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[PATCH v2 04/10] x86/syscalls: Remove __SYSCALL_COMMON and __SYSCALL_X32

Started byAndy Lutomirski <luto@kernel.org>
First post2016-01-29 00:20 +0100
Last post2016-01-30 19:50 +0100
Articles 9 — 6 participants

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  [PATCH v2 04/10] x86/syscalls: Remove __SYSCALL_COMMON and __SYSCALL_X32 Andy Lutomirski <luto@kernel.org> - 2016-01-29 00:20 +0100
    [tip:x86/asm] x86/syscalls:   Remove __SYSCALL_COMMON and __SYSCALL_X32 tip-bot for Andy Lutomirski <tipbot@zytor.com> - 2016-01-29 12:40 +0100
      Re: [tip:x86/asm] x86/syscalls:  Remove __SYSCALL_COMMON and __SYSCALL_X32 "H. Peter Anvin" <hpa@zytor.com> - 2016-01-29 22:30 +0100
        Re: [tip:x86/asm] x86/syscalls: Remove __SYSCALL_COMMON and __SYSCALL_X32 Brian Gerst <brgerst@gmail.com> - 2016-01-29 23:20 +0100
          Re: [tip:x86/asm] x86/syscalls: Remove __SYSCALL_COMMON and __SYSCALL_X32 Andy Lutomirski <luto@amacapital.net> - 2016-01-29 23:30 +0100
            Re: [tip:x86/asm] x86/syscalls: Remove __SYSCALL_COMMON and  __SYSCALL_X32 Ingo Molnar <mingo@kernel.org> - 2016-01-30 10:40 +0100
              Re: [tip:x86/asm] x86/syscalls: Remove __SYSCALL_COMMON and __SYSCALL_X32 Andy Lutomirski <luto@amacapital.net> - 2016-01-30 18:40 +0100
                Re: [tip:x86/asm] x86/syscalls: Remove __SYSCALL_COMMON and __SYSCALL_X32 "H. Peter Anvin" <hpa@zytor.com> - 2016-01-30 22:30 +0100
          Re: [tip:x86/asm] x86/syscalls: Remove __SYSCALL_COMMON and __SYSCALL_X32 "H. Peter Anvin" <hpa@zytor.com> - 2016-01-30 19:50 +0100

#1321140 — [PATCH v2 04/10] x86/syscalls: Remove __SYSCALL_COMMON and __SYSCALL_X32

FromAndy Lutomirski <luto@kernel.org>
Date2016-01-29 00:20 +0100
Subject[PATCH v2 04/10] x86/syscalls: Remove __SYSCALL_COMMON and __SYSCALL_X32
Message-ID<qW414-2cO-23@gated-at.bofh.it>
The common/64/x32 distinction has no effect other than determining
which kernels actually support the syscall.  Move the logic into
syscalltbl.sh.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
---
 arch/x86/entry/syscall_64.c           |  8 --------
 arch/x86/entry/syscalls/syscalltbl.sh | 17 ++++++++++++++++-
 arch/x86/kernel/asm-offsets_64.c      |  6 ------
 arch/x86/um/sys_call_table_64.c       |  3 ---
 arch/x86/um/user-offsets.c            |  2 --
 5 files changed, 16 insertions(+), 20 deletions(-)

diff --git a/arch/x86/entry/syscall_64.c b/arch/x86/entry/syscall_64.c
index 41283d22be7a..974fd89ac806 100644
--- a/arch/x86/entry/syscall_64.c
+++ b/arch/x86/entry/syscall_64.c
@@ -6,14 +6,6 @@
 #include <asm/asm-offsets.h>
 #include <asm/syscall.h>
 
-#define __SYSCALL_COMMON(nr, sym, compat) __SYSCALL_64(nr, sym, compat)
-
-#ifdef CONFIG_X86_X32_ABI
-# define __SYSCALL_X32(nr, sym, compat) __SYSCALL_64(nr, sym, compat)
-#else
-# define __SYSCALL_X32(nr, sym, compat) /* nothing */
-#endif
-
 #define __SYSCALL_64(nr, sym, compat) extern asmlinkage long sym(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long) ;
 #include <asm/syscalls_64.h>
 #undef __SYSCALL_64
diff --git a/arch/x86/entry/syscalls/syscalltbl.sh b/arch/x86/entry/syscalls/syscalltbl.sh
index 167965ee742e..5ebeaf1041e7 100644
--- a/arch/x86/entry/syscalls/syscalltbl.sh
+++ b/arch/x86/entry/syscalls/syscalltbl.sh
@@ -18,6 +18,21 @@ emit() {
 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"
+	if [ "$abi" == "COMMON" -o "$abi" == "64" ]; then
+	    # COMMON is the same as 64, except that we don't expect X32
+	    # programs to use it.  Our expectation has nothing to do with
+	    # any generated code, so treat them the same.
+	    emit 64 "$nr" "$entry" "$compat"
+	elif [ "$abi" == "X32" ]; then
+	    # X32 is equivalent to 64 on an X32-compatible kernel.
+	    echo "#ifdef CONFIG_X86_X32_ABI"
+	    emit 64 "$nr" "$entry" "$compat"
+	    echo "#endif"
+	elif [ "$abi" == "I386" ]; then
+	    emit "$abi" "$nr" "$entry" "$compat"
+	else
+	    echo "Unknown abi $abi" >&2
+	    exit 1
+	fi
     done
 ) > "$out"
diff --git a/arch/x86/kernel/asm-offsets_64.c b/arch/x86/kernel/asm-offsets_64.c
index f2edafb5f24e..29db3b3f550c 100644
--- a/arch/x86/kernel/asm-offsets_64.c
+++ b/arch/x86/kernel/asm-offsets_64.c
@@ -5,12 +5,6 @@
 #include <asm/ia32.h>
 
 #define __SYSCALL_64(nr, sym, compat) [nr] = 1,
-#define __SYSCALL_COMMON(nr, sym, compat) [nr] = 1,
-#ifdef CONFIG_X86_X32_ABI
-# define __SYSCALL_X32(nr, sym, compat) [nr] = 1,
-#else
-# define __SYSCALL_X32(nr, sym, compat) /* nothing */
-#endif
 static char syscalls_64[] = {
 #include <asm/syscalls_64.h>
 };
diff --git a/arch/x86/um/sys_call_table_64.c b/arch/x86/um/sys_call_table_64.c
index b74ea6c2c0e7..71a497cde921 100644
--- a/arch/x86/um/sys_call_table_64.c
+++ b/arch/x86/um/sys_call_table_64.c
@@ -35,9 +35,6 @@
 #define stub_execveat sys_execveat
 #define stub_rt_sigreturn sys_rt_sigreturn
 
