[PATCH 0/7] x86: fix warnings and refactor syscall code

[PATCH 0/7] x86: fix warnings and refactor syscall code

[Masahiro Yamada]

This patch series makes a lot of cleanups.
We can remove a lot of lines.
The code diff is attractive.



Masahiro Yamada (7):
  x86/syscalls: fix -Wmissing-prototypes warnings from COND_SYSCALL()
  x86/entry/x32: rename __x32_compat_sys_* to __x64_compat_sys_*
  x86/syscalls: switch to generic syscalltbl.sh
  x86/syscalls: stop filling syscall arrays with *_sys_ni_syscall
  x86/unistd: define X32_NR_syscalls only for 64-bit kernel
  x86/syscalls: use __NR_syscalls instead of __NR_syscall_max
  x86/syscalls: switch to generic syscallhdr.sh

 arch/um/kernel/skas/syscall.c          |  2 +-
 arch/x86/entry/syscall_32.c            | 20 +++++------
 arch/x86/entry/syscall_64.c            | 17 +++-------
 arch/x86/entry/syscall_x32.c           | 35 ++++----------------
 arch/x86/entry/syscalls/Makefile       | 36 +++++++++++---------
 arch/x86/entry/syscalls/syscallhdr.sh  | 35 --------------------
 arch/x86/entry/syscalls/syscalltbl.sh  | 46 --------------------------
 arch/x86/include/asm/Kbuild            |  1 +
 arch/x86/include/asm/syscall_wrapper.h | 11 +++---
 arch/x86/include/asm/unistd.h          |  8 ++---
 arch/x86/um/sys_call_table_32.c        | 14 +++-----
 arch/x86/um/sys_call_table_64.c        | 15 ++-------
 12 files changed, 61 insertions(+), 179 deletions(-)
 delete mode 100644 arch/x86/entry/syscalls/syscallhdr.sh
 delete mode 100644 arch/x86/entry/syscalls/syscalltbl.sh

-- 
2.27.0

[PATCH 1/7] x86/syscalls: fix -Wmissing-prototypes warnings from COND_SYSCALL()

[Masahiro Yamada]

Building kernel/sys_ni.c with W=1 emits tons of -Wmissing-prototypes
warnings.

$ make W=1 kernel/sys_ni.o
  [ snip ]
  CC      kernel/sys_ni.o
In file included from kernel/sys_ni.c:10:
./arch/x86/include/asm/syscall_wrapper.h:83:14: warning: no previous prototype for '__x64_sys_io_setup' [-Wmissing-prototypes]
   83 |  __weak long __##abi##_##name(const struct pt_regs *__unused) \
      |              ^~
./arch/x86/include/asm/syscall_wrapper.h:100:2: note: in expansion of macro '__COND_SYSCALL'
  100 |  __COND_SYSCALL(x64, sys_##name)
      |  ^~~~~~~~~~~~~~
./arch/x86/include/asm/syscall_wrapper.h:256:2: note: in expansion of macro '__X64_COND_SYSCALL'
  256 |  __X64_COND_SYSCALL(name)     \
      |  ^~~~~~~~~~~~~~~~~~
kernel/sys_ni.c:39:1: note: in expansion of macro 'COND_SYSCALL'
   39 | COND_SYSCALL(io_setup);
      | ^~~~~~~~~~~~
./arch/x86/include/asm/syscall_wrapper.h:83:14: warning: no previous prototype for '__ia32_sys_io_setup' [-Wmissing-prototypes]
   83 |  __weak long __##abi##_##name(const struct pt_regs *__unused) \
      |              ^~
./arch/x86/include/asm/syscall_wrapper.h:120:2: note: in expansion of macro '__COND_SYSCALL'
  120 |  __COND_SYSCALL(ia32, sys_##name)
      |  ^~~~~~~~~~~~~~
./arch/x86/include/asm/syscall_wrapper.h:257:2: note: in expansion of macro '__IA32_COND_SYSCALL'
  257 |  __IA32_COND_SYSCALL(name)
      |  ^~~~~~~~~~~~~~~~~~~
kernel/sys_ni.c:39:1: note: in expansion of macro 'COND_SYSCALL'
   39 | COND_SYSCALL(io_setup);
      | ^~~~~~~~~~~~
  ...

__SYS_STUB0() and __SYS_STUBx() defined a few lines above have forward
declarations. Let's do likewise for __COND_SYSCALL() to fix the
warnings.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Mickaël Salaün <mic@linux.microsoft.com>
---

 arch/x86/include/asm/syscall_wrapper.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/x86/include/asm/syscall_wrapper.h b/arch/x86/include/asm/syscall_wrapper.h
index a84333adeef2..80c08c7d5e72 100644
--- a/arch/x86/include/asm/syscall_wrapper.h
+++ b/arch/x86/include/asm/syscall_wrapper.h
@@ -80,6 +80,7 @@ extern long __ia32_sys_ni_syscall(const struct pt_regs *regs);
 	}
 
 #define __COND_SYSCALL(abi, name)					\
+	__weak long __##abi##_##name(const struct pt_regs *__unused);	\
 	__weak long __##abi##_##name(const struct pt_regs *__unused)	\
 	{								\
 		return sys_ni_syscall();				\
-- 
2.27.0

[PATCH 2/7] x86/entry/x32: rename __x32_compat_sys_* to __x64_compat_sys_*

[Masahiro Yamada]

In arch/x86/entry/syscall_x32.c, the macros are mapped to symbols
as follows:

  __SYSCALL_COMMON(nr, sym)  -->  __x64_<sym>
  __SYSCALL_X32(nr, sym)     -->  __x32_<sym>

Originally, the syscalls in the x32 special range (512-547) were all
compat.

This assumption is now broken after the following commits:

  55db9c0e8534 ("net: remove compat_sys_{get,set}sockopt")
  5f764d624a89 ("fs: remove the compat readv/writev syscalls")
  598b3cec831f ("fs: remove compat_sys_vmsplice")
  c3973b401ef2 ("mm: remove compat_process_vm_{readv,writev}")

Those commits redefined __x32_sys_* to __x64_sys_* because there is
no stub like __x32_sys_*.

I think defining as follows is more sensible and cleaner.

