From: Andy Lutomirski <luto@xxxxxxxxxx>
Subject: signal: consolidate {TS,TLF}_RESTORE_SIGMASK code
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.
Link: http://lkml.kernel.org/r/8a14321d64a28e40adfddc90e18a96c086a6d6f9.1468522723.git.luto@xxxxxxxxxx
Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx>
Tested-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx> [powerpc]
Cc: Richard Henderson <rth@xxxxxxxxxxx>
Cc: Ivan Kokshaysky <ink@xxxxxxxxxxxxxxxxxxxx>
Cc: Matt Turner <mattst88@xxxxxxxxx>
Cc: Tony Luck <tony.luck@xxxxxxxxx>
Cc: Fenghua Yu <fenghua.yu@xxxxxxxxx>
Cc: Michal Simek <monstr@xxxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Yoshinori Sato <ysato@xxxxxxxxxxxxxxxxxxxx>
Cc: Rich Felker <dalias@xxxxxxxx>
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Cc: Chris Metcalf <cmetcalf@xxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxx>
Cc: Brian Gerst <brgerst@xxxxxxxxx>
Cc: Dmitry Safonov <dsafonov@xxxxxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
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 -puN arch/alpha/include/asm/thread_info.h~signal-consolidate-tstlf_restore_sigmask-code arch/alpha/include/asm/thread_info.h
--- a/arch/alpha/include/asm/thread_info.h~signal-consolidate-tstlf_restore_sigmask-code
+++ a/arch/alpha/include/asm/thread_info.h
@@ -86,33 +86,6 @@ register struct thread_info *__current_t
#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 -puN arch/ia64/include/asm/thread_info.h~signal-consolidate-tstlf_restore_sigmask-code arch/ia64/include/asm/thread_info.h
--- a/arch/ia64/include/asm/thread_info.h~signal-consolidate-tstlf_restore_sigmask-code
+++ a/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 -puN arch/microblaze/include/asm/thread_info.h~signal-consolidate-tstlf_restore_sigmask-code arch/microblaze/include/asm/thread_info.h
--- a/arch/microblaze/include/asm/thread_info.h~signal-consolidate-tstlf_restore_sigmask-code
+++ a/arch/microblaze/include/asm/thread_info.h
@@ -148,33 +148,6 @@ static inline struct thread_info *curren
*/
/* 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 -puN arch/powerpc/include/asm/thread_info.h~signal-consolidate-tstlf_restore_sigmask-code arch/powerpc/include/asm/thread_info.h
--- a/arch/powerpc/include/asm/thread_info.h~signal-consolidate-tstlf_restore_sigmask-code
+++ a/arch/powerpc/include/asm/thread_info.h
@@ -138,40 +138,15 @@ static inline struct thread_info *curren
/* 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 -puN arch/sh/include/asm/thread_info.h~signal-consolidate-tstlf_restore_sigmask-code arch/sh/include/asm/thread_info.h
--- a/arch/sh/include/asm/thread_info.h~signal-consolidate-tstlf_restore_sigmask-code
+++ a/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_fa
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 -puN arch/sparc/include/asm/thread_info_64.h~signal-consolidate-tstlf_restore_sigmask-code arch/sparc/include/asm/thread_info_64.h
--- a/arch/sparc/include/asm/thread_info_64.h~signal-consolidate-tstlf_restore_sigmask-code
+++ a/arch/sparc/include/asm/thread_info_64.h
@@ -222,32 +222,8 @@ register struct thread_info *current_thr
*
* 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 -puN arch/tile/include/asm/thread_info.h~signal-consolidate-tstlf_restore_sigmask-code arch/tile/include/asm/thread_info.h
--- a/arch/tile/include/asm/thread_info.h~signal-consolidate-tstlf_restore_sigmask-code
+++ a/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 -puN arch/x86/include/asm/thread_info.h~signal-consolidate-tstlf_restore_sigmask-code arch/x86/include/asm/thread_info.h
--- a/arch/x86/include/asm/thread_info.h~signal-consolidate-tstlf_restore_sigmask-code
+++ a/arch/x86/include/asm/thread_info.h
@@ -219,32 +219,8 @@ static inline unsigned long current_stac
* 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 -puN include/linux/sched.h~signal-consolidate-tstlf_restore_sigmask-code include/linux/sched.h
--- a/include/linux/sched.h~signal-consolidate-tstlf_restore_sigmask-code
+++ a/include/linux/sched.h
@@ -1547,6 +1547,9 @@ 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
@@ -2680,6 +2683,66 @@ extern void sigqueue_free(struct sigqueu
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 -puN include/linux/thread_info.h~signal-consolidate-tstlf_restore_sigmask-code include/linux/thread_info.h
--- a/include/linux/thread_info.h~signal-consolidate-tstlf_restore_sigmask-code
+++ a/include/linux/thread_info.h
@@ -105,47 +105,6 @@ static inline int test_ti_thread_flag(st
#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 */
_
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