-#define __SYSCALL_COMMON(nr, sym, compat) __SYSCALL_64(nr, sym, compat)
-#define __SYSCALL_X32(nr, sym, compat) /* Not supported */
-
 #define __SYSCALL_64(nr, sym, compat) extern asmlinkage long sym(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long) ;
 #include <asm/syscalls_64.h>
 
diff --git a/arch/x86/um/user-offsets.c b/arch/x86/um/user-offsets.c
index ce7e3607a870..5edf4f4bbf53 100644
--- a/arch/x86/um/user-offsets.c
+++ b/arch/x86/um/user-offsets.c
@@ -15,8 +15,6 @@ static char syscalls[] = {
 };
 #else
 #define __SYSCALL_64(nr, sym, compat) [nr] = 1,
-#define __SYSCALL_COMMON(nr, sym, compat) [nr] = 1,
-#define __SYSCALL_X32(nr, sym, compat) /* Not supported */
 static char syscalls[] = {
 #include <asm/syscalls_64.h>
 };
-- 
2.5.0

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#1321689 — [tip:x86/asm] x86/syscalls: Remove __SYSCALL_COMMON and __SYSCALL_X32

Fromtip-bot for Andy Lutomirski <tipbot@zytor.com>
Date2016-01-29 12:40 +0100
Subject[tip:x86/asm] x86/syscalls: Remove __SYSCALL_COMMON and __SYSCALL_X32
Message-ID<qWfzd-2gW-41@gated-at.bofh.it>
In reply to#1321140
Commit-ID:  32324ce15ea8cb4c8acc28acb2fd36fabf73e9db
Gitweb:     http://git.kernel.org/tip/32324ce15ea8cb4c8acc28acb2fd36fabf73e9db
Author:     Andy Lutomirski <luto@kernel.org>
AuthorDate: Thu, 28 Jan 2016 15:11:22 -0800
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Fri, 29 Jan 2016 09:46:37 +0100

x86/syscalls: Remove __SYSCALL_COMMON and __SYSCALL_X32

The common/64/x32 distinction has no effect other than
determining which kernels actually support the syscall.  Move
the logic into syscalltbl.sh.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/58d4a95f40e43b894f93288b4a3633963d0ee22e.1454022279.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 arch/x86/entry/syscall_64.c           |  8 --------
 arch/x86/entry/syscalls/syscalltbl.sh | 17 ++++++++++++++++-
 arch/x86/kernel/asm-offsets_64.c      |  6 ------
 arch/x86/um/sys_call_table_64.c       |  3 ---
 arch/x86/um/user-offsets.c            |  2 --
 5 files changed, 16 insertions(+), 20 deletions(-)

diff --git a/arch/x86/entry/syscall_64.c b/arch/x86/entry/syscall_64.c
index 41283d2..974fd89 100644
--- a/arch/x86/entry/syscall_64.c
+++ b/arch/x86/entry/syscall_64.c
@@ -6,14 +6,6 @@
 #include <asm/asm-offsets.h>
 #include <asm/syscall.h>
 
-#define __SYSCALL_COMMON(nr, sym, compat) __SYSCALL_64(nr, sym, compat)
-
-#ifdef CONFIG_X86_X32_ABI
-# define __SYSCALL_X32(nr, sym, compat) __SYSCALL_64(nr, sym, compat)
-#else
-# define __SYSCALL_X32(nr, sym, compat) /* nothing */
-#endif
-
 #define __SYSCALL_64(nr, sym, compat) extern asmlinkage long sym(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long) ;
 #include <asm/syscalls_64.h>
 #undef __SYSCALL_64
diff --git a/arch/x86/entry/syscalls/syscalltbl.sh b/arch/x86/entry/syscalls/syscalltbl.sh
index 167965e..5ebeaf1 100644
--- a/arch/x86/entry/syscalls/syscalltbl.sh
+++ b/arch/x86/entry/syscalls/syscalltbl.sh
@@ -18,6 +18,21 @@ emit() {
 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"
+	if [ "$abi" == "COMMON" -o "$abi" == "64" ]; then
+	    # COMMON is the same as 64, except that we don't expect X32
+	    # programs to use it.  Our expectation has nothing to do with
+	    # any generated code, so treat them the same.
+	    emit 64 "$nr" "$entry" "$compat"
+	elif [ "$abi" == "X32" ]; then
+	    # X32 is equivalent to 64 on an X32-compatible kernel.
+	    echo "#ifdef CONFIG_X86_X32_ABI"
+	    emit 64 "$nr" "$entry" "$compat"
+	    echo "#endif"
+	elif [ "$abi" == "I386" ]; then
+	    emit "$abi" "$nr" "$entry" "$compat"
+	else
+	    echo "Unknown abi $abi" >&2
+	    exit 1
+	fi
     done
 ) > "$out"
diff --git a/arch/x86/kernel/asm-offsets_64.c b/arch/x86/kernel/asm-offsets_64.c
index f2edafb..29db3b3 100644
--- a/arch/x86/kernel/asm-offsets_64.c
+++ b/arch/x86/kernel/asm-offsets_64.c
@@ -5,12 +5,6 @@
 #include <asm/ia32.h>
 
 #define __SYSCALL_64(nr, sym, compat) [nr] = 1,
-#define __SYSCALL_COMMON(nr, sym, compat) [nr] = 1,
-#ifdef CONFIG_X86_X32_ABI
-# define __SYSCALL_X32(nr, sym, compat) [nr] = 1,
-#else
-# define __SYSCALL_X32(nr, sym, compat) /* nothing */
-#endif
 static char syscalls_64[] = {
 #include <asm/syscalls_64.h>
 };
diff --git a/arch/x86/um/sys_call_table_64.c b/arch/x86/um/sys_call_table_64.c
index b74ea6c..71a497c 100644
--- a/arch/x86/um/sys_call_table_64.c
+++ b/arch/x86/um/sys_call_table_64.c
@@ -35,9 +35,6 @@
 #define stub_execveat sys_execveat
 #define stub_rt_sigreturn sys_rt_sigreturn
 
-#define __SYSCALL_COMMON(nr, sym, compat) __SYSCALL_64(nr, sym, compat)
-#define __SYSCALL_X32(nr, sym, compat) /* Not supported */
-
 #define __SYSCALL_64(nr, sym, compat) extern asmlinkage long sym(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long) ;
 #include <asm/syscalls_64.h>
 
diff --git a/arch/x86/um/user-offsets.c b/arch/x86/um/user-offsets.c
index ce7e360..5edf4f4 100644
--- a/arch/x86/um/user-offsets.c
+++ b/arch/x86/um/user-offsets.c
@@ -15,8 +15,6 @@ static char syscalls[] = {
 };
 #else
 #define __SYSCALL_64(nr, sym, compat) [nr] = 1,
-#define __SYSCALL_COMMON(nr, sym, compat) [nr] = 1,
-#define __SYSCALL_X32(nr, sym, compat) /* Not supported */
 static char syscalls[] = {
 #include <asm/syscalls_64.h>
 };

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#1322099 — Re: [tip:x86/asm] x86/syscalls: Remove __SYSCALL_COMMON and __SYSCALL_X32

