* [PATCH v4 19/29] signal: Consolidate {TS,TLF}_RESTORE_SIGMASK code
[not found] <cover.1466974736.git.luto@kernel.org>
@ 2016-06-26 21:55 ` Andy Lutomirski
0 siblings, 0 replies; only message in thread
From: Andy Lutomirski @ 2016-06-26 21:55 UTC (permalink / raw)
To: x86
Cc: linux-kernel, linux-arch, Borislav Petkov, Nadav Amit, Kees Cook,
Brian Gerst, kernel-hardening@lists.openwall.com, Linus Torvalds,
Josh Poimboeuf, Jann Horn, Heiko Carstens, Andy Lutomirski,
Richard Henderson, Ivan Kokshaysky, Matt Turner, Tony Luck,
Fenghua Yu, Michal Simek, Benjamin Herrenschmidt, Paul Mackerras,
Michael Ellerman, Yoshinori Sato, Rich Felker, David S. Miller,
Chris Metcalf, Peter Zijlstra, Borislav Petkov, Dmitry Safonov,
Andrew Morton, linux-alpha, linux-ia64, linuxppc-dev, linux-sh,
sparclinux
In general, there's no need for the "restore sigmask" flag to live in
ti->flags. alpha, ia64, microblaze, powerpc, sh, sparc (64-bit only),
tile, and x86 use essentially identical alternative implementations,
placing the flag in ti->status.
Replace those optimized implementations with an equally good common
implementation that stores it in a bitfield in struct task_struct
and drop the custom implementations.
Additional architectures can opt in by removing their
TIF_RESTORE_SIGMASK defines.
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: x86@kernel.org
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dmitry Safonov <dsafonov@virtuozzo.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-alpha@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-ia64@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-sh@vger.kernel.org
Cc: sparclinux@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Signed-off-by: Andy Lutomirski <luto@kernel.org>
---
arch/alpha/include/asm/thread_info.h | 27 -------------
arch/ia64/include/asm/thread_info.h | 28 --------------
arch/microblaze/include/asm/thread_info.h | 27 -------------
arch/powerpc/include/asm/thread_info.h | 25 ------------
arch/sh/include/asm/thread_info.h | 26 -------------
arch/sparc/include/asm/thread_info_64.h | 24 ------------
arch/tile/include/asm/thread_info.h | 27 -------------
arch/x86/include/asm/thread_info.h | 24 ------------
include/linux/sched.h | 63 +++++++++++++++++++++++++++++++
include/linux/thread_info.h | 41 --------------------
10 files changed, 63 insertions(+), 249 deletions(-)
diff --git a/arch/alpha/include/asm/thread_info.h b/arch/alpha/include/asm/thread_info.h
index 32e920a83ae5..e9e90bfa2b50 100644
--- a/arch/alpha/include/asm/thread_info.h
+++ b/arch/alpha/include/asm/thread_info.h
@@ -86,33 +86,6 @@ register struct thread_info *__current_thread_info __asm__("$8");
#define TS_UAC_NOPRINT 0x0001 /* ! Preserve the following three */
#define TS_UAC_NOFIX 0x0002 /* ! flags as they match */
#define TS_UAC_SIGBUS 0x0004 /* ! userspace part of 'osf_sysinfo' */
-#define TS_RESTORE_SIGMASK 0x0008 /* restore signal mask in do_signal() */
-
-#ifndef __ASSEMBLY__
-#define HAVE_SET_RESTORE_SIGMASK 1
-static inline void set_restore_sigmask(void)
-{
- struct thread_info *ti = current_thread_info();
- ti->status |= TS_RESTORE_SIGMASK;
- WARN_ON(!test_bit(TIF_SIGPENDING, (unsigned long *)&ti->flags));
-}
-static inline void clear_restore_sigmask(void)
