Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Thomas Gleixner:
 "A set of fixes and updates for x86:

   - Address a swiotlb regression which was caused by the recent DMA
     rework and made driver fail because dma_direct_supported() returned
     false

   - Fix a signedness bug in the APIC ID validation which caused invalid
     APIC IDs to be detected as valid thereby bloating the CPU possible
     space.

   - Fix inconsisten config dependcy/select magic for the MFD_CS5535
     driver.

   - Fix a corruption of the physical address space bits when encryption
     has reduced the address space and late cpuinfo updates overwrite
     the reduced bit information with the original value.

   - Dominiks syscall rework which consolidates the architecture
     specific syscall functions so all syscalls can be wrapped with the
     same macros. This allows to switch x86/64 to struct pt_regs based
     syscalls. Extend the clearing of user space controlled registers in
     the entry patch to the lower registers"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/apic: Fix signedness bug in APIC ID validity checks
  x86/cpu: Prevent cpuinfo_x86::x86_phys_bits adjustment corruption
  x86/olpc: Fix inconsistent MFD_CS5535 configuration
  swiotlb: Use dma_direct_supported() for swiotlb_ops
  syscalls/x86: Adapt syscall_wrapper.h to the new syscall stub naming convention
  syscalls/core, syscalls/x86: Rename struct pt_regs-based sys_*() to __x64_sys_*()
  syscalls/core, syscalls/x86: Clean up compat syscall stub naming convention
  syscalls/core, syscalls/x86: Clean up syscall stub naming convention
  syscalls/x86: Extend register clearing on syscall entry to lower registers
  syscalls/x86: Unconditionally enable 'struct pt_regs' based syscalls on x86_64
  syscalls/x86: Use 'struct pt_regs' based syscall calling for IA32_EMULATION and x32
  syscalls/core: Prepare CONFIG_ARCH_HAS_SYSCALL_WRAPPER=y for compat syscalls
  syscalls/x86: Use 'struct pt_regs' based syscall calling convention for 64-bit syscalls
  syscalls/core: Introduce CONFIG_ARCH_HAS_SYSCALL_WRAPPER=y
  x86/syscalls: Don't pointlessly reload the system call number
  x86/mm: Fix documentation of module mapping range with 4-level paging
  x86/cpuid: Switch to 'static const' specifier

1 files changed, 39 insertions, 12 deletions

diff --git a/include/linux/compat.h b/include/linux/compat.h
index f188eab10570..081281ad5772 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -24,6 +24,17 @@
 #include <asm/siginfo.h>
 #include <asm/signal.h>
 
+#ifdef CONFIG_ARCH_HAS_SYSCALL_WRAPPER
+/*
+ * It may be useful for an architecture to override the definitions of the
+ * COMPAT_SYSCALL_DEFINE0 and COMPAT_SYSCALL_DEFINEx() macros, in particular
+ * to use a different calling convention for syscalls. To allow for that,
+ + the prototypes for the compat_sys_*() functions below will *not* be included
+ * if CONFIG_ARCH_HAS_SYSCALL_WRAPPER is enabled.
+ */
+#include <asm/syscall_wrapper.h>
+#endif /* CONFIG_ARCH_HAS_SYSCALL_WRAPPER */
+
 #ifndef COMPAT_USE_64BIT_TIME
 #define COMPAT_USE_64BIT_TIME 0
 #endif
@@ -32,10 +43,12 @@
 #define __SC_DELOUSE(t,v) ((__force t)(unsigned long)(v))
 #endif
 
+#ifndef COMPAT_SYSCALL_DEFINE0
 #define COMPAT_SYSCALL_DEFINE0(name) \
 	asmlinkage long compat_sys_##name(void); \
 	ALLOW_ERROR_INJECTION(compat_sys_##name, ERRNO); \
 	asmlinkage long compat_sys_##name(void)
+#endif /* COMPAT_SYSCALL_DEFINE0 */
 
 #define COMPAT_SYSCALL_DEFINE1(name, ...) \
         COMPAT_SYSCALL_DEFINEx(1, _##name, __VA_ARGS__)
@@ -50,18 +63,25 @@
 #define COMPAT_SYSCALL_DEFINE6(name, ...) \
 	COMPAT_SYSCALL_DEFINEx(6, _##name, __VA_ARGS__)
 
-#define COMPAT_SYSCALL_DEFINEx(x, name, ...)				\
-	asmlinkage long compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__));\
-	asmlinkage long compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__))\
-		__attribute__((alias(__stringify(compat_SyS##name))));  \
-	ALLOW_ERROR_INJECTION(compat_sys##name, ERRNO);	\
-	static inline long C_SYSC##name(__MAP(x,__SC_DECL,__VA_ARGS__));\
-	asmlinkage long compat_SyS##name(__MAP(x,__SC_LONG,__VA_ARGS__));\
-	asmlinkage long compat_SyS##name(__MAP(x,__SC_LONG,__VA_ARGS__))\
-	{								\
-		return C_SYSC##name(__MAP(x,__SC_DELOUSE,__VA_ARGS__));	\
-	}								\
-	static inline long C_SYSC##name(__MAP(x,__SC_DECL,__VA_ARGS__))
+/*
+ * The asmlinkage stub is aliased to a function named __se_compat_sys_*() which
+ * sign-extends 32-bit ints to longs whenever needed. The actual work is
+ * done within __do_compat_sys_*().
+ */
+#ifndef COMPAT_SYSCALL_DEFINEx
+#define COMPAT_SYSCALL_DEFINEx(x, name, ...)					\
+	asmlinkage long compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__));	\
+	asmlinkage long compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__))	\
+		__attribute__((alias(__stringify(__se_compat_sys##name))));	\
+	ALLOW_ERROR_INJECTION(compat_sys##name, ERRNO);				\
+	static inline long __do_compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__));\
+	asmlinkage long __se_compat_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__));	\
+	asmlinkage long __se_compat_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__))	\
+	{									\
+		return __do_compat_sys##name(__MAP(x,__SC_DELOUSE,__VA_ARGS__));\
+	}									\
+	static inline long __do_compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__))
+#endif /* COMPAT_SYSCALL_DEFINEx */
 
 #ifndef compat_user_stack_pointer
 #define compat_user_stack_pointer() current_user_stack_pointer()
@@ -519,7 +539,12 @@ int __compat_save_altstack(compat_stack_t __user *, unsigned long);
  * Please note that these prototypes here are only provided for information
  * purposes, for static analysis, and for linking from the syscall table.
  * These functions should not be called elsewhere from kernel code.
+ *
+ * As the syscall calling convention may be different from the default
+ * for architectures overriding the syscall calling convention, do not
+ * include the prototypes if CONFIG_ARCH_HAS_SYSCALL_WRAPPER is enabled.
  */
+#ifndef CONFIG_ARCH_HAS_SYSCALL_WRAPPER
 asmlinkage long compat_sys_io_setup(unsigned nr_reqs, u32 __user *ctx32p);
 asmlinkage long compat_sys_io_submit(compat_aio_context_t ctx_id, int nr,
 				     u32 __user *iocb);
@@ -957,6 +982,8 @@ asmlinkage long compat_sys_stime(compat_time_t __user *tptr);
 /* obsolete: net/socket.c */
 asmlinkage long compat_sys_socketcall(int call, u32 __user *args);
 
+#endif /* CONFIG_ARCH_HAS_SYSCALL_WRAPPER */
+
 
 /*
  * For most but not all architectures, "am I in a compat syscall?" and