Merge tag 'locking-urgent-2020-06-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull atomics rework from Thomas Gleixner:
 "Peter Zijlstras rework of atomics and fallbacks. This solves two
  problems:

   1) Compilers uninline small atomic_* static inline functions which
      can expose them to instrumentation.

   2) The instrumentation of atomic primitives was done at the
      architecture level while composites or fallbacks were provided at
      the generic level. As a result there are no uninstrumented
      variants of the fallbacks.

  Both issues were in the way of fully isolating fragile entry code
  pathes and especially the text poke int3 handler which is prone to an
  endless recursion problem when anything in that code path is about to
  be instrumented. This was always a problem, but got elevated due to
  the new batch mode updates of tracing.

  The solution is to mark the functions __always_inline and to flip the
  fallback and instrumentation so the non-instrumented variants are at
  the architecture level and the instrumentation is done in generic
  code.

  The latter introduces another fallback variant which will go away once
  all architectures have been moved over to arch_atomic_*"

* tag 'locking-urgent-2020-06-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/atomics: Flip fallbacks and instrumentation
  asm-generic/atomic: Use __always_inline for fallback wrappers

21 files changed, 84 insertions, 84 deletions

diff --git a/scripts/atomic/fallbacks/acquire b/scripts/atomic/fallbacks/acquire
index e38871e64db6..59c00529dc7c 100755
--- a/scripts/atomic/fallbacks/acquire
+++ b/scripts/atomic/fallbacks/acquire
@@ -1,8 +1,8 @@
 cat <<EOF
-static inline ${ret}
-${atomic}_${pfx}${name}${sfx}_acquire(${params})
+static __always_inline ${ret}
+${arch}${atomic}_${pfx}${name}${sfx}_acquire(${params})
 {
-	${ret} ret = ${atomic}_${pfx}${name}${sfx}_relaxed(${args});
+	${ret} ret = ${arch}${atomic}_${pfx}${name}${sfx}_relaxed(${args});
 	__atomic_acquire_fence();
 	return ret;
 }
diff --git a/scripts/atomic/fallbacks/add_negative b/scripts/atomic/fallbacks/add_negative
index e6f4815637de..a66635bceefb 100755
--- a/scripts/atomic/fallbacks/add_negative
+++ b/scripts/atomic/fallbacks/add_negative
@@ -1,6 +1,6 @@
 cat <<EOF
 /**
- * ${atomic}_add_negative - add and test if negative
+ * ${arch}${atomic}_add_negative - add and test if negative
  * @i: integer value to add
  * @v: pointer of type ${atomic}_t
  *
@@ -8,9 +8,9 @@ cat <<EOF
  * if the result is negative, or false when
  * result is greater than or equal to zero.
  */
-static inline bool
-${atomic}_add_negative(${int} i, ${atomic}_t *v)
+static __always_inline bool
+${arch}${atomic}_add_negative(${int} i, ${atomic}_t *v)
 {
-	return ${atomic}_add_return(i, v) < 0;
+	return ${arch}${atomic}_add_return(i, v) < 0;
 }
 EOF
diff --git a/scripts/atomic/fallbacks/add_unless b/scripts/atomic/fallbacks/add_unless
index 792533885fbf..2ff598a3f9ec 100755
--- a/scripts/atomic/fallbacks/add_unless
+++ b/scripts/atomic/fallbacks/add_unless
@@ -1,6 +1,6 @@
 cat << EOF
 /**