-{
- current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
-}
-static inline bool test_restore_sigmask(void)
-{
- return current_thread_info()->status & TS_RESTORE_SIGMASK;
-}
-static inline bool test_and_clear_restore_sigmask(void)
-{
- struct thread_info *ti = current_thread_info();
- if (!(ti->status & TS_RESTORE_SIGMASK))
- return false;
- ti->status &= ~TS_RESTORE_SIGMASK;
- return true;
-}
-#endif
#define SET_UNALIGN_CTL(task,value) ({ \
__u32 status = task_thread_info(task)->status & ~UAC_BITMASK; \
diff --git a/arch/ia64/include/asm/thread_info.h b/arch/ia64/include/asm/thread_info.h
index f0a72e98e5a4..c7026429816b 100644
--- a/arch/ia64/include/asm/thread_info.h
+++ b/arch/ia64/include/asm/thread_info.h
@@ -121,32 +121,4 @@ struct thread_info {
/* like TIF_ALLWORK_BITS but sans TIF_SYSCALL_TRACE or TIF_SYSCALL_AUDIT */
#define TIF_WORK_MASK (TIF_ALLWORK_MASK&~(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT))
-#define TS_RESTORE_SIGMASK 2 /* restore signal mask in do_signal() */
-
-#ifndef __ASSEMBLY__
-#define HAVE_SET_RESTORE_SIGMASK 1
-static inline void set_restore_sigmask(void)
-{
- struct thread_info *ti = current_thread_info();
- ti->status |= TS_RESTORE_SIGMASK;
- WARN_ON(!test_bit(TIF_SIGPENDING, &ti->flags));
-}
-static inline void clear_restore_sigmask(void)
-{
- current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
-}
-static inline bool test_restore_sigmask(void)
-{
- return current_thread_info()->status & TS_RESTORE_SIGMASK;
-}
-static inline bool test_and_clear_restore_sigmask(void)
-{
- struct thread_info *ti = current_thread_info();
- if (!(ti->status & TS_RESTORE_SIGMASK))
- return false;
- ti->status &= ~TS_RESTORE_SIGMASK;
- return true;
-}
-#endif /* !__ASSEMBLY__ */
-
#endif /* _ASM_IA64_THREAD_INFO_H */
diff --git a/arch/microblaze/include/asm/thread_info.h b/arch/microblaze/include/asm/thread_info.h
index 383f387b4eee..e7e8954e9815 100644
--- a/arch/microblaze/include/asm/thread_info.h
+++ b/arch/microblaze/include/asm/thread_info.h
@@ -148,33 +148,6 @@ static inline struct thread_info *current_thread_info(void)
*/
/* FPU was used by this task this quantum (SMP) */
#define TS_USEDFPU 0x0001
-#define TS_RESTORE_SIGMASK 0x0002
-
-#ifndef __ASSEMBLY__
-#define HAVE_SET_RESTORE_SIGMASK 1
-static inline void set_restore_sigmask(void)
-{
- struct thread_info *ti = current_thread_info();
- ti->status |= TS_RESTORE_SIGMASK;
- WARN_ON(!test_bit(TIF_SIGPENDING, (unsigned long *)&ti->flags));
-}
-static inline void clear_restore_sigmask(void)
-{
- current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
-}
-static inline bool test_restore_sigmask(void)
-{
- return current_thread_info()->status & TS_RESTORE_SIGMASK;
-}
-static inline bool test_and_clear_restore_sigmask(void)
-{
- struct thread_info *ti = current_thread_info();
- if (!(ti->status & TS_RESTORE_SIGMASK))
- return false;
- ti->status &= ~TS_RESTORE_SIGMASK;
- return true;
-}
-#endif
#endif /* __KERNEL__ */
#endif /* _ASM_MICROBLAZE_THREAD_INFO_H */
diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h
index 8febc3f66d53..cfc35195f95e 100644
--- a/arch/powerpc/include/asm/thread_info.h
+++ b/arch/powerpc/include/asm/thread_info.h
