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[13/13] nptl: s390x: Fix Race conditions in pthread cancellation (BZ#12683)

Message ID 1444234995-9542-14-git-send-email-adhemerval.zanella@linaro.com
State Dropped
Headers show

Commit Message

Adhemerval Zanella Oct. 7, 2015, 4:23 p.m. UTC
This patch adds the s390 modifications required for the BZ#12683 fix.
It basically removes the enable_asynccancel/disable_asynccancel function
usage on code, provide a arch-specific symbol that contains global
markers to be used in SIGCANCEL handler.

Checked on s390x (thanks to Stefan Liebler <stli@linux.vnet.ibm.com>).

    * sysdeps/unix/sysv/linux/s390/s390-64/syscall_cancel.S: New file.
    * sysdeps/unix/sysv/linux/s390/s390-64/sysdep-cancel.h (PSEUDO): Redefine
     to call __syscall_cancel function for cancellable syscalls.
     (__pthread_get_ip): Add implementation.
    * sysdeps/unix/sysv/linux/s390/s390-64/sysdep.h (SYSCALL_CANCEL_ERROR): Add
    definition.
    (SYSCALL_CANCEL_ERRNO): Likewise.
---
 ChangeLog                                          |   8 ++
 .../unix/sysv/linux/s390/s390-64/syscall_cancel.S  |  87 ++++++++++++++++
 .../unix/sysv/linux/s390/s390-64/sysdep-cancel.h   | 116 ++++++++++-----------
 sysdeps/unix/sysv/linux/s390/s390-64/sysdep.h      |   8 ++
 4 files changed, 160 insertions(+), 59 deletions(-)
 create mode 100644 sysdeps/unix/sysv/linux/s390/s390-64/syscall_cancel.S
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Patch

diff --git a/ChangeLog b/ChangeLog
index cdb4190..021373f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,6 +1,14 @@ 
 2015-10-07  Adhemerval Zanella  <adhemerval.zanella@linaro.org>
 	    Stefan Liebler  <stli@linux.vnet.ibm.com>
 
+	* sysdeps/unix/sysv/linux/s390/s390-64/syscall_cancel.S: New file.
+	* sysdeps/unix/sysv/linux/s390/s390-64/sysdep-cancel.h (PSEUDO): Redefine
+	to call __syscall_cancel function for cancellable syscalls.
+	(__pthread_get_ip): Add implementation.
+	* sysdeps/unix/sysv/linux/s390/s390-64/sysdep.h (SYSCALL_CANCEL_ERROR): Add
+	definition.
+	(SYSCALL_CANCEL_ERRNO): Likewise.
+
 	* sysdeps/unix/sysv/linux/s390/s390-32/syscall_cancel.S: New file.
 	* sysdeps/unix/sysv/linux/s390/s390-32/sysdep-cancel.h (PSEUDO): Redefine
 	to call __syscall_cancel function for cancellable syscalls.
diff --git a/sysdeps/unix/sysv/linux/s390/s390-64/syscall_cancel.S b/sysdeps/unix/sysv/linux/s390/s390-64/syscall_cancel.S
new file mode 100644
index 0000000..2da44a5
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/s390/s390-64/syscall_cancel.S
@@ -0,0 +1,87 @@ 
+/* Cancellable syscall wrapper - s390x version.
+   Copyright (C) 2015 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <sysdep.h>
+
+/* long int [r2] __syscall_cancel_arch (int *cancelhandling [r2],
+					long int nr   [r3],
+					long int arg1 [r4],
+					long int arg2 [r5],
+					long int arg3 [r6],
+					long int arg4 [SP+160],
+					long int arg5 [SP+168],
+					long int arg6 [SP+176])  */
+
+ENTRY (__syscall_cancel_arch)
+
+	/* Save registers and setup stack.  */
+	stmg	%r6,%r15,48(%r15)  /* Save registers.  */
+	cfi_offset (%r15,-40)
+	cfi_offset (%r14,-48)
+	cfi_offset (%r13,-56)
+	cfi_offset (%r12,-64)
+	cfi_offset (%r11,-72)
+	cfi_offset (%r10,-80)
+	cfi_offset (%r9,-88)
+	cfi_offset (%r8,-96)
+	cfi_offset (%r7,-104)
+	cfi_offset (%r6,-112)
+	lgr	%r1,%r15
+	lg	%r0,8(%r15)	   /* Load eos.	 */
+	aghi	%r15,-160	   /* Buy stack space.	*/
+	cfi_adjust_cfa_offset (160)
+	stg	%r1,0(%r15)	   /* Store back chain.	 */
+	stg	%r0,8(%r15)	   /* Store eos.  */
+
+	.globl __syscall_cancel_arch_start
+	.type  __syscall_cancel_arch_start,@function
+__syscall_cancel_arch_start:
+
+	/* if (*cancelhandling & CANCELED_BITMASK)
+	     __syscall_do_cancel()  */
+	tm	3(%r2),4
+	jne	1f
+
+	/* Issue a 6 argument syscall  */
+	lgr	%r1,%r3		/* Move syscall number.  */
+	lgr	%r2,%r4		/* First parameter.  */
+	lgr	%r3,%r5		/* Second parameter.  */
+	lgr	%r4,%r6		/* Third parameter.  */
+	lg	%r5,320(%r15)	/* Fourth parameter.  */
+	lg	%r6,328(%r15)	/* Fifth parameter.  */
+	lg	%r7,336(%r15)	/* Sixth parameter.  */
+
+	svc	0		/* svc number is always in r1.  */
+
+	.globl __syscall_cancel_arch_end
+	.type  __syscall_cancel_arch_end,@function
+__syscall_cancel_arch_end:
+	lg	%r15,0(%r15)	/* load back chain */
+	cfi_adjust_cfa_offset (-160)
+	lmg	%r6,%r15,48(%r15) /* Load registers.  */
+
+	br	%r14
+
+	/* Branch to __syscall_do_cancel  */
+1:
+	lg	%r15,0(%r15)	/* load back chain */
+	cfi_adjust_cfa_offset (-160)
+	lmg	%r6,%r15,48(%r15) /* Load registers.  */
+	jg	__syscall_do_cancel
+END (__syscall_cancel_arch)
+libc_hidden_def (__syscall_cancel_arch)
diff --git a/sysdeps/unix/sysv/linux/s390/s390-64/sysdep-cancel.h b/sysdeps/unix/sysv/linux/s390/s390-64/sysdep-cancel.h
index e054dc9..d8da8c2 100644
--- a/sysdeps/unix/sysv/linux/s390/s390-64/sysdep-cancel.h
+++ b/sysdeps/unix/sysv/linux/s390/s390-64/sysdep-cancel.h
@@ -24,93 +24,85 @@ 
 
