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Message-ID: <160797733667.10793.7109332068482192551.tglx@nanos>
Date: Mon, 14 Dec 2020 20:22:16 -0000
From: Thomas Gleixner <tglx@...utronix.de>
To: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: linux-kernel@...r.kernel.org, x86@...nel.org
Subject: [GIT pull] perf/kprobes for v5.11-rc1
Linus,
please pull the latest perf/kprobes branch from:
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git perf-kprobes-2020-12-14
up to: a70a04b3844f: locking/atomics: Regenerate the atomics-check SHA1's
perf/kprobes updates:
- Make kretprobes lockless to avoid the rp->lock performance and potential
lock ordering issues.
Thanks,
tglx
------------------>
Ingo Molnar (1):
locking/atomics: Regenerate the atomics-check SHA1's
Peter Zijlstra (5):
llist: Add nonatomic __llist_add() and __llist_dell_all()
kprobes: Remove kretprobe hash
asm-generic/atomic: Add try_cmpxchg() fallbacks
freelist: Implement lockless freelist
kprobes: Replace rp->free_instance with freelist
arch/x86/include/asm/atomic.h | 2 +-
arch/x86/include/asm/atomic64_64.h | 2 +-
arch/x86/include/asm/cmpxchg.h | 2 +-
include/asm-generic/atomic-instrumented.h | 216 ++++++++++++--------
include/linux/atomic-arch-fallback.h | 90 ++++++++-
include/linux/atomic-fallback.h | 90 ++++++++-
include/linux/freelist.h | 129 ++++++++++++
include/linux/kprobes.h | 25 ++-
include/linux/llist.h | 23 +++
include/linux/sched.h | 4 +
kernel/fork.c | 4 +
kernel/kprobes.c | 314 +++++++++---------------------
kernel/trace/trace_kprobe.c | 3 +-
scripts/atomic/gen-atomic-fallback.sh | 63 +++++-
scripts/atomic/gen-atomic-instrumented.sh | 29 ++-
scripts/atomic/gen-atomics.sh | 0
16 files changed, 646 insertions(+), 350 deletions(-)
create mode 100644 include/linux/freelist.h
mode change 100644 => 100755 scripts/atomic/gen-atomics.sh
diff --git a/arch/x86/include/asm/atomic.h b/arch/x86/include/asm/atomic.h
index b6cac6e9bb70..f732741ad7c7 100644
--- a/arch/x86/include/asm/atomic.h
+++ b/arch/x86/include/asm/atomic.h
@@ -199,7 +199,7 @@ static __always_inline int arch_atomic_cmpxchg(atomic_t *v, int old, int new)
static __always_inline bool arch_atomic_try_cmpxchg(atomic_t *v, int *old, int new)
{
- return try_cmpxchg(&v->counter, old, new);
+ return arch_try_cmpxchg(&v->counter, old, new);
}
#define arch_atomic_try_cmpxchg arch_atomic_try_cmpxchg
diff --git a/arch/x86/include/asm/atomic64_64.h b/arch/x86/include/asm/atomic64_64.h
index 809bd010a751..7886d0578fc9 100644
--- a/arch/x86/include/asm/atomic64_64.h
+++ b/arch/x86/include/asm/atomic64_64.h
@@ -187,7 +187,7 @@ static inline s64 arch_atomic64_cmpxchg(atomic64_t *v, s64 old, s64 new)
static __always_inline bool arch_atomic64_try_cmpxchg(atomic64_t *v, s64 *old, s64 new)
{
- return try_cmpxchg(&v->counter, old, new);
+ return arch_try_cmpxchg(&v->counter, old, new);
}
#define arch_atomic64_try_cmpxchg arch_atomic64_try_cmpxchg
diff --git a/arch/x86/include/asm/cmpxchg.h b/arch/x86/include/asm/cmpxchg.h
index a8bfac131256..4d4ec5cbdc51 100644
--- a/arch/x86/include/asm/cmpxchg.h
+++ b/arch/x86/include/asm/cmpxchg.h
@@ -221,7 +221,7 @@ extern void __add_wrong_size(void)
#define __try_cmpxchg(ptr, pold, new, size) \
__raw_try_cmpxchg((ptr), (pold), (new), (size), LOCK_PREFIX)
-#define try_cmpxchg(ptr, pold, new) \
+#define arch_try_cmpxchg(ptr, pold, new) \
__try_cmpxchg((ptr), (pold), (new), sizeof(*(ptr)))
/*
diff --git a/include/asm-generic/atomic-instrumented.h b/include/asm-generic/atomic-instrumented.h
index cd223b68b69d..888b6cfeed91 100644
--- a/include/asm-generic/atomic-instrumented.h
+++ b/include/asm-generic/atomic-instrumented.h
@@ -1642,148 +1642,192 @@ atomic64_dec_if_positive(atomic64_t *v)
#endif
#if !defined(arch_xchg_relaxed) || defined(arch_xchg)
-#define xchg(ptr, ...) \
-({ \
- typeof(ptr) __ai_ptr = (ptr); \
- instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
- arch_xchg(__ai_ptr, __VA_ARGS__); \
+#define xchg(ptr, ...) \
+({ \
+ typeof(ptr) __ai_ptr = (ptr); \
+ instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+ arch_xchg(__ai_ptr, __VA_ARGS__); \
})
#endif
#if defined(arch_xchg_acquire)
-#define xchg_acquire(ptr, ...) \
-({ \
- typeof(ptr) __ai_ptr = (ptr); \
- instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
- arch_xchg_acquire(__ai_ptr, __VA_ARGS__); \
+#define xchg_acquire(ptr, ...) \
+({ \
+ typeof(ptr) __ai_ptr = (ptr); \
+ instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+ arch_xchg_acquire(__ai_ptr, __VA_ARGS__); \
})
#endif
#if defined(arch_xchg_release)
-#define xchg_release(ptr, ...) \
-({ \
- typeof(ptr) __ai_ptr = (ptr); \
- instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
- arch_xchg_release(__ai_ptr, __VA_ARGS__); \
+#define xchg_release(ptr, ...) \
+({ \
+ typeof(ptr) __ai_ptr = (ptr); \
+ instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+ arch_xchg_release(__ai_ptr, __VA_ARGS__); \
})
#endif
#if defined(arch_xchg_relaxed)
-#define xchg_relaxed(ptr, ...) \
-({ \
- typeof(ptr) __ai_ptr = (ptr); \
- instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
- arch_xchg_relaxed(__ai_ptr, __VA_ARGS__); \
+#define xchg_relaxed(ptr, ...) \
+({ \
+ typeof(ptr) __ai_ptr = (ptr); \
+ instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+ arch_xchg_relaxed(__ai_ptr, __VA_ARGS__); \
})
#endif
#if !defined(arch_cmpxchg_relaxed) || defined(arch_cmpxchg)
-#define cmpxchg(ptr, ...) \
-({ \
- typeof(ptr) __ai_ptr = (ptr); \
- instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
- arch_cmpxchg(__ai_ptr, __VA_ARGS__); \
+#define cmpxchg(ptr, ...) \
+({ \
+ typeof(ptr) __ai_ptr = (ptr); \
+ instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+ arch_cmpxchg(__ai_ptr, __VA_ARGS__); \