  __SYSCALL_COMMON(nr, sym)  -->  __x64_<sym>
  __SYSCALL_X32(nr, sym)     -->  __x64_<sym>

This works because both x86_64 and x32 use the same ABI
(RDI, RSI, RDX, R10, R8, R9)

The ugly #define __x32_sys_* will go away.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---

 arch/x86/entry/syscall_x32.c           | 16 ++--------------
 arch/x86/include/asm/syscall_wrapper.h | 10 +++++-----
 2 files changed, 7 insertions(+), 19 deletions(-)

diff --git a/arch/x86/entry/syscall_x32.c b/arch/x86/entry/syscall_x32.c
index f2fe0a33bcfd..3fea8fb9cd6a 100644
--- a/arch/x86/entry/syscall_x32.c
+++ b/arch/x86/entry/syscall_x32.c
@@ -8,27 +8,15 @@
 #include <asm/unistd.h>
 #include <asm/syscall.h>
 
-/*
- * Reuse the 64-bit entry points for the x32 versions that occupy different
- * slots in the syscall table.
- */
-#define __x32_sys_readv		__x64_sys_readv
-#define __x32_sys_writev	__x64_sys_writev
-#define __x32_sys_getsockopt	__x64_sys_getsockopt
-#define __x32_sys_setsockopt	__x64_sys_setsockopt
-#define __x32_sys_vmsplice	__x64_sys_vmsplice
-#define __x32_sys_process_vm_readv	__x64_sys_process_vm_readv
-#define __x32_sys_process_vm_writev	__x64_sys_process_vm_writev
-
 #define __SYSCALL_64(nr, sym)
 
-#define __SYSCALL_X32(nr, sym) extern long __x32_##sym(const struct pt_regs *);
+#define __SYSCALL_X32(nr, sym) extern long __x64_##sym(const struct pt_regs *);
 #define __SYSCALL_COMMON(nr, sym) extern long __x64_##sym(const struct pt_regs *);
 #include <asm/syscalls_64.h>
 #undef __SYSCALL_X32
 #undef __SYSCALL_COMMON
 
-#define __SYSCALL_X32(nr, sym) [nr] = __x32_##sym,
+#define __SYSCALL_X32(nr, sym) [nr] = __x64_##sym,
 #define __SYSCALL_COMMON(nr, sym) [nr] = __x64_##sym,
 
 asmlinkage const sys_call_ptr_t x32_sys_call_table[__NR_x32_syscall_max+1] = {
diff --git a/arch/x86/include/asm/syscall_wrapper.h b/arch/x86/include/asm/syscall_wrapper.h
index 80c08c7d5e72..6a2827d0681f 100644
--- a/arch/x86/include/asm/syscall_wrapper.h
+++ b/arch/x86/include/asm/syscall_wrapper.h
@@ -17,7 +17,7 @@ extern long __ia32_sys_ni_syscall(const struct pt_regs *regs);
  * __x64_sys_*()         - 64-bit native syscall
  * __ia32_sys_*()        - 32-bit native syscall or common compat syscall
  * __ia32_compat_sys_*() - 32-bit compat syscall
- * __x32_compat_sys_*()  - 64-bit X32 compat syscall
+ * __x64_compat_sys_*()  - 64-bit X32 compat syscall
  *
  * The registers are decoded according to the ABI:
  * 64-bit: RDI, RSI, RDX, R10, R8, R9
@@ -166,17 +166,17 @@ extern long __ia32_sys_ni_syscall(const struct pt_regs *regs);
  * with x86_64 obviously do not need such care.
  */
 #define __X32_COMPAT_SYS_STUB0(name)					\
-	__SYS_STUB0(x32, compat_sys_##name)
+	__SYS_STUB0(x64, compat_sys_##name)
 
 #define __X32_COMPAT_SYS_STUBx(x, name, ...)				\
-	__SYS_STUBx(x32, compat_sys##name,				\
+	__SYS_STUBx(x64, compat_sys##name,				\
 		    SC_X86_64_REGS_TO_ARGS(x, __VA_ARGS__))
 
 #define __X32_COMPAT_COND_SYSCALL(name)					\
-	__COND_SYSCALL(x32, compat_sys_##name)
+	__COND_SYSCALL(x64, compat_sys_##name)
 
 #define __X32_COMPAT_SYS_NI(name)					\
-	__SYS_NI(x32, compat_sys_##name)
+	__SYS_NI(x64, compat_sys_##name)
 #else /* CONFIG_X86_X32 */
 #define __X32_COMPAT_SYS_STUB0(name)
 #define __X32_COMPAT_SYS_STUBx(x, name, ...)
-- 
2.27.0

[PATCH 3/7] x86/syscalls: switch to generic syscalltbl.sh

[Masahiro Yamada]

Many architectures duplicate similar shell scripts.

This commit converts x86 and UML to use scripts/syscalltbl.sh.

Currently, syscall_64.h mixes up x86_64 and x32 syscalls. This commit
splits it into syscall_64.h and syscall_x32.h.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---

 arch/x86/entry/syscall_32.c           | 12 +++++--
 arch/x86/entry/syscall_64.c           |  9 ++----
 arch/x86/entry/syscall_x32.c          | 15 +++------
 arch/x86/entry/syscalls/Makefile      | 10 ++++--
 arch/x86/entry/syscalls/syscalltbl.sh | 46 ---------------------------
 arch/x86/include/asm/Kbuild           |  1 +
 arch/x86/um/sys_call_table_32.c       |  8 +++--
 arch/x86/um/sys_call_table_64.c       |  9 ++----
 8 files changed, 34 insertions(+), 76 deletions(-)
 delete mode 100644 arch/x86/entry/syscalls/syscalltbl.sh

diff --git a/arch/x86/entry/syscall_32.c b/arch/x86/entry/syscall_32.c
index 86eb0d89d46f..70bf46e73b1c 100644
--- a/arch/x86/entry/syscall_32.c
+++ b/arch/x86/entry/syscall_32.c
@@ -8,12 +8,18 @@
 #include <asm/unistd.h>
 #include <asm/syscall.h>
 
-#define __SYSCALL_I386(nr, sym) extern long __ia32_##sym(const struct pt_regs *);
+#ifdef CONFIG_IA32_EMULATION
+#define __SYSCALL_WITH_COMPAT(nr, native, compat)	__SYSCALL(nr, compat)
+#else
+#define __SYSCALL_WITH_COMPAT(nr, native, compat)	__SYSCALL(nr, native)
+#endif
+
+#define __SYSCALL(nr, sym) extern long __ia32_##sym(const struct pt_regs *);
 
 #include <asm/syscalls_32.h>
-#undef __SYSCALL_I386
+#undef __SYSCALL
 
-#define __SYSCALL_I386(nr, sym) [nr] = __ia32_##sym,
+#define __SYSCALL(nr, sym) [nr] = __ia32_##sym,
 
