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:
"The main changes in this cycle centered around adding support for
32-bit compatible C/R of the vDSO on 64-bit kernels, by Dmitry
Safonov"
* 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/vdso: Use CONFIG_X86_X32_ABI to enable vdso prctl
x86/vdso: Only define map_vdso_randomized() if CONFIG_X86_64
x86/vdso: Only define prctl_map_vdso() if CONFIG_CHECKPOINT_RESTORE
x86/signal: Add SA_{X32,IA32}_ABI sa_flags
x86/ptrace: Down with test_thread_flag(TIF_IA32)
x86/coredump: Use pr_reg size, rather that TIF_IA32 flag
x86/arch_prctl/vdso: Add ARCH_MAP_VDSO_*
x86/vdso: Replace calculate_addr in map_vdso() with addr
x86/vdso: Unmap vdso blob on vvar mapping failure
diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c
index f840766..23c881c 100644
--- a/arch/x86/entry/vdso/vma.c
+++ b/arch/x86/entry/vdso/vma.c
@@ -37,54 +37,6 @@
struct linux_binprm;
-/*
- * Put the vdso above the (randomized) stack with another randomized
- * offset. This way there is no hole in the middle of address space.
- * To save memory make sure it is still in the same PTE as the stack
- * top. This doesn't give that many random bits.
- *
- * Note that this algorithm is imperfect: the distribution of the vdso
- * start address within a PMD is biased toward the end.
- *
- * Only used for the 64-bit and x32 vdsos.
- */
-static unsigned long vdso_addr(unsigned long start, unsigned len)
-{
-#ifdef CONFIG_X86_32
- return 0;
-#else
- unsigned long addr, end;
- unsigned offset;
-
- /*
- * Round up the start address. It can start out unaligned as a result
- * of stack start randomization.
- */
- start = PAGE_ALIGN(start);
-
- /* Round the lowest possible end address up to a PMD boundary. */
- end = (start + len + PMD_SIZE - 1) & PMD_MASK;
- if (end >= TASK_SIZE_MAX)
- end = TASK_SIZE_MAX;
- end -= len;
-
- if (end > start) {
- offset = get_random_int() % (((end - start) >> PAGE_SHIFT) + 1);
- addr = start + (offset << PAGE_SHIFT);
- } else {
- addr = start;
- }
-
- /*
- * Forcibly align the final address in case we have a hardware
- * issue that requires alignment for performance reasons.
- */
- addr = align_vdso_addr(addr);
-
- return addr;
-#endif
-}
-
static int vdso_fault(const struct vm_special_mapping *sm,
struct vm_area_struct *vma, struct vm_fault *vmf)
{
@@ -176,30 +128,28 @@
return VM_FAULT_SIGBUS;
}
-static int map_vdso(const struct vdso_image *image, bool calculate_addr)
+static const struct vm_special_mapping vdso_mapping = {
+ .name = "[vdso]",
+ .fault = vdso_fault,
+ .mremap = vdso_mremap,
+};
+static const struct vm_special_mapping vvar_mapping = {
+ .name = "[vvar]",
+ .fault = vvar_fault,
+};
+
+/*
+ * Add vdso and vvar mappings to current process.
+ * @image - blob to map
+ * @addr - request a specific address (zero to map at free addr)
+ */
+static int map_vdso(const struct vdso_image *image, unsigned long addr)
{
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
- unsigned long addr, text_start;
+ unsigned long text_start;
int ret = 0;
- static const struct vm_special_mapping vdso_mapping = {
- .name = "[vdso]",
- .fault = vdso_fault,
- .mremap = vdso_mremap,
- };
- static const struct vm_special_mapping vvar_mapping = {
- .name = "[vvar]",
- .fault = vvar_fault,
- };
-
- if (calculate_addr) {
- addr = vdso_addr(current->mm->start_stack,
- image->size - image->sym_vvar_start);
- } else {
- addr = 0;
- }
-
if (down_write_killable(&mm->mmap_sem))
return -EINTR;
@@ -238,24 +188,104 @@
if (IS_ERR(vma)) {
ret = PTR_ERR(vma);
- goto up_fail;
+ do_munmap(mm, text_start, image->size);
}
up_fail:
- if (ret)
+ if (ret) {
current->mm->context.vdso = NULL;
+ current->mm->context.vdso_image = NULL;
+ }
up_write(&mm->mmap_sem);
return ret;
}
+#ifdef CONFIG_X86_64
+/*
+ * Put the vdso above the (randomized) stack with another randomized
+ * offset. This way there is no hole in the middle of address space.