})
#endif
#if defined(arch_cmpxchg_acquire)
-#define cmpxchg_acquire(ptr, ...) \
-({ \
- typeof(ptr) __ai_ptr = (ptr); \
- instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
- arch_cmpxchg_acquire(__ai_ptr, __VA_ARGS__); \
+#define cmpxchg_acquire(ptr, ...) \
+({ \
+ typeof(ptr) __ai_ptr = (ptr); \
+ instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+ arch_cmpxchg_acquire(__ai_ptr, __VA_ARGS__); \
})
#endif
#if defined(arch_cmpxchg_release)
-#define cmpxchg_release(ptr, ...) \
-({ \
- typeof(ptr) __ai_ptr = (ptr); \
- instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
- arch_cmpxchg_release(__ai_ptr, __VA_ARGS__); \
+#define cmpxchg_release(ptr, ...) \
+({ \
+ typeof(ptr) __ai_ptr = (ptr); \
+ instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+ arch_cmpxchg_release(__ai_ptr, __VA_ARGS__); \
})
#endif
#if defined(arch_cmpxchg_relaxed)
-#define cmpxchg_relaxed(ptr, ...) \
-({ \
- typeof(ptr) __ai_ptr = (ptr); \
- instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
- arch_cmpxchg_relaxed(__ai_ptr, __VA_ARGS__); \
+#define cmpxchg_relaxed(ptr, ...) \
+({ \
+ typeof(ptr) __ai_ptr = (ptr); \
+ instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+ arch_cmpxchg_relaxed(__ai_ptr, __VA_ARGS__); \
})
#endif
#if !defined(arch_cmpxchg64_relaxed) || defined(arch_cmpxchg64)
-#define cmpxchg64(ptr, ...) \
-({ \
- typeof(ptr) __ai_ptr = (ptr); \
- instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
- arch_cmpxchg64(__ai_ptr, __VA_ARGS__); \
+#define cmpxchg64(ptr, ...) \
+({ \
+ typeof(ptr) __ai_ptr = (ptr); \
+ instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+ arch_cmpxchg64(__ai_ptr, __VA_ARGS__); \
})
#endif
#if defined(arch_cmpxchg64_acquire)
-#define cmpxchg64_acquire(ptr, ...) \
-({ \
- typeof(ptr) __ai_ptr = (ptr); \
- instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
- arch_cmpxchg64_acquire(__ai_ptr, __VA_ARGS__); \
+#define cmpxchg64_acquire(ptr, ...) \
+({ \
+ typeof(ptr) __ai_ptr = (ptr); \
+ instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+ arch_cmpxchg64_acquire(__ai_ptr, __VA_ARGS__); \
})
#endif
#if defined(arch_cmpxchg64_release)
-#define cmpxchg64_release(ptr, ...) \
-({ \
- typeof(ptr) __ai_ptr = (ptr); \
- instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
- arch_cmpxchg64_release(__ai_ptr, __VA_ARGS__); \
+#define cmpxchg64_release(ptr, ...) \
+({ \
+ typeof(ptr) __ai_ptr = (ptr); \
+ instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+ arch_cmpxchg64_release(__ai_ptr, __VA_ARGS__); \
})
#endif
#if defined(arch_cmpxchg64_relaxed)
-#define cmpxchg64_relaxed(ptr, ...) \
-({ \
- typeof(ptr) __ai_ptr = (ptr); \
- instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
- arch_cmpxchg64_relaxed(__ai_ptr, __VA_ARGS__); \
+#define cmpxchg64_relaxed(ptr, ...) \
+({ \
+ typeof(ptr) __ai_ptr = (ptr); \
+ instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+ arch_cmpxchg64_relaxed(__ai_ptr, __VA_ARGS__); \
})
#endif
-#define cmpxchg_local(ptr, ...) \
-({ \
- typeof(ptr) __ai_ptr = (ptr); \
- instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
- arch_cmpxchg_local(__ai_ptr, __VA_ARGS__); \
+#if !defined(arch_try_cmpxchg_relaxed) || defined(arch_try_cmpxchg)
+#define try_cmpxchg(ptr, oldp, ...) \
+({ \
+ typeof(ptr) __ai_ptr = (ptr); \
+ typeof(oldp) __ai_oldp = (oldp); \
+ instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+ instrument_atomic_write(__ai_oldp, sizeof(*__ai_oldp)); \
+ arch_try_cmpxchg(__ai_ptr, __ai_oldp, __VA_ARGS__); \
+})
+#endif
+
+#if defined(arch_try_cmpxchg_acquire)
+#define try_cmpxchg_acquire(ptr, oldp, ...) \
+({ \
+ typeof(ptr) __ai_ptr = (ptr); \
+ typeof(oldp) __ai_oldp = (oldp); \
+ instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+ instrument_atomic_write(__ai_oldp, sizeof(*__ai_oldp)); \
+ arch_try_cmpxchg_acquire(__ai_ptr, __ai_oldp, __VA_ARGS__); \
+})
+#endif
+
+#if defined(arch_try_cmpxchg_release)
+#define try_cmpxchg_release(ptr, oldp, ...) \
+({ \
+ typeof(ptr) __ai_ptr = (ptr); \
+ typeof(oldp) __ai_oldp = (oldp); \
+ instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+ instrument_atomic_write(__ai_oldp, sizeof(*__ai_oldp)); \
+ arch_try_cmpxchg_release(__ai_ptr, __ai_oldp, __VA_ARGS__); \
+})
+#endif
+
+#if defined(arch_try_cmpxchg_relaxed)
+#define try_cmpxchg_relaxed(ptr, oldp, ...) \
+({ \
+ typeof(ptr) __ai_ptr = (ptr); \
+ typeof(oldp) __ai_oldp = (oldp); \
+ instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+ instrument_atomic_write(__ai_oldp, sizeof(*__ai_oldp)); \
+ arch_try_cmpxchg_relaxed(__ai_ptr, __ai_oldp, __VA_ARGS__); \
+})
+#endif
+
+#define cmpxchg_local(ptr, ...) \
+({ \
+ typeof(ptr) __ai_ptr = (ptr); \
+ instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+ arch_cmpxchg_local(__ai_ptr, __VA_ARGS__); \
})
-#define cmpxchg64_local(ptr, ...) \
-({ \
- typeof(ptr) __ai_ptr = (ptr); \
- instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
- arch_cmpxchg64_local(__ai_ptr, __VA_ARGS__); \
+#define cmpxchg64_local(ptr, ...) \
+({ \
+ typeof(ptr) __ai_ptr = (ptr); \
+ instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+ arch_cmpxchg64_local(__ai_ptr, __VA_ARGS__); \
})
-#define sync_cmpxchg(ptr, ...) \
-({ \
- typeof(ptr) __ai_ptr = (ptr); \
- instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
- arch_sync_cmpxchg(__ai_ptr, __VA_ARGS__); \
+#define sync_cmpxchg(ptr, ...) \
+({ \
+ typeof(ptr) __ai_ptr = (ptr); \
+ instrument_atomic_write(__ai_ptr, sizeof(*__ai_ptr)); \
+ arch_sync_cmpxchg(__ai_ptr, __VA_ARGS__); \
})
-#define cmpxchg_double(ptr, ...) \
-({ \
- typeof(ptr) __ai_ptr = (ptr); \
- instrument_atomic_write(__ai_ptr, 2 * sizeof(*__ai_ptr)); \
- arch_cmpxchg_double(__ai_ptr, __VA_ARGS__); \
