summaryrefslogtreecommitdiff
path: root/recipes/kexecboot/linux-kexecboot-2.6.29/0001-implement-TIF_RESTORE_SIGMASK-support-and-enable-the.patch
blob: 7852f0afdb9afac7de16541f1e52e55bf4721448 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
From 8a7643b09856f4f661403dcedbe0455b3cbeeea9 Mon Sep 17 00:00:00 2001
From: Steven Newbury <s_j_newbury@yahoo.co.uk>
Date: Fri, 22 May 2009 14:25:40 +0200
Subject: [PATCH] implement TIF_RESTORE_SIGMASK support and enable the related
 syscalls:

pselect6
ppoll
epoll_pwait

Based on http://www.spinics.net/lists/arm-kernel/msg38114.html
---
 arch/arm/include/asm/thread_info.h |    2 +
 arch/arm/include/asm/unistd.h      |    7 ++-
 arch/arm/kernel/calls.S            |    6 +-
 arch/arm/kernel/signal.c           |   90 +++++++++++++++---------------------
 4 files changed, 46 insertions(+), 59 deletions(-)

diff --git a/arch/arm/include/asm/thread_info.h b/arch/arm/include/asm/thread_info.h
index 4f88482..2cf0917 100644
--- a/arch/arm/include/asm/thread_info.h
+++ b/arch/arm/include/asm/thread_info.h
@@ -136,6 +136,7 @@ extern void vfp_sync_state(struct thread_info *thread);
 #define TIF_SIGPENDING		0
 #define TIF_NEED_RESCHED	1
 #define TIF_SYSCALL_TRACE	8
+#define TIF_RESTORE_SIGMASK	9       /* restore signal mask in do_signal */
 #define TIF_POLLING_NRFLAG	16
 #define TIF_USING_IWMMXT	17
 #define TIF_MEMDIE		18
@@ -144,6 +145,7 @@ extern void vfp_sync_state(struct thread_info *thread);
 #define _TIF_SIGPENDING		(1 << TIF_SIGPENDING)
 #define _TIF_NEED_RESCHED	(1 << TIF_NEED_RESCHED)
 #define _TIF_SYSCALL_TRACE	(1 << TIF_SYSCALL_TRACE)
+#define _TIF_RESTORE_SIGMASK	(1 << TIF_RESTORE_SIGMASK)
 #define _TIF_POLLING_NRFLAG	(1 << TIF_POLLING_NRFLAG)
 #define _TIF_USING_IWMMXT	(1 << TIF_USING_IWMMXT)
 #define _TIF_FREEZE		(1 << TIF_FREEZE)
diff --git a/arch/arm/include/asm/unistd.h b/arch/arm/include/asm/unistd.h
index 94cc58e..cd1eaa0 100644
--- a/arch/arm/include/asm/unistd.h
+++ b/arch/arm/include/asm/unistd.h
@@ -360,8 +360,8 @@
 #define __NR_readlinkat			(__NR_SYSCALL_BASE+332)
 #define __NR_fchmodat			(__NR_SYSCALL_BASE+333)
 #define __NR_faccessat			(__NR_SYSCALL_BASE+334)
-					/* 335 for pselect6 */
-					/* 336 for ppoll */
+#define __NR_pselect6			(__NR_SYSCALL_BASE+335)
+#define __NR_ppoll			(__NR_SYSCALL_BASE+336)
 #define __NR_unshare			(__NR_SYSCALL_BASE+337)
 #define __NR_set_robust_list		(__NR_SYSCALL_BASE+338)
 #define __NR_get_robust_list		(__NR_SYSCALL_BASE+339)
@@ -372,7 +372,7 @@
 #define __NR_vmsplice			(__NR_SYSCALL_BASE+343)
 #define __NR_move_pages			(__NR_SYSCALL_BASE+344)
 #define __NR_getcpu			(__NR_SYSCALL_BASE+345)
-					/* 346 for epoll_pwait */
+#define __NR_epoll_pwait		(__NR_SYSCALL_BASE+346)
 #define __NR_kexec_load			(__NR_SYSCALL_BASE+347)
 #define __NR_utimensat			(__NR_SYSCALL_BASE+348)
 #define __NR_signalfd			(__NR_SYSCALL_BASE+349)
@@ -430,6 +430,7 @@
 #define __ARCH_WANT_SYS_SIGPENDING
 #define __ARCH_WANT_SYS_SIGPROCMASK
 #define __ARCH_WANT_SYS_RT_SIGACTION
+#define __ARCH_WANT_SYS_RT_SIGSUSPEND
 