+ * To save memory make sure it is still in the same PTE as the stack
+ * top. This doesn't give that many random bits.
+ *
+ * Note that this algorithm is imperfect: the distribution of the vdso
+ * start address within a PMD is biased toward the end.
+ *
+ * Only used for the 64-bit and x32 vdsos.
+ */
+static unsigned long vdso_addr(unsigned long start, unsigned len)
+{
+ unsigned long addr, end;
+ unsigned offset;
+
+ /*
+ * Round up the start address. It can start out unaligned as a result
+ * of stack start randomization.
+ */
+ start = PAGE_ALIGN(start);
+
+ /* Round the lowest possible end address up to a PMD boundary. */
+ end = (start + len + PMD_SIZE - 1) & PMD_MASK;
+ if (end >= TASK_SIZE_MAX)
+ end = TASK_SIZE_MAX;
+ end -= len;
+
+ if (end > start) {
+ offset = get_random_int() % (((end - start) >> PAGE_SHIFT) + 1);
+ addr = start + (offset << PAGE_SHIFT);
+ } else {
+ addr = start;
+ }
+
+ /*
+ * Forcibly align the final address in case we have a hardware
+ * issue that requires alignment for performance reasons.
+ */
+ addr = align_vdso_addr(addr);
+
+ return addr;
+}
+
+static int map_vdso_randomized(const struct vdso_image *image)
+{
+ unsigned long addr = vdso_addr(current->mm->start_stack, image->size-image->sym_vvar_start);
+
+ return map_vdso(image, addr);
+}
+#endif
+
+int map_vdso_once(const struct vdso_image *image, unsigned long addr)
+{
+ struct mm_struct *mm = current->mm;
+ struct vm_area_struct *vma;
+
+ down_write(&mm->mmap_sem);
+ /*
+ * Check if we have already mapped vdso blob - fail to prevent
+ * abusing from userspace install_speciall_mapping, which may
+ * not do accounting and rlimit right.
+ * We could search vma near context.vdso, but it's a slowpath,
+ * so let's explicitely check all VMAs to be completely sure.