+#define cmpxchg_double(ptr, ...) \
+({ \
+ typeof(ptr) __ai_ptr = (ptr); \
+ instrument_atomic_write(__ai_ptr, 2 * sizeof(*__ai_ptr)); \
+ arch_cmpxchg_double(__ai_ptr, __VA_ARGS__); \
})
-#define cmpxchg_double_local(ptr, ...) \
-({ \
- typeof(ptr) __ai_ptr = (ptr); \
- instrument_atomic_write(__ai_ptr, 2 * sizeof(*__ai_ptr)); \
- arch_cmpxchg_double_local(__ai_ptr, __VA_ARGS__); \
+#define cmpxchg_double_local(ptr, ...) \
+({ \
+ typeof(ptr) __ai_ptr = (ptr); \
+ instrument_atomic_write(__ai_ptr, 2 * sizeof(*__ai_ptr)); \
+ arch_cmpxchg_double_local(__ai_ptr, __VA_ARGS__); \
})
#endif /* _ASM_GENERIC_ATOMIC_INSTRUMENTED_H */
-// 9d5e6a315fb1335d02f0ccd3655a91c3dafcc63e
+// 4bec382e44520f4d8267e42620054db26a659ea3
diff --git a/include/linux/atomic-arch-fallback.h b/include/linux/atomic-arch-fallback.h
index bcb6aa27cfa6..a3dba31df01e 100644
--- a/include/linux/atomic-arch-fallback.h
+++ b/include/linux/atomic-arch-fallback.h
@@ -9,9 +9,9 @@
#include <linux/compiler.h>
#ifndef arch_xchg_relaxed
-#define arch_xchg_relaxed arch_xchg
-#define arch_xchg_acquire arch_xchg
-#define arch_xchg_release arch_xchg
+#define arch_xchg_acquire arch_xchg
+#define arch_xchg_release arch_xchg
+#define arch_xchg_relaxed arch_xchg
#else /* arch_xchg_relaxed */
#ifndef arch_xchg_acquire
@@ -32,9 +32,9 @@
#endif /* arch_xchg_relaxed */
#ifndef arch_cmpxchg_relaxed
-#define arch_cmpxchg_relaxed arch_cmpxchg
-#define arch_cmpxchg_acquire arch_cmpxchg
-#define arch_cmpxchg_release arch_cmpxchg
+#define arch_cmpxchg_acquire arch_cmpxchg
+#define arch_cmpxchg_release arch_cmpxchg
+#define arch_cmpxchg_relaxed arch_cmpxchg
#else /* arch_cmpxchg_relaxed */
#ifndef arch_cmpxchg_acquire
@@ -55,9 +55,9 @@
#endif /* arch_cmpxchg_relaxed */
#ifndef arch_cmpxchg64_relaxed
-#define arch_cmpxchg64_relaxed arch_cmpxchg64
-#define arch_cmpxchg64_acquire arch_cmpxchg64
-#define arch_cmpxchg64_release arch_cmpxchg64
+#define arch_cmpxchg64_acquire arch_cmpxchg64
+#define arch_cmpxchg64_release arch_cmpxchg64
+#define arch_cmpxchg64_relaxed arch_cmpxchg64
#else /* arch_cmpxchg64_relaxed */
#ifndef arch_cmpxchg64_acquire
@@ -77,6 +77,76 @@
#endif /* arch_cmpxchg64_relaxed */
+#ifndef arch_try_cmpxchg_relaxed
+#ifdef arch_try_cmpxchg
+#define arch_try_cmpxchg_acquire arch_try_cmpxchg
+#define arch_try_cmpxchg_release arch_try_cmpxchg
+#define arch_try_cmpxchg_relaxed arch_try_cmpxchg
+#endif /* arch_try_cmpxchg */
+
+#ifndef arch_try_cmpxchg
+#define arch_try_cmpxchg(_ptr, _oldp, _new) \
+({ \
+ typeof(*(_ptr)) *___op = (_oldp), ___o = *___op, ___r; \
+ ___r = arch_cmpxchg((_ptr), ___o, (_new)); \
+ if (unlikely(___r != ___o)) \
+ *___op = ___r; \
+ likely(___r == ___o); \
+})
+#endif /* arch_try_cmpxchg */
+
+#ifndef arch_try_cmpxchg_acquire
+#define arch_try_cmpxchg_acquire(_ptr, _oldp, _new) \
+({ \
+ typeof(*(_ptr)) *___op = (_oldp), ___o = *___op, ___r; \
+ ___r = arch_cmpxchg_acquire((_ptr), ___o, (_new)); \
+ if (unlikely(___r != ___o)) \
+ *___op = ___r; \
+ likely(___r == ___o); \
+})
+#endif /* arch_try_cmpxchg_acquire */
+
+#ifndef arch_try_cmpxchg_release
+#define arch_try_cmpxchg_release(_ptr, _oldp, _new) \
+({ \
+ typeof(*(_ptr)) *___op = (_oldp), ___o = *___op, ___r; \
+ ___r = arch_cmpxchg_release((_ptr), ___o, (_new)); \
+ if (unlikely(___r != ___o)) \
+ *___op = ___r; \
+ likely(___r == ___o); \
+})
+#endif /* arch_try_cmpxchg_release */
+
+#ifndef arch_try_cmpxchg_relaxed
+#define arch_try_cmpxchg_relaxed(_ptr, _oldp, _new) \
+({ \
+ typeof(*(_ptr)) *___op = (_oldp), ___o = *___op, ___r; \
+ ___r = arch_cmpxchg_relaxed((_ptr), ___o, (_new)); \
+ if (unlikely(___r != ___o)) \
+ *___op = ___r; \
+ likely(___r == ___o); \
+})
+#endif /* arch_try_cmpxchg_relaxed */
+
+#else /* arch_try_cmpxchg_relaxed */
+
+#ifndef arch_try_cmpxchg_acquire
+#define arch_try_cmpxchg_acquire(...) \
+ __atomic_op_acquire(arch_try_cmpxchg, __VA_ARGS__)
+#endif
+
+#ifndef arch_try_cmpxchg_release
+#define arch_try_cmpxchg_release(...) \
+ __atomic_op_release(arch_try_cmpxchg, __VA_ARGS__)
+#endif
+
+#ifndef arch_try_cmpxchg
+#define arch_try_cmpxchg(...) \
+ __atomic_op_fence(arch_try_cmpxchg, __VA_ARGS__)
+#endif
+
+#endif /* arch_try_cmpxchg_relaxed */
+
#ifndef arch_atomic_read_acquire
static __always_inline int
arch_atomic_read_acquire(const atomic_t *v)
@@ -2288,4 +2358,4 @@ arch_atomic64_dec_if_positive(atomic64_t *v)
#endif
#endif /* _LINUX_ATOMIC_FALLBACK_H */
-// 90cd26cfd69d2250303d654955a0cc12620fb91b
+// cca554917d7ea73d5e3e7397dd70c484cad9b2c4
diff --git a/include/linux/atomic-fallback.h b/include/linux/atomic-fallback.h
index fd525c71d676..2a3f55d98be9 100644
--- a/include/linux/atomic-fallback.h
+++ b/include/linux/atomic-fallback.h
@@ -9,9 +9,9 @@
#include <linux/compiler.h>
#ifndef xchg_relaxed
-#define xchg_relaxed xchg
-#define xchg_acquire xchg
-#define xchg_release xchg
+#define xchg_acquire xchg
+#define xchg_release xchg
+#define xchg_relaxed xchg
#else /* xchg_relaxed */
#ifndef xchg_acquire
@@ -32,9 +32,9 @@
#endif /* xchg_relaxed */
#ifndef cmpxchg_relaxed
-#define cmpxchg_relaxed cmpxchg
-#define cmpxchg_acquire cmpxchg
-#define cmpxchg_release cmpxchg
+#define cmpxchg_acquire cmpxchg
+#define cmpxchg_release cmpxchg
+#define cmpxchg_relaxed cmpxchg
#else /* cmpxchg_relaxed */
#ifndef cmpxchg_acquire
@@ -55,9 +55,9 @@
#endif /* cmpxchg_relaxed */
#ifndef cmpxchg64_relaxed
-#define cmpxchg64_relaxed cmpxchg64
-#define cmpxchg64_acquire cmpxchg64
-#define cmpxchg64_release cmpxchg64
+#define cmpxchg64_acquire cmpxchg64
+#define cmpxchg64_release cmpxchg64
+#define cmpxchg64_relaxed cmpxchg64
#else /* cmpxchg64_relaxed */
#ifndef cmpxchg64_acquire
@@ -77,6 +77,76 @@
#endif /* cmpxchg64_relaxed */
+#ifndef try_cmpxchg_relaxed