From"H. Peter Anvin" <hpa@zytor.com>
Date2016-01-29 22:30 +0100
SubjectRe: [tip:x86/asm] x86/syscalls: Remove __SYSCALL_COMMON and __SYSCALL_X32
Message-ID<qWoMb-IK-33@gated-at.bofh.it>
In reply to#1321689
On January 29, 2016 3:34:44 AM PST, tip-bot for Andy Lutomirski <tipbot@zytor.com> wrote:
>Commit-ID:  32324ce15ea8cb4c8acc28acb2fd36fabf73e9db
>Gitweb:    
>http://git.kernel.org/tip/32324ce15ea8cb4c8acc28acb2fd36fabf73e9db
>Author:     Andy Lutomirski <luto@kernel.org>
>AuthorDate: Thu, 28 Jan 2016 15:11:22 -0800
>Committer:  Ingo Molnar <mingo@kernel.org>
>CommitDate: Fri, 29 Jan 2016 09:46:37 +0100
>
>x86/syscalls: Remove __SYSCALL_COMMON and __SYSCALL_X32
>
>The common/64/x32 distinction has no effect other than
>determining which kernels actually support the syscall.  Move
>the logic into syscalltbl.sh.
>
>Signed-off-by: Andy Lutomirski <luto@kernel.org>
>Cc: Andy Lutomirski <luto@amacapital.net>
>Cc: Borislav Petkov <bp@alien8.de>
>Cc: Brian Gerst <brgerst@gmail.com>
>Cc: Denys Vlasenko <dvlasenk@redhat.com>
>Cc: Frederic Weisbecker <fweisbec@gmail.com>
>Cc: H. Peter Anvin <hpa@zytor.com>
>Cc: Linus Torvalds <torvalds@linux-foundation.org>
>Cc: Peter Zijlstra <peterz@infradead.org>
>Cc: Thomas Gleixner <tglx@linutronix.de>
>Link:
>http://lkml.kernel.org/r/58d4a95f40e43b894f93288b4a3633963d0ee22e.1454022279.git.luto@kernel.org
>Signed-off-by: Ingo Molnar <mingo@kernel.org>
>---
> arch/x86/entry/syscall_64.c           |  8 --------
> arch/x86/entry/syscalls/syscalltbl.sh | 17 ++++++++++++++++-
> arch/x86/kernel/asm-offsets_64.c      |  6 ------
> arch/x86/um/sys_call_table_64.c       |  3 ---
> arch/x86/um/user-offsets.c            |  2 --
> 5 files changed, 16 insertions(+), 20 deletions(-)
>
>diff --git a/arch/x86/entry/syscall_64.c b/arch/x86/entry/syscall_64.c
>index 41283d2..974fd89 100644
>--- a/arch/x86/entry/syscall_64.c
>+++ b/arch/x86/entry/syscall_64.c
>@@ -6,14 +6,6 @@
> #include <asm/asm-offsets.h>
> #include <asm/syscall.h>
> 
>-#define __SYSCALL_COMMON(nr, sym, compat) __SYSCALL_64(nr, sym,
>compat)
>-
>-#ifdef CONFIG_X86_X32_ABI
>-# define __SYSCALL_X32(nr, sym, compat) __SYSCALL_64(nr, sym, compat)
>-#else
>-# define __SYSCALL_X32(nr, sym, compat) /* nothing */
>-#endif
>-
>#define __SYSCALL_64(nr, sym, compat) extern asmlinkage long
>sym(unsigned long, unsigned long, unsigned long, unsigned long,
>unsigned long, unsigned long) ;
> #include <asm/syscalls_64.h>
> #undef __SYSCALL_64
>diff --git a/arch/x86/entry/syscalls/syscalltbl.sh
>b/arch/x86/entry/syscalls/syscalltbl.sh
>index 167965e..5ebeaf1 100644
>--- a/arch/x86/entry/syscalls/syscalltbl.sh
>+++ b/arch/x86/entry/syscalls/syscalltbl.sh
>@@ -18,6 +18,21 @@ emit() {
> 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"
>+	if [ "$abi" == "COMMON" -o "$abi" == "64" ]; then
>+	    # COMMON is the same as 64, except that we don't expect X32
>+	    # programs to use it.  Our expectation has nothing to do with
>+	    # any generated code, so treat them the same.
>+	    emit 64 "$nr" "$entry" "$compat"
>+	elif [ "$abi" == "X32" ]; then
>+	    # X32 is equivalent to 64 on an X32-compatible kernel.
>+	    echo "#ifdef CONFIG_X86_X32_ABI"
>+	    emit 64 "$nr" "$entry" "$compat"
>+	    echo "#endif"
>+	elif [ "$abi" == "I386" ]; then
>+	    emit "$abi" "$nr" "$entry" "$compat"
>+	else
>+	    echo "Unknown abi $abi" >&2
>+	    exit 1
>+	fi
>     done
> ) > "$out"
>diff --git a/arch/x86/kernel/asm-offsets_64.c
>b/arch/x86/kernel/asm-offsets_64.c
>index f2edafb..29db3b3 100644
>--- a/arch/x86/kernel/asm-offsets_64.c
>+++ b/arch/x86/kernel/asm-offsets_64.c
>@@ -5,12 +5,6 @@
> #include <asm/ia32.h>
> 
> #define __SYSCALL_64(nr, sym, compat) [nr] = 1,
>-#define __SYSCALL_COMMON(nr, sym, compat) [nr] = 1,
>-#ifdef CONFIG_X86_X32_ABI
>-# define __SYSCALL_X32(nr, sym, compat) [nr] = 1,
>-#else
>-# define __SYSCALL_X32(nr, sym, compat) /* nothing */
>-#endif
> static char syscalls_64[] = {
> #include <asm/syscalls_64.h>
> };
>diff --git a/arch/x86/um/sys_call_table_64.c
>b/arch/x86/um/sys_call_table_64.c
>index b74ea6c..71a497c 100644
>--- a/arch/x86/um/sys_call_table_64.c
>+++ b/arch/x86/um/sys_call_table_64.c
>@@ -35,9 +35,6 @@
> #define stub_execveat sys_execveat
> #define stub_rt_sigreturn sys_rt_sigreturn
> 
>-#define __SYSCALL_COMMON(nr, sym, compat) __SYSCALL_64(nr, sym,
>compat)
>-#define __SYSCALL_X32(nr, sym, compat) /* Not supported */
>-
>#define __SYSCALL_64(nr, sym, compat) extern asmlinkage long
>sym(unsigned long, unsigned long, unsigned long, unsigned long,
>unsigned long, unsigned long) ;
> #include <asm/syscalls_64.h>
> 
>diff --git a/arch/x86/um/user-offsets.c b/arch/x86/um/user-offsets.c
>index ce7e360..5edf4f4 100644
>--- a/arch/x86/um/user-offsets.c
>+++ b/arch/x86/um/user-offsets.c
>@@ -15,8 +15,6 @@ static char syscalls[] = {
> };
> #else
> #define __SYSCALL_64(nr, sym, compat) [nr] = 1,
>-#define __SYSCALL_COMMON(nr, sym, compat) [nr] = 1,
>-#define __SYSCALL_X32(nr, sym, compat) /* Not supported */
> static char syscalls[] = {
> #include <asm/syscalls_64.h>
> };

I am really unhappy about this change.  syscalltbl.sh is written so that other architectures can use it, and so I would really prefer for it to stay arch-neutral and encourage other arches to use it, too.
-- 
Sent from my Android device with K-9 Mail. Please excuse brevity and formatting.

