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, 35 insertions, 7 deletions

diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index b961184f597a..70fcda1a9049 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -81,6 +81,17 @@ union bpf_attr;
 #include <linux/key.h>
 #include <trace/syscall.h>
 
+#ifdef CONFIG_ARCH_HAS_SYSCALL_WRAPPER
+/*
+ * It may be useful for an architecture to override the definitions of the
+ * SYSCALL_DEFINE0() and __SYSCALL_DEFINEx() macros, in particular to use a
+ * different calling convention for syscalls. To allow for that, the prototypes
+ * for the 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 */
+
 /*
  * __MAP - apply a macro to syscall arguments
  * __MAP(n, m, t1, a1, t2, a2, ..., tn, an) will expand to
@@ -91,7 +102,7 @@ union bpf_attr;
  * for SYSCALL_DEFINE<n>/COMPAT_SYSCALL_DEFINE<n>
  */
 #define __MAP0(m,...)
-#define __MAP1(m,t,a) m(t,a)
+#define __MAP1(m,t,a,...) m(t,a)
 #define __MAP2(m,t,a,...) m(t,a), __MAP1(m,__VA_ARGS__)
 #define __MAP3(m,t,a,...) m(t,a), __MAP2(m,__VA_ARGS__)
 #define __MAP4(m,t,a,...) m(t,a), __MAP3(m,__VA_ARGS__)
@@ -189,11 +200,13 @@ static inline int is_syscall_trace_event(struct trace_event_call *tp_event)
 }
 #endif
 
+#ifndef SYSCALL_DEFINE0
 #define SYSCALL_DEFINE0(sname)					\
 	SYSCALL_METADATA(_##sname, 0);				\
 	asmlinkage long sys_##sname(void);			\
 	ALLOW_ERROR_INJECTION(sys_##sname, ERRNO);		\
 	asmlinkage long sys_##sname(void)
+#endif /* SYSCALL_DEFINE0 */
 
 #define SYSCALL_DEFINE1(name, ...) SYSCALL_DEFINEx(1, _##name, __VA_ARGS__)
 #define SYSCALL_DEFINE2(name, ...) SYSCALL_DEFINEx(2, _##name, __VA_ARGS__)
@@ -209,20 +222,28 @@ static inline int is_syscall_trace_event(struct trace_event_call *tp_event)
 	__SYSCALL_DEFINEx(x, sname, __VA_ARGS__)
 
 #define __PROTECT(...) asmlinkage_protect(__VA_ARGS__)
+
+/*
+ * The asmlinkage stub is aliased to a function named __se_sys_*() which
+ * sign-extends 32-bit ints to longs whenever needed. The actual work is
+ * done within __do_sys_*().
+ */
+#ifndef __SYSCALL_DEFINEx
 #define __SYSCALL_DEFINEx(x, name, ...)					\
 	asmlinkage long sys##name(__MAP(x,__SC_DECL,__VA_ARGS__))	\
-		__attribute__((alias(__stringify(SyS##name))));		\
+		__attribute__((alias(__stringify(__se_sys##name))));	\
 	ALLOW_ERROR_INJECTION(sys##name, ERRNO);			\
-	static inline long SYSC##name(__MAP(x,__SC_DECL,__VA_ARGS__));	\
-	asmlinkage long SyS##name(__MAP(x,__SC_LONG,__VA_ARGS__));	\
-	asmlinkage long SyS##name(__MAP(x,__SC_LONG,__VA_ARGS__))	\
+	static inline long __do_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__));\
+	asmlinkage long __se_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__));	\
+	asmlinkage long __se_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__))	\
 	{								\
-		long ret = SYSC##name(__MAP(x,__SC_CAST,__VA_ARGS__));	\
+		long ret = __do_sys##name(__MAP(x,__SC_CAST,__VA_ARGS__));\
 		__MAP(x,__SC_TEST,__VA_ARGS__);				\
 		__PROTECT(x, ret,__MAP(x,__SC_ARGS,__VA_ARGS__));	\
 		return ret;						\
 	}								\
-	static inline long SYSC##name(__MAP(x,__SC_DECL,__VA_ARGS__))
+	static inline long __do_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__))
+#endif /* __SYSCALL_DEFINEx */
 
 /*
  * Called before coming back to user-mode. Returning to user-mode with an
@@ -252,7 +273,12 @@ static inline void addr_limit_user_check(void)
  * 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 sys_io_setup(unsigned nr_reqs, aio_context_t __user *ctx);
 asmlinkage long sys_io_destroy(aio_context_t ctx);
 asmlinkage long sys_io_submit(aio_context_t, long,
@@ -1076,6 +1102,8 @@ asmlinkage long sys_old_mmap(struct mmap_arg_struct __user *arg);
  */
 asmlinkage long sys_ni_syscall(void);
 
+#endif /* CONFIG_ARCH_HAS_SYSCALL_WRAPPER */
+
 
 /*
  * Kernel code should not call syscalls (i.e., sys_xyzyyz()) directly.