 #if !defined(CONFIG_AEABI) || defined(CONFIG_OABI_COMPAT)
 #define __ARCH_WANT_SYS_TIME
diff --git a/arch/arm/kernel/calls.S b/arch/arm/kernel/calls.S
index 1680e9e..534000d 100644
--- a/arch/arm/kernel/calls.S
+++ b/arch/arm/kernel/calls.S
@@ -344,8 +344,8 @@
 		CALL(sys_readlinkat)
 		CALL(sys_fchmodat)
 		CALL(sys_faccessat)
-/* 335 */	CALL(sys_ni_syscall)		/* eventually pselect6 */
-		CALL(sys_ni_syscall)		/* eventually ppoll */
+/* 335 */	CALL(sys_pselect6)
+		CALL(sys_ppoll)
 		CALL(sys_unshare)
 		CALL(sys_set_robust_list)
 		CALL(sys_get_robust_list)
@@ -355,7 +355,7 @@
 		CALL(sys_vmsplice)
 		CALL(sys_move_pages)
 /* 345 */	CALL(sys_getcpu)
-		CALL(sys_ni_syscall)		/* eventually epoll_pwait */
+		CALL(sys_epoll_pwait)
 		CALL(sys_kexec_load)
 		CALL(sys_utimensat)
 		CALL(sys_signalfd)
diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c
index 80b8b5c..7645048 100644
--- a/arch/arm/kernel/signal.c
+++ b/arch/arm/kernel/signal.c
@@ -47,57 +47,23 @@ const unsigned long sigreturn_codes[7] = {
 	MOV_R7_NR_RT_SIGRETURN, SWI_SYS_RT_SIGRETURN, SWI_THUMB_RT_SIGRETURN,
 };
 
-static int do_signal(sigset_t *oldset, struct pt_regs * regs, int syscall);
+static void do_signal(struct pt_regs * regs, int syscall);
 
 /*
  * atomically swap in the new signal mask, and wait for a signal.
  */
-asmlinkage int sys_sigsuspend(int restart, unsigned long oldmask, old_sigset_t mask, struct pt_regs *regs)
+asmlinkage int sys_sigsuspend(int restart, unsigned long oldmask, old_sigset_t mask)
 {
-	sigset_t saveset;
-
 	mask &= _BLOCKABLE;
 	spin_lock_irq(&current->sighand->siglock);
-	saveset = current->blocked;
+	current->saved_sigmask = current->blocked;
 	siginitset(&current->blocked, mask);
 	recalc_sigpending();
 	spin_unlock_irq(&current->sighand->siglock);
-	regs->ARM_r0 = -EINTR;
-
-	while (1) {
-		current->state = TASK_INTERRUPTIBLE;
-		schedule();
-		if (do_signal(&saveset, regs, 0))
-			return regs->ARM_r0;
-	}
-}
-
-asmlinkage int
-sys_rt_sigsuspend(sigset_t __user *unewset, size_t sigsetsize, struct pt_regs *regs)
-{
-	sigset_t saveset, newset;
-
-	/* XXX: Don't preclude handling different sized sigset_t's. */
-	if (sigsetsize != sizeof(sigset_t))
-		return -EINVAL;
-
-	if (copy_from_user(&newset, unewset, sizeof(newset)))
-		return -EFAULT;
-	sigdelsetmask(&newset, ~_BLOCKABLE);
-
-	spin_lock_irq(&current->sighand->siglock);
-	saveset = current->blocked;
-	current->blocked = newset;
-	recalc_sigpending();
-	spin_unlock_irq(&current->sighand->siglock);
-	regs->ARM_r0 = -EINTR;
-
-	while (1) {
-		current->state = TASK_INTERRUPTIBLE;
-		schedule();
-		if (do_signal(&saveset, regs, 0))
-			return regs->ARM_r0;
-	}
+	current->state = TASK_INTERRUPTIBLE;
+	schedule();
+	set_thread_flag(TIF_RESTORE_SIGMASK);
+	return -ERESTARTNOHAND;
 }
 