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#1322127 — Re: [tip:x86/asm] x86/syscalls: Remove __SYSCALL_COMMON and __SYSCALL_X32

FromBrian Gerst <brgerst@gmail.com>
Date2016-01-29 23:20 +0100
SubjectRe: [tip:x86/asm] x86/syscalls: Remove __SYSCALL_COMMON and __SYSCALL_X32
Message-ID<qWpyy-1lv-17@gated-at.bofh.it>
In reply to#1322099
On Fri, Jan 29, 2016 at 4:23 PM, H. Peter Anvin <hpa@zytor.com> wrote:
> On January 29, 2016 3:34:44 AM PST, tip-bot for Andy Lutomirski <tipbot@zytor.com> wrote:
>>Commit-ID:  32324ce15ea8cb4c8acc28acb2fd36fabf73e9db
>>Gitweb:
>>http://git.kernel.org/tip/32324ce15ea8cb4c8acc28acb2fd36fabf73e9db
>>Author:     Andy Lutomirski <luto@kernel.org>
>>AuthorDate: Thu, 28 Jan 2016 15:11:22 -0800
>>Committer:  Ingo Molnar <mingo@kernel.org>
>>CommitDate: Fri, 29 Jan 2016 09:46:37 +0100
>>
>>x86/syscalls: Remove __SYSCALL_COMMON and __SYSCALL_X32
>>
>>The common/64/x32 distinction has no effect other than
>>determining which kernels actually support the syscall.  Move
>>the logic into syscalltbl.sh.
>>
>>Signed-off-by: Andy Lutomirski <luto@kernel.org>
>>Cc: Andy Lutomirski <luto@amacapital.net>
>>Cc: Borislav Petkov <bp@alien8.de>
>>Cc: Brian Gerst <brgerst@gmail.com>
>>Cc: Denys Vlasenko <dvlasenk@redhat.com>
>>Cc: Frederic Weisbecker <fweisbec@gmail.com>
>>Cc: H. Peter Anvin <hpa@zytor.com>
>>Cc: Linus Torvalds <torvalds@linux-foundation.org>
>>Cc: Peter Zijlstra <peterz@infradead.org>
>>Cc: Thomas Gleixner <tglx@linutronix.de>
>>Link:
>>http://lkml.kernel.org/r/58d4a95f40e43b894f93288b4a3633963d0ee22e.1454022279.git.luto@kernel.org
>>Signed-off-by: Ingo Molnar <mingo@kernel.org>
>>---
>> arch/x86/entry/syscall_64.c           |  8 --------
>> arch/x86/entry/syscalls/syscalltbl.sh | 17 ++++++++++++++++-
>> arch/x86/kernel/asm-offsets_64.c      |  6 ------
>> arch/x86/um/sys_call_table_64.c       |  3 ---
>> arch/x86/um/user-offsets.c            |  2 --
>> 5 files changed, 16 insertions(+), 20 deletions(-)
>>
>>diff --git a/arch/x86/entry/syscall_64.c b/arch/x86/entry/syscall_64.c
>>index 41283d2..974fd89 100644
>>--- a/arch/x86/entry/syscall_64.c
>>+++ b/arch/x86/entry/syscall_64.c
>>@@ -6,14 +6,6 @@
>> #include <asm/asm-offsets.h>
>> #include <asm/syscall.h>
>>
>>-#define __SYSCALL_COMMON(nr, sym, compat) __SYSCALL_64(nr, sym,
>>compat)
>>-
>>-#ifdef CONFIG_X86_X32_ABI
>>-# define __SYSCALL_X32(nr, sym, compat) __SYSCALL_64(nr, sym, compat)
>>-#else
>>-# define __SYSCALL_X32(nr, sym, compat) /* nothing */
>>-#endif
>>-
>>#define __SYSCALL_64(nr, sym, compat) extern asmlinkage long
>>sym(unsigned long, unsigned long, unsigned long, unsigned long,
>>unsigned long, unsigned long) ;
>> #include <asm/syscalls_64.h>
>> #undef __SYSCALL_64
>>diff --git a/arch/x86/entry/syscalls/syscalltbl.sh
>>b/arch/x86/entry/syscalls/syscalltbl.sh
>>index 167965e..5ebeaf1 100644
>>--- a/arch/x86/entry/syscalls/syscalltbl.sh
>>+++ b/arch/x86/entry/syscalls/syscalltbl.sh
>>@@ -18,6 +18,21 @@ emit() {
>> 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"
>>+      if [ "$abi" == "COMMON" -o "$abi" == "64" ]; then
>>+          # COMMON is the same as 64, except that we don't expect X32
>>+          # programs to use it.  Our expectation has nothing to do with
>>+          # any generated code, so treat them the same.
>>+          emit 64 "$nr" "$entry" "$compat"
>>+      elif [ "$abi" == "X32" ]; then
>>+          # X32 is equivalent to 64 on an X32-compatible kernel.
>>+          echo "#ifdef CONFIG_X86_X32_ABI"
>>+          emit 64 "$nr" "$entry" "$compat"
>>+          echo "#endif"
>>+      elif [ "$abi" == "I386" ]; then
>>+          emit "$abi" "$nr" "$entry" "$compat"
>>+      else
>>+          echo "Unknown abi $abi" >&2
>>+          exit 1
>>+      fi
>>     done
>> ) > "$out"
>>diff --git a/arch/x86/kernel/asm-offsets_64.c
>>b/arch/x86/kernel/asm-offsets_64.c
>>index f2edafb..29db3b3 100644
>>--- a/arch/x86/kernel/asm-offsets_64.c
>>+++ b/arch/x86/kernel/asm-offsets_64.c
>>@@ -5,12 +5,6 @@
>> #include <asm/ia32.h>
>>
>> #define __SYSCALL_64(nr, sym, compat) [nr] = 1,
>>-#define __SYSCALL_COMMON(nr, sym, compat) [nr] = 1,
>>-#ifdef CONFIG_X86_X32_ABI
>>-# define __SYSCALL_X32(nr, sym, compat) [nr] = 1,
>>-#else
>>-# define __SYSCALL_X32(nr, sym, compat) /* nothing */
>>-#endif
>> static char syscalls_64[] = {
>> #include <asm/syscalls_64.h>
>> };
>>diff --git a/arch/x86/um/sys_call_table_64.c
>>b/arch/x86/um/sys_call_table_64.c
>>index b74ea6c..71a497c 100644
>>--- a/arch/x86/um/sys_call_table_64.c
>>+++ b/arch/x86/um/sys_call_table_64.c
>>@@ -35,9 +35,6 @@
>> #define stub_execveat sys_execveat
>> #define stub_rt_sigreturn sys_rt_sigreturn
>>
>>-#define __SYSCALL_COMMON(nr, sym, compat) __SYSCALL_64(nr, sym,
>>compat)
>>-#define __SYSCALL_X32(nr, sym, compat) /* Not supported */
>>-
>>#define __SYSCALL_64(nr, sym, compat) extern asmlinkage long
>>sym(unsigned long, unsigned long, unsigned long, unsigned long,
>>unsigned long, unsigned long) ;
>> #include <asm/syscalls_64.h>
>>
>>diff --git a/arch/x86/um/user-offsets.c b/arch/x86/um/user-offsets.c
>>index ce7e360..5edf4f4 100644
>>--- a/arch/x86/um/user-offsets.c
>>+++ b/arch/x86/um/user-offsets.c
>>@@ -15,8 +15,6 @@ static char syscalls[] = {
>> };
>> #else
>> #define __SYSCALL_64(nr, sym, compat) [nr] = 1,
>>-#define __SYSCALL_COMMON(nr, sym, compat) [nr] = 1,
>>-#define __SYSCALL_X32(nr, sym, compat) /* Not supported */
>> static char syscalls[] = {
>> #include <asm/syscalls_64.h>
>> };
>
> I am really unhappy about this change.  syscalltbl.sh is written so that other architectures can use it, and so I would really prefer for it to stay arch-neutral and encourage other arches to use it, too.

