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authorLinus Torvalds <torvalds@linux-foundation.org>2012-12-20 18:05:28 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2012-12-20 18:05:28 -0800
commit54d46ea993744c5408e39ce0cb4851e13cbea716 (patch)
tree8e38fa92cc2ae72e0353c44e1e68be9bf5a7a058 /kernel
parentf59dc2bb5a50b26ea751f9eac1c81e4cc7de5257 (diff)
parent50ececcfa7d1acee085b2c518cad495062db6379 (diff)
downloadlinaro-lsk-54d46ea993744c5408e39ce0cb4851e13cbea716.tar.gz
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal
Pull signal handling cleanups from Al Viro: "sigaltstack infrastructure + conversion for x86, alpha and um, COMPAT_SYSCALL_DEFINE infrastructure. Note that there are several conflicts between "unify SS_ONSTACK/SS_DISABLE definitions" and UAPI patches in mainline; resolution is trivial - just remove definitions of SS_ONSTACK and SS_DISABLED from arch/*/uapi/asm/signal.h; they are all identical and include/uapi/linux/signal.h contains the unified variant." Fixed up conflicts as per Al. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: alpha: switch to generic sigaltstack new helpers: __save_altstack/__compat_save_altstack, switch x86 and um to those generic compat_sys_sigaltstack() introduce generic sys_sigaltstack(), switch x86 and um to it new helper: compat_user_stack_pointer() new helper: restore_altstack() unify SS_ONSTACK/SS_DISABLE definitions new helper: current_user_stack_pointer() missing user_stack_pointer() instances Bury the conditionals from kernel_thread/kernel_execve series COMPAT_SYSCALL_DEFINE: infrastructure
Diffstat (limited to 'kernel')
-rw-r--r--kernel/fork.c2
-rw-r--r--kernel/kmod.c6
-rw-r--r--kernel/signal.c74
3 files changed, 77 insertions, 5 deletions
diff --git a/kernel/fork.c b/kernel/fork.c
index 85f6d536608..a31b823b3c2 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1613,7 +1613,6 @@ long do_fork(unsigned long clone_flags,
return nr;
}
-#ifdef CONFIG_GENERIC_KERNEL_THREAD
/*
* Create a kernel thread.
*/
@@ -1622,7 +1621,6 @@ pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
return do_fork(flags|CLONE_VM|CLONE_UNTRACED, (unsigned long)fn,
(unsigned long)arg, NULL, NULL);
}
-#endif
#ifdef __ARCH_WANT_SYS_FORK
SYSCALL_DEFINE0(fork)
diff --git a/kernel/kmod.c b/kernel/kmod.c
index 1c317e38683..0023a87e8de 100644
--- a/kernel/kmod.c
+++ b/kernel/kmod.c
@@ -219,9 +219,9 @@ static int ____call_usermodehelper(void *data)
commit_creds(new);
- retval = kernel_execve(sub_info->path,
- (const char *const *)sub_info->argv,
- (const char *const *)sub_info->envp);
+ retval = do_execve(sub_info->path,
+ (const char __user *const __user *)sub_info->argv,
+ (const char __user *const __user *)sub_info->envp);
if (!retval)
return 0;
diff --git a/kernel/signal.c b/kernel/signal.c
index 580a91e6347..7aaa51d8e5b 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -31,6 +31,7 @@
#include <linux/nsproxy.h>
#include <linux/user_namespace.h>
#include <linux/uprobes.h>
+#include <linux/compat.h>
#define CREATE_TRACE_POINTS
#include <trace/events/signal.h>
@@ -3094,6 +3095,79 @@ do_sigaltstack (const stack_t __user *uss, stack_t __user *uoss, unsigned long s
out:
return error;
}
+#ifdef CONFIG_GENERIC_SIGALTSTACK
+SYSCALL_DEFINE2(sigaltstack,const stack_t __user *,uss, stack_t __user *,uoss)
+{
+ return do_sigaltstack(uss, uoss, current_user_stack_pointer());
+}
+#endif
+
+int restore_altstack(const stack_t __user *uss)
+{
+ int err = do_sigaltstack(uss, NULL, current_user_stack_pointer());
+ /* squash all but EFAULT for now */
+ return err == -EFAULT ? err : 0;
+}
+
+int __save_altstack(stack_t __user *uss, unsigned long sp)
+{
+ struct task_struct *t = current;
+ return __put_user((void __user *)t->sas_ss_sp, &uss->ss_sp) |
+ __put_user(sas_ss_flags(sp), &uss->ss_flags) |
+ __put_user(t->sas_ss_size, &uss->ss_size);
+}
+
+#ifdef CONFIG_COMPAT
+#ifdef CONFIG_GENERIC_SIGALTSTACK
+asmlinkage long compat_sys_sigaltstack(const compat_stack_t __user *uss_ptr,
+ compat_stack_t __user *uoss_ptr)
+{
+ stack_t uss, uoss;
+ int ret;
+ mm_segment_t seg;
+
+ if (uss_ptr) {
+ compat_stack_t uss32;
+
+ memset(&uss, 0, sizeof(stack_t));
+ if (copy_from_user(&uss32, uss_ptr, sizeof(compat_stack_t)))
+ return -EFAULT;
+ uss.ss_sp = compat_ptr(uss32.ss_sp);
+ uss.ss_flags = uss32.ss_flags;
+ uss.ss_size = uss32.ss_size;
+ }
+ seg = get_fs();
+ set_fs(KERNEL_DS);
+ ret = do_sigaltstack((stack_t __force __user *) (uss_ptr ? &uss : NULL),
+ (stack_t __force __user *) &uoss,
+ compat_user_stack_pointer());
+ set_fs(seg);
+ if (ret >= 0 && uoss_ptr) {
+ if (!access_ok(VERIFY_WRITE, uoss_ptr, sizeof(compat_stack_t)) ||
+ __put_user(ptr_to_compat(uoss.ss_sp), &uoss_ptr->ss_sp) ||
+ __put_user(uoss.ss_flags, &uoss_ptr->ss_flags) ||
+ __put_user(uoss.ss_size, &uoss_ptr->ss_size))
+ ret = -EFAULT;
+ }
+ return ret;
+}
+
+int compat_restore_altstack(const compat_stack_t __user *uss)
+{
+ int err = compat_sys_sigaltstack(uss, NULL);
+ /* squash all but -EFAULT for now */
+ return err == -EFAULT ? err : 0;
+}
+
+int __compat_save_altstack(compat_stack_t __user *uss, unsigned long sp)
+{
+ struct task_struct *t = current;
+ return __put_user(ptr_to_compat((void __user *)t->sas_ss_sp), &uss->ss_sp) |
+ __put_user(sas_ss_flags(sp), &uss->ss_flags) |
+ __put_user(t->sas_ss_size, &uss->ss_size);
+}
+#endif
+#endif
#ifdef __ARCH_WANT_SYS_SIGPENDING