 __visible const sys_call_ptr_t ia32_sys_call_table[__NR_ia32_syscall_max+1] = {
 	/*
diff --git a/arch/x86/entry/syscall_64.c b/arch/x86/entry/syscall_64.c
index 1594ec72bcbb..82670bb10931 100644
--- a/arch/x86/entry/syscall_64.c
+++ b/arch/x86/entry/syscall_64.c
@@ -8,14 +8,11 @@
 #include <asm/unistd.h>
 #include <asm/syscall.h>
 
-#define __SYSCALL_X32(nr, sym)
-#define __SYSCALL_COMMON(nr, sym) __SYSCALL_64(nr, sym)
-
-#define __SYSCALL_64(nr, sym) extern long __x64_##sym(const struct pt_regs *);
+#define __SYSCALL(nr, sym) extern long __x64_##sym(const struct pt_regs *);
 #include <asm/syscalls_64.h>
-#undef __SYSCALL_64
+#undef __SYSCALL
 
-#define __SYSCALL_64(nr, sym) [nr] = __x64_##sym,
+#define __SYSCALL(nr, sym) [nr] = __x64_##sym,
 
 asmlinkage const sys_call_ptr_t sys_call_table[__NR_syscall_max+1] = {
 	/*
diff --git a/arch/x86/entry/syscall_x32.c b/arch/x86/entry/syscall_x32.c
index 3fea8fb9cd6a..6d2ef887d7b6 100644
--- a/arch/x86/entry/syscall_x32.c
+++ b/arch/x86/entry/syscall_x32.c
@@ -8,16 +8,11 @@
 #include <asm/unistd.h>
 #include <asm/syscall.h>
 
-#define __SYSCALL_64(nr, sym)
+#define __SYSCALL(nr, sym) extern long __x64_##sym(const struct pt_regs *);
+#include <asm/syscalls_x32.h>
+#undef __SYSCALL
 
-#define __SYSCALL_X32(nr, sym) extern long __x64_##sym(const struct pt_regs *);
-#define __SYSCALL_COMMON(nr, sym) extern long __x64_##sym(const struct pt_regs *);
-#include <asm/syscalls_64.h>
-#undef __SYSCALL_X32
-#undef __SYSCALL_COMMON
-
-#define __SYSCALL_X32(nr, sym) [nr] = __x64_##sym,
-#define __SYSCALL_COMMON(nr, sym) [nr] = __x64_##sym,
+#define __SYSCALL(nr, sym) [nr] = __x64_##sym,
 
 asmlinkage const sys_call_ptr_t x32_sys_call_table[__NR_x32_syscall_max+1] = {
 	/*
@@ -25,5 +20,5 @@ asmlinkage const sys_call_ptr_t x32_sys_call_table[__NR_x32_syscall_max+1] = {
 	 * when the & below is removed.
 	 */
 	[0 ... __NR_x32_syscall_max] = &__x64_sys_ni_syscall,
-#include <asm/syscalls_64.h>
+#include <asm/syscalls_x32.h>
 };
diff --git a/arch/x86/entry/syscalls/Makefile b/arch/x86/entry/syscalls/Makefile
index d8c4f6c9eadc..c4bd8dd82bb1 100644
--- a/arch/x86/entry/syscalls/Makefile
+++ b/arch/x86/entry/syscalls/Makefile
@@ -10,7 +10,7 @@ syscall32 := $(src)/syscall_32.tbl
 syscall64 := $(src)/syscall_64.tbl
 
 syshdr := $(srctree)/$(src)/syscallhdr.sh
-systbl := $(srctree)/$(src)/syscalltbl.sh
+systbl := $(srctree)/scripts/syscalltbl.sh
 
 quiet_cmd_syshdr = SYSHDR  $@
       cmd_syshdr = $(CONFIG_SHELL) '$(syshdr)' '$<' '$@' \
@@ -18,7 +18,7 @@ quiet_cmd_syshdr = SYSHDR  $@
 		   '$(syshdr_pfx_$(basetarget))' \
 		   '$(syshdr_offset_$(basetarget))'
 quiet_cmd_systbl = SYSTBL  $@
-      cmd_systbl = $(CONFIG_SHELL) '$(systbl)' $< $@
+      cmd_systbl = $(CONFIG_SHELL) $(systbl) --abis $(abis) $< $@
 
 quiet_cmd_hypercalls = HYPERCALLS $@
       cmd_hypercalls = $(CONFIG_SHELL) '$<' $@ $(filter-out $<, $(real-prereqs))
@@ -46,10 +46,15 @@ syshdr_pfx_unistd_64_x32 := x32_
 $(out)/unistd_64_x32.h: $(syscall64) $(syshdr) FORCE
 	$(call if_changed,syshdr)
 
+$(out)/syscalls_32.h: abis := i386
 $(out)/syscalls_32.h: $(syscall32) $(systbl) FORCE
 	$(call if_changed,systbl)
+$(out)/syscalls_64.h: abis := common,64
 $(out)/syscalls_64.h: $(syscall64) $(systbl) FORCE
 	$(call if_changed,systbl)
+$(out)/syscalls_x32.h: abis := common,x32
+$(out)/syscalls_x32.h: $(syscall64) $(systbl) FORCE
+	$(call if_changed,systbl)
 
 $(out)/xen-hypercalls.h: $(srctree)/scripts/xen-hypercalls.sh FORCE
 	$(call if_changed,hypercalls)
@@ -60,6 +65,7 @@ uapisyshdr-y			+= unistd_32.h unistd_64.h unistd_x32.h
 syshdr-y			+= syscalls_32.h
 syshdr-$(CONFIG_X86_64)		+= unistd_32_ia32.h unistd_64_x32.h
 syshdr-$(CONFIG_X86_64)		+= syscalls_64.h
+syshdr-$(CONFIG_X86_X32)	+= syscalls_x32.h
 syshdr-$(CONFIG_XEN)		+= xen-hypercalls.h
 