We could use a qualifier (ie. /x32 or /x32ptregs) instead.

--
Brian Gerst

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#1322128 — Re: [tip:x86/asm] x86/syscalls: Remove __SYSCALL_COMMON and __SYSCALL_X32

FromAndy Lutomirski <luto@amacapital.net>
Date2016-01-29 23:30 +0100
SubjectRe: [tip:x86/asm] x86/syscalls: Remove __SYSCALL_COMMON and __SYSCALL_X32
Message-ID<qWpId-1q3-1@gated-at.bofh.it>
In reply to#1322127
On Fri, Jan 29, 2016 at 2:19 PM, Brian Gerst <brgerst@gmail.com> wrote:
> On Fri, Jan 29, 2016 at 4:23 PM, H. Peter Anvin <hpa@zytor.com> wrote:
>> On January 29, 2016 3:34:44 AM PST, tip-bot for Andy Lutomirski <tipbot@zytor.com> wrote:
>>>Commit-ID:  32324ce15ea8cb4c8acc28acb2fd36fabf73e9db
>>>Gitweb:
>>>http://git.kernel.org/tip/32324ce15ea8cb4c8acc28acb2fd36fabf73e9db
>>>Author:     Andy Lutomirski <luto@kernel.org>
>>>AuthorDate: Thu, 28 Jan 2016 15:11:22 -0800
>>>Committer:  Ingo Molnar <mingo@kernel.org>
>>>CommitDate: Fri, 29 Jan 2016 09:46:37 +0100
>>>
>>>x86/syscalls: Remove __SYSCALL_COMMON and __SYSCALL_X32
>>>
>>>The common/64/x32 distinction has no effect other than
>>>determining which kernels actually support the syscall.  Move
>>>the logic into syscalltbl.sh.
>>>
>>>Signed-off-by: Andy Lutomirski <luto@kernel.org>
>>>Cc: Andy Lutomirski <luto@amacapital.net>
>>>Cc: Borislav Petkov <bp@alien8.de>
>>>Cc: Brian Gerst <brgerst@gmail.com>
>>>Cc: Denys Vlasenko <dvlasenk@redhat.com>
>>>Cc: Frederic Weisbecker <fweisbec@gmail.com>
>>>Cc: H. Peter Anvin <hpa@zytor.com>
>>>Cc: Linus Torvalds <torvalds@linux-foundation.org>
>>>Cc: Peter Zijlstra <peterz@infradead.org>
>>>Cc: Thomas Gleixner <tglx@linutronix.de>
>>>Link:
>>>http://lkml.kernel.org/r/58d4a95f40e43b894f93288b4a3633963d0ee22e.1454022279.git.luto@kernel.org
>>>Signed-off-by: Ingo Molnar <mingo@kernel.org>
>>>---
>>> arch/x86/entry/syscall_64.c           |  8 --------
>>> arch/x86/entry/syscalls/syscalltbl.sh | 17 ++++++++++++++++-
>>> arch/x86/kernel/asm-offsets_64.c      |  6 ------
>>> arch/x86/um/sys_call_table_64.c       |  3 ---
>>> arch/x86/um/user-offsets.c            |  2 --
>>> 5 files changed, 16 insertions(+), 20 deletions(-)
>>>
>>>diff --git a/arch/x86/entry/syscall_64.c b/arch/x86/entry/syscall_64.c
>>>index 41283d2..974fd89 100644
>>>--- a/arch/x86/entry/syscall_64.c
>>>+++ b/arch/x86/entry/syscall_64.c
>>>@@ -6,14 +6,6 @@
>>> #include <asm/asm-offsets.h>
>>> #include <asm/syscall.h>
>>>
>>>-#define __SYSCALL_COMMON(nr, sym, compat) __SYSCALL_64(nr, sym,
>>>compat)
>>>-
>>>-#ifdef CONFIG_X86_X32_ABI
>>>-# define __SYSCALL_X32(nr, sym, compat) __SYSCALL_64(nr, sym, compat)
>>>-#else
>>>-# define __SYSCALL_X32(nr, sym, compat) /* nothing */
>>>-#endif
>>>-
>>>#define __SYSCALL_64(nr, sym, compat) extern asmlinkage long
>>>sym(unsigned long, unsigned long, unsigned long, unsigned long,
>>>unsigned long, unsigned long) ;
>>> #include <asm/syscalls_64.h>
>>> #undef __SYSCALL_64
>>>diff --git a/arch/x86/entry/syscalls/syscalltbl.sh
>>>b/arch/x86/entry/syscalls/syscalltbl.sh
>>>index 167965e..5ebeaf1 100644
>>>--- a/arch/x86/entry/syscalls/syscalltbl.sh
>>>+++ b/arch/x86/entry/syscalls/syscalltbl.sh
>>>@@ -18,6 +18,21 @@ emit() {
>>> 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"
>>>+      if [ "$abi" == "COMMON" -o "$abi" == "64" ]; then
>>>+          # COMMON is the same as 64, except that we don't expect X32
>>>+          # programs to use it.  Our expectation has nothing to do with
>>>+          # any generated code, so treat them the same.
>>>+          emit 64 "$nr" "$entry" "$compat"
>>>+      elif [ "$abi" == "X32" ]; then
>>>+          # X32 is equivalent to 64 on an X32-compatible kernel.
>>>+          echo "#ifdef CONFIG_X86_X32_ABI"
>>>+          emit 64 "$nr" "$entry" "$compat"
>>>+          echo "#endif"
>>>+      elif [ "$abi" == "I386" ]; then
>>>+          emit "$abi" "$nr" "$entry" "$compat"
>>>+      else
>>>+          echo "Unknown abi $abi" >&2
>>>+          exit 1
>>>+      fi
>>>     done
>>> ) > "$out"
>>>diff --git a/arch/x86/kernel/asm-offsets_64.c
>>>b/arch/x86/kernel/asm-offsets_64.c
>>>index f2edafb..29db3b3 100644
>>>--- a/arch/x86/kernel/asm-offsets_64.c
>>>+++ b/arch/x86/kernel/asm-offsets_64.c
>>>@@ -5,12 +5,6 @@
>>> #include <asm/ia32.h>
>>>
>>> #define __SYSCALL_64(nr, sym, compat) [nr] = 1,
>>>-#define __SYSCALL_COMMON(nr, sym, compat) [nr] = 1,
>>>-#ifdef CONFIG_X86_X32_ABI
>>>-# define __SYSCALL_X32(nr, sym, compat) [nr] = 1,
>>>-#else
>>>-# define __SYSCALL_X32(nr, sym, compat) /* nothing */
>>>-#endif
>>> static char syscalls_64[] = {
>>> #include <asm/syscalls_64.h>
>>> };
>>>diff --git a/arch/x86/um/sys_call_table_64.c
>>>b/arch/x86/um/sys_call_table_64.c
>>>index b74ea6c..71a497c 100644
>>>--- a/arch/x86/um/sys_call_table_64.c
>>>+++ b/arch/x86/um/sys_call_table_64.c
>>>@@ -35,9 +35,6 @@
>>> #define stub_execveat sys_execveat
>>> #define stub_rt_sigreturn sys_rt_sigreturn
>>>
>>>-#define __SYSCALL_COMMON(nr, sym, compat) __SYSCALL_64(nr, sym,
>>>compat)
>>>-#define __SYSCALL_X32(nr, sym, compat) /* Not supported */
>>>-
>>>#define __SYSCALL_64(nr, sym, compat) extern asmlinkage long
>>>sym(unsigned long, unsigned long, unsigned long, unsigned long,
>>>unsigned long, unsigned long) ;
>>> #include <asm/syscalls_64.h>
>>>
>>>diff --git a/arch/x86/um/user-offsets.c b/arch/x86/um/user-offsets.c
>>>index ce7e360..5edf4f4 100644
>>>--- a/arch/x86/um/user-offsets.c
>>>+++ b/arch/x86/um/user-offsets.c
>>>@@ -15,8 +15,6 @@ static char syscalls[] = {
>>> };
>>> #else
>>> #define __SYSCALL_64(nr, sym, compat) [nr] = 1,
>>>-#define __SYSCALL_COMMON(nr, sym, compat) [nr] = 1,
>>>-#define __SYSCALL_X32(nr, sym, compat) /* Not supported */
>>> static char syscalls[] = {
>>> #include <asm/syscalls_64.h>
>>> };
>>
>> I am really unhappy about this change.  syscalltbl.sh is written so that other architectures can use it, and so I would really prefer for it to stay arch-neutral and encourage other arches to use it, too.
>
> We could use a qualifier (ie. /x32 or /x32ptregs) instead.