- * ${atomic}_add_unless - add unless the number is already a given value
+ * ${arch}${atomic}_add_unless - add unless the number is already a given value
  * @v: pointer of type ${atomic}_t
  * @a: the amount to add to v...
  * @u: ...unless v is equal to u.
@@ -8,9 +8,9 @@ cat << EOF
  * Atomically adds @a to @v, if @v was not already @u.
  * Returns true if the addition was done.
  */
-static inline bool
-${atomic}_add_unless(${atomic}_t *v, ${int} a, ${int} u)
+static __always_inline bool
+${arch}${atomic}_add_unless(${atomic}_t *v, ${int} a, ${int} u)
 {
-	return ${atomic}_fetch_add_unless(v, a, u) != u;
+	return ${arch}${atomic}_fetch_add_unless(v, a, u) != u;
 }
 EOF
diff --git a/scripts/atomic/fallbacks/andnot b/scripts/atomic/fallbacks/andnot
index 9f3a3216b5e3..3f18663dcefb 100755
--- a/scripts/atomic/fallbacks/andnot
+++ b/scripts/atomic/fallbacks/andnot
@@ -1,7 +1,7 @@
 cat <<EOF
-static inline ${ret}
-${atomic}_${pfx}andnot${sfx}${order}(${int} i, ${atomic}_t *v)
+static __always_inline ${ret}
+${arch}${atomic}_${pfx}andnot${sfx}${order}(${int} i, ${atomic}_t *v)
 {
-	${retstmt}${atomic}_${pfx}and${sfx}${order}(~i, v);
+	${retstmt}${arch}${atomic}_${pfx}and${sfx}${order}(~i, v);
 }
 EOF
diff --git a/scripts/atomic/fallbacks/dec b/scripts/atomic/fallbacks/dec
index 10bbc82be31d..e2e01f0574bb 100755
--- a/scripts/atomic/fallbacks/dec
+++ b/scripts/atomic/fallbacks/dec
@@ -1,7 +1,7 @@
 cat <<EOF
-static inline ${ret}
-${atomic}_${pfx}dec${sfx}${order}(${atomic}_t *v)
+static __always_inline ${ret}
+${arch}${atomic}_${pfx}dec${sfx}${order}(${atomic}_t *v)
 {
-	${retstmt}${atomic}_${pfx}sub${sfx}${order}(1, v);
+	${retstmt}${arch}${atomic}_${pfx}sub${sfx}${order}(1, v);
 }
 EOF
diff --git a/scripts/atomic/fallbacks/dec_and_test b/scripts/atomic/fallbacks/dec_and_test
index 0ce7103b3df2..e8a5e492eb5f 100755
--- a/scripts/atomic/fallbacks/dec_and_test
+++ b/scripts/atomic/fallbacks/dec_and_test
@@ -1,15 +1,15 @@
 cat <<EOF
 /**
- * ${atomic}_dec_and_test - decrement and test
+ * ${arch}${atomic}_dec_and_test - decrement and test
  * @v: pointer of type ${atomic}_t
  *
  * Atomically decrements @v by 1 and
  * returns true if the result is 0, or false for all other
  * cases.
  */
-static inline bool
-${atomic}_dec_and_test(${atomic}_t *v)
+static __always_inline bool
+${arch}${atomic}_dec_and_test(${atomic}_t *v)
 {
-	return ${atomic}_dec_return(v) == 0;
+	return ${arch}${atomic}_dec_return(v) == 0;
 }
 EOF
diff --git a/scripts/atomic/fallbacks/dec_if_positive b/scripts/atomic/fallbacks/dec_if_positive
index c52eacec43c8..527adec89c37 100755
--- a/scripts/atomic/fallbacks/dec_if_positive
+++ b/scripts/atomic/fallbacks/dec_if_positive
@@ -1,14 +1,14 @@
 cat <<EOF
-static inline ${ret}
-${atomic}_dec_if_positive(${atomic}_t *v)
+static __always_inline ${ret}
+${arch}${atomic}_dec_if_positive(${atomic}_t *v)
 {
-	${int} dec, c = ${atomic}_read(v);
+	${int} dec, c = ${arch}${atomic}_read(v);
 
 	do {
 		dec = c - 1;
 		if (unlikely(dec < 0))
 			break;
-	} while (!${atomic}_try_cmpxchg(v, &c, dec));
+	} while (!${arch}${atomic}_try_cmpxchg(v, &c, dec));
 