@@ -134,40 +134,15 @@ static inline struct thread_info *current_thread_info(void)
/* Don't move TLF_NAPPING without adjusting the code in entry_32.S */
#define TLF_NAPPING 0 /* idle thread enabled NAP mode */
#define TLF_SLEEPING 1 /* suspend code enabled SLEEP mode */
-#define TLF_RESTORE_SIGMASK 2 /* Restore signal mask in do_signal */
#define TLF_LAZY_MMU 3 /* tlb_batch is active */
#define TLF_RUNLATCH 4 /* Is the runlatch enabled? */
#define _TLF_NAPPING (1 << TLF_NAPPING)
#define _TLF_SLEEPING (1 << TLF_SLEEPING)
-#define _TLF_RESTORE_SIGMASK (1 << TLF_RESTORE_SIGMASK)
#define _TLF_LAZY_MMU (1 << TLF_LAZY_MMU)
#define _TLF_RUNLATCH (1 << TLF_RUNLATCH)
#ifndef __ASSEMBLY__
-#define HAVE_SET_RESTORE_SIGMASK 1
-static inline void set_restore_sigmask(void)
-{
- struct thread_info *ti = current_thread_info();
- ti->local_flags |= _TLF_RESTORE_SIGMASK;
- WARN_ON(!test_bit(TIF_SIGPENDING, &ti->flags));
-}
-static inline void clear_restore_sigmask(void)
-{
- current_thread_info()->local_flags &= ~_TLF_RESTORE_SIGMASK;
-}
-static inline bool test_restore_sigmask(void)
-{
- return current_thread_info()->local_flags & _TLF_RESTORE_SIGMASK;
-}
-static inline bool test_and_clear_restore_sigmask(void)
-{
- struct thread_info *ti = current_thread_info();
- if (!(ti->local_flags & _TLF_RESTORE_SIGMASK))
- return false;
- ti->local_flags &= ~_TLF_RESTORE_SIGMASK;
- return true;
-}
static inline bool test_thread_local_flags(unsigned int flags)
{
diff --git a/arch/sh/include/asm/thread_info.h b/arch/sh/include/asm/thread_info.h
index 2afa321157be..6c65dcd470ab 100644
--- a/arch/sh/include/asm/thread_info.h
+++ b/arch/sh/include/asm/thread_info.h
@@ -151,19 +151,10 @@ extern void init_thread_xstate(void);
* ever touches our thread-synchronous status, so we don't
* have to worry about atomic accesses.
*/
-#define TS_RESTORE_SIGMASK 0x0001 /* restore signal mask in do_signal() */
#define TS_USEDFPU 0x0002 /* FPU used by this task this quantum */
#ifndef __ASSEMBLY__
-#define HAVE_SET_RESTORE_SIGMASK 1
-static inline void set_restore_sigmask(void)
-{
- struct thread_info *ti = current_thread_info();
- ti->status |= TS_RESTORE_SIGMASK;
- WARN_ON(!test_bit(TIF_SIGPENDING, (unsigned long *)&ti->flags));
-}
-
#define TI_FLAG_FAULT_CODE_SHIFT 24
/*
@@ -182,23 +173,6 @@ static inline unsigned int get_thread_fault_code(void)
return ti->flags >> TI_FLAG_FAULT_CODE_SHIFT;
}
-static inline void clear_restore_sigmask(void)
-{
- current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
-}
-static inline bool test_restore_sigmask(void)
-{
- return current_thread_info()->status & TS_RESTORE_SIGMASK;
-}
-static inline bool test_and_clear_restore_sigmask(void)
-{
- struct thread_info *ti = current_thread_info();
- if (!(ti->status & TS_RESTORE_SIGMASK))
- return false;
- ti->status &= ~TS_RESTORE_SIGMASK;
- return true;
-}
-
#endif /* !__ASSEMBLY__ */
#endif /* __KERNEL__ */
diff --git a/arch/sparc/include/asm/thread_info_64.h b/arch/sparc/include/asm/thread_info_64.h
index bde59825d06c..3d7b925f6516 100644
--- a/arch/sparc/include/asm/thread_info_64.h
+++ b/arch/sparc/include/asm/thread_info_64.h
@@ -222,32 +222,8 @@ register struct thread_info *current_thread_info_reg asm("g6");
*
* Note that there are only 8 bits available.