+ */
+ for (vma = mm->mmap; vma; vma = vma->vm_next) {
+ if (vma_is_special_mapping(vma, &vdso_mapping) ||
+ vma_is_special_mapping(vma, &vvar_mapping)) {
+ up_write(&mm->mmap_sem);
+ return -EEXIST;
+ }
+ }
+ up_write(&mm->mmap_sem);
+
+ return map_vdso(image, addr);
+}
+
#if defined(CONFIG_X86_32) || defined(CONFIG_IA32_EMULATION)
static int load_vdso32(void)
{
if (vdso32_enabled != 1) /* Other values all mean "disabled" */
return 0;
- return map_vdso(&vdso_image_32, false);
+ return map_vdso(&vdso_image_32, 0);
}
#endif
@@ -265,7 +295,7 @@
if (!vdso64_enabled)
return 0;
- return map_vdso(&vdso_image_64, true);
+ return map_vdso_randomized(&vdso_image_64);
}
#ifdef CONFIG_COMPAT
@@ -276,8 +306,7 @@
if (test_thread_flag(TIF_X32)) {
if (!vdso64_enabled)
return 0;
-
- return map_vdso(&vdso_image_x32, true);
+ return map_vdso_randomized(&vdso_image_x32);
}
#endif
#ifdef CONFIG_IA32_EMULATION
diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c
index 2f29f4e..cb13c05 100644
--- a/arch/x86/ia32/ia32_signal.c
+++ b/arch/x86/ia32/ia32_signal.c
@@ -378,7 +378,7 @@
put_user_ex(*((u64 *)&code), (u64 __user *)frame->retcode);
} put_user_catch(err);
- err |= copy_siginfo_to_user32(&frame->info, &ksig->info);
+ err |= __copy_siginfo_to_user32(&frame->info, &ksig->info, false);
err |= ia32_setup_sigcontext(&frame->uc.uc_mcontext, fpstate,
regs, set->sig[0]);
err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
diff --git a/arch/x86/include/asm/compat.h b/arch/x86/include/asm/compat.h
index a188061..03d269b 100644
--- a/arch/x86/include/asm/compat.h
+++ b/arch/x86/include/asm/compat.h
@@ -275,10 +275,10 @@
#ifdef CONFIG_X86_X32_ABI
typedef struct user_regs_struct compat_elf_gregset_t;
-#define PR_REG_SIZE(S) (test_thread_flag(TIF_IA32) ? 68 : 216)
-#define PRSTATUS_SIZE(S) (test_thread_flag(TIF_IA32) ? 144 : 296)
-#define SET_PR_FPVALID(S,V) \
- do { *(int *) (((void *) &((S)->pr_reg)) + PR_REG_SIZE(0)) = (V); } \
+/* Full regset -- prstatus on x32, otherwise on ia32 */
+#define PRSTATUS_SIZE(S, R) (R != sizeof(S.pr_reg) ? 144 : 296)
+#define SET_PR_FPVALID(S, V, R) \
+ do { *(int *) (((void *) &((S)->pr_reg)) + R) = (V); } \
while (0)
#define COMPAT_USE_64BIT_TIME \
diff --git a/arch/x86/include/asm/fpu/signal.h b/arch/x86/include/asm/fpu/signal.h
index 0e970d0..20a1fbf 100644
--- a/arch/x86/include/asm/fpu/signal.h
+++ b/arch/x86/include/asm/fpu/signal.h
@@ -19,6 +19,12 @@
# define ia32_setup_rt_frame __setup_rt_frame
#endif
+#ifdef CONFIG_COMPAT
+int __copy_siginfo_to_user32(compat_siginfo_t __user *to,
+ const siginfo_t *from, bool x32_ABI);
+#endif
+
+
extern void convert_from_fxsr(struct user_i387_ia32_struct *env,
struct task_struct *tsk);
extern void convert_to_fxsr(struct task_struct *tsk,
diff --git a/arch/x86/include/asm/signal.h b/arch/x86/include/asm/signal.h
index dd1e7d6..8af22be 100644
--- a/arch/x86/include/asm/signal.h
+++ b/arch/x86/include/asm/signal.h
@@ -23,6 +23,10 @@
unsigned long sig[_NSIG_WORDS];
} sigset_t;
+/* non-uapi in-kernel SA_FLAGS for those indicates ABI for a signal frame */
+#define SA_IA32_ABI 0x02000000u
+#define SA_X32_ABI 0x01000000u
+
#ifndef CONFIG_COMPAT
typedef sigset_t compat_sigset_t;
#endif
diff --git a/arch/x86/include/asm/vdso.h b/arch/x86/include/asm/vdso.h
index 43dc55b..2444189 100644
--- a/arch/x86/include/asm/vdso.h
