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Date: Tue, 2 Apr 2019 16:02:31 +0800
From: guoren@...nel.org
To: arnd@...db.de, palmer@...ive.com
Cc: linux-kernel@...r.kernel.org, linux-arch@...r.kernel.org,
ren_guo@...ky.com, linux-riscv@...ts.infradead.org
Subject: [PATCH 1/3] csky: Use in_syscall & forget_syscall instead of r11_sig
From: Guo Ren <ren_guo@...ky.com>
We could use regs->sr 16-24 bits to detect syscall: VEC_TRAP0 and
r11_sig is no necessary for current implementation.
In this patch, we implement the in_syscall and forget_syscall which are
inspired from arm & nds32, but csky pt_regs has no syscall_num element
and we just set zero to regs->sr's vector-bits-field instead.
For ret_from_fork, current task was forked from parent which is in syscall
progress and its regs->sr has been already setted with VEC_TRAP0. See:
arch/csky/kernel/process.c: copy_thread()
Signed-off-by: Guo Ren <ren_guo@...ky.com>
Cc: Arnd Bergmann <arnd@...db.de>
---
arch/csky/abiv1/inc/abi/regdef.h | 2 --
arch/csky/abiv2/inc/abi/regdef.h | 2 --
arch/csky/include/asm/ptrace.h | 12 ++++++++++++
arch/csky/kernel/entry.S | 11 +----------
arch/csky/kernel/signal.c | 15 +++++++++------
5 files changed, 22 insertions(+), 20 deletions(-)
diff --git a/arch/csky/abiv1/inc/abi/regdef.h b/arch/csky/abiv1/inc/abi/regdef.h
index 8766892..9e7e692 100644
--- a/arch/csky/abiv1/inc/abi/regdef.h
+++ b/arch/csky/abiv1/inc/abi/regdef.h
@@ -5,8 +5,6 @@
#define __ASM_CSKY_REGDEF_H
#define syscallid r1
-#define r11_sig r11
-
#define regs_syscallid(regs) regs->regs[9]
/*
diff --git a/arch/csky/abiv2/inc/abi/regdef.h b/arch/csky/abiv2/inc/abi/regdef.h
index c72abb7..652f5ce 100644
--- a/arch/csky/abiv2/inc/abi/regdef.h
+++ b/arch/csky/abiv2/inc/abi/regdef.h
@@ -5,8 +5,6 @@
#define __ASM_CSKY_REGDEF_H
#define syscallid r7
-#define r11_sig r11
-
#define regs_syscallid(regs) regs->regs[3]
/*
diff --git a/arch/csky/include/asm/ptrace.h b/arch/csky/include/asm/ptrace.h
index 1e00578..d0aba7b 100644
--- a/arch/csky/include/asm/ptrace.h
+++ b/arch/csky/include/asm/ptrace.h
@@ -5,6 +5,8 @@
#define __ASM_CSKY_PTRACE_H
#include <uapi/asm/ptrace.h>
+#include <asm/traps.h>
+#include <linux/types.h>
#ifndef __ASSEMBLY__
@@ -20,6 +22,16 @@
#define instruction_pointer(regs) ((regs)->pc)
#define profile_pc(regs) instruction_pointer(regs)
+static inline bool in_syscall(struct pt_regs const *regs)
+{
+ return ((regs->sr >> 16) & 0xff) == VEC_TRAP0;
+}
+
+static inline void forget_syscall(struct pt_regs *regs)
+{
+ regs->sr &= ~(0xff << 16);
+}
+
static inline unsigned long regs_return_value(struct pt_regs *regs)
{
return regs->a0;
diff --git a/arch/csky/kernel/entry.S b/arch/csky/kernel/entry.S
index c18859a..d40fbd5 100644
--- a/arch/csky/kernel/entry.S
+++ b/arch/csky/kernel/entry.S
@@ -32,7 +32,6 @@
RD_MEH a1
psrset ee, ie
jbsr do_page_fault
- movi r11_sig, 0 /* r11 = 0, Not a syscall. */
jmpi ret_from_exception
.endm
