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Message-Id: <20181204212340.3915309-1-arnd@arndb.de>
Date: Tue, 4 Dec 2018 22:23:07 +0100
From: Arnd Bergmann <arnd@...db.de>
To: firoz.khan@...aro.org
Cc: y2038@...ts.linaro.org, linux-arch@...r.kernel.org,
deepa.kernel@...il.com, Arnd Bergmann <arnd@...db.de>,
Benjamin Herrenschmidt <benh@...nel.crashing.org>,
Paul Mackerras <paulus@...ba.org>,
Michael Ellerman <mpe@...erman.id.au>,
Nicholas Piggin <npiggin@...il.com>,
Madhavan Srinivasan <maddy@...ux.vnet.ibm.com>,
Christophe Leroy <christophe.leroy@....fr>,
Joel Stanley <joel@....id.au>, linuxppc-dev@...ts.ozlabs.org,
linux-kernel@...r.kernel.org
Subject: [PATCH] powerpc: split compat syscall table out from native table
PowerPC uses a syscall table with native and compat calls interleaved,
which is a slightly simpler way to define two matching tables.
As we move to having the tables generated, that advantage is no longer
important, but the interleaved table gets in the way of using the
same scripts as on the other architectures.
Split out a new compat_sys_call_table symbol that contains all the
compat calls, and leave the main table for the native calls, to more
closely match the method we use everywhere else.
Signed-off-by: Arnd Bergmann <arnd@...db.de>
---
This is completely untested, it's just for illustration and to
get comments about whether this is a good idea.
Firoz, can you try to get this working?
---
arch/powerpc/include/asm/syscall.h | 3 +--
arch/powerpc/kernel/entry_64.S | 7 ++++--
arch/powerpc/kernel/systbl.S | 37 ++++++++++++++++++++++++------
arch/powerpc/kernel/vdso.c | 7 ++++--
4 files changed, 41 insertions(+), 13 deletions(-)
diff --git a/arch/powerpc/include/asm/syscall.h b/arch/powerpc/include/asm/syscall.h
index ab9f3f0a8637..1a0e7a8b1c81 100644
--- a/arch/powerpc/include/asm/syscall.h
+++ b/arch/powerpc/include/asm/syscall.h
@@ -18,9 +18,8 @@
#include <linux/thread_info.h>
/* ftrace syscalls requires exporting the sys_call_table */
-#ifdef CONFIG_FTRACE_SYSCALLS
extern const unsigned long sys_call_table[];
-#endif /* CONFIG_FTRACE_SYSCALLS */
+extern const unsigned long compat_sys_call_table[];
static inline int syscall_get_nr(struct task_struct *task, struct pt_regs *regs)
{
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 7b1693adff2a..5574d92646f1 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -54,6 +54,9 @@
SYS_CALL_TABLE:
.tc sys_call_table[TC],sys_call_table
+COMPAT_SYS_CALL_TABLE:
+ .tc compat_sys_call_table[TC],compat_sys_call_table
+
/* This value is used to mark exception frames on the stack. */
exception_marker:
.tc ID_EXC_MARKER[TC],STACK_FRAME_REGS_MARKER
@@ -173,7 +176,7 @@ system_call: /* label this so stack traces look sane */
ld r11,SYS_CALL_TABLE@toc(2)
andis. r10,r10,_TIF_32BIT@h
beq 15f
- addi r11,r11,8 /* use 32-bit syscall entries */
+ ld r11,COMPAT_SYS_CALL_TABLE@toc(2)
clrldi r3,r3,32
clrldi r4,r4,32