+#ifdef try_cmpxchg
+#define try_cmpxchg_acquire try_cmpxchg
+#define try_cmpxchg_release try_cmpxchg
+#define try_cmpxchg_relaxed try_cmpxchg
+#endif /* try_cmpxchg */
+
+#ifndef try_cmpxchg
+#define try_cmpxchg(_ptr, _oldp, _new) \
+({ \
+ typeof(*(_ptr)) *___op = (_oldp), ___o = *___op, ___r; \
+ ___r = cmpxchg((_ptr), ___o, (_new)); \
+ if (unlikely(___r != ___o)) \
+ *___op = ___r; \
+ likely(___r == ___o); \
+})
+#endif /* try_cmpxchg */
+
+#ifndef try_cmpxchg_acquire
+#define try_cmpxchg_acquire(_ptr, _oldp, _new) \
+({ \
+ typeof(*(_ptr)) *___op = (_oldp), ___o = *___op, ___r; \
+ ___r = cmpxchg_acquire((_ptr), ___o, (_new)); \
+ if (unlikely(___r != ___o)) \
+ *___op = ___r; \
+ likely(___r == ___o); \
+})
+#endif /* try_cmpxchg_acquire */
+
+#ifndef try_cmpxchg_release
+#define try_cmpxchg_release(_ptr, _oldp, _new) \
+({ \
+ typeof(*(_ptr)) *___op = (_oldp), ___o = *___op, ___r; \
+ ___r = cmpxchg_release((_ptr), ___o, (_new)); \
+ if (unlikely(___r != ___o)) \
+ *___op = ___r; \
+ likely(___r == ___o); \
+})
+#endif /* try_cmpxchg_release */
+
+#ifndef try_cmpxchg_relaxed
+#define try_cmpxchg_relaxed(_ptr, _oldp, _new) \
+({ \
+ typeof(*(_ptr)) *___op = (_oldp), ___o = *___op, ___r; \
+ ___r = cmpxchg_relaxed((_ptr), ___o, (_new)); \
+ if (unlikely(___r != ___o)) \
+ *___op = ___r; \
+ likely(___r == ___o); \
+})
+#endif /* try_cmpxchg_relaxed */
+
+#else /* try_cmpxchg_relaxed */
+
+#ifndef try_cmpxchg_acquire
+#define try_cmpxchg_acquire(...) \
+ __atomic_op_acquire(try_cmpxchg, __VA_ARGS__)
+#endif
+
+#ifndef try_cmpxchg_release
+#define try_cmpxchg_release(...) \
+ __atomic_op_release(try_cmpxchg, __VA_ARGS__)
+#endif
+
+#ifndef try_cmpxchg
+#define try_cmpxchg(...) \
+ __atomic_op_fence(try_cmpxchg, __VA_ARGS__)
+#endif
+
+#endif /* try_cmpxchg_relaxed */
+
#define arch_atomic_read atomic_read
#define arch_atomic_read_acquire atomic_read_acquire
@@ -2522,4 +2592,4 @@ atomic64_dec_if_positive(atomic64_t *v)
#endif
#endif /* _LINUX_ATOMIC_FALLBACK_H */
-// 9d95b56f98d82a2a26c7b79ccdd0c47572d50a6f
+// d78e6c293c661c15188f0ec05bce45188c8d5892
diff --git a/include/linux/freelist.h b/include/linux/freelist.h
new file mode 100644
index 000000000000..fc1842b96469
--- /dev/null
+++ b/include/linux/freelist.h
@@ -0,0 +1,129 @@
+/* SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause */
+#ifndef FREELIST_H
+#define FREELIST_H
+
+#include <linux/atomic.h>
+
+/*
+ * Copyright: cameron@...dycamel.com
+ *
+ * A simple CAS-based lock-free free list. Not the fastest thing in the world
+ * under heavy contention, but simple and correct (assuming nodes are never
+ * freed until after the free list is destroyed), and fairly speedy under low
+ * contention.
+ *
+ * Adapted from: https://moodycamel.com/blog/2014/solving-the-aba-problem-for-lock-free-free-lists
+ */
+
+struct freelist_node {
+ atomic_t refs;
+ struct freelist_node *next;
+};
+
+struct freelist_head {
+ struct freelist_node *head;
+};
+
+#define REFS_ON_FREELIST 0x80000000
+#define REFS_MASK 0x7FFFFFFF
+
+static inline void __freelist_add(struct freelist_node *node, struct freelist_head *list)
+{
+ /*
+ * Since the refcount is zero, and nobody can increase it once it's
+ * zero (except us, and we run only one copy of this method per node at
+ * a time, i.e. the single thread case), then we know we can safely
+ * change the next pointer of the node; however, once the refcount is
+ * back above zero, then other threads could increase it (happens under
+ * heavy contention, when the refcount goes to zero in between a load
+ * and a refcount increment of a node in try_get, then back up to
+ * something non-zero, then the refcount increment is done by the other
+ * thread) -- so if the CAS to add the node to the actual list fails,
+ * decrese the refcount and leave the add operation to the next thread
+ * who puts the refcount back to zero (which could be us, hence the
+ * loop).
+ */
+ struct freelist_node *head = READ_ONCE(list->head);
+
+ for (;;) {
+ WRITE_ONCE(node->next, head);
+ atomic_set_release(&node->refs, 1);
+
+ if (!try_cmpxchg_release(&list->head, &head, node)) {
+ /*
+ * Hmm, the add failed, but we can only try again when
+ * the refcount goes back to zero.
+ */
+ if (atomic_fetch_add_release(REFS_ON_FREELIST - 1, &node->refs) == 1)
+ continue;
+ }
+ return;
+ }
+}
+
+static inline void freelist_add(struct freelist_node *node, struct freelist_head *list)
+{
+ /*
+ * We know that the should-be-on-freelist bit is 0 at this point, so
+ * it's safe to set it using a fetch_add.
+ */
+ if (!atomic_fetch_add_release(REFS_ON_FREELIST, &node->refs)) {
+ /*
+ * Oh look! We were the last ones referencing this node, and we
+ * know we want to add it to the free list, so let's do it!
+ */
+ __freelist_add(node, list);
+ }
+}
+
+static inline struct freelist_node *freelist_try_get(struct freelist_head *list)
+{
+ struct freelist_node *prev, *next, *head = smp_load_acquire(&list->head);
+ unsigned int refs;
+
+ while (head) {
+ prev = head;
+ refs = atomic_read(&head->refs);
+ if ((refs & REFS_MASK) == 0 ||
+ !atomic_try_cmpxchg_acquire(&head->refs, &refs, refs+1)) {
+ head = smp_load_acquire(&list->head);
+ continue;
+ }
+
+ /*
+ * Good, reference count has been incremented (it wasn't at
+ * zero), which means we can read the next and not worry about
+ * it changing between now and the time we do the CAS.
+ */
+ next = READ_ONCE(head->next);
+ if (try_cmpxchg_acquire(&list->head, &head, next)) {
+ /*
+ * Yay, got the node. This means it was on the list,
+ * which means should-be-on-freelist must be false no
+ * matter the refcount (because nobody else knows it's
+ * been taken off yet, it can't have been put back on).
