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Diffstat (limited to 'arch/x86/kernel/signal_64.c')
-rw-r--r--arch/x86/kernel/signal_64.c362
1 files changed, 152 insertions, 210 deletions
diff --git a/arch/x86/kernel/signal_64.c b/arch/x86/kernel/signal_64.c
index ca316b5b742c..a5c9627f4db9 100644
--- a/arch/x86/kernel/signal_64.c
+++ b/arch/x86/kernel/signal_64.c
@@ -15,17 +15,21 @@
#include <linux/errno.h>
#include <linux/wait.h>
#include <linux/ptrace.h>
+#include <linux/tracehook.h>
#include <linux/unistd.h>
#include <linux/stddef.h>
#include <linux/personality.h>
#include <linux/compiler.h>
+#include <linux/uaccess.h>
+
#include <asm/processor.h>
#include <asm/ucontext.h>
-#include <asm/uaccess.h>
#include <asm/i387.h>
#include <asm/proto.h>
#include <asm/ia32_unistd.h>
#include <asm/mce.h>
+#include <asm/syscall.h>
+#include <asm/syscalls.h>
#include "sigframe.h"
#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
@@ -41,11 +45,6 @@
# define FIX_EFLAGS __FIX_EFLAGS
#endif
-int ia32_setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
- sigset_t *set, struct pt_regs * regs);
-int ia32_setup_frame(int sig, struct k_sigaction *ka,
- sigset_t *set, struct pt_regs * regs);
-
asmlinkage long
sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
struct pt_regs *regs)
@@ -53,67 +52,14 @@ sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
return do_sigaltstack(uss, uoss, regs->sp);
}
-/*
- * Signal frame handlers.
- */
-
-static inline int save_i387(struct _fpstate __user *buf)
-{
- struct task_struct *tsk = current;
- int err = 0;
-
- BUILD_BUG_ON(sizeof(struct user_i387_struct) !=
- sizeof(tsk->thread.xstate->fxsave));
-
- if ((unsigned long)buf % 16)
- printk("save_i387: bad fpstate %p\n", buf);
-
- if (!used_math())
- return 0;
- clear_used_math(); /* trigger finit */
- if (task_thread_info(tsk)->status & TS_USEDFPU) {
- err = save_i387_checking((struct i387_fxsave_struct __user *)
- buf);
- if (err)
- return err;
- task_thread_info(tsk)->status &= ~TS_USEDFPU;
- stts();
- } else {
- if (__copy_to_user(buf, &tsk->thread.xstate->fxsave,
- sizeof(struct i387_fxsave_struct)))
- return -1;
- }
- return 1;
+#define COPY(x) { \
+ err |= __get_user(regs->x, &sc->x); \
}
-/*
- * This restores directly out of user space. Exceptions are handled.
- */
-static inline int restore_i387(struct _fpstate __user *buf)
-{
- struct task_struct *tsk = current;
- int err;
-
- if (!used_math()) {
- err = init_fpu(tsk);
- if (err)
- return err;
- }
-
- if (!(task_thread_info(current)->status & TS_USEDFPU)) {
- clts();
- task_thread_info(current)->status |= TS_USEDFPU;
- }
- err = restore_fpu_checking((__force struct i387_fxsave_struct *)buf);
- if (unlikely(err)) {
- /*
- * Encountered an error while doing the restore from the
- * user buffer, clear the fpu state.
- */
- clear_fpu(tsk);
- clear_used_math();
- }
- return err;
+#define COPY_SEG_STRICT(seg) { \
+ unsigned short tmp; \
+ err |= __get_user(tmp, &sc->seg); \
+ regs->seg = tmp | 3; \
}
/*
@@ -123,13 +69,13 @@ static int
restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
unsigned long *pax)
{
+ void __user *buf;
+ unsigned int tmpflags;
unsigned int err = 0;
/* Always make any pending restarted system calls return -EINTR */
current_thread_info()->restart_block.fn = do_no_restart_syscall;
-#define COPY(x) err |= __get_user(regs->x, &sc->x)
-
COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx);
COPY(dx); COPY(cx); COPY(ip);
COPY(r8);
@@ -144,48 +90,24 @@ restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
/* Kernel saves and restores only the CS segment register on signals,
* which is the bare minimum needed to allow mixed 32/64-bit code.