No combinatorial explosion, please.  We could use __SYSCALL(nr, sym,
abi, qual), though.

--Andy

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#1322299 — Re: [tip:x86/asm] x86/syscalls: Remove __SYSCALL_COMMON and __SYSCALL_X32

FromIngo Molnar <mingo@kernel.org>
Date2016-01-30 10:40 +0100
SubjectRe: [tip:x86/asm] x86/syscalls: Remove __SYSCALL_COMMON and __SYSCALL_X32
Message-ID<qWAaB-Eg-1@gated-at.bofh.it>
In reply to#1322128
* Andy Lutomirski <luto@amacapital.net> wrote:

> >>>+      if [ "$abi" == "COMMON" -o "$abi" == "64" ]; then
> >>>+          # COMMON is the same as 64, except that we don't expect X32
> >>>+          # programs to use it.  Our expectation has nothing to do with
> >>>+          # any generated code, so treat them the same.
> >>>+          emit 64 "$nr" "$entry" "$compat"
> >>>+      elif [ "$abi" == "X32" ]; then
> >>>+          # X32 is equivalent to 64 on an X32-compatible kernel.
> >>>+          echo "#ifdef CONFIG_X86_X32_ABI"
> >>>+          emit 64 "$nr" "$entry" "$compat"
> >>>+          echo "#endif"
> >>>+      elif [ "$abi" == "I386" ]; then
> >>>+          emit "$abi" "$nr" "$entry" "$compat"
> >>>+      else
> >>>+          echo "Unknown abi $abi" >&2
> >>>+          exit 1
> >>>+      fi

> No combinatorial explosion, please.  We could use __SYSCALL(nr, sym,
> abi, qual), though.

Mind fixing it, so that we get back the arch-neutral property?

Thanks,

	Ingo

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#1322450 — Re: [tip:x86/asm] x86/syscalls: Remove __SYSCALL_COMMON and __SYSCALL_X32

FromAndy Lutomirski <luto@amacapital.net>
Date2016-01-30 18:40 +0100
SubjectRe: [tip:x86/asm] x86/syscalls: Remove __SYSCALL_COMMON and __SYSCALL_X32
Message-ID<qWHF9-7he-15@gated-at.bofh.it>
In reply to#1322299
On Sat, Jan 30, 2016 at 1:31 AM, Ingo Molnar <mingo@kernel.org> wrote:
>
> * Andy Lutomirski <luto@amacapital.net> wrote:
>
>> >>>+      if [ "$abi" == "COMMON" -o "$abi" == "64" ]; then
>> >>>+          # COMMON is the same as 64, except that we don't expect X32
>> >>>+          # programs to use it.  Our expectation has nothing to do with
>> >>>+          # any generated code, so treat them the same.
>> >>>+          emit 64 "$nr" "$entry" "$compat"
>> >>>+      elif [ "$abi" == "X32" ]; then
>> >>>+          # X32 is equivalent to 64 on an X32-compatible kernel.
>> >>>+          echo "#ifdef CONFIG_X86_X32_ABI"
>> >>>+          emit 64 "$nr" "$entry" "$compat"
>> >>>+          echo "#endif"
>> >>>+      elif [ "$abi" == "I386" ]; then
>> >>>+          emit "$abi" "$nr" "$entry" "$compat"
>> >>>+      else
>> >>>+          echo "Unknown abi $abi" >&2
>> >>>+          exit 1
>> >>>+      fi
>
>> No combinatorial explosion, please.  We could use __SYSCALL(nr, sym,
>> abi, qual), though.
>
> Mind fixing it, so that we get back the arch-neutral property?
>

I need some guidance as to the goal to do a good job.

In the version in -tip, I have this thing:

if [ "$abi" == "64" -a -n "$compat" ]; then
    echo "a compat entry for a 64-bit syscall makes no sense" >&2
    exit 1
fi

Moving that outside the script will either be impossible or an
exercise in really awful C preprocessor hacks.  We could keep that
under the theory that it's arch-neutral.

It might be nice to add a similar warning that a compat entry for an
x32 syscall makes so sense.  That's a little less arch-neutral,
although it wouldn't be actively harmful on any architecture, since
"x32" wouldn't occur in the first place.

