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author | 2012-12-20 18:05:28 -0800 | |
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committer | 2012-12-20 18:05:28 -0800 | |
commit | 54d46ea993744c5408e39ce0cb4851e13cbea716 (patch) | |
tree | 8e38fa92cc2ae72e0353c44e1e68be9bf5a7a058 /kernel | |
parent | Merge branch 'fixes' of git://git.linaro.org/people/rmk/linux-arm (diff) | |
parent | alpha: switch to generic sigaltstack (diff) | |
download | linux-54d46ea993744c5408e39ce0cb4851e13cbea716.tar.gz linux-54d46ea993744c5408e39ce0cb4851e13cbea716.tar.bz2 linux-54d46ea993744c5408e39ce0cb4851e13cbea716.zip |
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.c | 2 | ||||
-rw-r--r-- | kernel/kmod.c | 6 | ||||
-rw-r--r-- | kernel/signal.c | 74 |
3 files changed, 77 insertions, 5 deletions
diff --git a/kernel/fork.c b/kernel/fork.c index 85f6d536608d..a31b823b3c2d 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 1c317e386831..0023a87e8de6 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 580a91e63471..7aaa51d8e5b8 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 |