* App's signal handler can save/restore other segments if needed. */
- {
- unsigned cs;
- err |= __get_user(cs, &sc->cs);
- regs->cs = cs | 3; /* Force into user mode */
- }
+ COPY_SEG_STRICT(cs);
- {
- unsigned int tmpflags;
- err |= __get_user(tmpflags, &sc->flags);
- regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS);
- regs->orig_ax = -1; /* disable syscall checks */
- }
+ err |= __get_user(tmpflags, &sc->flags);
+ regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS);
+ regs->orig_ax = -1; /* disable syscall checks */
- {
- struct _fpstate __user * buf;
- err |= __get_user(buf, &sc->fpstate);
-
- if (buf) {
- if (!access_ok(VERIFY_READ, buf, sizeof(*buf)))
- goto badframe;
- err |= restore_i387(buf);
- } else {
- struct task_struct *me = current;
- if (used_math()) {
- clear_fpu(me);
- clear_used_math();
- }
- }
- }
+ err |= __get_user(buf, &sc->fpstate);
+ err |= restore_i387_xstate(buf);
err |= __get_user(*pax, &sc->ax);
return err;
-
-badframe:
- return 1;
}
-asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)
+static long do_rt_sigreturn(struct pt_regs *regs)
{
struct rt_sigframe __user *frame;
- sigset_t set;
unsigned long ax;
+ sigset_t set;
frame = (struct rt_sigframe __user *)(regs->sp - sizeof(long));
if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
@@ -198,7 +120,7 @@ asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)
current->blocked = set;
recalc_sigpending();
spin_unlock_irq(&current->sighand->siglock);
-
+
if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &ax))
goto badframe;
@@ -208,16 +130,22 @@ asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)
return ax;
badframe:
- signal_fault(regs,frame,"sigreturn");
+ signal_fault(regs, frame, "rt_sigreturn");
return 0;
-}
+}
+
+asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)
+{
+ return do_rt_sigreturn(regs);
+}
/*
* Set up a signal frame.
*/
static inline int
-setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, unsigned long mask, struct task_struct *me)
+setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
+ unsigned long mask, struct task_struct *me)
{
int err = 0;
@@ -269,41 +197,40 @@ get_stack(struct k_sigaction *ka, struct pt_regs *regs, unsigned long size)
sp = current->sas_ss_sp + current->sas_ss_size;
}
- return (void __user *)round_down(sp - size, 16);
+ return (void __user *)round_down(sp - size, 64);
}
-static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
- sigset_t *set, struct pt_regs * regs)
+static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
+ sigset_t *set, struct pt_regs *regs)
{
struct rt_sigframe __user *frame;
- struct _fpstate __user *fp = NULL;
+ void __user *fp = NULL;
int err = 0;
struct task_struct *me = current;
if (used_math()) {
- fp = get_stack(ka, regs, sizeof(struct _fpstate));
+ fp = get_stack(ka, regs, sig_xstate_size);
frame = (void __user *)round_down(
(unsigned long)fp - sizeof(struct rt_sigframe), 16) - 8;
- if (!access_ok(VERIFY_WRITE, fp, sizeof(struct _fpstate)))
- goto give_sigsegv;
-
- if (save_i387(fp) < 0)
- err |= -1;
+ if (save_i387_xstate(fp) < 0)
+ return -EFAULT;
} else
frame = get_stack(ka, regs, sizeof(struct rt_sigframe)) - 8;
if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
- goto give_sigsegv;
+ return -EFAULT;
- if (ka->sa.sa_flags & SA_SIGINFO) {
- err |= copy_siginfo_to_user(&frame->info, info);
- if (err)
- goto give_sigsegv;
+ if (ka->sa.sa_flags & SA_SIGINFO) {
+ if (copy_siginfo_to_user(&frame->info, info))
+ return -EFAULT;
}
-
+
/* Create the ucontext. */
- err |= __put_user(0, &frame->uc.uc_flags);
+ if (cpu_has_xsave)
+ err |= __put_user(UC_FP_XSTATE, &frame->uc.uc_flags);
+ else
+ err |= __put_user(0, &frame->uc.uc_flags);
err |= __put_user(0, &frame->uc.uc_link);
err |= __put_user(me->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
err |= __put_user(sas_ss_flags(regs->sp),
@@ -311,9 +238,9 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
err |= __put_user(me->sas_ss_size, &frame->uc.uc_stack.ss_size);
err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0], me);
err |= __put_user(fp, &frame->uc.uc_mcontext.fpstate);
- if (sizeof(*set) == 16) {
+ if (sizeof(*set) == 16) {
__put_user(set->sig[0], &frame->uc.uc_sigmask.sig[0]);
- __put_user(set->sig[1], &frame->uc.uc_sigmask.sig[1]);
+ __put_user(set->sig[1], &frame->uc.uc_sigmask.sig[1]);
} else
err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
@@ -324,15 +251,15 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
err |= __put_user(ka->sa.sa_restorer, &frame->pretcode);
} else {
/* could use a vstub here */
- goto give_sigsegv;
+ return -EFAULT;
}
if (err)
- goto give_sigsegv;
+ return -EFAULT;
/* Set up registers for signal handler */
regs->di = sig;
- /* In case the signal handler was declared without prototypes */
+ /* In case the signal handler was declared without prototypes */
regs->ax = 0;
/* This also works for non SA_SIGINFO handlers because they expect the
@@ -348,44 +275,45 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
regs->cs = __USER_CS;
return 0;
-
-give_sigsegv:
- force_sigsegv(sig, current);
- return -EFAULT;
}
/*
- * Return -1L or the syscall number that @regs is executing.