Other than that, I could add a little header called
syscall_abi_mapping.h containing something like:

#ifndef __SYSCALL_ABI_MAPPING_H
#define __SYSCALL_ABI_MAPPING_H

#ifdef CONFIG_X86_32

/* Only I386 entries should ever be compiled into 32-bit kernels. */
#define __SYSCALL_ABI_I386(nr, entry, qual, compat, compat_qual)
__SYSCALL_I386(nr, entry, qual)

#else

/* I386 entries on 64-bit kernels use the compat entry point. */
#define __SYSCALL_ABI_I386(nr, entry, qual, compat, compat_qual)
__SYSCALL_I386(nr, compat, compat_qual)

#define __SYSCALL_ABI_common(nr, entry, compat, qual)
#define __SYSCALL_ABI_64(nr, entry, qual, compat, compat_qual)
__SYSCALL_64(nr, entry, qual)
#ifdef CONFIG_X86_X32
#define __SYSCALL_ABI_x32(nr, entry, qual, compat, compat_qual)
__SYSCALL_64(nr, entry, qual)
#else
#define __SYSCALL_ABI_x32(nr, entry, qual, compat, compat_qual)
__SYSCALL_64(nr, entry, qual)
#endif

#endif

#endif

and teach syscalltbl.sh to emit #include <asm/syscall_abi_mapping.h>
at the beginning of syscalls_32.h and syscalls_64.h and to reference
those macros.

hpa, would that meet your requirements?

IMO this is quite a bit messier than the code in -tip, and I'm
honestly not convinced it's an improvement.

--Andy

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#1322514 — Re: [tip:x86/asm] x86/syscalls: Remove __SYSCALL_COMMON and __SYSCALL_X32

From"H. Peter Anvin" <hpa@zytor.com>
Date2016-01-30 22:30 +0100
SubjectRe: [tip:x86/asm] x86/syscalls: Remove __SYSCALL_COMMON and __SYSCALL_X32
Message-ID<qWLfI-1nH-1@gated-at.bofh.it>
In reply to#1322450
On January 30, 2016 9:35:57 AM PST, Andy Lutomirski <luto@amacapital.net> wrote:
>On Sat, Jan 30, 2016 at 1:31 AM, Ingo Molnar <mingo@kernel.org> wrote:
>>
>> * Andy Lutomirski <luto@amacapital.net> wrote:
>>
>>> >>>+      if [ "$abi" == "COMMON" -o "$abi" == "64" ]; then
>>> >>>+          # COMMON is the same as 64, except that we don't
>expect X32
>>> >>>+          # programs to use it.  Our expectation has nothing to
>do with
>>> >>>+          # any generated code, so treat them the same.
>>> >>>+          emit 64 "$nr" "$entry" "$compat"
>>> >>>+      elif [ "$abi" == "X32" ]; then
>>> >>>+          # X32 is equivalent to 64 on an X32-compatible kernel.
>>> >>>+          echo "#ifdef CONFIG_X86_X32_ABI"
>>> >>>+          emit 64 "$nr" "$entry" "$compat"
>>> >>>+          echo "#endif"
>>> >>>+      elif [ "$abi" == "I386" ]; then
>>> >>>+          emit "$abi" "$nr" "$entry" "$compat"
>>> >>>+      else
>>> >>>+          echo "Unknown abi $abi" >&2
>>> >>>+          exit 1
>>> >>>+      fi
>>
>>> No combinatorial explosion, please.  We could use __SYSCALL(nr, sym,
>>> abi, qual), though.
>>
>> Mind fixing it, so that we get back the arch-neutral property?
>>
>
>I need some guidance as to the goal to do a good job.
>
>In the version in -tip, I have this thing:
>
>if [ "$abi" == "64" -a -n "$compat" ]; then
>    echo "a compat entry for a 64-bit syscall makes no sense" >&2
>    exit 1
>fi
>
>Moving that outside the script will either be impossible or an
>exercise in really awful C preprocessor hacks.  We could keep that
>under the theory that it's arch-neutral.
>
>It might be nice to add a similar warning that a compat entry for an
>x32 syscall makes so sense.  That's a little less arch-neutral,
>although it wouldn't be actively harmful on any architecture, since
>"x32" wouldn't occur in the first place.
>
>Other than that, I could add a little header called
>syscall_abi_mapping.h containing something like:
>
>#ifndef __SYSCALL_ABI_MAPPING_H
>#define __SYSCALL_ABI_MAPPING_H
>
>#ifdef CONFIG_X86_32
>
>/* Only I386 entries should ever be compiled into 32-bit kernels. */
>#define __SYSCALL_ABI_I386(nr, entry, qual, compat, compat_qual)
>__SYSCALL_I386(nr, entry, qual)
>
>#else
>
>/* I386 entries on 64-bit kernels use the compat entry point. */
>#define __SYSCALL_ABI_I386(nr, entry, qual, compat, compat_qual)
>__SYSCALL_I386(nr, compat, compat_qual)
>
>#define __SYSCALL_ABI_common(nr, entry, compat, qual)
>#define __SYSCALL_ABI_64(nr, entry, qual, compat, compat_qual)
>__SYSCALL_64(nr, entry, qual)
>#ifdef CONFIG_X86_X32
>#define __SYSCALL_ABI_x32(nr, entry, qual, compat, compat_qual)
>__SYSCALL_64(nr, entry, qual)
>#else
>#define __SYSCALL_ABI_x32(nr, entry, qual, compat, compat_qual)
>__SYSCALL_64(nr, entry, qual)
>#endif
>
>#endif
>
>#endif
>
>and teach syscalltbl.sh to emit #include <asm/syscall_abi_mapping.h>
>at the beginning of syscalls_32.h and syscalls_64.h and to reference
>those macros.
>
>hpa, would that meet your requirements?
>
>IMO this is quite a bit messier than the code in -tip, and I'm
>honestly not convinced it's an improvement.
>
>--Andy

Something like that... however, I can't look at in detail right now.
-- 
Sent from my Android device with K-9 Mail. Please excuse brevity and formatting.

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#1322487 — Re: [tip:x86/asm] x86/syscalls: Remove __SYSCALL_COMMON and __SYSCALL_X32