+++ b/arch/x86/include/asm/vdso.h
@@ -41,6 +41,8 @@
extern void __init init_vdso_image(const struct vdso_image *image);
+extern int map_vdso_once(const struct vdso_image *image, unsigned long addr);
+
#endif /* __ASSEMBLER__ */
#endif /* _ASM_X86_VDSO_H */
diff --git a/arch/x86/include/uapi/asm/prctl.h b/arch/x86/include/uapi/asm/prctl.h
index 3ac5032..ae135de 100644
--- a/arch/x86/include/uapi/asm/prctl.h
+++ b/arch/x86/include/uapi/asm/prctl.h
@@ -6,4 +6,10 @@
#define ARCH_GET_FS 0x1003
#define ARCH_GET_GS 0x1004
+#ifdef CONFIG_CHECKPOINT_RESTORE
+# define ARCH_MAP_VDSO_X32 0x2001
+# define ARCH_MAP_VDSO_32 0x2002
+# define ARCH_MAP_VDSO_64 0x2003
+#endif
+
#endif /* _ASM_X86_PRCTL_H */
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index de9acaf..ee944bd 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -49,6 +49,7 @@
#include <asm/debugreg.h>
#include <asm/switch_to.h>
#include <asm/xen/hypervisor.h>
+#include <asm/vdso.h>
__visible DEFINE_PER_CPU(unsigned long, rsp_scratch);
@@ -523,6 +524,19 @@
}
EXPORT_SYMBOL_GPL(set_personality_ia32);
+#ifdef CONFIG_CHECKPOINT_RESTORE
+static long prctl_map_vdso(const struct vdso_image *image, unsigned long addr)
+{
+ int ret;
+
+ ret = map_vdso_once(image, addr);
+ if (ret)
+ return ret;
+
+ return (long)image->size;
+}
+#endif
+
long do_arch_prctl(struct task_struct *task, int code, unsigned long addr)
{
int ret = 0;
@@ -576,6 +590,19 @@
break;
}
+#ifdef CONFIG_CHECKPOINT_RESTORE
+# ifdef CONFIG_X86_X32_ABI
+ case ARCH_MAP_VDSO_X32:
+ return prctl_map_vdso(&vdso_image_x32, addr);
+# endif
+# if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
+ case ARCH_MAP_VDSO_32:
+ return prctl_map_vdso(&vdso_image_32, addr);
+# endif
+ case ARCH_MAP_VDSO_64:
+ return prctl_map_vdso(&vdso_image_64, addr);
+#endif
+
default:
ret = -EINVAL;
break;
diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index ce94c38..0e63c02 100644
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -1358,7 +1358,7 @@
const struct user_regset_view *task_user_regset_view(struct task_struct *task)
{
#ifdef CONFIG_IA32_EMULATION
- if (test_tsk_thread_flag(task, TIF_IA32))
+ if (!user_64bit_mode(task_pt_regs(task)))
#endif
#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
return &user_x86_32_view;
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index da20ecb..763af1d 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -42,6 +42,7 @@
#include <asm/syscalls.h>
#include <asm/sigframe.h>
+#include <asm/signal.h>
#define COPY(x) do { \
get_user_ex(regs->x, &sc->x); \
@@ -547,7 +548,7 @@
return -EFAULT;
if (ksig->ka.sa.sa_flags & SA_SIGINFO) {
- if (copy_siginfo_to_user32(&frame->info, &ksig->info))
+ if (__copy_siginfo_to_user32(&frame->info, &ksig->info, true))
return -EFAULT;
}
@@ -660,20 +661,21 @@
return 0;
}
-static inline int is_ia32_compat_frame(void)
+static inline int is_ia32_compat_frame(struct ksignal *ksig)
{
return IS_ENABLED(CONFIG_IA32_EMULATION) &&
- test_thread_flag(TIF_IA32);
+ ksig->ka.sa.sa_flags & SA_IA32_ABI;
}
-static inline int is_ia32_frame(void)
+static inline int is_ia32_frame(struct ksignal *ksig)
{
- return IS_ENABLED(CONFIG_X86_32) || is_ia32_compat_frame();
+ return IS_ENABLED(CONFIG_X86_32) || is_ia32_compat_frame(ksig);
}
-static inline int is_x32_frame(void)