clrldi r5,r5,32
@@ -181,7 +184,7 @@ system_call: /* label this so stack traces look sane */
clrldi r7,r7,32
clrldi r8,r8,32
15:
- slwi r0,r0,4
+ slwi r0,r0,3
barrier_nospec_asm
/*
diff --git a/arch/powerpc/kernel/systbl.S b/arch/powerpc/kernel/systbl.S
index 919a32746ede..883b8e36964c 100644
--- a/arch/powerpc/kernel/systbl.S
+++ b/arch/powerpc/kernel/systbl.S
@@ -17,13 +17,13 @@
#include <asm/ppc_asm.h>
#ifdef CONFIG_PPC64
-#define SYSCALL(func) .8byte DOTSYM(sys_##func),DOTSYM(sys_##func)
-#define COMPAT_SYS(func) .8byte DOTSYM(sys_##func),DOTSYM(compat_sys_##func)
-#define PPC_SYS(func) .8byte DOTSYM(ppc_##func),DOTSYM(ppc_##func)
-#define OLDSYS(func) .8byte DOTSYM(sys_ni_syscall),DOTSYM(sys_ni_syscall)
-#define SYS32ONLY(func) .8byte DOTSYM(sys_ni_syscall),DOTSYM(compat_sys_##func)
-#define PPC64ONLY(func) .8byte DOTSYM(ppc_##func),DOTSYM(sys_ni_syscall)
-#define SYSX(f, f3264, f32) .8byte DOTSYM(f),DOTSYM(f3264)
+#define SYSCALL(func) .8byte DOTSYM(sys_##func)
+#define COMPAT_SYS(func) .8byte DOTSYM(sys_##func)
+#define PPC_SYS(func) .8byte DOTSYM(ppc_##func)
+#define OLDSYS(func) .8byte DOTSYM(sys_ni_syscall)
+#define SYS32ONLY(func) .8byte DOTSYM(sys_ni_syscall)
+#define PPC64ONLY(func) .8byte DOTSYM(ppc_##func)
+#define SYSX(f, f3264, f32) .8byte DOTSYM(f)
#else
#define SYSCALL(func) .long sys_##func
#define COMPAT_SYS(func) .long sys_##func
@@ -48,3 +48,26 @@
sys_call_table:
#include <asm/systbl.h>
+
+#undef SYSCALL
+#undef COMPAT_SYS
+#undef PPC_SYS
+#undef OLDSYS
+#undef SYS32ONLY
+#undef PPC64ONLY
+#undef SYSX
+
+#ifdef CONFIG_COMPAT
+#define SYSCALL(func) .8byte DOTSYM(sys_##func)
+#define COMPAT_SYS(func) .8byte DOTSYM(compat_sys_##func)
+#define PPC_SYS(func) .8byte DOTSYM(ppc_##func)
+#define OLDSYS(func) .8byte DOTSYM(sys_ni_syscall)
+#define SYS32ONLY(func) .8byte DOTSYM(compat_sys_##func)
+#define PPC64ONLY(func) .8byte DOTSYM(sys_ni_syscall)
+#define SYSX(f, f3264, f32) .8byte DOTSYM(f3264)
+
+.globl compat_sys_call_table
+compat_sys_call_table:
+
+#include <asm/systbl.h>
+#endif
diff --git a/arch/powerpc/kernel/vdso.c b/arch/powerpc/kernel/vdso.c
index 65b3bdb99f0b..7725a9714736 100644
--- a/arch/powerpc/kernel/vdso.c
+++ b/arch/powerpc/kernel/vdso.c
@@ -671,15 +671,18 @@ static void __init vdso_setup_syscall_map(void)
{
unsigned int i;
extern unsigned long *sys_call_table;
+#ifdef CONFIG_PPC64
+ extern unsigned long *compat_sys_call_table;
+#endif
extern unsigned long sys_ni_syscall;
for (i = 0; i < NR_syscalls; i++) {
#ifdef CONFIG_PPC64
- if (sys_call_table[i*2] != sys_ni_syscall)
+ if (sys_call_table[i] != sys_ni_syscall)
vdso_data->syscall_map_64[i >> 5] |=
0x80000000UL >> (i & 0x1f);
- if (sys_call_table[i*2+1] != sys_ni_syscall)
+ if (compat_sys_call_table[i] != sys_ni_syscall)
vdso_data->syscall_map_32[i >> 5] |=
0x80000000UL >> (i & 0x1f);
#else /* CONFIG_PPC64 */
--
2.18.0
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