 uapisyshdr-y	:= $(addprefix $(uapi)/, $(uapisyshdr-y))
diff --git a/arch/x86/entry/syscalls/syscalltbl.sh b/arch/x86/entry/syscalls/syscalltbl.sh
deleted file mode 100644
index 929bde120d6b..000000000000
--- a/arch/x86/entry/syscalls/syscalltbl.sh
+++ /dev/null
@@ -1,46 +0,0 @@
-#!/bin/bash
-# SPDX-License-Identifier: GPL-2.0
-
-in="$1"
-out="$2"
-
-syscall_macro() {
-    local abi="$1"
-    local nr="$2"
-    local entry="$3"
-
-    echo "__SYSCALL_${abi}($nr, $entry)"
-}
-
-emit() {
-    local abi="$1"
-    local nr="$2"
-    local entry="$3"
-    local compat="$4"
-
-    if [ "$abi" != "I386" -a -n "$compat" ]; then
-	echo "a compat entry ($abi: $compat) for a 64-bit syscall makes no sense" >&2
-	exit 1
-    fi
-
-    if [ -z "$compat" ]; then
-	if [ -n "$entry" ]; then
-	    syscall_macro "$abi" "$nr" "$entry"
-	fi
-    else
-	echo "#ifdef CONFIG_X86_32"
-	if [ -n "$entry" ]; then
-	    syscall_macro "$abi" "$nr" "$entry"
-	fi
-	echo "#else"
-	syscall_macro "$abi" "$nr" "$compat"
-	echo "#endif"
-    fi
-}
-
-grep '^[0-9]' "$in" | sort -n | (
-    while read nr abi name entry compat; do
-	abi=`echo "$abi" | tr '[a-z]' '[A-Z]'`
-	emit "$abi" "$nr" "$entry" "$compat"
-    done
-) > "$out"
diff --git a/arch/x86/include/asm/Kbuild b/arch/x86/include/asm/Kbuild
index b19ec8282d50..1e51650b79d7 100644
--- a/arch/x86/include/asm/Kbuild
+++ b/arch/x86/include/asm/Kbuild
@@ -3,6 +3,7 @@
 
 generated-y += syscalls_32.h
 generated-y += syscalls_64.h
+generated-y += syscalls_x32.h
 generated-y += unistd_32_ia32.h
 generated-y += unistd_64_x32.h
 generated-y += xen-hypercalls.h
diff --git a/arch/x86/um/sys_call_table_32.c b/arch/x86/um/sys_call_table_32.c
index 2ed81e581755..e83619c365dc 100644
--- a/arch/x86/um/sys_call_table_32.c
+++ b/arch/x86/um/sys_call_table_32.c
@@ -26,11 +26,13 @@
 
 #define old_mmap sys_old_mmap
 
-#define __SYSCALL_I386(nr, sym) extern asmlinkage long sym(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long) ;
+#define __SYSCALL_WITH_COMPAT(nr, native, compat)	__SYSCALL(nr, native)
+
+#define __SYSCALL(nr, sym) extern asmlinkage long sym(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long);
 #include <asm/syscalls_32.h>
 
-#undef __SYSCALL_I386
-#define __SYSCALL_I386(nr, sym) [ nr ] = sym,
+#undef __SYSCALL
+#define __SYSCALL(nr, sym) [ nr ] = sym,
 
 extern asmlinkage long sys_ni_syscall(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long);
 
diff --git a/arch/x86/um/sys_call_table_64.c b/arch/x86/um/sys_call_table_64.c
index 2e8544dafbb0..6fb75af7cf54 100644
--- a/arch/x86/um/sys_call_table_64.c
+++ b/arch/x86/um/sys_call_table_64.c
@@ -36,14 +36,11 @@
 #define stub_execveat sys_execveat
 #define stub_rt_sigreturn sys_rt_sigreturn
 
-#define __SYSCALL_X32(nr, sym)
-#define __SYSCALL_COMMON(nr, sym) __SYSCALL_64(nr, sym)
-
-#define __SYSCALL_64(nr, sym) extern asmlinkage long sym(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long) ;
+#define __SYSCALL(nr, sym) extern asmlinkage long sym(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long);
 #include <asm/syscalls_64.h>
 
-#undef __SYSCALL_64
-#define __SYSCALL_64(nr, sym) [ nr ] = sym,
+#undef __SYSCALL
+#define __SYSCALL(nr, sym) [ nr ] = sym,
 
 extern asmlinkage long sys_ni_syscall(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long);
 
-- 
2.27.0

[PATCH 4/7] x86/syscalls: stop filling syscall arrays with *_sys_ni_syscall

[Masahiro Yamada]

This is a follow-up cleanup after switching to the generic
syscalltbl.sh.

The old arch/x86/entry/syscalls/syscalltbl.sh skipped non-existing
syscalls. So, the generated syscalls_64.h, for example, had a big
hole in the syscall numbers 335-423 range. That is why there exists
[0 ... __NR_*_syscall_max] = &__*_sys_ni_cyscall.

The new script, scripts/syscalltbl.sh automatically fills holes
with __SYSCALL(<nr>, sys_ni_syscall), hence such ugly code can
go away. The designated initializers, '[nr] =' are also unneeded.

Also, there is no need to give __NR_*_syscall_max+1 because the array
size is implied by the number of syscalls in the generated headers.
Hence, there is no need to include <asm/unistd.h>, either.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---

 arch/x86/entry/syscall_32.c     | 10 ++--------
 arch/x86/entry/syscall_64.c     | 10 ++--------
 arch/x86/entry/syscall_x32.c    | 10 ++--------
 arch/x86/um/sys_call_table_32.c |  6 ------
 arch/x86/um/sys_call_table_64.c |  6 ------
 5 files changed, 6 insertions(+), 36 deletions(-)

diff --git a/arch/x86/entry/syscall_32.c b/arch/x86/entry/syscall_32.c
index 70bf46e73b1c..8cfc9bc73e7f 100644
--- a/arch/x86/entry/syscall_32.c
+++ b/arch/x86/entry/syscall_32.c
@@ -5,7 +5,6 @@
 #include <linux/sys.h>
 #include <linux/cache.h>
 #include <linux/syscalls.h>
-#include <asm/unistd.h>
 #include <asm/syscall.h>
 
 #ifdef CONFIG_IA32_EMULATION
@@ -19,13 +18,8 @@
 #include <asm/syscalls_32.h>
 #undef __SYSCALL
 
-#define __SYSCALL(nr, sym) [nr] = __ia32_##sym,
+#define __SYSCALL(nr, sym) __ia32_##sym,
 
-__visible const sys_call_ptr_t ia32_sys_call_table[__NR_ia32_syscall_max+1] = {
-	/*
-	 * Smells like a compiler bug -- it doesn't work
-	 * when the & below is removed.
-	 */
-	[0 ... __NR_ia32_syscall_max] = &__ia32_sys_ni_syscall,
+__visible const sys_call_ptr_t ia32_sys_call_table[] = {
 #include <asm/syscalls_32.h>
 };
diff --git a/arch/x86/entry/syscall_64.c b/arch/x86/entry/syscall_64.c
index 82670bb10931..be120eec1fc9 100644
--- a/arch/x86/entry/syscall_64.c
+++ b/arch/x86/entry/syscall_64.c
@@ -5,20 +5,14 @@
 #include <linux/sys.h>
 #include <linux/cache.h>
 #include <linux/syscalls.h>
-#include <asm/unistd.h>
 #include <asm/syscall.h>
 