 #if IS_IN (libc) || IS_IN (libpthread) || IS_IN (librt)
 
+# if IS_IN (libc)
+#  define JMP_SYSCALL_CANCEL HIDDEN_JUMPTARGET(__syscall_cancel)
+# else
+#  define JMP_SYSCALL_CANCEL __syscall_cancel@plt
+# endif
+
+# define STORE_0 /* Nothing */
+# define STORE_1 /* Nothing */
+# define STORE_2 /* Nothing */
+# define STORE_3 /* Nothing */
+# define STORE_4 stg %r6,48(%r15);		\
+ cfi_offset (%r6,-112);
+# define STORE_5 STORE_4
+# define STORE_6 STORE_4
+
+# define LOAD_0 /* Nothing */
+# define LOAD_1 /* Nothing */
+# define LOAD_2 /* Nothing */
+# define LOAD_3 /* Nothing */
+# define LOAD_4 lg %r6,48(%r15);
+# define LOAD_5 LOAD_4
+# define LOAD_6 LOAD_4
+
+# define MOVE_ARGS_0
+# define MOVE_ARGS_1 lgr %r3,%r2;		\
+	 MOVE_ARGS_0
+# define MOVE_ARGS_2 lgr %r4,%r3;		\
+	 MOVE_ARGS_1
+# define MOVE_ARGS_3 lgr %r5,%r4;		\
+	 MOVE_ARGS_2
+# define MOVE_ARGS_4 lgr %r6,%r5;		\
+	 MOVE_ARGS_3
+# define MOVE_ARGS_5 stg %r6,160(%r15);		\
+	 MOVE_ARGS_4
+# define MOVE_ARGS_6 lg %r14,160(%r14);		\
+	 stg %r14,168(%r15);			\
+	 MOVE_ARGS_5
+
+
 # undef PSEUDO
 # define PSEUDO(name, syscall_name, args)				      \
 	.text;								      \
 L(pseudo_cancel):							      \
 	cfi_startproc;							      \
-	STM_##args							      \
-	stmg	%r13,%r15,104(%r15);					      \
+	stmg	%r14,%r15,112(%r15);					      \
 	cfi_offset (%r15,-40);						      \
 	cfi_offset (%r14,-48);						      \
-	cfi_offset (%r13,-56);						      \
+	STORE_##args							      \
 	lgr	%r14,%r15;						      \
-	aghi	%r15,-160;						      \
-	cfi_adjust_cfa_offset (160);					      \
+	aghi	%r15,-176;						      \
+	cfi_adjust_cfa_offset (176);					      \
 	stg	%r14,0(%r15);						      \
-	brasl	%r14,CENABLE;						      \
-	lgr	%r0,%r2;						      \
-	LM_##args							      \
-	.if SYS_ify (syscall_name) < 256;				      \
-	svc SYS_ify (syscall_name);					      \
-	.else;								      \
-	lghi %r1,SYS_ify (syscall_name);				      \
-	svc 0;								      \
-	.endif;								      \
-	LR7_##args							      \
-	lgr	%r13,%r2;						      \
-	lgr	%r2,%r0;						      \
-	brasl	%r14,CDISABLE;						      \
-	lgr	%r2,%r13;						      \
-	lmg	%r13,%r15,104+160(%r15);				      \
+	MOVE_ARGS_##args						      \
+	lghi	%r2,SYS_ify (syscall_name);				      \
+	brasl	%r14,JMP_SYSCALL_CANCEL;				      \
+	lmg	%r14,%r15,112+176(%r15);			      	      \
+	cfi_restore (%r14);						      \
+	cfi_restore (%r15);						      \
+	LOAD_##args							      \
 	cfi_endproc;							      \
 	j	L(pseudo_check);					      \
 ENTRY(name)								      \
 	SINGLE_THREAD_P							      \
 	jne	L(pseudo_cancel);					      \
-.type	__##syscall_name##_nocancel,@function;				      \
-.globl	__##syscall_name##_nocancel;					      \
-__##syscall_name##_nocancel:						      \
 	DO_CALL(syscall_name, args);					      \
 L(pseudo_check):							      \
 	lghi	%r4,-4095;						      \
 	clgr	%r2,%r4;						      \
 	jgnl	SYSCALL_ERROR_LABEL;					      \
-.size	__##syscall_name##_nocancel,.-__##syscall_name##_nocancel;	      \
 L(pseudo_end):
 
