generic compat_sys_sigaltstack()
Again, conditional on CONFIG_GENERIC_SIGALTSTACK
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c
index efc6a95..a866411 100644
--- a/arch/x86/ia32/ia32_signal.c
+++ b/arch/x86/ia32/ia32_signal.c
@@ -136,52 +136,6 @@
return sigsuspend(&blocked);
}
-asmlinkage long sys32_sigaltstack(const stack_ia32_t __user *uss_ptr,
- stack_ia32_t __user *uoss_ptr,
- struct pt_regs *regs)
-{
- stack_t uss, uoss;
- int ret, err = 0;
- mm_segment_t seg;
-
- if (uss_ptr) {
- u32 ptr;
-
- memset(&uss, 0, sizeof(stack_t));
- if (!access_ok(VERIFY_READ, uss_ptr, sizeof(stack_ia32_t)))
- return -EFAULT;
-
- get_user_try {
- get_user_ex(ptr, &uss_ptr->ss_sp);
- get_user_ex(uss.ss_flags, &uss_ptr->ss_flags);
- get_user_ex(uss.ss_size, &uss_ptr->ss_size);
- } get_user_catch(err);
-
- if (err)
- return -EFAULT;
- uss.ss_sp = compat_ptr(ptr);
- }
- seg = get_fs();
- set_fs(KERNEL_DS);
- ret = do_sigaltstack((stack_t __force __user *) (uss_ptr ? &uss : NULL),
- (stack_t __force __user *) &uoss, regs->sp);
- set_fs(seg);
- if (ret >= 0 && uoss_ptr) {
- if (!access_ok(VERIFY_WRITE, uoss_ptr, sizeof(stack_ia32_t)))
- return -EFAULT;
-
- put_user_try {
- put_user_ex(ptr_to_compat(uoss.ss_sp), &uoss_ptr->ss_sp);
- put_user_ex(uoss.ss_flags, &uoss_ptr->ss_flags);
- put_user_ex(uoss.ss_size, &uoss_ptr->ss_size);
- } put_user_catch(err);
-
- if (err)
- ret = -EFAULT;
- }
- return ret;
-}
-
/*
* Do a signal return; undo the signal stack.
*/
@@ -292,7 +246,6 @@
struct rt_sigframe_ia32 __user *frame;
sigset_t set;
unsigned int ax;
- struct pt_regs tregs;
frame = (struct rt_sigframe_ia32 __user *)(regs->sp - 4);
@@ -306,8 +259,7 @@
if (ia32_restore_sigcontext(regs, &frame->uc.uc_mcontext, &ax))
goto badframe;
- tregs = *regs;
- if (sys32_sigaltstack(&frame->uc.uc_stack, NULL, &tregs) == -EFAULT)
+ if (compat_restore_altstack(&frame->uc.uc_stack))
goto badframe;
return ax;
diff --git a/arch/x86/ia32/ia32entry.S b/arch/x86/ia32/ia32entry.S
index 32e6f05..102ff7c 100644
--- a/arch/x86/ia32/ia32entry.S
+++ b/arch/x86/ia32/ia32entry.S
@@ -464,7 +464,6 @@
PTREGSCALL stub32_rt_sigreturn, sys32_rt_sigreturn, %rdi
PTREGSCALL stub32_sigreturn, sys32_sigreturn, %rdi
- PTREGSCALL stub32_sigaltstack, sys32_sigaltstack, %rdx
PTREGSCALL stub32_execve, compat_sys_execve, %rcx
PTREGSCALL stub32_fork, sys_fork, %rdi
PTREGSCALL stub32_vfork, sys_vfork, %rdi
diff --git a/arch/x86/include/asm/ia32.h b/arch/x86/include/asm/ia32.h
index e623277..4c6da2e 100644
--- a/arch/x86/include/asm/ia32.h
+++ b/arch/x86/include/asm/ia32.h
@@ -29,16 +29,10 @@
unsigned int sa_restorer; /* Another 32 bit pointer */
};
-typedef struct sigaltstack_ia32 {
- unsigned int ss_sp;
- int ss_flags;
- unsigned int ss_size;
-} stack_ia32_t;
-
struct ucontext_ia32 {
unsigned int uc_flags;
unsigned int uc_link;
- stack_ia32_t uc_stack;
+ compat_stack_t uc_stack;
struct sigcontext_ia32 uc_mcontext;
compat_sigset_t uc_sigmask; /* mask last for extensibility */
};
@@ -46,7 +40,7 @@
struct ucontext_x32 {
unsigned int uc_flags;
unsigned int uc_link;
- stack_ia32_t uc_stack;
+ compat_stack_t uc_stack;
unsigned int uc__pad0; /* needed for alignment */
struct sigcontext uc_mcontext; /* the 64-bit sigcontext type */
compat_sigset_t uc_sigmask; /* mask last for extensibility */
diff --git a/arch/x86/include/asm/sys_ia32.h b/arch/x86/include/asm/sys_ia32.h
index c76fae4..31f61f9 100644
--- a/arch/x86/include/asm/sys_ia32.h
+++ b/arch/x86/include/asm/sys_ia32.h