*/
-#define TS_RESTORE_SIGMASK 0x0001 /* restore signal mask in do_signal() */
#ifndef __ASSEMBLY__
-#define HAVE_SET_RESTORE_SIGMASK 1
-static inline void set_restore_sigmask(void)
-{
- struct thread_info *ti = current_thread_info();
- ti->status |= TS_RESTORE_SIGMASK;
- WARN_ON(!test_bit(TIF_SIGPENDING, &ti->flags));
-}
-static inline void clear_restore_sigmask(void)
-{
- current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
-}
-static inline bool test_restore_sigmask(void)
-{
- return current_thread_info()->status & TS_RESTORE_SIGMASK;
-}
-static inline bool test_and_clear_restore_sigmask(void)
-{
- struct thread_info *ti = current_thread_info();
- if (!(ti->status & TS_RESTORE_SIGMASK))
- return false;
- ti->status &= ~TS_RESTORE_SIGMASK;
- return true;
-}
#define thread32_stack_is_64bit(__SP) (((__SP) & 0x1) != 0)
#define test_thread_64bit_stack(__SP) \
diff --git a/arch/tile/include/asm/thread_info.h b/arch/tile/include/asm/thread_info.h
index c1467ac59ce6..b7659b8f1117 100644
--- a/arch/tile/include/asm/thread_info.h
+++ b/arch/tile/include/asm/thread_info.h
@@ -166,32 +166,5 @@ extern void _cpu_idle(void);
#ifdef __tilegx__
#define TS_COMPAT 0x0001 /* 32-bit compatibility mode */
#endif
-#define TS_RESTORE_SIGMASK 0x0008 /* restore signal mask in do_signal */
-
-#ifndef __ASSEMBLY__
-#define HAVE_SET_RESTORE_SIGMASK 1
-static inline void set_restore_sigmask(void)
-{
- struct thread_info *ti = current_thread_info();
- ti->status |= TS_RESTORE_SIGMASK;
- WARN_ON(!test_bit(TIF_SIGPENDING, &ti->flags));
-}
-static inline void clear_restore_sigmask(void)
-{
- current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
-}
-static inline bool test_restore_sigmask(void)
-{
- return current_thread_info()->status & TS_RESTORE_SIGMASK;
-}
-static inline bool test_and_clear_restore_sigmask(void)
-{
- struct thread_info *ti = current_thread_info();
- if (!(ti->status & TS_RESTORE_SIGMASK))
- return false;
- ti->status &= ~TS_RESTORE_SIGMASK;
- return true;
-}
-#endif /* !__ASSEMBLY__ */
#endif /* _ASM_TILE_THREAD_INFO_H */
diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h
index 89bff044a6f5..b45ffdda3549 100644
--- a/arch/x86/include/asm/thread_info.h
+++ b/arch/x86/include/asm/thread_info.h
@@ -219,32 +219,8 @@ static inline unsigned long current_stack_pointer(void)
* have to worry about atomic accesses.
*/
#define TS_COMPAT 0x0002 /* 32bit syscall active (64BIT)*/
-#define TS_RESTORE_SIGMASK 0x0008 /* restore signal mask in do_signal() */
#ifndef __ASSEMBLY__
-#define HAVE_SET_RESTORE_SIGMASK 1
-static inline void set_restore_sigmask(void)
-{
- struct thread_info *ti = current_thread_info();
- ti->status |= TS_RESTORE_SIGMASK;
- WARN_ON(!test_bit(TIF_SIGPENDING, (unsigned long *)&ti->flags));
-}
-static inline void clear_restore_sigmask(void)
-{
- current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
-}
-static inline bool test_restore_sigmask(void)
-{
- return current_thread_info()->status & TS_RESTORE_SIGMASK;
-}
-static inline bool test_and_clear_restore_sigmask(void)
-{
- struct thread_info *ti = current_thread_info();
- if (!(ti->status & TS_RESTORE_SIGMASK))
- return false;
- ti->status &= ~TS_RESTORE_SIGMASK;
- return true;
-}
static inline bool in_ia32_syscall(void)
{
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 26869dba21f1..569df670407a 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1545,6 +1545,9 @@ struct task_struct {
/* unserialized, strictly 'current' */
unsigned in_execve:1; /* bit to tell LSMs we're in execve */
unsigned in_iowait:1;
+#if !defined(TIF_RESTORE_SIGMASK)
+ unsigned restore_sigmask:1;
+#endif
#ifdef CONFIG_MEMCG
unsigned memcg_may_oom:1;
#ifndef CONFIG_SLOB
@@ -2664,6 +2667,66 @@ extern void sigqueue_free(struct sigqueue *);
extern int send_sigqueue(struct sigqueue *, struct task_struct *, int group);
extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *);
+#ifdef TIF_RESTORE_SIGMASK
+/*
+ * Legacy restore_sigmask accessors. These are inefficient on
+ * SMP architectures because they require atomic operations.