 # if IS_IN (libpthread)
-#  define CENABLE	__pthread_enable_asynccancel
-#  define CDISABLE	__pthread_disable_asynccancel
 #  define __local_multiple_threads	__pthread_multiple_threads
 # elif IS_IN (libc)
-#  define CENABLE	__libc_enable_asynccancel
-#  define CDISABLE	__libc_disable_asynccancel
 #  define __local_multiple_threads	__libc_multiple_threads
-# elif IS_IN (librt)
-#  define CENABLE	__librt_enable_asynccancel
-#  define CDISABLE	__librt_disable_asynccancel
-# else
+# elif !IS_IN (librt)
 #  error Unsupported library
 # endif
 
-#define STM_0		/* Nothing */
-#define STM_1		stg %r2,16(%r15);
-#define STM_2		stmg %r2,%r3,16(%r15);
-#define STM_3		stmg %r2,%r4,16(%r15);
-#define STM_4		stmg %r2,%r5,16(%r15);
-#define STM_5		stmg %r2,%r5,16(%r15);
-#define STM_6		stmg %r2,%r7,16(%r15);
-
-#define LM_0		/* Nothing */
-#define LM_1		lg %r2,16+160(%r15);
-#define LM_2		lmg %r2,%r3,16+160(%r15);
-#define LM_3		lmg %r2,%r4,16+160(%r15);
-#define LM_4		lmg %r2,%r5,16+160(%r15);
-#define LM_5		lmg %r2,%r5,16+160(%r15);
-#define LM_6		lmg %r2,%r5,16+160(%r15); \
-			cfi_offset (%r7, -104); \
-			lg %r7,160+160(%r15);
-
-#define LR7_0		/* Nothing */
-#define LR7_1		/* Nothing */
-#define LR7_2		/* Nothing */
-#define LR7_3		/* Nothing */
-#define LR7_4		/* Nothing */
-#define LR7_5		/* Nothing */
-#define LR7_6		lg %r7,56+160(%r15); \
-			cfi_restore (%r7);
-
 # if IS_IN (libpthread) || IS_IN (libc)
 #  ifndef __ASSEMBLER__
 extern int __local_multiple_threads attribute_hidden;
@@ -149,4 +141,10 @@  extern int __local_multiple_threads attribute_hidden;
 # define RTLD_SINGLE_THREAD_P \
   __builtin_expect (THREAD_GETMEM (THREAD_SELF, \
 				   header.multiple_threads) == 0, 1)
+
+static inline
+long int __pthread_get_ip (const struct ucontext *uc)
+{
+  return uc->uc_mcontext.psw.addr;
+}
 #endif
diff --git a/sysdeps/unix/sysv/linux/s390/s390-64/sysdep.h b/sysdeps/unix/sysv/linux/s390/s390-64/sysdep.h
index c041153..4be051e 100644
--- a/sysdeps/unix/sysv/linux/s390/s390-64/sysdep.h
+++ b/sysdeps/unix/sysv/linux/s390/s390-64/sysdep.h
@@ -249,6 +249,14 @@ 
 #undef INTERNAL_SYSCALL_ERRNO
 #define INTERNAL_SYSCALL_ERRNO(val, err)	(-(val))
 
+#undef SYSCALL_CANCEL_ERROR
+#define SYSCALL_CANCEL_ERROR(__val)		\
+  ((unsigned long) (__val) >= -4095UL)
+
+#undef SYSCALL_CANCEL_ERRNO
+#define SYSCALL_CANCEL_ERRNO(__val) \
+  (-(__val))
+
 #define DECLARGS_0()
 #define DECLARGS_1(arg1) \
 	register unsigned long gpr2 asm ("2") = (unsigned long)(arg1);