 	return dec;
 }
diff --git a/scripts/atomic/fallbacks/dec_unless_positive b/scripts/atomic/fallbacks/dec_unless_positive
index 8a2578f14268..dcab6848ca1e 100755
--- a/scripts/atomic/fallbacks/dec_unless_positive
+++ b/scripts/atomic/fallbacks/dec_unless_positive
@@ -1,13 +1,13 @@
 cat <<EOF
-static inline bool
-${atomic}_dec_unless_positive(${atomic}_t *v)
+static __always_inline bool
+${arch}${atomic}_dec_unless_positive(${atomic}_t *v)
 {
-	${int} c = ${atomic}_read(v);
+	${int} c = ${arch}${atomic}_read(v);
 
 	do {
 		if (unlikely(c > 0))
 			return false;
-	} while (!${atomic}_try_cmpxchg(v, &c, c - 1));
+	} while (!${arch}${atomic}_try_cmpxchg(v, &c, c - 1));
 
 	return true;
 }
diff --git a/scripts/atomic/fallbacks/fence b/scripts/atomic/fallbacks/fence
index 82f68fa6931a..3764fc8ce945 100755
--- a/scripts/atomic/fallbacks/fence
+++ b/scripts/atomic/fallbacks/fence
@@ -1,10 +1,10 @@
 cat <<EOF
-static inline ${ret}
-${atomic}_${pfx}${name}${sfx}(${params})
+static __always_inline ${ret}
+${arch}${atomic}_${pfx}${name}${sfx}(${params})
 {
 	${ret} ret;
 	__atomic_pre_full_fence();
-	ret = ${atomic}_${pfx}${name}${sfx}_relaxed(${args});
+	ret = ${arch}${atomic}_${pfx}${name}${sfx}_relaxed(${args});
 	__atomic_post_full_fence();
 	return ret;
 }
diff --git a/scripts/atomic/fallbacks/fetch_add_unless b/scripts/atomic/fallbacks/fetch_add_unless
index d2c091db7eae..0e0b9aef1515 100755
--- a/scripts/atomic/fallbacks/fetch_add_unless
+++ b/scripts/atomic/fallbacks/fetch_add_unless
@@ -1,6 +1,6 @@
 cat << EOF
 /**
- * ${atomic}_fetch_add_unless - add unless the number is already a given value
+ * ${arch}${atomic}_fetch_add_unless - add unless the number is already a given value
  * @v: pointer of type ${atomic}_t
  * @a: the amount to add to v...
  * @u: ...unless v is equal to u.
@@ -8,15 +8,15 @@ cat << EOF
  * Atomically adds @a to @v, so long as @v was not already @u.
  * Returns original value of @v
  */
-static inline ${int}
-${atomic}_fetch_add_unless(${atomic}_t *v, ${int} a, ${int} u)
+static __always_inline ${int}
+${arch}${atomic}_fetch_add_unless(${atomic}_t *v, ${int} a, ${int} u)
 {
-	${int} c = ${atomic}_read(v);
+	${int} c = ${arch}${atomic}_read(v);
 
 	do {
 		if (unlikely(c == u))
 			break;
-	} while (!${atomic}_try_cmpxchg(v, &c, c + a));
+	} while (!${arch}${atomic}_try_cmpxchg(v, &c, c + a));
 