 #define __SYSCALL(nr, sym) extern long __x64_##sym(const struct pt_regs *);
 #include <asm/syscalls_64.h>
 #undef __SYSCALL
 
-#define __SYSCALL(nr, sym) [nr] = __x64_##sym,
+#define __SYSCALL(nr, sym) __x64_##sym,
 
-asmlinkage const sys_call_ptr_t sys_call_table[__NR_syscall_max+1] = {
-	/*
-	 * Smells like a compiler bug -- it doesn't work
-	 * when the & below is removed.
-	 */
-	[0 ... __NR_syscall_max] = &__x64_sys_ni_syscall,
+asmlinkage const sys_call_ptr_t sys_call_table[] = {
 #include <asm/syscalls_64.h>
 };
diff --git a/arch/x86/entry/syscall_x32.c b/arch/x86/entry/syscall_x32.c
index 6d2ef887d7b6..bdd0e03a1265 100644
--- a/arch/x86/entry/syscall_x32.c
+++ b/arch/x86/entry/syscall_x32.c
@@ -5,20 +5,14 @@
 #include <linux/sys.h>
 #include <linux/cache.h>
 #include <linux/syscalls.h>
-#include <asm/unistd.h>
 #include <asm/syscall.h>
 
 #define __SYSCALL(nr, sym) extern long __x64_##sym(const struct pt_regs *);
 #include <asm/syscalls_x32.h>
 #undef __SYSCALL
 
-#define __SYSCALL(nr, sym) [nr] = __x64_##sym,
+#define __SYSCALL(nr, sym) __x64_##sym,
 
-asmlinkage const sys_call_ptr_t x32_sys_call_table[__NR_x32_syscall_max+1] = {
-	/*
-	 * Smells like a compiler bug -- it doesn't work
-	 * when the & below is removed.
-	 */
-	[0 ... __NR_x32_syscall_max] = &__x64_sys_ni_syscall,
+asmlinkage const sys_call_ptr_t x32_sys_call_table[] = {
 #include <asm/syscalls_x32.h>
 };
diff --git a/arch/x86/um/sys_call_table_32.c b/arch/x86/um/sys_call_table_32.c
index e83619c365dc..f8323104e353 100644
--- a/arch/x86/um/sys_call_table_32.c
+++ b/arch/x86/um/sys_call_table_32.c
@@ -7,7 +7,6 @@
 #include <linux/linkage.h>
 #include <linux/sys.h>
 #include <linux/cache.h>
-#include <asm/unistd.h>
 #include <asm/syscall.h>
 
 #define __NO_STUBS
@@ -37,11 +36,6 @@
 extern asmlinkage long sys_ni_syscall(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long);
 
 const sys_call_ptr_t sys_call_table[] ____cacheline_aligned = {
-	/*
-	 * Smells like a compiler bug -- it doesn't work
-	 * when the & below is removed.
-	 */
-	[0 ... __NR_syscall_max] = &sys_ni_syscall,
 #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 6fb75af7cf54..5ed665dc785f 100644
--- a/arch/x86/um/sys_call_table_64.c
+++ b/arch/x86/um/sys_call_table_64.c
@@ -7,7 +7,6 @@
 #include <linux/linkage.h>
 #include <linux/sys.h>
 #include <linux/cache.h>
-#include <asm/unistd.h>
 #include <asm/syscall.h>
 
 #define __NO_STUBS
@@ -45,11 +44,6 @@
 extern asmlinkage long sys_ni_syscall(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long);
 
 const sys_call_ptr_t sys_call_table[] ____cacheline_aligned = {
-	/*
-	 * Smells like a compiler bug -- it doesn't work
-	 * when the & below is removed.
-	 */
-	[0 ... __NR_syscall_max] = &sys_ni_syscall,
 #include <asm/syscalls_64.h>
 };
 
-- 
2.27.0

[PATCH 5/7] x86/unistd: define X32_NR_syscalls only for 64-bit kernel

[Masahiro Yamada]

X32_NR_syscalls is needed only when building arch/x86/entry/common.c
for x86_64 kernel. It is not used for i386 kernel.

Move it to the else part of #ifdef CONFIG_X86_32.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---

 arch/x86/include/asm/unistd.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/unistd.h b/arch/x86/include/asm/unistd.h
index c1c3d31b15c0..1bc6020bc58d 100644
--- a/arch/x86/include/asm/unistd.h
+++ b/arch/x86/include/asm/unistd.h
@@ -26,11 +26,11 @@
 #  define __ARCH_WANT_COMPAT_SYS_PWRITEV64
 #  define __ARCH_WANT_COMPAT_SYS_PREADV64V2
 #  define __ARCH_WANT_COMPAT_SYS_PWRITEV64V2
+#  define X32_NR_syscalls (__NR_x32_syscall_max + 1)
 
 # endif
 
 # define NR_syscalls (__NR_syscall_max + 1)
-# define X32_NR_syscalls (__NR_x32_syscall_max + 1)
 # define IA32_NR_syscalls (__NR_ia32_syscall_max + 1)
 
 # define __ARCH_WANT_NEW_STAT
-- 
2.27.0

[PATCH 6/7] x86/syscalls: use __NR_syscalls instead of __NR_syscall_max

[Masahiro Yamada]

__NR_syscall_max is only used by x86 and UML in the following two files:

  - arch/um/kernel/skas/syscall.c
  - arch/x86/include/asm/unistd.h

In contrast, __NR_syscalls is widely used by all the architectures.

Let's convert __NR_syscall_max to __NR_syscalls by adding one.