+ */
+ WARN_ON_ONCE(atomic_read(&head->refs) & REFS_ON_FREELIST);
+
+ /*
+ * Decrease refcount twice, once for our ref, and once
+ * for the list's ref.
+ */
+ atomic_fetch_add(-2, &head->refs);
+
+ return head;
+ }
+
+ /*
+ * OK, the head must have changed on us, but we still need to decrement
+ * the refcount we increased.
+ */
+ refs = atomic_fetch_add(-1, &prev->refs);
+ if (refs == REFS_ON_FREELIST + 1)
+ __freelist_add(prev, list);
+ }
+
+ return NULL;
+}
+
+#endif /* FREELIST_H */
diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h
index 629abaf25681..a79404433812 100644
--- a/include/linux/kprobes.h
+++ b/include/linux/kprobes.h
@@ -27,6 +27,8 @@
#include <linux/rcupdate.h>
#include <linux/mutex.h>
#include <linux/ftrace.h>
+#include <linux/refcount.h>
+#include <linux/freelist.h>
#include <asm/kprobes.h>
#ifdef CONFIG_KPROBES
@@ -144,6 +146,11 @@ static inline int kprobe_ftrace(struct kprobe *p)
* ignored, due to maxactive being too low.
*
*/
+struct kretprobe_holder {
+ struct kretprobe *rp;
+ refcount_t ref;
+};
+
struct kretprobe {
struct kprobe kp;
kretprobe_handler_t handler;
@@ -151,18 +158,18 @@ struct kretprobe {
int maxactive;
int nmissed;
size_t data_size;
- struct hlist_head free_instances;
- raw_spinlock_t lock;
+ struct freelist_head freelist;
+ struct kretprobe_holder *rph;
};
struct kretprobe_instance {
union {
- struct hlist_node hlist;
+ struct freelist_node freelist;
struct rcu_head rcu;
};
- struct kretprobe *rp;
+ struct llist_node llist;
+ struct kretprobe_holder *rph;
kprobe_opcode_t *ret_addr;
- struct task_struct *task;
void *fp;
char data[];
};
@@ -221,6 +228,14 @@ unsigned long kretprobe_trampoline_handler(struct pt_regs *regs,
return ret;
}
+static nokprobe_inline struct kretprobe *get_kretprobe(struct kretprobe_instance *ri)
+{
+ RCU_LOCKDEP_WARN(!rcu_read_lock_any_held(),
+ "Kretprobe is accessed from instance under preemptive context");
+
+ return READ_ONCE(ri->rph->rp);
+}
+
#else /* CONFIG_KRETPROBES */
static inline void arch_prepare_kretprobe(struct kretprobe *rp,
struct pt_regs *regs)
diff --git a/include/linux/llist.h b/include/linux/llist.h
index 2e9c7215882b..24f207b0190b 100644
--- a/include/linux/llist.h
+++ b/include/linux/llist.h
@@ -197,6 +197,16 @@ static inline struct llist_node *llist_next(struct llist_node *node)
extern bool llist_add_batch(struct llist_node *new_first,
struct llist_node *new_last,
struct llist_head *head);
+
+static inline bool __llist_add_batch(struct llist_node *new_first,
+ struct llist_node *new_last,
+ struct llist_head *head)
+{
+ new_last->next = head->first;
+ head->first = new_first;
+ return new_last->next == NULL;
+}
+
/**
* llist_add - add a new entry
* @new: new entry to be added
@@ -209,6 +219,11 @@ static inline bool llist_add(struct llist_node *new, struct llist_head *head)
return llist_add_batch(new, new, head);
}
+static inline bool __llist_add(struct llist_node *new, struct llist_head *head)
+{
+ return __llist_add_batch(new, new, head);
+}
+
/**
* llist_del_all - delete all entries from lock-less list
* @head: the head of lock-less list to delete all entries
@@ -222,6 +237,14 @@ static inline struct llist_node *llist_del_all(struct llist_head *head)
return xchg(&head->first, NULL);
}
+static inline struct llist_node *__llist_del_all(struct llist_head *head)
+{
+ struct llist_node *first = head->first;
+
+ head->first = NULL;
+ return first;
+}
+
extern struct llist_node *llist_del_first(struct llist_head *head);
struct llist_node *llist_reverse_order(struct llist_node *head);
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 063cd120b459..393db0690101 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1326,6 +1326,10 @@ struct task_struct {
struct callback_head mce_kill_me;
#endif
+#ifdef CONFIG_KRETPROBES
+ struct llist_head kretprobe_instances;
+#endif
+
/*
* New fields for task_struct should be added above here, so that
* they are included in the randomized portion of task_struct.
diff --git a/kernel/fork.c b/kernel/fork.c
index 32083db7a2a2..b9c289d0f4ef 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -2187,6 +2187,10 @@ static __latent_entropy struct task_struct *copy_process(
INIT_LIST_HEAD(&p->thread_group);
p->task_works = NULL;
+#ifdef CONFIG_KRETPROBES
+ p->kretprobe_instances.first = NULL;
+#endif
+
/*
* Ensure that the cgroup subsystem policies allow the new process to be
* forked. It should be noted that the new process's css_set can be changed
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 41fdbb7953c6..f7fb5d135930 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -36,7 +36,6 @@
#include <linux/cpu.h>
#include <linux/jump_label.h>
#include <linux/perf_event.h>
-#include <linux/static_call.h>
#include <asm/sections.h>
#include <asm/cacheflush.h>
@@ -54,7 +53,6 @@ static int kprobes_initialized;
* - RCU hlist traversal under disabling preempt (breakpoint handlers)
*/
static struct hlist_head kprobe_table[KPROBE_TABLE_SIZE];
-static struct hlist_head kretprobe_inst_table[KPROBE_TABLE_SIZE];
/* NOTE: change this value only with kprobe_mutex held */
static bool kprobes_all_disarmed;
@@ -62,9 +60,6 @@ static bool kprobes_all_disarmed;
/* This protects kprobe_table and optimizing_list */
static DEFINE_MUTEX(kprobe_mutex);
static DEFINE_PER_CPU(struct kprobe *, kprobe_instance) = NULL;
-static struct {
- raw_spinlock_t lock ____cacheline_aligned_in_smp;
-} kretprobe_table_locks[KPROBE_TABLE_SIZE];
kprobe_opcode_t * __weak kprobe_lookup_name(const char *name,
unsigned int __unused)
@@ -72,11 +67,6 @@ kprobe_opcode_t * __weak kprobe_lookup_name(const char *name,
return ((kprobe_opcode_t *)(kallsyms_lookup_name(name)));
}
-static raw_spinlock_t *kretprobe_table_lock_ptr(unsigned long hash)
-{
- return &(kretprobe_table_locks[hash].lock);
-}
-
/* Blacklist -- list of struct kprobe_blacklist_entry */
static LIST_HEAD(kprobe_blacklist);
@@ -1224,76 +1214,26 @@ void kprobes_inc_nmissed_count(struct kprobe *p)
}
NOKPROBE_SYMBOL(kprobes_inc_nmissed_count);
-static void recycle_rp_inst(struct kretprobe_instance *ri)
+static void free_rp_inst_rcu(struct rcu_head *head)
{
- struct kretprobe *rp = ri->rp;
+ struct kretprobe_instance *ri = container_of(head, struct kretprobe_instance, rcu);
- /* remove rp inst off the rprobe_inst_table */
- hlist_del(&ri->hlist);
- INIT_HLIST_NODE(&ri->hlist);
- if (likely(rp)) {
- raw_spin_lock(&rp->lock);
- hlist_add_head(&ri->hlist, &rp->free_instances);
- raw_spin_unlock(&rp->lock);
- } else
- kfree_rcu(ri, rcu);
+ if (refcount_dec_and_test(&ri->rph->ref))
+ kfree(ri->rph);
+ kfree(ri);
}
-NOKPROBE_SYMBOL(recycle_rp_inst);
-
-static void kretprobe_hash_lock(struct task_struct *tsk,
- struct hlist_head **head, unsigned long *flags)
-__acquires(hlist_lock)
-{
- unsigned long hash = hash_ptr(tsk, KPROBE_HASH_BITS);
- raw_spinlock_t *hlist_lock;
+NOKPROBE_SYMBOL(free_rp_inst_rcu);
- *head = &kretprobe_inst_table[hash];
- hlist_lock = kretprobe_table_lock_ptr(hash);
- /*
- * Nested is a workaround that will soon not be needed.