+ * OK, we're invoking a handler
*/
-static long current_syscall(struct pt_regs *regs)
+static int signr_convert(int sig)
{
- /*
- * We always sign-extend a -1 value being set here,
- * so this is always either -1L or a syscall number.
- */
- return regs->orig_ax;
+ return sig;
}
-/*
- * Return a value that is -EFOO if the system call in @regs->orig_ax
- * returned an error. This only works for @regs from @current.
- */
-static long current_syscall_ret(struct pt_regs *regs)
-{
#ifdef CONFIG_IA32_EMULATION
- if (test_thread_flag(TIF_IA32))
- /*
- * Sign-extend the value so (int)-EFOO becomes (long)-EFOO
- * and will match correctly in comparisons.
- */
- return (int) regs->ax;
+#define is_ia32 test_thread_flag(TIF_IA32)
+#else
+#define is_ia32 0
#endif
- return regs->ax;
-}
-/*
- * OK, we're invoking a handler
- */
+static int
+setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
+ sigset_t *set, struct pt_regs *regs)
+{
+ int usig = signr_convert(sig);
+ int ret;
+
+ /* Set up the stack frame */
+ if (is_ia32) {
+ if (ka->sa.sa_flags & SA_SIGINFO)
+ ret = ia32_setup_rt_frame(usig, ka, info, set, regs);
+ else
+ ret = ia32_setup_frame(usig, ka, set, regs);
+ } else
+ ret = __setup_rt_frame(sig, ka, info, set, regs);
+
+ if (ret) {
+ force_sigsegv(sig, current);
+ return -EFAULT;
+ }
+
+ return ret;
+}
static int
handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
@@ -394,9 +322,9 @@ handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
int ret;
/* Are we from a system call? */
- if (current_syscall(regs) >= 0) {
+ if (syscall_get_nr(current, regs) >= 0) {
/* If so, check system call restarting.. */
- switch (current_syscall_ret(regs)) {
+ switch (syscall_get_error(current, regs)) {
case -ERESTART_RESTARTBLOCK:
case -ERESTARTNOHAND:
regs->ax = -EINTR;
@@ -423,50 +351,48 @@ handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
likely(test_and_clear_thread_flag(TIF_FORCED_TF)))
regs->flags &= ~X86_EFLAGS_TF;
-#ifdef CONFIG_IA32_EMULATION
- if (test_thread_flag(TIF_IA32)) {
- if (ka->sa.sa_flags & SA_SIGINFO)
- ret = ia32_setup_rt_frame(sig, ka, info, oldset, regs);
- else
- ret = ia32_setup_frame(sig, ka, oldset, regs);
- } else
-#endif
ret = setup_rt_frame(sig, ka, info, oldset, regs);
- if (ret == 0) {
- /*
- * This has nothing to do with segment registers,
- * despite the name. This magic affects uaccess.h
- * macros' behavior. Reset it to the normal setting.
- */
- set_fs(USER_DS);
+ if (ret)
+ return ret;
- /*
- * Clear the direction flag as per the ABI for function entry.
- */
- regs->flags &= ~X86_EFLAGS_DF;
+#ifdef CONFIG_X86_64
+ /*
+ * This has nothing to do with segment registers,
+ * despite the name. This magic affects uaccess.h
+ * macros' behavior. Reset it to the normal setting.
+ */
+ set_fs(USER_DS);
+#endif
- /*
- * Clear TF when entering the signal handler, but
- * notify any tracer that was single-stepping it.
- * The tracer may want to single-step inside the
- * handler too.
- */
- regs->flags &= ~X86_EFLAGS_TF;
- if (test_thread_flag(TIF_SINGLESTEP))
- ptrace_notify(SIGTRAP);
-
- spin_lock_irq(&current->sighand->siglock);
- sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
- if (!(ka->sa.sa_flags & SA_NODEFER))
- sigaddset(&current->blocked,sig);
- recalc_sigpending();
- spin_unlock_irq(&current->sighand->siglock);
- }
+ /*
+ * Clear the direction flag as per the ABI for function entry.
+ */
+ regs->flags &= ~X86_EFLAGS_DF;
- return ret;
+ /*
+ * Clear TF when entering the signal handler, but
+ * notify any tracer that was single-stepping it.