This makes arch/x86/include/asm/unistd.h look cleaner, and also
prepares x86 to switch to the generic scripts/syscallhdr.sh from
arch/x86/entry/syscalls/syscallhdr.sh.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---

 arch/um/kernel/skas/syscall.c         | 2 +-
 arch/x86/entry/syscalls/syscallhdr.sh | 2 +-
 arch/x86/include/asm/unistd.h         | 8 ++++----
 3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/arch/um/kernel/skas/syscall.c b/arch/um/kernel/skas/syscall.c
index 3d91f89fd852..9ee19e566da3 100644
--- a/arch/um/kernel/skas/syscall.c
+++ b/arch/um/kernel/skas/syscall.c
@@ -41,7 +41,7 @@ void handle_syscall(struct uml_pt_regs *r)
 		goto out;
 
 	syscall = UPT_SYSCALL_NR(r);
-	if (syscall >= 0 && syscall <= __NR_syscall_max)
+	if (syscall >= 0 && syscall < __NR_syscalls)
 		PT_REGS_SET_SYSCALL_RETURN(regs,
 				EXECUTE_SYSCALL(syscall, regs));
 
diff --git a/arch/x86/entry/syscalls/syscallhdr.sh b/arch/x86/entry/syscalls/syscallhdr.sh
index cc1e63857427..75e66af06773 100644
--- a/arch/x86/entry/syscalls/syscallhdr.sh
+++ b/arch/x86/entry/syscalls/syscallhdr.sh
@@ -28,7 +28,7 @@ grep -E "^[0-9A-Fa-fXx]+[[:space:]]+${my_abis}" "$in" | sort -n | (
 
     echo ""
     echo "#ifdef __KERNEL__"
-    echo "#define __NR_${prefix}syscall_max $max"
+    echo "#define __NR_${prefix}syscalls $(($max + 1))"
     echo "#endif"
     echo ""
     echo "#endif /* ${fileguard} */"
diff --git a/arch/x86/include/asm/unistd.h b/arch/x86/include/asm/unistd.h
index 1bc6020bc58d..80e9d5206a71 100644
--- a/arch/x86/include/asm/unistd.h
+++ b/arch/x86/include/asm/unistd.h
@@ -13,7 +13,7 @@
 #  define __ARCH_WANT_SYS_OLD_MMAP
 #  define __ARCH_WANT_SYS_OLD_SELECT
 
-#  define __NR_ia32_syscall_max __NR_syscall_max
+#  define IA32_NR_syscalls (__NR_syscalls)
 
 # else
 
@@ -26,12 +26,12 @@
 #  define __ARCH_WANT_COMPAT_SYS_PWRITEV64
 #  define __ARCH_WANT_COMPAT_SYS_PREADV64V2
 #  define __ARCH_WANT_COMPAT_SYS_PWRITEV64V2
-#  define X32_NR_syscalls (__NR_x32_syscall_max + 1)
+#  define X32_NR_syscalls (__NR_x32_syscalls)
+#  define IA32_NR_syscalls (__NR_ia32_syscalls)
 
 # endif
 
-# define NR_syscalls (__NR_syscall_max + 1)
-# define IA32_NR_syscalls (__NR_ia32_syscall_max + 1)
+# define NR_syscalls (__NR_syscalls)
 
 # define __ARCH_WANT_NEW_STAT
 # define __ARCH_WANT_OLD_READDIR
-- 
2.27.0

[PATCH 7/7] x86/syscalls: switch to generic syscallhdr.sh

[Masahiro Yamada]

Many architectures duplicate similar shell scripts.

This commit converts x86 to use scripts/syscallhdr.sh.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---

 arch/x86/entry/syscalls/Makefile      | 26 ++++++++++----------
 arch/x86/entry/syscalls/syscallhdr.sh | 35 ---------------------------
 2 files changed, 13 insertions(+), 48 deletions(-)
 delete mode 100644 arch/x86/entry/syscalls/syscallhdr.sh

diff --git a/arch/x86/entry/syscalls/Makefile b/arch/x86/entry/syscalls/Makefile
index c4bd8dd82bb1..8eb014bca8c9 100644
--- a/arch/x86/entry/syscalls/Makefile
+++ b/arch/x86/entry/syscalls/Makefile
@@ -9,40 +9,40 @@ _dummy := $(shell [ -d '$(out)' ] || mkdir -p '$(out)') \
 syscall32 := $(src)/syscall_32.tbl
 syscall64 := $(src)/syscall_64.tbl
 
-syshdr := $(srctree)/$(src)/syscallhdr.sh
+syshdr := $(srctree)/scripts/syscallhdr.sh
 systbl := $(srctree)/scripts/syscalltbl.sh
 
 quiet_cmd_syshdr = SYSHDR  $@
-      cmd_syshdr = $(CONFIG_SHELL) '$(syshdr)' '$<' '$@' \
-		   '$(syshdr_abi_$(basetarget))' \
-		   '$(syshdr_pfx_$(basetarget))' \
-		   '$(syshdr_offset_$(basetarget))'
+      cmd_syshdr = $(CONFIG_SHELL) $(syshdr) --abis $(abis) --emit-nr \
+		$(if $(offset),--offset $(offset)) \
+		$(if $(prefix),--prefix $(prefix)) \
+		$< $@
 quiet_cmd_systbl = SYSTBL  $@
       cmd_systbl = $(CONFIG_SHELL) $(systbl) --abis $(abis) $< $@
 
 quiet_cmd_hypercalls = HYPERCALLS $@
       cmd_hypercalls = $(CONFIG_SHELL) '$<' $@ $(filter-out $<, $(real-prereqs))
 
-syshdr_abi_unistd_32 := i386
+$(uapi)/unistd_32.h: abis := i386
 $(uapi)/unistd_32.h: $(syscall32) $(syshdr) FORCE
 	$(call if_changed,syshdr)
 
-syshdr_abi_unistd_32_ia32 := i386
-syshdr_pfx_unistd_32_ia32 := ia32_
+$(out)/unistd_32_ia32.h: abis := i386
+$(out)/unistd_32_ia32.h: prefix := ia32_
 $(out)/unistd_32_ia32.h: $(syscall32) $(syshdr) FORCE
 	$(call if_changed,syshdr)
 
-syshdr_abi_unistd_x32 := common,x32
-syshdr_offset_unistd_x32 := __X32_SYSCALL_BIT
+$(uapi)/unistd_x32.h: abis := common,x32
+$(uapi)/unistd_x32.h: offset := __X32_SYSCALL_BIT
 $(uapi)/unistd_x32.h: $(syscall64) $(syshdr) FORCE
 	$(call if_changed,syshdr)
 
-syshdr_abi_unistd_64 := common,64
+$(uapi)/unistd_64.h: abis := common,64
 $(uapi)/unistd_64.h: $(syscall64) $(syshdr) FORCE
 	$(call if_changed,syshdr)
 
