introduce generic sys_sigaltstack(), switch x86 and um to it
Conditional on CONFIG_GENERIC_SIGALTSTACK; architectures that do not
select it are completely unaffected
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/arch/Kconfig b/arch/Kconfig
index 0a8dd05..3301768 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -335,6 +335,9 @@
Modules only use ELF REL relocations. Modules with ELF RELA
relocations will give an error.
+config GENERIC_SIGALTSTACK
+ bool
+
#
# ABI hall of shame
#
diff --git a/arch/um/kernel/signal.c b/arch/um/kernel/signal.c
index db18eb6..48ccf71 100644
--- a/arch/um/kernel/signal.c
+++ b/arch/um/kernel/signal.c
@@ -132,8 +132,3 @@
siginitset(&blocked, mask);
return sigsuspend(&blocked);
}
-
-long sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss)
-{
- return do_sigaltstack(uss, uoss, PT_REGS_SP(¤t->thread.regs));
-}
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 01ca0eb..f380614 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -111,6 +111,7 @@
select MODULES_USE_ELF_REL if X86_32
select MODULES_USE_ELF_RELA if X86_64
select CLONE_BACKWARDS if X86_32
+ select GENERIC_SIGALTSTACK
config INSTRUCTION_DECODER
def_bool y
diff --git a/arch/x86/include/asm/syscalls.h b/arch/x86/include/asm/syscalls.h
index 2f83747..58b7e3e 100644
--- a/arch/x86/include/asm/syscalls.h
+++ b/arch/x86/include/asm/syscalls.h
@@ -25,9 +25,6 @@
/* kernel/signal.c */
long sys_rt_sigreturn(struct pt_regs *);
-long sys_sigaltstack(const stack_t __user *, stack_t __user *,
- struct pt_regs *);
-
/* kernel/tls.c */
asmlinkage int sys_set_thread_area(struct user_desc __user *);
diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S
index c763116..ff84d54 100644
--- a/arch/x86/kernel/entry_32.S
+++ b/arch/x86/kernel/entry_32.S
@@ -739,7 +739,6 @@
ENDPROC(ptregs_##name)
PTREGSCALL1(iopl)
-PTREGSCALL2(sigaltstack)
PTREGSCALL0(sigreturn)
PTREGSCALL0(rt_sigreturn)
PTREGSCALL2(vm86)
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 2363e82..6e46201 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -864,7 +864,6 @@
FORK_LIKE clone
FORK_LIKE fork
FORK_LIKE vfork
- PTREGSCALL stub_sigaltstack, sys_sigaltstack, %rdx
PTREGSCALL stub_iopl, sys_iopl, %rsi
ENTRY(ptregscall_common)
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 70b27ee..16d065c 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -602,13 +602,6 @@
}
#endif /* CONFIG_X86_32 */
-long
-sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
- struct pt_regs *regs)
-{
- return do_sigaltstack(uss, uoss, regs->sp);
-}
-
/*
* Do a signal return; undo the signal stack.
*/
diff --git a/arch/x86/syscalls/syscall_32.tbl b/arch/x86/syscalls/syscall_32.tbl
index ee3c220..62c7b22 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 ptregs_sigaltstack stub32_sigaltstack
+186 i386 sigaltstack sys_sigaltstack stub32_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 a582bfe..6ffa7f9 100644
--- a/arch/x86/syscalls/syscall_64.tbl
+++ b/arch/x86/syscalls/syscall_64.tbl
@@ -137,7 +137,7 @@
128 64 rt_sigtimedwait sys_rt_sigtimedwait
129 64 rt_sigqueueinfo sys_rt_sigqueueinfo
130 common rt_sigsuspend sys_rt_sigsuspend
-131 64 sigaltstack stub_sigaltstack
+131 64 sigaltstack sys_sigaltstack
132 common utime sys_utime
133 common mknod sys_mknod
134 64 uselib
diff --git a/arch/x86/um/Kconfig b/arch/x86/um/Kconfig
index 0fd20f2..96b89d8 100644
--- a/arch/x86/um/Kconfig
+++ b/arch/x86/um/Kconfig
@@ -13,6 +13,7 @@
config UML_X86
def_bool y
select GENERIC_FIND_FIRST_BIT
+ select GENERIC_SIGALTSTACK
config 64BIT
bool "64-bit kernel" if SUBARCH = "x86"
diff --git a/arch/x86/um/sys_call_table_32.c b/arch/x86/um/sys_call_table_32.c
index 812e98c..a0c3b0d 100644
--- a/arch/x86/um/sys_call_table_32.c
+++ b/arch/x86/um/sys_call_table_32.c
@@ -27,7 +27,6 @@
#define ptregs_iopl sys_iopl
#define ptregs_vm86old sys_vm86old
#define ptregs_vm86 sys_vm86
-#define ptregs_sigaltstack sys_sigaltstack
#define __SYSCALL_I386(nr, sym, compat) extern asmlinkage void sym(void) ;
#include <asm/syscalls_32.h>
diff --git a/arch/x86/um/sys_call_table_64.c b/arch/x86/um/sys_call_table_64.c
index 170bd92..f2f0723 100644
--- a/arch/x86/um/sys_call_table_64.c
+++ b/arch/x86/um/sys_call_table_64.c
@@ -31,7 +31,6 @@
#define stub_fork sys_fork
#define stub_vfork sys_vfork
#define stub_execve sys_execve
-#define stub_sigaltstack sys_sigaltstack
#define stub_rt_sigreturn sys_rt_sigreturn
#define __SYSCALL_COMMON(nr, sym, compat) __SYSCALL_64(nr, sym, compat)
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 9fe5f94..6ca1e08 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -63,6 +63,7 @@
struct old_linux_dirent;
struct perf_event_attr;
struct file_handle;
+struct sigaltstack;
#include <linux/types.h>
#include <linux/aio_abi.h>
@@ -299,6 +300,11 @@
asmlinkage long sys_sigpending(old_sigset_t __user *set);
asmlinkage long sys_sigprocmask(int how, old_sigset_t __user *set,
old_sigset_t __user *oset);
+#ifdef CONFIG_GENERIC_SIGALTSTACK
+asmlinkage long sys_sigaltstack(const struct sigaltstack __user *uss,
+ struct sigaltstack __user *uoss);
+#endif
+
asmlinkage long sys_getitimer(int which, struct itimerval __user *value);
asmlinkage long sys_setitimer(int which,
struct itimerval __user *value,
diff --git a/kernel/signal.c b/kernel/signal.c
index 887f2fe..f05f4c4 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -3102,6 +3102,12 @@
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)
{