+ * The tracer may want to single-step inside the
+ * handler too.
+ */
+ regs->flags &= ~X86_EFLAGS_TF;
+
+ spin_lock_irq(&current->sighand->siglock);
+ sigorsets(&current->blocked, &current->blocked, &ka->sa.sa_mask);
+ if (!(ka->sa.sa_flags & SA_NODEFER))
+ sigaddset(&current->blocked, sig);
+ recalc_sigpending();
+ spin_unlock_irq(&current->sighand->siglock);
+
+ tracehook_signal_handler(sig, info, ka, regs,
+ test_thread_flag(TIF_SINGLESTEP));
+
+ return 0;
}
+#define NR_restart_syscall \
+ test_thread_flag(TIF_IA32) ? __NR_ia32_restart_syscall : __NR_restart_syscall
/*
* Note that 'init' is a special process: it doesn't get signals it doesn't
* want to handle. Thus you cannot kill init even with a SIGKILL even by
@@ -496,7 +422,8 @@ static void do_signal(struct pt_regs *regs)
signr = get_signal_to_deliver(&info, &ka, regs, NULL);
if (signr > 0) {
- /* Re-enable any watchpoints before delivering the
+ /*
+ * Re-enable any watchpoints before delivering the
* signal to user space. The processor register will
* have been cleared if the watchpoint triggered
* inside the kernel.
@@ -504,7 +431,7 @@ static void do_signal(struct pt_regs *regs)
if (current->thread.debugreg7)
set_debugreg(current->thread.debugreg7, 7);
- /* Whee! Actually deliver the signal. */
+ /* Whee! Actually deliver the signal. */
if (handle_signal(signr, &info, &ka, oldset, regs) == 0) {
/*
* A signal was successfully delivered; the saved
@@ -518,19 +445,18 @@ static void do_signal(struct pt_regs *regs)
}
/* Did we come from a system call? */
- if (current_syscall(regs) >= 0) {
+ if (syscall_get_nr(current, regs) >= 0) {
/* Restart the system call - no handlers present */
- switch (current_syscall_ret(regs)) {
+ switch (syscall_get_error(current, regs)) {
case -ERESTARTNOHAND:
case -ERESTARTSYS:
case -ERESTARTNOINTR:
regs->ax = regs->orig_ax;
regs->ip -= 2;
break;
+
case -ERESTART_RESTARTBLOCK:
- regs->ax = test_thread_flag(TIF_IA32) ?
- __NR_ia32_restart_syscall :
- __NR_restart_syscall;
+ regs->ax = NR_restart_syscall;
regs->ip -= 2;
break;
}
@@ -546,29 +472,45 @@ static void do_signal(struct pt_regs *regs)
}
}
-void do_notify_resume(struct pt_regs *regs, void *unused,
- __u32 thread_info_flags)
+/*
+ * notification of userspace execution resumption
+ * - triggered by the TIF_WORK_MASK flags
+ */
+void
+do_notify_resume(struct pt_regs *regs, void *unused, __u32 thread_info_flags)
{
-#ifdef CONFIG_X86_MCE
+#if defined(CONFIG_X86_64) && defined(CONFIG_X86_MCE)
/* notify userspace of pending MCEs */
if (thread_info_flags & _TIF_MCE_NOTIFY)
mce_notify_user();
-#endif /* CONFIG_X86_MCE */
+#endif /* CONFIG_X86_64 && CONFIG_X86_MCE */
/* deal with pending signal delivery */
if (thread_info_flags & _TIF_SIGPENDING)
do_signal(regs);
+
+ if (thread_info_flags & _TIF_NOTIFY_RESUME) {
+ clear_thread_flag(TIF_NOTIFY_RESUME);
+ tracehook_notify_resume(regs);
+ }
+
+#ifdef CONFIG_X86_32
+ clear_thread_flag(TIF_IRET);
+#endif /* CONFIG_X86_32 */
}
void signal_fault(struct pt_regs *regs, void __user *frame, char *where)
-{
- struct task_struct *me = current;
+{
+ struct task_struct *me = current;
+
if (show_unhandled_signals && printk_ratelimit()) {
- printk("%s[%d] bad frame in %s frame:%p ip:%lx sp:%lx orax:%lx",
- me->comm,me->pid,where,frame,regs->ip,regs->sp,regs->orig_ax);
+ printk(KERN_INFO
+ "%s[%d] bad frame in %s frame:%p ip:%lx sp:%lx orax:%lx",
+ me->comm, me->pid, where, frame,
+ regs->ip, regs->sp, regs->orig_ax);
print_vma_addr(" in ", regs->ip);
- printk("\n");
+ printk(KERN_CONT "\n");
}
- force_sig(SIGSEGV, me);
-}
+ force_sig(SIGSEGV, me);
+}