data = &vdso_enabled,
.maxlen = sizeof(vdso_enabled),
+#endif
.mode = 0644,
.proc_handler = proc_dointvec,
.extra1 = &zero,