From"H. Peter Anvin" <hpa@zytor.com>
Date2016-01-30 19:50 +0100
SubjectRe: [tip:x86/asm] x86/syscalls: Remove __SYSCALL_COMMON and __SYSCALL_X32
Message-ID<qWIKR-81s-1@gated-at.bofh.it>
In reply to#1322127
On January 29, 2016 2:19:29 PM PST, Brian Gerst <brgerst@gmail.com> wrote:
>On Fri, Jan 29, 2016 at 4:23 PM, H. Peter Anvin <hpa@zytor.com> wrote:
>> On January 29, 2016 3:34:44 AM PST, tip-bot for Andy Lutomirski
><tipbot@zytor.com> wrote:
>>>Commit-ID:  32324ce15ea8cb4c8acc28acb2fd36fabf73e9db
>>>Gitweb:
>>>http://git.kernel.org/tip/32324ce15ea8cb4c8acc28acb2fd36fabf73e9db
>>>Author:     Andy Lutomirski <luto@kernel.org>
>>>AuthorDate: Thu, 28 Jan 2016 15:11:22 -0800
>>>Committer:  Ingo Molnar <mingo@kernel.org>
>>>CommitDate: Fri, 29 Jan 2016 09:46:37 +0100
>>>
>>>x86/syscalls: Remove __SYSCALL_COMMON and __SYSCALL_X32
>>>
>>>The common/64/x32 distinction has no effect other than
>>>determining which kernels actually support the syscall.  Move
>>>the logic into syscalltbl.sh.
>>>
>>>Signed-off-by: Andy Lutomirski <luto@kernel.org>
>>>Cc: Andy Lutomirski <luto@amacapital.net>
>>>Cc: Borislav Petkov <bp@alien8.de>
>>>Cc: Brian Gerst <brgerst@gmail.com>
>>>Cc: Denys Vlasenko <dvlasenk@redhat.com>
>>>Cc: Frederic Weisbecker <fweisbec@gmail.com>
>>>Cc: H. Peter Anvin <hpa@zytor.com>
>>>Cc: Linus Torvalds <torvalds@linux-foundation.org>
>>>Cc: Peter Zijlstra <peterz@infradead.org>
>>>Cc: Thomas Gleixner <tglx@linutronix.de>
>>>Link:
>>>http://lkml.kernel.org/r/58d4a95f40e43b894f93288b4a3633963d0ee22e.1454022279.git.luto@kernel.org
>>>Signed-off-by: Ingo Molnar <mingo@kernel.org>
>>>---
>>> arch/x86/entry/syscall_64.c           |  8 --------
>>> arch/x86/entry/syscalls/syscalltbl.sh | 17 ++++++++++++++++-
>>> arch/x86/kernel/asm-offsets_64.c      |  6 ------
>>> arch/x86/um/sys_call_table_64.c       |  3 ---
>>> arch/x86/um/user-offsets.c            |  2 --
>>> 5 files changed, 16 insertions(+), 20 deletions(-)
>>>
>>>diff --git a/arch/x86/entry/syscall_64.c
>b/arch/x86/entry/syscall_64.c
>>>index 41283d2..974fd89 100644
>>>--- a/arch/x86/entry/syscall_64.c
>>>+++ b/arch/x86/entry/syscall_64.c
>>>@@ -6,14 +6,6 @@
>>> #include <asm/asm-offsets.h>
>>> #include <asm/syscall.h>
>>>
>>>-#define __SYSCALL_COMMON(nr, sym, compat) __SYSCALL_64(nr, sym,
>>>compat)
>>>-
>>>-#ifdef CONFIG_X86_X32_ABI
>>>-# define __SYSCALL_X32(nr, sym, compat) __SYSCALL_64(nr, sym,
>compat)
>>>-#else
>>>-# define __SYSCALL_X32(nr, sym, compat) /* nothing */
>>>-#endif
>>>-
>>>#define __SYSCALL_64(nr, sym, compat) extern asmlinkage long
>>>sym(unsigned long, unsigned long, unsigned long, unsigned long,
>>>unsigned long, unsigned long) ;
>>> #include <asm/syscalls_64.h>
>>> #undef __SYSCALL_64
>>>diff --git a/arch/x86/entry/syscalls/syscalltbl.sh
>>>b/arch/x86/entry/syscalls/syscalltbl.sh
>>>index 167965e..5ebeaf1 100644
>>>--- a/arch/x86/entry/syscalls/syscalltbl.sh
>>>+++ b/arch/x86/entry/syscalls/syscalltbl.sh
>>>@@ -18,6 +18,21 @@ emit() {
>>> 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"
>>>+      if [ "$abi" == "COMMON" -o "$abi" == "64" ]; then
>>>+          # COMMON is the same as 64, except that we don't expect
>X32
>>>+          # programs to use it.  Our expectation has nothing to do
>with
>>>+          # any generated code, so treat them the same.
>>>+          emit 64 "$nr" "$entry" "$compat"
>>>+      elif [ "$abi" == "X32" ]; then
>>>+          # X32 is equivalent to 64 on an X32-compatible kernel.
>>>+          echo "#ifdef CONFIG_X86_X32_ABI"
>>>+          emit 64 "$nr" "$entry" "$compat"
>>>+          echo "#endif"
>>>+      elif [ "$abi" == "I386" ]; then
>>>+          emit "$abi" "$nr" "$entry" "$compat"
>>>+      else
>>>+          echo "Unknown abi $abi" >&2
>>>+          exit 1
>>>+      fi
>>>     done
>>> ) > "$out"
>>>diff --git a/arch/x86/kernel/asm-offsets_64.c
>>>b/arch/x86/kernel/asm-offsets_64.c
>>>index f2edafb..29db3b3 100644
>>>--- a/arch/x86/kernel/asm-offsets_64.c
>>>+++ b/arch/x86/kernel/asm-offsets_64.c
>>>@@ -5,12 +5,6 @@
>>> #include <asm/ia32.h>
>>>
>>> #define __SYSCALL_64(nr, sym, compat) [nr] = 1,
>>>-#define __SYSCALL_COMMON(nr, sym, compat) [nr] = 1,
>>>-#ifdef CONFIG_X86_X32_ABI
>>>-# define __SYSCALL_X32(nr, sym, compat) [nr] = 1,
>>>-#else
>>>-# define __SYSCALL_X32(nr, sym, compat) /* nothing */
>>>-#endif
>>> static char syscalls_64[] = {
>>> #include <asm/syscalls_64.h>
>>> };
>>>diff --git a/arch/x86/um/sys_call_table_64.c
>>>b/arch/x86/um/sys_call_table_64.c
>>>index b74ea6c..71a497c 100644
>>>--- a/arch/x86/um/sys_call_table_64.c
>>>+++ b/arch/x86/um/sys_call_table_64.c
>>>@@ -35,9 +35,6 @@
>>> #define stub_execveat sys_execveat
>>> #define stub_rt_sigreturn sys_rt_sigreturn
>>>
>>>-#define __SYSCALL_COMMON(nr, sym, compat) __SYSCALL_64(nr, sym,
>>>compat)
>>>-#define __SYSCALL_X32(nr, sym, compat) /* Not supported */
>>>-
>>>#define __SYSCALL_64(nr, sym, compat) extern asmlinkage long
>>>sym(unsigned long, unsigned long, unsigned long, unsigned long,
>>>unsigned long, unsigned long) ;
>>> #include <asm/syscalls_64.h>
>>>
>>>diff --git a/arch/x86/um/user-offsets.c b/arch/x86/um/user-offsets.c
>>>index ce7e360..5edf4f4 100644
>>>--- a/arch/x86/um/user-offsets.c
>>>+++ b/arch/x86/um/user-offsets.c
>>>@@ -15,8 +15,6 @@ static char syscalls[] = {
>>> };
>>> #else
>>> #define __SYSCALL_64(nr, sym, compat) [nr] = 1,
>>>-#define __SYSCALL_COMMON(nr, sym, compat) [nr] = 1,
>>>-#define __SYSCALL_X32(nr, sym, compat) /* Not supported */
>>> static char syscalls[] = {
>>> #include <asm/syscalls_64.h>
>>> };
>>
>> I am really unhappy about this change.  syscalltbl.sh is written so
>that other architectures can use it, and so I would really prefer for
>it to stay arch-neutral and encourage other arches to use it, too.
>
>We could use a qualifier (ie. /x32 or /x32ptregs) instead.
>
>--
>Brian Gerst

I like that idea much better.
-- 
Sent from my Android device with K-9 Mail. Please excuse brevity and formatting.

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