 	return c;
 }
diff --git a/scripts/atomic/fallbacks/inc b/scripts/atomic/fallbacks/inc
index f866b3ad2353..15ec62946e8c 100755
--- a/scripts/atomic/fallbacks/inc
+++ b/scripts/atomic/fallbacks/inc
@@ -1,7 +1,7 @@
 cat <<EOF
-static inline ${ret}
-${atomic}_${pfx}inc${sfx}${order}(${atomic}_t *v)
+static __always_inline ${ret}
+${arch}${atomic}_${pfx}inc${sfx}${order}(${atomic}_t *v)
 {
-	${retstmt}${atomic}_${pfx}add${sfx}${order}(1, v);
+	${retstmt}${arch}${atomic}_${pfx}add${sfx}${order}(1, v);
 }
 EOF
diff --git a/scripts/atomic/fallbacks/inc_and_test b/scripts/atomic/fallbacks/inc_and_test
index 4e2068869f7e..cecc8322a21f 100755
--- a/scripts/atomic/fallbacks/inc_and_test
+++ b/scripts/atomic/fallbacks/inc_and_test
@@ -1,15 +1,15 @@
 cat <<EOF
 /**
- * ${atomic}_inc_and_test - increment and test
+ * ${arch}${atomic}_inc_and_test - increment and test
  * @v: pointer of type ${atomic}_t
  *
  * Atomically increments @v by 1
  * and returns true if the result is zero, or false for all
  * other cases.
  */
-static inline bool
-${atomic}_inc_and_test(${atomic}_t *v)
+static __always_inline bool
+${arch}${atomic}_inc_and_test(${atomic}_t *v)
 {
-	return ${atomic}_inc_return(v) == 0;
+	return ${arch}${atomic}_inc_return(v) == 0;
 }
 EOF
diff --git a/scripts/atomic/fallbacks/inc_not_zero b/scripts/atomic/fallbacks/inc_not_zero
index a7c45c8d107c..50f2d4d48279 100755
--- a/scripts/atomic/fallbacks/inc_not_zero
+++ b/scripts/atomic/fallbacks/inc_not_zero
@@ -1,14 +1,14 @@
 cat <<EOF
 /**
- * ${atomic}_inc_not_zero - increment unless the number is zero
+ * ${arch}${atomic}_inc_not_zero - increment unless the number is zero
  * @v: pointer of type ${atomic}_t
  *
  * Atomically increments @v by 1, if @v is non-zero.
  * Returns true if the increment was done.
  */
-static inline bool
-${atomic}_inc_not_zero(${atomic}_t *v)
+static __always_inline bool
+${arch}${atomic}_inc_not_zero(${atomic}_t *v)
 {
-	return ${atomic}_add_unless(v, 1, 0);
+	return ${arch}${atomic}_add_unless(v, 1, 0);
 }
 EOF
diff --git a/scripts/atomic/fallbacks/inc_unless_negative b/scripts/atomic/fallbacks/inc_unless_negative
index 0c266e71dbd4..87629e0d4a80 100755
--- a/scripts/atomic/fallbacks/inc_unless_negative
+++ b/scripts/atomic/fallbacks/inc_unless_negative
@@ -1,13 +1,13 @@
 cat <<EOF
-static inline bool
-${atomic}_inc_unless_negative(${atomic}_t *v)
+static __always_inline bool
+${arch}${atomic}_inc_unless_negative(${atomic}_t *v)
 {
-	${int} c = ${atomic}_read(v);
+	${int} c = ${arch}${atomic}_read(v);
 
 	do {
 		if (unlikely(c < 0))
 			return false;
-	} while (!${atomic}_try_cmpxchg(v, &c, c + 1));
+	} while (!${arch}${atomic}_try_cmpxchg(v, &c, c + 1));
 