@@ -69,8 +69,6 @@
/* ia32/ia32_signal.c */
asmlinkage long sys32_sigsuspend(int, int, old_sigset_t);
-asmlinkage long sys32_sigaltstack(const stack_ia32_t __user *,
- stack_ia32_t __user *, struct pt_regs *);
asmlinkage long sys32_sigreturn(struct pt_regs *);
asmlinkage long sys32_rt_sigreturn(struct pt_regs *);
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 6e46201..86d8119 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -912,8 +912,6 @@
END(stub_rt_sigreturn)
#ifdef CONFIG_X86_X32_ABI
- PTREGSCALL stub_x32_sigaltstack, sys32_sigaltstack, %rdx
-
ENTRY(stub_x32_rt_sigreturn)
CFI_STARTPROC
addq $8, %rsp
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 16d065c..b17ed37 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -857,7 +857,6 @@
struct rt_sigframe_x32 __user *frame;
sigset_t set;
unsigned long ax;
- struct pt_regs tregs;
frame = (struct rt_sigframe_x32 __user *)(regs->sp - 8);
@@ -871,8 +870,7 @@
if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &ax))
goto badframe;
- tregs = *regs;
- if (sys32_sigaltstack(&frame->uc.uc_stack, NULL, &tregs) == -EFAULT)
+ if (compat_restore_altstack(&frame->uc.uc_stack))
goto badframe;
return ax;
diff --git a/arch/x86/syscalls/syscall_32.tbl b/arch/x86/syscalls/syscall_32.tbl
index 62c7b22..235226e 100644
--- a/arch/x86/syscalls/syscall_32.tbl
+++ b/arch/x86/syscalls/syscall_32.tbl
@@ -192,7 +192,7 @@
183 i386 getcwd sys_getcwd
184 i386 capget sys_capget
185 i386 capset sys_capset
-186 i386 sigaltstack sys_sigaltstack stub32_sigaltstack
+186 i386 sigaltstack sys_sigaltstack compat_sys_sigaltstack
187 i386 sendfile sys_sendfile sys32_sendfile
188 i386 getpmsg
189 i386 putpmsg
diff --git a/arch/x86/syscalls/syscall_64.tbl b/arch/x86/syscalls/syscall_64.tbl
index 6ffa7f9..c68cbe7 100644
--- a/arch/x86/syscalls/syscall_64.tbl
+++ b/arch/x86/syscalls/syscall_64.tbl
@@ -337,7 +337,7 @@
522 x32 rt_sigpending sys32_rt_sigpending
523 x32 rt_sigtimedwait compat_sys_rt_sigtimedwait
524 x32 rt_sigqueueinfo sys32_rt_sigqueueinfo
-525 x32 sigaltstack stub_x32_sigaltstack
+525 x32 sigaltstack compat_sys_sigaltstack
526 x32 timer_create compat_sys_timer_create
527 x32 mq_notify compat_sys_mq_notify
528 x32 kexec_load compat_sys_kexec_load
diff --git a/include/linux/compat.h b/include/linux/compat.h
index 62bb76f..cb5637e 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -68,6 +68,16 @@
#ifndef compat_user_stack_pointer
#define compat_user_stack_pointer() current_user_stack_pointer()
#endif
+#ifdef CONFIG_GENERIC_SIGALTSTACK
+#ifndef compat_sigaltstack /* we'll need that for MIPS */
+typedef struct compat_sigaltstack {
+ compat_uptr_t ss_sp;
+ int ss_flags;
+ compat_size_t ss_size;
+} compat_stack_t;
+#endif
+#endif
+
#define compat_jiffies_to_clock_t(x) \
(((unsigned long)(x) * COMPAT_USER_HZ) / HZ)
@@ -632,6 +642,12 @@
asmlinkage long compat_sys_sendfile(int out_fd, int in_fd,
compat_off_t __user *offset, compat_size_t count);
+#ifdef CONFIG_GENERIC_SIGALTSTACK
+asmlinkage long compat_sys_sigaltstack(const compat_stack_t __user *uss_ptr,
+ compat_stack_t __user *uoss_ptr);
+
+int compat_restore_altstack(const compat_stack_t __user *uss);
+#endif
#else
diff --git a/kernel/signal.c b/kernel/signal.c
index f05f4c4..aee85bd 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>
@@ -3116,6 +3117,50 @@
return err == -EFAULT ? err : 0;
}
+#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;
+}
+#endif
+#endif
+
#ifdef __ARCH_WANT_SYS_SIGPENDING
/**