+ */
+
+/**
+ * set_restore_sigmask() - make sure saved_sigmask processing gets done
+ *
+ * This sets TIF_RESTORE_SIGMASK and ensures that the arch signal code
+ * will run before returning to user mode, to process the flag. For
+ * all callers, TIF_SIGPENDING is already set or it's no harm to set
+ * it. TIF_RESTORE_SIGMASK need not be in the set of bits that the
+ * arch code will notice on return to user mode, in case those bits
+ * are scarce. We set TIF_SIGPENDING here to ensure that the arch
+ * signal code always gets run when TIF_RESTORE_SIGMASK is set.
+ */
+static inline void set_restore_sigmask(void)
+{
+ set_thread_flag(TIF_RESTORE_SIGMASK);
+ WARN_ON(!test_thread_flag(TIF_SIGPENDING));
+}
+static inline void clear_restore_sigmask(void)
+{
+ clear_thread_flag(TIF_RESTORE_SIGMASK);
+}
+static inline bool test_restore_sigmask(void)
+{
+ return test_thread_flag(TIF_RESTORE_SIGMASK);
+}
+static inline bool test_and_clear_restore_sigmask(void)
+{
+ return test_and_clear_thread_flag(TIF_RESTORE_SIGMASK);
+}
+
+#else /* TIF_RESTORE_SIGMASK */
+
+/* Higher-quality implementation, used if TIF_RESTORE_SIGMASK doesn't exist. */
+static inline void set_restore_sigmask(void)
+{
+ current->restore_sigmask = true;
+ WARN_ON(!test_thread_flag(TIF_SIGPENDING));
+}
+static inline void clear_restore_sigmask(void)
+{
+ current->restore_sigmask = false;
+}
+static inline bool test_restore_sigmask(void)
+{
+ return current->restore_sigmask;
+}
+static inline bool test_and_clear_restore_sigmask(void)
+{
+ if (!current->restore_sigmask)
+ return false;
+ current->restore_sigmask = false;
+ return true;
+}
+#endif
+
static inline void restore_saved_sigmask(void)
{
if (test_and_clear_restore_sigmask())
diff --git a/include/linux/thread_info.h b/include/linux/thread_info.h
index b4c2a485b28a..352b1542f5cc 100644
--- a/include/linux/thread_info.h
+++ b/include/linux/thread_info.h
@@ -105,47 +105,6 @@ static inline int test_ti_thread_flag(struct thread_info *ti, int flag)
#define tif_need_resched() test_thread_flag(TIF_NEED_RESCHED)
-#if defined TIF_RESTORE_SIGMASK && !defined HAVE_SET_RESTORE_SIGMASK
-/*
- * An arch can define its own version of set_restore_sigmask() to get the
- * job done however works, with or without TIF_RESTORE_SIGMASK.
- */
-#define HAVE_SET_RESTORE_SIGMASK 1
-
-/**
- * set_restore_sigmask() - make sure saved_sigmask processing gets done
- *
- * This sets TIF_RESTORE_SIGMASK and ensures that the arch signal code
- * will run before returning to user mode, to process the flag. For
- * all callers, TIF_SIGPENDING is already set or it's no harm to set
- * it. TIF_RESTORE_SIGMASK need not be in the set of bits that the
- * arch code will notice on return to user mode, in case those bits
- * are scarce. We set TIF_SIGPENDING here to ensure that the arch
- * signal code always gets run when TIF_RESTORE_SIGMASK is set.
- */
-static inline void set_restore_sigmask(void)
-{
- set_thread_flag(TIF_RESTORE_SIGMASK);
- WARN_ON(!test_thread_flag(TIF_SIGPENDING));
-}
-static inline void clear_restore_sigmask(void)
-{
- clear_thread_flag(TIF_RESTORE_SIGMASK);
-}
-static inline bool test_restore_sigmask(void)
-{
- return test_thread_flag(TIF_RESTORE_SIGMASK);
-}
-static inline bool test_and_clear_restore_sigmask(void)
-{
- return test_and_clear_thread_flag(TIF_RESTORE_SIGMASK);
-}
-#endif /* TIF_RESTORE_SIGMASK && !HAVE_SET_RESTORE_SIGMASK */
-
-#ifndef HAVE_SET_RESTORE_SIGMASK
-#error "no set_restore_sigmask() provided and default one won't work"
-#endif
-
#endif /* __KERNEL__ */
#endif /* _LINUX_THREAD_INFO_H */
--
2.7.4
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