- * There's other protections that make sure the same lock
- * is not taken on the same CPU that lockdep is unaware of.
- * Differentiate when it is taken in NMI context.
- */
- raw_spin_lock_irqsave_nested(hlist_lock, *flags, !!in_nmi());
-}
-NOKPROBE_SYMBOL(kretprobe_hash_lock);
-
-static void kretprobe_table_lock(unsigned long hash,
- unsigned long *flags)
-__acquires(hlist_lock)
-{
- raw_spinlock_t *hlist_lock = kretprobe_table_lock_ptr(hash);
- /*
- * Nested is a workaround that will soon not be needed.
- * There's other protections that make sure the same lock
- * is not taken on the same CPU that lockdep is unaware of.
- * Differentiate when it is taken in NMI context.
- */
- raw_spin_lock_irqsave_nested(hlist_lock, *flags, !!in_nmi());
-}
-NOKPROBE_SYMBOL(kretprobe_table_lock);
-
-static void kretprobe_hash_unlock(struct task_struct *tsk,
- unsigned long *flags)
-__releases(hlist_lock)
+static void recycle_rp_inst(struct kretprobe_instance *ri)
{
- unsigned long hash = hash_ptr(tsk, KPROBE_HASH_BITS);
- raw_spinlock_t *hlist_lock;
-
- hlist_lock = kretprobe_table_lock_ptr(hash);
- raw_spin_unlock_irqrestore(hlist_lock, *flags);
-}
-NOKPROBE_SYMBOL(kretprobe_hash_unlock);
+ struct kretprobe *rp = get_kretprobe(ri);
-static void kretprobe_table_unlock(unsigned long hash,
- unsigned long *flags)
-__releases(hlist_lock)
-{
- raw_spinlock_t *hlist_lock = kretprobe_table_lock_ptr(hash);
- raw_spin_unlock_irqrestore(hlist_lock, *flags);
+ if (likely(rp)) {
+ freelist_add(&ri->freelist, &rp->freelist);
+ } else
+ call_rcu(&ri->rcu, free_rp_inst_rcu);
}
-NOKPROBE_SYMBOL(kretprobe_table_unlock);
+NOKPROBE_SYMBOL(recycle_rp_inst);
static struct kprobe kprobe_busy = {
.addr = (void *) get_kprobe,
@@ -1324,24 +1264,21 @@ void kprobe_busy_end(void)
void kprobe_flush_task(struct task_struct *tk)
{
struct kretprobe_instance *ri;
- struct hlist_head *head;
- struct hlist_node *tmp;
- unsigned long hash, flags = 0;
+ struct llist_node *node;
+ /* Early boot, not yet initialized. */
if (unlikely(!kprobes_initialized))
- /* Early boot. kretprobe_table_locks not yet initialized. */
return;
kprobe_busy_begin();
- hash = hash_ptr(tk, KPROBE_HASH_BITS);
- head = &kretprobe_inst_table[hash];
- kretprobe_table_lock(hash, &flags);
- hlist_for_each_entry_safe(ri, tmp, head, hlist) {
- if (ri->task == tk)
- recycle_rp_inst(ri);
+ node = __llist_del_all(&tk->kretprobe_instances);
+ while (node) {
+ ri = container_of(node, struct kretprobe_instance, llist);
+ node = node->next;
+
+ recycle_rp_inst(ri);
}
- kretprobe_table_unlock(hash, &flags);
kprobe_busy_end();
}
@@ -1350,37 +1287,23 @@ NOKPROBE_SYMBOL(kprobe_flush_task);
static inline void free_rp_inst(struct kretprobe *rp)
{
struct kretprobe_instance *ri;
- struct hlist_node *next;
+ struct freelist_node *node;
+ int count = 0;
+
+ node = rp->freelist.head;
+ while (node) {
+ ri = container_of(node, struct kretprobe_instance, freelist);
+ node = node->next;
- hlist_for_each_entry_safe(ri, next, &rp->free_instances, hlist) {
- hlist_del(&ri->hlist);
kfree(ri);
+ count++;
}
-}
-
-static void cleanup_rp_inst(struct kretprobe *rp)
-{
- unsigned long flags, hash;
- struct kretprobe_instance *ri;
- struct hlist_node *next;
- struct hlist_head *head;
- /* To avoid recursive kretprobe by NMI, set kprobe busy here */
- kprobe_busy_begin();
- for (hash = 0; hash < KPROBE_TABLE_SIZE; hash++) {
- kretprobe_table_lock(hash, &flags);
- head = &kretprobe_inst_table[hash];
- hlist_for_each_entry_safe(ri, next, head, hlist) {
- if (ri->rp == rp)
- ri->rp = NULL;
- }
- kretprobe_table_unlock(hash, &flags);
+ if (refcount_sub_and_test(count, &rp->rph->ref)) {
+ kfree(rp->rph);
+ rp->rph = NULL;
}
- kprobe_busy_end();
-
- free_rp_inst(rp);
}
-NOKPROBE_SYMBOL(cleanup_rp_inst);
/* Add the new probe to ap->list */
static int add_new_kprobe(struct kprobe *ap, struct kprobe *p)
@@ -1643,7 +1566,6 @@ static int check_kprobe_address_safe(struct kprobe *p,
if (!kernel_text_address((unsigned long) p->addr) ||
within_kprobe_blacklist((unsigned long) p->addr) ||
jump_label_text_reserved(p->addr, p->addr) ||
- static_call_text_reserved(p->addr, p->addr) ||
find_bug((unsigned long)p->addr)) {
ret = -EINVAL;
goto out;
@@ -1942,88 +1864,56 @@ unsigned long __kretprobe_trampoline_handler(struct pt_regs *regs,
void *trampoline_address,
void *frame_pointer)
{
- struct kretprobe_instance *ri = NULL, *last = NULL;
- struct hlist_head *head;
- struct hlist_node *tmp;
- unsigned long flags;
kprobe_opcode_t *correct_ret_addr = NULL;
- bool skipped = false;
+ struct kretprobe_instance *ri = NULL;
+ struct llist_node *first, *node;
+ struct kretprobe *rp;
- kretprobe_hash_lock(current, &head, &flags);
+ /* Find all nodes for this frame. */
+ first = node = current->kretprobe_instances.first;
+ while (node) {
+ ri = container_of(node, struct kretprobe_instance, llist);
- /*
- * It is possible to have multiple instances associated with a given
- * task either because multiple functions in the call path have
- * return probes installed on them, and/or more than one
- * return probe was registered for a target function.
- *
- * We can handle this because:
- * - instances are always pushed into the head of the list
- * - when multiple return probes are registered for the same
- * function, the (chronologically) first instance's ret_addr
- * will be the real return address, and all the rest will
- * point to kretprobe_trampoline.