+static inline int is_x32_frame(struct ksignal *ksig)
{
- return IS_ENABLED(CONFIG_X86_X32_ABI) && test_thread_flag(TIF_X32);
+ return IS_ENABLED(CONFIG_X86_X32_ABI) &&
+ ksig->ka.sa.sa_flags & SA_X32_ABI;
}
static int
@@ -684,12 +686,12 @@
compat_sigset_t *cset = (compat_sigset_t *) set;
/* Set up the stack frame */
- if (is_ia32_frame()) {
+ if (is_ia32_frame(ksig)) {
if (ksig->ka.sa.sa_flags & SA_SIGINFO)
return ia32_setup_rt_frame(usig, ksig, cset, regs);
else
return ia32_setup_frame(usig, ksig, cset, regs);
- } else if (is_x32_frame()) {
+ } else if (is_x32_frame(ksig)) {
return x32_setup_rt_frame(ksig, cset, regs);
} else {
return __setup_rt_frame(ksig->sig, ksig, set, regs);
diff --git a/arch/x86/kernel/signal_compat.c b/arch/x86/kernel/signal_compat.c
index b44564b..40df337 100644
--- a/arch/x86/kernel/signal_compat.c
+++ b/arch/x86/kernel/signal_compat.c
@@ -1,5 +1,6 @@
#include <linux/compat.h>
#include <linux/uaccess.h>
+#include <linux/ptrace.h>
/*
* The compat_siginfo_t structure and handing code is very easy
@@ -92,10 +93,31 @@
/* any new si_fields should be added here */
}
-int copy_siginfo_to_user32(compat_siginfo_t __user *to, const siginfo_t *from)
+void sigaction_compat_abi(struct k_sigaction *act, struct k_sigaction *oact)
+{
+ /* Don't leak in-kernel non-uapi flags to user-space */
+ if (oact)
+ oact->sa.sa_flags &= ~(SA_IA32_ABI | SA_X32_ABI);
+
+ if (!act)
+ return;
+
+ /* Don't let flags to be set from userspace */
+ act->sa.sa_flags &= ~(SA_IA32_ABI | SA_X32_ABI);
+
+ if (user_64bit_mode(current_pt_regs()))
+ return;
+
+ if (in_ia32_syscall())
+ act->sa.sa_flags |= SA_IA32_ABI;
+ if (in_x32_syscall())
+ act->sa.sa_flags |= SA_X32_ABI;
+}
+
+int __copy_siginfo_to_user32(compat_siginfo_t __user *to, const siginfo_t *from,
+ bool x32_ABI)
{
int err = 0;
- bool ia32 = test_thread_flag(TIF_IA32);
signal_compat_build_tests();
@@ -146,7 +168,7 @@
put_user_ex(from->si_arch, &to->si_arch);
break;
case __SI_CHLD >> 16:
- if (ia32) {
+ if (!x32_ABI) {
put_user_ex(from->si_utime, &to->si_utime);
put_user_ex(from->si_stime, &to->si_stime);
} else {
@@ -180,6 +202,12 @@
return err;
}
+/* from syscall's path, where we know the ABI */
+int copy_siginfo_to_user32(compat_siginfo_t __user *to, const siginfo_t *from)
+{
+ return __copy_siginfo_to_user32(to, from, in_x32_syscall());
+}
+
int copy_siginfo_from_user32(siginfo_t *to, compat_siginfo_t __user *from)
{
int err = 0;
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index e5495f3..2472af2 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -1624,20 +1624,12 @@
regset->writeback(task, regset, 1);
}
-#ifndef PR_REG_SIZE
-#define PR_REG_SIZE(S) sizeof(S)
-#endif
-
#ifndef PRSTATUS_SIZE
-#define PRSTATUS_SIZE(S) sizeof(S)
-#endif
-
-#ifndef PR_REG_PTR
-#define PR_REG_PTR(S) (&((S)->pr_reg))
+#define PRSTATUS_SIZE(S, R) sizeof(S)
#endif
#ifndef SET_PR_FPVALID
-#define SET_PR_FPVALID(S, V) ((S)->pr_fpvalid = (V))
+#define SET_PR_FPVALID(S, V, R) ((S)->pr_fpvalid = (V))
#endif
static int fill_thread_core_info(struct elf_thread_core_info *t,
@@ -1645,6 +1637,7 @@
long signr, size_t *total)
{
unsigned int i;
+ unsigned int regset_size = view->regsets[0].n * view->regsets[0].size;
/*
* NT_PRSTATUS is the one special case, because the regset data
@@ -1653,12 +1646,11 @@
* We assume that regset 0 is NT_PRSTATUS.