-syshdr_abi_unistd_64_x32 := x32
-syshdr_pfx_unistd_64_x32 := x32_
+$(out)/unistd_64_x32.h: abis := x32
+$(out)/unistd_64_x32.h: prefix := x32_
 $(out)/unistd_64_x32.h: $(syscall64) $(syshdr) FORCE
 	$(call if_changed,syshdr)
 
diff --git a/arch/x86/entry/syscalls/syscallhdr.sh b/arch/x86/entry/syscalls/syscallhdr.sh
deleted file mode 100644
index 75e66af06773..000000000000
--- a/arch/x86/entry/syscalls/syscallhdr.sh
+++ /dev/null
@@ -1,35 +0,0 @@
-#!/bin/sh
-# SPDX-License-Identifier: GPL-2.0
-
-in="$1"
-out="$2"
-my_abis=`echo "($3)" | tr ',' '|'`
-prefix="$4"
-offset="$5"
-
-fileguard=_ASM_X86_`basename "$out" | sed \
-    -e 'y/abcdefghijklmnopqrstuvwxyz/ABCDEFGHIJKLMNOPQRSTUVWXYZ/' \
-    -e 's/[^A-Z0-9_]/_/g' -e 's/__/_/g'`
-grep -E "^[0-9A-Fa-fXx]+[[:space:]]+${my_abis}" "$in" | sort -n | (
-    echo "#ifndef ${fileguard}"
-    echo "#define ${fileguard} 1"
-    echo ""
-
-    max=0
-    while read nr abi name entry ; do
-	if [ -z "$offset" ]; then
-	    echo "#define __NR_${prefix}${name} $nr"
-	else
-	    echo "#define __NR_${prefix}${name} ($offset + $nr)"
-        fi
-
-	max=$nr
-    done
-
-    echo ""
-    echo "#ifdef __KERNEL__"
-    echo "#define __NR_${prefix}syscalls $(($max + 1))"
-    echo "#endif"
-    echo ""
-    echo "#endif /* ${fileguard} */"
-) > "$out"
-- 
2.27.0

Re: [PATCH 1/7] x86/syscalls: fix -Wmissing-prototypes warnings from COND_SYSCALL()

[Mickaël Salaün]

Hi Masahiro,

What is the status of this patch? Could you please push it to -next?
This would avoid emails from lkp:
https://lore.kernel.org/linux-security-module/202103191423.Jl0jVzfL-lkp@intel.com/

Thanks,
 Mickaël

On 01/03/2021 14:15, Masahiro Yamada wrote:
> Building kernel/sys_ni.c with W=1 emits tons of -Wmissing-prototypes
> warnings.
> 
> $ make W=1 kernel/sys_ni.o
>   [ snip ]
>   CC      kernel/sys_ni.o
> In file included from kernel/sys_ni.c:10:
> ./arch/x86/include/asm/syscall_wrapper.h:83:14: warning: no previous prototype for '__x64_sys_io_setup' [-Wmissing-prototypes]
>    83 |  __weak long __##abi##_##name(const struct pt_regs *__unused) \
>       |              ^~
> ./arch/x86/include/asm/syscall_wrapper.h:100:2: note: in expansion of macro '__COND_SYSCALL'
>   100 |  __COND_SYSCALL(x64, sys_##name)
>       |  ^~~~~~~~~~~~~~
> ./arch/x86/include/asm/syscall_wrapper.h:256:2: note: in expansion of macro '__X64_COND_SYSCALL'
>   256 |  __X64_COND_SYSCALL(name)     \
>       |  ^~~~~~~~~~~~~~~~~~
> kernel/sys_ni.c:39:1: note: in expansion of macro 'COND_SYSCALL'
>    39 | COND_SYSCALL(io_setup);
>       | ^~~~~~~~~~~~
> ./arch/x86/include/asm/syscall_wrapper.h:83:14: warning: no previous prototype for '__ia32_sys_io_setup' [-Wmissing-prototypes]
>    83 |  __weak long __##abi##_##name(const struct pt_regs *__unused) \
>       |              ^~
> ./arch/x86/include/asm/syscall_wrapper.h:120:2: note: in expansion of macro '__COND_SYSCALL'
>   120 |  __COND_SYSCALL(ia32, sys_##name)
>       |  ^~~~~~~~~~~~~~
> ./arch/x86/include/asm/syscall_wrapper.h:257:2: note: in expansion of macro '__IA32_COND_SYSCALL'
>   257 |  __IA32_COND_SYSCALL(name)
>       |  ^~~~~~~~~~~~~~~~~~~
> kernel/sys_ni.c:39:1: note: in expansion of macro 'COND_SYSCALL'
>    39 | COND_SYSCALL(io_setup);
>       | ^~~~~~~~~~~~
>   ...
> 
> __SYS_STUB0() and __SYS_STUBx() defined a few lines above have forward
> declarations. Let's do likewise for __COND_SYSCALL() to fix the
> warnings.
> 
> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
> Tested-by: Mickaël Salaün <mic@linux.microsoft.com>
> ---
> 
>  arch/x86/include/asm/syscall_wrapper.h | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/arch/x86/include/asm/syscall_wrapper.h b/arch/x86/include/asm/syscall_wrapper.h
> index a84333adeef2..80c08c7d5e72 100644
> --- a/arch/x86/include/asm/syscall_wrapper.h
> +++ b/arch/x86/include/asm/syscall_wrapper.h
> @@ -80,6 +80,7 @@ extern long __ia32_sys_ni_syscall(const struct pt_regs *regs);
>  	}
>  
>  #define __COND_SYSCALL(abi, name)					\
> +	__weak long __##abi##_##name(const struct pt_regs *__unused);	\
>  	__weak long __##abi##_##name(const struct pt_regs *__unused)	\
>  	{								\
>  		return sys_ni_syscall();				\
> 

Re: [PATCH 1/7] x86/syscalls: fix -Wmissing-prototypes warnings from COND_SYSCALL()

[Masahiro Yamada]

On Thu, Mar 25, 2021 at 8:48 PM Mickaël Salaün <mic@digikod.net> wrote:
>
> Hi Masahiro,
>
> What is the status of this patch? Could you please push it to -next?
> This would avoid emails from lkp:
> https://lore.kernel.org/linux-security-module/202103191423.Jl0jVzfL-lkp@intel.com/


Hmm, I also want to know the answer.
This is the *third* time that I resent this patch
to the x86 ML.

This is a territory of the x86 subsystem
because it is only touching
arch/x86/include/asm/syscall_wrapper.h
It is preferred to get this in via the x86 tree.

x86 Maintainers,
could you take a look please?