- */
- hlist_for_each_entry(ri, head, hlist) {
- if (ri->task != current)
- /* another task is sharing our hash bucket */
- continue;
- /*
- * Return probes must be pushed on this hash list correct
- * order (same as return order) so that it can be popped
- * correctly. However, if we find it is pushed it incorrect
- * order, this means we find a function which should not be
- * probed, because the wrong order entry is pushed on the
- * path of processing other kretprobe itself.
- */
- if (ri->fp != frame_pointer) {
- if (!skipped)
- pr_warn("kretprobe is stacked incorrectly. Trying to fixup.\n");
- skipped = true;
- continue;
- }
+ BUG_ON(ri->fp != frame_pointer);
- correct_ret_addr = ri->ret_addr;
- if (skipped)
- pr_warn("%ps must be blacklisted because of incorrect kretprobe order\n",
- ri->rp->kp.addr);
-
- if (correct_ret_addr != trampoline_address)
+ if (ri->ret_addr != trampoline_address) {
+ correct_ret_addr = ri->ret_addr;
/*
* This is the real return address. Any other
* instances associated with this task are for
* other calls deeper on the call stack
*/
- break;
+ goto found;
+ }
+
+ node = node->next;
}
+ pr_err("Oops! Kretprobe fails to find correct return address.\n");
+ BUG_ON(1);
- BUG_ON(!correct_ret_addr || (correct_ret_addr == trampoline_address));
- last = ri;
+found:
+ /* Unlink all nodes for this frame. */
+ current->kretprobe_instances.first = node->next;
+ node->next = NULL;
- hlist_for_each_entry_safe(ri, tmp, head, hlist) {
- if (ri->task != current)
- /* another task is sharing our hash bucket */
- continue;
- if (ri->fp != frame_pointer)
- continue;
+ /* Run them.. */
+ while (first) {
+ ri = container_of(first, struct kretprobe_instance, llist);
+ first = first->next;
- if (ri->rp && ri->rp->handler) {
+ rp = get_kretprobe(ri);
+ if (rp && rp->handler) {
struct kprobe *prev = kprobe_running();
- __this_cpu_write(current_kprobe, &ri->rp->kp);
+ __this_cpu_write(current_kprobe, &rp->kp);
ri->ret_addr = correct_ret_addr;
- ri->rp->handler(ri, regs);
+ rp->handler(ri, regs);
__this_cpu_write(current_kprobe, prev);
}
recycle_rp_inst(ri);
-
- if (ri == last)
- break;
}
- kretprobe_hash_unlock(current, &flags);
-
return (unsigned long)correct_ret_addr;
}
NOKPROBE_SYMBOL(__kretprobe_trampoline_handler)
@@ -2035,44 +1925,26 @@ NOKPROBE_SYMBOL(__kretprobe_trampoline_handler)
static int pre_handler_kretprobe(struct kprobe *p, struct pt_regs *regs)
{
struct kretprobe *rp = container_of(p, struct kretprobe, kp);
- unsigned long hash, flags = 0;
struct kretprobe_instance *ri;
+ struct freelist_node *fn;
- /* TODO: consider to only swap the RA after the last pre_handler fired */
- hash = hash_ptr(current, KPROBE_HASH_BITS);
- /*
- * Nested is a workaround that will soon not be needed.
- * There's other protections that make sure the same lock
- * is not taken on the same CPU that lockdep is unaware of.
- */
- raw_spin_lock_irqsave_nested(&rp->lock, flags, 1);
- if (!hlist_empty(&rp->free_instances)) {
- ri = hlist_entry(rp->free_instances.first,
- struct kretprobe_instance, hlist);
- hlist_del(&ri->hlist);
- raw_spin_unlock_irqrestore(&rp->lock, flags);
-
- ri->rp = rp;
- ri->task = current;
-
- if (rp->entry_handler && rp->entry_handler(ri, regs)) {
- raw_spin_lock_irqsave_nested(&rp->lock, flags, 1);
- hlist_add_head(&ri->hlist, &rp->free_instances);
- raw_spin_unlock_irqrestore(&rp->lock, flags);
- return 0;
- }
+ fn = freelist_try_get(&rp->freelist);
+ if (!fn) {
+ rp->nmissed++;
+ return 0;
+ }
- arch_prepare_kretprobe(ri, regs);
+ ri = container_of(fn, struct kretprobe_instance, freelist);
- /* XXX(hch): why is there no hlist_move_head? */
- INIT_HLIST_NODE(&ri->hlist);
- kretprobe_table_lock(hash, &flags);
- hlist_add_head(&ri->hlist, &kretprobe_inst_table[hash]);
- kretprobe_table_unlock(hash, &flags);
- } else {
- rp->nmissed++;
- raw_spin_unlock_irqrestore(&rp->lock, flags);
+ if (rp->entry_handler && rp->entry_handler(ri, regs)) {
+ freelist_add(&ri->freelist, &rp->freelist);
+ return 0;
}
+
+ arch_prepare_kretprobe(ri, regs);
+
+ __llist_add(&ri->llist, ¤t->kretprobe_instances);
+
return 0;
}
NOKPROBE_SYMBOL(pre_handler_kretprobe);
@@ -2129,18 +2001,24 @@ int register_kretprobe(struct kretprobe *rp)
rp->maxactive = num_possible_cpus();
#endif
}
- raw_spin_lock_init(&rp->lock);
- INIT_HLIST_HEAD(&rp->free_instances);
+ rp->freelist.head = NULL;
+ rp->rph = kzalloc(sizeof(struct kretprobe_holder), GFP_KERNEL);
+ if (!rp->rph)
+ return -ENOMEM;
+
+ rp->rph->rp = rp;
for (i = 0; i < rp->maxactive; i++) {
- inst = kmalloc(sizeof(struct kretprobe_instance) +
+ inst = kzalloc(sizeof(struct kretprobe_instance) +
rp->data_size, GFP_KERNEL);
if (inst == NULL) {
+ refcount_set(&rp->rph->ref, i);
free_rp_inst(rp);
return -ENOMEM;
}
- INIT_HLIST_NODE(&inst->hlist);
- hlist_add_head(&inst->hlist, &rp->free_instances);
+ inst->rph = rp->rph;
+ freelist_add(&inst->freelist, &rp->freelist);
}
+ refcount_set(&rp->rph->ref, i);
rp->nmissed = 0;
/* Establish function entry probe point */
@@ -2182,16 +2060,18 @@ void unregister_kretprobes(struct kretprobe **rps, int num)
if (num <= 0)
return;
mutex_lock(&kprobe_mutex);
- for (i = 0; i < num; i++)
+ for (i = 0; i < num; i++) {
if (__unregister_kprobe_top(&rps[i]->kp) < 0)
rps[i]->kp.addr = NULL;
+ rps[i]->rph->rp = NULL;
+ }
mutex_unlock(&kprobe_mutex);
synchronize_rcu();
for (i = 0; i < num; i++) {
if (rps[i]->kp.addr) {
__unregister_kprobe_bottom(&rps[i]->kp);
- cleanup_rp_inst(rps[i]);
+ free_rp_inst(rps[i]);
}
}
}
@@ -2235,9 +2115,6 @@ static void kill_kprobe(struct kprobe *p)
