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Subject[PATCH v4 4/5] powerpc: split compat syscall table out from native table
Date
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 archit-
ectures.

Split out a new compat_sys_call_table symbol that contains
all the compat calls, and leave the main table for the nat-
ive calls, to more closely match the method we use every-
where else.

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Firoz Khan <firoz.khan@linaro.org>
---
arch/powerpc/include/asm/syscall.h | 3 +--
arch/powerpc/kernel/entry_64.S | 7 +++++--
arch/powerpc/kernel/systbl.S | 35 ++++++++++++++++++++++++++++-------
arch/powerpc/kernel/vdso.c | 7 +++++--
4 files changed, 39 insertions(+), 13 deletions(-)

diff --git a/arch/powerpc/include/asm/syscall.h b/arch/powerpc/include/asm/syscall.h
index ab9f3f0..1a0e7a8 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 7b1693a..5574d92 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 9ff1913..0fa84e1 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
@@ -46,6 +46,27 @@

.globl sys_call_table
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:
#define compat_sys_sigsuspend sys_sigsuspend
#include <asm/systbl.h>
+#endif
diff --git a/arch/powerpc/kernel/vdso.c b/arch/powerpc/kernel/vdso.c
index 65b3bdb..7725a97 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 */
--
1.9.1
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