*/
fill_prstatus(&t->prstatus, t->task, signr);
- (void) view->regsets[0].get(t->task, &view->regsets[0],
- 0, PR_REG_SIZE(t->prstatus.pr_reg),
- PR_REG_PTR(&t->prstatus), NULL);
+ (void) view->regsets[0].get(t->task, &view->regsets[0], 0, regset_size,
+ &t->prstatus.pr_reg, NULL);
fill_note(&t->notes[0], "CORE", NT_PRSTATUS,
- PRSTATUS_SIZE(t->prstatus), &t->prstatus);
+ PRSTATUS_SIZE(t->prstatus, regset_size), &t->prstatus);
*total += notesize(&t->notes[0]);
do_thread_regset_writeback(t->task, &view->regsets[0]);
@@ -1688,7 +1680,8 @@
regset->core_note_type,
size, data);
else {
- SET_PR_FPVALID(&t->prstatus, 1);
+ SET_PR_FPVALID(&t->prstatus,
+ 1, regset_size);
fill_note(&t->notes[i], "CORE",
NT_PRFPREG, size, data);
}
diff --git a/include/linux/mm.h b/include/linux/mm.h
index ef815b9..5f14534 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2019,6 +2019,8 @@
extern bool may_expand_vm(struct mm_struct *, vm_flags_t, unsigned long npages);
extern void vm_stat_account(struct mm_struct *, vm_flags_t, long npages);
+extern bool vma_is_special_mapping(const struct vm_area_struct *vma,
+ const struct vm_special_mapping *sm);
extern struct vm_area_struct *_install_special_mapping(struct mm_struct *mm,
unsigned long addr, unsigned long len,
unsigned long flags,
diff --git a/kernel/signal.c b/kernel/signal.c
index af21afc..75761ac 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -3044,6 +3044,11 @@
}
EXPORT_SYMBOL(kernel_sigaction);
+void __weak sigaction_compat_abi(struct k_sigaction *act,
+ struct k_sigaction *oact)
+{
+}
+
int do_sigaction(int sig, struct k_sigaction *act, struct k_sigaction *oact)
{
struct task_struct *p = current, *t;
@@ -3059,6 +3064,8 @@
if (oact)
*oact = *k;
+ sigaction_compat_abi(act, oact);
+
if (act) {
sigdelsetmask(&act->sa.sa_mask,
sigmask(SIGKILL) | sigmask(SIGSTOP));
diff --git a/mm/mmap.c b/mm/mmap.c
index 69cad56..7a0707a 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -3068,6 +3068,14 @@
return ERR_PTR(ret);
}
+bool vma_is_special_mapping(const struct vm_area_struct *vma,
+ const struct vm_special_mapping *sm)
+{
+ return vma->vm_private_data == sm &&
+ (vma->vm_ops == &special_mapping_vmops ||
+ vma->vm_ops == &legacy_special_mapping_vmops);
+}
+
/*
* Called with mm->mmap_sem held for writing.
* Insert a new vma covering the given region, with the given flags.