lockdep_assert_held(&kprobe_mutex);
- if (WARN_ON_ONCE(kprobe_gone(p)))
- return;
-
p->flags |= KPROBE_FLAG_GONE;
if (kprobe_aggrprobe(p)) {
/*
@@ -2518,10 +2395,7 @@ static int kprobes_module_callback(struct notifier_block *nb,
mutex_lock(&kprobe_mutex);
for (i = 0; i < KPROBE_TABLE_SIZE; i++) {
head = &kprobe_table[i];
- hlist_for_each_entry(p, head, hlist) {
- if (kprobe_gone(p))
- continue;
-
+ hlist_for_each_entry(p, head, hlist)
if (within_module_init((unsigned long)p->addr, mod) ||
(checkcore &&
within_module_core((unsigned long)p->addr, mod))) {
@@ -2538,7 +2412,6 @@ static int kprobes_module_callback(struct notifier_block *nb,
*/
kill_kprobe(p);
}
- }
}
if (val == MODULE_STATE_GOING)
remove_module_kprobe_blacklist(mod);
@@ -2583,11 +2456,8 @@ static int __init init_kprobes(void)
/* FIXME allocate the probe table, currently defined statically */
/* initialize all list heads */
- for (i = 0; i < KPROBE_TABLE_SIZE; i++) {
+ for (i = 0; i < KPROBE_TABLE_SIZE; i++)
INIT_HLIST_HEAD(&kprobe_table[i]);
- INIT_HLIST_HEAD(&kretprobe_inst_table[i]);
- raw_spin_lock_init(&(kretprobe_table_locks[i].lock));
- }
err = populate_kprobe_blacklist(__start_kprobe_blacklist,
__stop_kprobe_blacklist);
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index b911e9f6d9f5..97c7a7782db7 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -1731,7 +1731,8 @@ NOKPROBE_SYMBOL(kprobe_dispatcher);
static int
kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs)
{
- struct trace_kprobe *tk = container_of(ri->rp, struct trace_kprobe, rp);
+ struct kretprobe *rp = get_kretprobe(ri);
+ struct trace_kprobe *tk = container_of(rp, struct trace_kprobe, rp);
raw_cpu_inc(*tk->nhit);
diff --git a/scripts/atomic/gen-atomic-fallback.sh b/scripts/atomic/gen-atomic-fallback.sh
index 693dfa1de430..317a6cec76e1 100755
--- a/scripts/atomic/gen-atomic-fallback.sh
+++ b/scripts/atomic/gen-atomic-fallback.sh
@@ -144,15 +144,11 @@ gen_proto_order_variants()
printf "#endif /* ${basename}_relaxed */\n\n"
}
-gen_xchg_fallbacks()
+gen_order_fallbacks()
{
local xchg="$1"; shift
+
cat <<EOF
-#ifndef ${xchg}_relaxed
-#define ${xchg}_relaxed ${xchg}
-#define ${xchg}_acquire ${xchg}
-#define ${xchg}_release ${xchg}
-#else /* ${xchg}_relaxed */
#ifndef ${xchg}_acquire
#define ${xchg}_acquire(...) \\
@@ -169,11 +165,62 @@ cat <<EOF
__atomic_op_fence(${xchg}, __VA_ARGS__)
#endif
-#endif /* ${xchg}_relaxed */
+EOF
+}
+
+gen_xchg_fallbacks()
+{
+ local xchg="$1"; shift
+ printf "#ifndef ${xchg}_relaxed\n"
+
+ gen_basic_fallbacks ${xchg}
+
+ printf "#else /* ${xchg}_relaxed */\n"
+
+ gen_order_fallbacks ${xchg}
+
+ printf "#endif /* ${xchg}_relaxed */\n\n"
+}
+
+gen_try_cmpxchg_fallback()
+{
+ local order="$1"; shift;
+
+cat <<EOF
+#ifndef ${ARCH}try_cmpxchg${order}
+#define ${ARCH}try_cmpxchg${order}(_ptr, _oldp, _new) \\
+({ \\
+ typeof(*(_ptr)) *___op = (_oldp), ___o = *___op, ___r; \\
+ ___r = ${ARCH}cmpxchg${order}((_ptr), ___o, (_new)); \\
+ if (unlikely(___r != ___o)) \\
+ *___op = ___r; \\
+ likely(___r == ___o); \\
+})
+#endif /* ${ARCH}try_cmpxchg${order} */
EOF
}
+gen_try_cmpxchg_fallbacks()
+{
+ printf "#ifndef ${ARCH}try_cmpxchg_relaxed\n"
+ printf "#ifdef ${ARCH}try_cmpxchg\n"
+
+ gen_basic_fallbacks "${ARCH}try_cmpxchg"
+
+ printf "#endif /* ${ARCH}try_cmpxchg */\n\n"
+
+ for order in "" "_acquire" "_release" "_relaxed"; do
+ gen_try_cmpxchg_fallback "${order}"
+ done
+
+ printf "#else /* ${ARCH}try_cmpxchg_relaxed */\n"
+
+ gen_order_fallbacks "${ARCH}try_cmpxchg"
+
+ printf "#endif /* ${ARCH}try_cmpxchg_relaxed */\n\n"
+}
+
cat << EOF
// SPDX-License-Identifier: GPL-2.0
@@ -191,6 +238,8 @@ for xchg in "${ARCH}xchg" "${ARCH}cmpxchg" "${ARCH}cmpxchg64"; do
gen_xchg_fallbacks "${xchg}"
done
+gen_try_cmpxchg_fallbacks
+
grep '^[a-z]' "$1" | while read name meta args; do
gen_proto "${meta}" "${name}" "${ARCH}" "atomic" "int" ${args}
done
diff --git a/scripts/atomic/gen-atomic-instrumented.sh b/scripts/atomic/gen-atomic-instrumented.sh
index 2b7fec7e6abc..5766ffcec7c5 100755
--- a/scripts/atomic/gen-atomic-instrumented.sh
+++ b/scripts/atomic/gen-atomic-instrumented.sh
@@ -112,14 +112,31 @@ gen_xchg()
local xchg="$1"; shift
local mult="$1"; shift
+ if [ "${xchg%${xchg#try_cmpxchg}}" = "try_cmpxchg" ] ; then
+
+cat <<EOF
+#define ${xchg}(ptr, oldp, ...) \\
+({ \\
+ typeof(ptr) __ai_ptr = (ptr); \\
+ typeof(oldp) __ai_oldp = (oldp); \\
+ instrument_atomic_write(__ai_ptr, ${mult}sizeof(*__ai_ptr)); \\
+ instrument_atomic_write(__ai_oldp, ${mult}sizeof(*__ai_oldp)); \\
+ arch_${xchg}(__ai_ptr, __ai_oldp, __VA_ARGS__); \\
+})
+EOF
+
+ else
+
cat <<EOF
-#define ${xchg}(ptr, ...) \\
-({ \\
- typeof(ptr) __ai_ptr = (ptr); \\
- instrument_atomic_write(__ai_ptr, ${mult}sizeof(*__ai_ptr)); \\
- arch_${xchg}(__ai_ptr, __VA_ARGS__); \\
+#define ${xchg}(ptr, ...) \\
+({ \\
+ typeof(ptr) __ai_ptr = (ptr); \\
+ instrument_atomic_write(__ai_ptr, ${mult}sizeof(*__ai_ptr)); \\
+ arch_${xchg}(__ai_ptr, __VA_ARGS__); \\
})
EOF
+
+ fi
}
gen_optional_xchg()
@@ -169,7 +186,7 @@ grep '^[a-z]' "$1" | while read name meta args; do
gen_proto "${meta}" "${name}" "atomic64" "s64" ${args}
done
-for xchg in "xchg" "cmpxchg" "cmpxchg64"; do
+for xchg in "xchg" "cmpxchg" "cmpxchg64" "try_cmpxchg"; do
for order in "" "_acquire" "_release" "_relaxed"; do
gen_optional_xchg "${xchg}" "${order}"
done
diff --git a/scripts/atomic/gen-atomics.sh b/scripts/atomic/gen-atomics.sh
old mode 100644
new mode 100755
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