@@ -125,7 +124,6 @@ ENTRY(ret_from_fork)
bmaski r10, THREAD_SHIFT
andn r9, r10
ldw r8, (r9, TINFO_FLAGS)
- movi r11_sig, 1
ANDI_R3 r8, (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_TRACEPOINT | _TIF_SYSCALL_AUDIT)
cmpnei r8, 0
bf 3f
@@ -160,12 +158,8 @@ exit_work:
/* If thread_info->flag is empty, RESTORE_ALL */
cmpnei r8, 0
bf 1b
- mov a1, sp
mov a0, r8
- mov a2, r11_sig /* syscall? */
- btsti r8, TIF_SIGPENDING /* delivering a signal? */
- /* prevent further restarts(set r11 = 0) */
- clrt r11_sig
+ mov a1, sp
jbsr do_notify_resume /* do signals */
br resume_userspace
@@ -175,13 +169,11 @@ work_resched:
jmpi schedule
ENTRY(sys_rt_sigreturn)
- movi r11_sig, 0
jmpi do_rt_sigreturn
ENTRY(csky_trap)
SAVE_ALL EPC_KEEP
psrset ee
- movi r11_sig, 0 /* r11 = 0, Not a syscall. */
mov a0, sp /* Push Stack pointer arg */
jbsr trap_c /* Call C-level trap handler */
jmpi ret_from_exception
@@ -215,7 +207,6 @@ ENTRY(csky_get_tls)
ENTRY(csky_irq)
SAVE_ALL EPC_KEEP
psrset ee
- movi r11_sig, 0 /* r11 = 0, Not a syscall. */
#ifdef CONFIG_PREEMPT
mov r9, sp /* Get current stack pointer */
diff --git a/arch/csky/kernel/signal.c b/arch/csky/kernel/signal.c
index 207a891..5a18940 100644
--- a/arch/csky/kernel/signal.c
+++ b/arch/csky/kernel/signal.c
@@ -224,7 +224,7 @@ handle_signal(struct ksignal *ksig, struct pt_regs *regs)
* that the kernel can handle, and then we build all the user-level signal
* handling stack-frames in one go after that.
*/
-static void do_signal(struct pt_regs *regs, int syscall)
+static void do_signal(struct pt_regs *regs)
{
unsigned int retval = 0, continue_addr = 0, restart_addr = 0;
struct ksignal ksig;
@@ -241,7 +241,9 @@ static void do_signal(struct pt_regs *regs, int syscall)
/*
* If we were from a system call, check for system call restarting...
*/
- if (syscall) {
+ if (in_syscall(regs)) {
+ forget_syscall(regs);
+
continue_addr = regs->pc;
#if defined(__CSKYABIV2__)
restart_addr = continue_addr - 4;
@@ -249,7 +251,6 @@ static void do_signal(struct pt_regs *regs, int syscall)
restart_addr = continue_addr - 2;
#endif
retval = regs->a0;
-
/*
* Prepare for system call restart. We do this here so that a
* debugger will see the already changed.
@@ -304,7 +305,9 @@ static void do_signal(struct pt_regs *regs, int syscall)
}
no_signal:
- if (syscall) {
+ if (in_syscall(regs)) {
+ forget_syscall(regs);
+
/*
* Handle restarting a different system call. As above,
* if a debugger has chosen to restart at a different PC,
@@ -333,10 +336,10 @@ static void do_signal(struct pt_regs *regs, int syscall)
}
asmlinkage void
-do_notify_resume(unsigned int thread_flags, struct pt_regs *regs, int syscall)
+do_notify_resume(unsigned int thread_flags, struct pt_regs *regs)
{
if (thread_flags & _TIF_SIGPENDING)
- do_signal(regs, syscall);
+ do_signal(regs);
if (thread_flags & _TIF_NOTIFY_RESUME) {
clear_thread_flag(TIF_NOTIFY_RESUME);
--
2.7.4
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