 asmlinkage int 
@@ -290,7 +256,7 @@ asmlinkage int sys_sigreturn(struct pt_regs *regs)
 
 badframe:
 	force_sig(SIGSEGV, current);
-	return 0;
+	return -EFAULT;
 }
 
 asmlinkage int sys_rt_sigreturn(struct pt_regs *regs)
@@ -325,7 +291,7 @@ asmlinkage int sys_rt_sigreturn(struct pt_regs *regs)
 
 badframe:
 	force_sig(SIGSEGV, current);
-	return 0;
+	return -EFAULT;
 }
 
 static int
@@ -541,7 +507,7 @@ static inline void restart_syscall(struct pt_regs *regs)
 /*
  * OK, we're invoking a handler
  */	
-static void
+static int
 handle_signal(unsigned long sig, struct k_sigaction *ka,
 	      siginfo_t *info, sigset_t *oldset,
 	      struct pt_regs * regs, int syscall)
@@ -592,7 +558,7 @@ handle_signal(unsigned long sig, struct k_sigaction *ka,
 
 	if (ret != 0) {
 		force_sigsegv(sig, tsk);
-		return;
+		return ret;
 	}
 
 	/*
@@ -606,6 +572,7 @@ handle_signal(unsigned long sig, struct k_sigaction *ka,
 	recalc_sigpending();
 	spin_unlock_irq(&tsk->sighand->siglock);
 
+	return ret;
 }
 
 /*
@@ -617,11 +584,12 @@ handle_signal(unsigned long sig, struct k_sigaction *ka,
  * the kernel can handle, and then we build all the user-level signal handling
  * stack-frames in one go after that.
  */
-static int do_signal(sigset_t *oldset, struct pt_regs *regs, int syscall)
+static void do_signal(struct pt_regs *regs, int syscall)
 {
 	struct k_sigaction ka;
 	siginfo_t info;
 	int signr;
+	sigset_t *oldset;
 
 	/*
 	 * We want the common case to go fast, which
@@ -630,18 +598,29 @@ static int do_signal(sigset_t *oldset, struct pt_regs *regs, int syscall)
 	 * if so.
 	 */
 	if (!user_mode(regs))
-		return 0;
+		return;
 
 	if (try_to_freeze())
 		goto no_signal;
 
 	single_step_clear(current);
 
+	if (test_thread_flag(TIF_RESTORE_SIGMASK))
+		oldset = &current->saved_sigmask;
+	else
+		oldset = &current->blocked;
+
 	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
 	if (signr > 0) {
-		handle_signal(signr, &ka, &info, oldset, regs, syscall);
+		if (handle_signal(signr, &ka, &info, oldset, regs, syscall) == 0) {
+			/* a signal was successfully delivered; the saved
+			 * sigmask will have been stored in the signal frame,
+			 * and will be restored by sigreturn, so we can simply
+			 * clear the TIF_RESTORE_SIGMASK flag */
+			clear_thread_flag(TIF_RESTORE_SIGMASK);
+		}
 		single_step_set(current);
-		return 1;
+		return;
 	}
 
  no_signal:
@@ -665,7 +644,7 @@ static int do_signal(sigset_t *oldset, struct pt_regs *regs, int syscall)
 				usp = (u32 __user *)regs->ARM_sp;
 
 				/*
-				 * Either we supports OABI only, or we have
+				 * Either we support OABI only, or we have
 				 * EABI with the OABI compat layer enabled.
 				 * In the later case we don't know if user
 				 * space is EABI or not, and if not we must
@@ -695,12 +674,17 @@ static int do_signal(sigset_t *oldset, struct pt_regs *regs, int syscall)
 		}
 	}
 	single_step_set(current);
-	return 0;
+        /* if there's no signal to deliver, we just put the saved sigmask
+           back. */
+		if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
+			clear_thread_flag(TIF_RESTORE_SIGMASK);
+			sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
+		}
 }
 
 asmlinkage void
 do_notify_resume(struct pt_regs *regs, unsigned int thread_flags, int syscall)
 {
-	if (thread_flags & _TIF_SIGPENDING)
-		do_signal(&current->blocked, regs, syscall);
+	if (thread_flags & (_TIF_SIGPENDING|_TIF_RESTORE_SIGMASK))
+		do_signal(regs, syscall);
 }
-- 
1.6.2.4