> Thanks,
>  Mickaël
>
> On 01/03/2021 14:15, Masahiro Yamada wrote:
> > Building kernel/sys_ni.c with W=1 emits tons of -Wmissing-prototypes
> > warnings.
> >
> > $ make W=1 kernel/sys_ni.o
> >   [ snip ]
> >   CC      kernel/sys_ni.o
> > In file included from kernel/sys_ni.c:10:
> > ./arch/x86/include/asm/syscall_wrapper.h:83:14: warning: no previous prototype for '__x64_sys_io_setup' [-Wmissing-prototypes]
> >    83 |  __weak long __##abi##_##name(const struct pt_regs *__unused) \
> >       |              ^~
> > ./arch/x86/include/asm/syscall_wrapper.h:100:2: note: in expansion of macro '__COND_SYSCALL'
> >   100 |  __COND_SYSCALL(x64, sys_##name)
> >       |  ^~~~~~~~~~~~~~
> > ./arch/x86/include/asm/syscall_wrapper.h:256:2: note: in expansion of macro '__X64_COND_SYSCALL'
> >   256 |  __X64_COND_SYSCALL(name)     \
> >       |  ^~~~~~~~~~~~~~~~~~
> > kernel/sys_ni.c:39:1: note: in expansion of macro 'COND_SYSCALL'
> >    39 | COND_SYSCALL(io_setup);
> >       | ^~~~~~~~~~~~
> > ./arch/x86/include/asm/syscall_wrapper.h:83:14: warning: no previous prototype for '__ia32_sys_io_setup' [-Wmissing-prototypes]
> >    83 |  __weak long __##abi##_##name(const struct pt_regs *__unused) \
> >       |              ^~
> > ./arch/x86/include/asm/syscall_wrapper.h:120:2: note: in expansion of macro '__COND_SYSCALL'
> >   120 |  __COND_SYSCALL(ia32, sys_##name)
> >       |  ^~~~~~~~~~~~~~
> > ./arch/x86/include/asm/syscall_wrapper.h:257:2: note: in expansion of macro '__IA32_COND_SYSCALL'
> >   257 |  __IA32_COND_SYSCALL(name)
> >       |  ^~~~~~~~~~~~~~~~~~~
> > kernel/sys_ni.c:39:1: note: in expansion of macro 'COND_SYSCALL'
> >    39 | COND_SYSCALL(io_setup);
> >       | ^~~~~~~~~~~~
> >   ...
> >
> > __SYS_STUB0() and __SYS_STUBx() defined a few lines above have forward
> > declarations. Let's do likewise for __COND_SYSCALL() to fix the
> > warnings.
> >
> > Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
> > Tested-by: Mickaël Salaün <mic@linux.microsoft.com>
> > ---
> >
> >  arch/x86/include/asm/syscall_wrapper.h | 1 +
> >  1 file changed, 1 insertion(+)
> >
> > diff --git a/arch/x86/include/asm/syscall_wrapper.h b/arch/x86/include/asm/syscall_wrapper.h
> > index a84333adeef2..80c08c7d5e72 100644
> > --- a/arch/x86/include/asm/syscall_wrapper.h
> > +++ b/arch/x86/include/asm/syscall_wrapper.h
> > @@ -80,6 +80,7 @@ extern long __ia32_sys_ni_syscall(const struct pt_regs *regs);
> >       }
> >
> >  #define __COND_SYSCALL(abi, name)                                    \
> > +     __weak long __##abi##_##name(const struct pt_regs *__unused);   \
> >       __weak long __##abi##_##name(const struct pt_regs *__unused)    \
> >       {                                                               \
> >               return sys_ni_syscall();                                \
> >



--
Best Regards
Masahiro Yamada

[tip: x86/cleanups] x86/syscalls: Fix -Wmissing-prototypes warnings from COND_SYSCALL()

[tip-bot2 for Masahiro Yamada]

The following commit has been merged into the x86/cleanups branch of tip:

Commit-ID:     7dfe553affd0d003c7535b7ba60d09193471ea9d
Gitweb:        https://git.kernel.org/tip/7dfe553affd0d003c7535b7ba60d09193471ea9d
Author:        Masahiro Yamada <masahiroy@kernel.org>
AuthorDate:    Mon, 01 Mar 2021 22:15:26 +09:00
Committer:     Ingo Molnar <mingo@kernel.org>
CommitterDate: Thu, 25 Mar 2021 16:20:41 +01:00

x86/syscalls: Fix -Wmissing-prototypes warnings from COND_SYSCALL()

Building kernel/sys_ni.c with W=1 emits tons of -Wmissing-prototypes warnings:

  $ make W=1 kernel/sys_ni.o
    [ snip ]
    CC      kernel/sys_ni.o
     ./arch/x86/include/asm/syscall_wrapper.h:83:14: warning: no previous prototype for '__ia32_sys_io_setup' [-Wmissing-prototypes]
     ...

The problem is in __COND_SYSCALL(), the __SYS_STUB0() and __SYS_STUBx() macros
defined a few lines above already have forward declarations.

Let's do likewise for __COND_SYSCALL() to fix the warnings.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Mickaël Salaün <mic@linux.microsoft.com>
Link: https://lore.kernel.org/r/20210301131533.64671-2-masahiroy@kernel.org
---
 arch/x86/include/asm/syscall_wrapper.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/x86/include/asm/syscall_wrapper.h b/arch/x86/include/asm/syscall_wrapper.h
index a84333a..80c08c7 100644
--- a/arch/x86/include/asm/syscall_wrapper.h
+++ b/arch/x86/include/asm/syscall_wrapper.h
@@ -80,6 +80,7 @@ extern long __ia32_sys_ni_syscall(const struct pt_regs *regs);
 	}
 
 #define __COND_SYSCALL(abi, name)					\
+	__weak long __##abi##_##name(const struct pt_regs *__unused);	\
 	__weak long __##abi##_##name(const struct pt_regs *__unused)	\
 	{								\
 		return sys_ni_syscall();				\

Re: [PATCH 1/7] x86/syscalls: fix -Wmissing-prototypes warnings from COND_SYSCALL()

[Masahiro Yamada]

Hello, x86 maintainers,


Thanks for picking up 1/7.

Could you check 2/7 - 7/7, please?


Thank you.


On Thu, Mar 25, 2021 at 11:31 PM Masahiro Yamada <masahiroy@kernel.org> wrote:
>
> On Thu, Mar 25, 2021 at 8:48 PM Mickaël Salaün <mic@digikod.net> wrote:
> >
> > Hi Masahiro,
> >
> > What is the status of this patch? Could you please push it to -next?
> > This would avoid emails from lkp:
> > https://lore.kernel.org/linux-security-module/202103191423.Jl0jVzfL-lkp@intel.com/
>
>
> Hmm, I also want to know the answer.
> This is the *third* time that I resent this patch
> to the x86 ML.
>
> This is a territory of the x86 subsystem
> because it is only touching
> arch/x86/include/asm/syscall_wrapper.h
> It is preferred to get this in via the x86 tree.
>
> x86 Maintainers,
> could you take a look please?
>
>
>


-- 
Best Regards
Masahiro Yamada