 	return true;
 }
diff --git a/scripts/atomic/fallbacks/read_acquire b/scripts/atomic/fallbacks/read_acquire
index 75863b5203f7..341a88dccaa7 100755
--- a/scripts/atomic/fallbacks/read_acquire
+++ b/scripts/atomic/fallbacks/read_acquire
@@ -1,6 +1,6 @@
 cat <<EOF
-static inline ${ret}
-${atomic}_read_acquire(const ${atomic}_t *v)
+static __always_inline ${ret}
+${arch}${atomic}_read_acquire(const ${atomic}_t *v)
 {
 	return smp_load_acquire(&(v)->counter);
 }
diff --git a/scripts/atomic/fallbacks/release b/scripts/atomic/fallbacks/release
index 3f628a3802d9..f8906d537c0f 100755
--- a/scripts/atomic/fallbacks/release
+++ b/scripts/atomic/fallbacks/release
@@ -1,8 +1,8 @@
 cat <<EOF
-static inline ${ret}
-${atomic}_${pfx}${name}${sfx}_release(${params})
+static __always_inline ${ret}
+${arch}${atomic}_${pfx}${name}${sfx}_release(${params})
 {
 	__atomic_release_fence();
-	${retstmt}${atomic}_${pfx}${name}${sfx}_relaxed(${args});
+	${retstmt}${arch}${atomic}_${pfx}${name}${sfx}_relaxed(${args});
 }
 EOF
diff --git a/scripts/atomic/fallbacks/set_release b/scripts/atomic/fallbacks/set_release
index 45bb5e0cfc08..76068272d5f5 100755
--- a/scripts/atomic/fallbacks/set_release
+++ b/scripts/atomic/fallbacks/set_release
@@ -1,6 +1,6 @@
 cat <<EOF
-static inline void
-${atomic}_set_release(${atomic}_t *v, ${int} i)
+static __always_inline void
+${arch}${atomic}_set_release(${atomic}_t *v, ${int} i)
 {
 	smp_store_release(&(v)->counter, i);
 }
diff --git a/scripts/atomic/fallbacks/sub_and_test b/scripts/atomic/fallbacks/sub_and_test
index 289ef17a2d7a..c580f4c2136e 100755
--- a/scripts/atomic/fallbacks/sub_and_test
+++ b/scripts/atomic/fallbacks/sub_and_test
@@ -1,6 +1,6 @@
 cat <<EOF
 /**
- * ${atomic}_sub_and_test - subtract value from variable and test result
+ * ${arch}${atomic}_sub_and_test - subtract value from variable and test result
  * @i: integer value to subtract
  * @v: pointer of type ${atomic}_t
  *
@@ -8,9 +8,9 @@ cat <<EOF
  * true if the result is zero, or false for all
  * other cases.
  */
-static inline bool
-${atomic}_sub_and_test(${int} i, ${atomic}_t *v)
+static __always_inline bool
+${arch}${atomic}_sub_and_test(${int} i, ${atomic}_t *v)
 {
-	return ${atomic}_sub_return(i, v) == 0;
+	return ${arch}${atomic}_sub_return(i, v) == 0;
 }
 EOF
diff --git a/scripts/atomic/fallbacks/try_cmpxchg b/scripts/atomic/fallbacks/try_cmpxchg
index 4ed85e2f5378..06db0f738e45 100755
--- a/scripts/atomic/fallbacks/try_cmpxchg
+++ b/scripts/atomic/fallbacks/try_cmpxchg
@@ -1,9 +1,9 @@
 cat <<EOF
-static inline bool
-${atomic}_try_cmpxchg${order}(${atomic}_t *v, ${int} *old, ${int} new)
+static __always_inline bool
+${arch}${atomic}_try_cmpxchg${order}(${atomic}_t *v, ${int} *old, ${int} new)
 {
 	${int} r, o = *old;
-	r = ${atomic}_cmpxchg${order}(v, o, new);
+	r = ${arch}${atomic}_cmpxchg${order}(v, o, new);
 	if (unlikely(r != o))
 		*old = r;
 	return likely(r == o);
diff --git a/scripts/atomic/gen-atomic-fallback.sh b/scripts/atomic/gen-atomic-fallback.sh
index 1bd7c1707633..0fd1cf0c2b94 100755
--- a/scripts/atomic/gen-atomic-fallback.sh
+++ b/scripts/atomic/gen-atomic-fallback.sh
@@ -2,10 +2,11 @@
 # SPDX-License-Identifier: GPL-2.0
 
 ATOMICDIR=$(dirname $0)
+ARCH=$2
 
 . ${ATOMICDIR}/atomic-tbl.sh
 
-#gen_template_fallback(template, meta, pfx, name, sfx, order, atomic, int, args...)
+#gen_template_fallback(template, meta, pfx, name, sfx, order, arch, atomic, int, args...)
 gen_template_fallback()
 {
 	local template="$1"; shift
@@ -14,10 +15,11 @@ gen_template_fallback()
 	local name="$1"; shift
 	local sfx="$1"; shift
 	local order="$1"; shift
+	local arch="$1"; shift
 	local atomic="$1"; shift
 	local int="$1"; shift
 
-	local atomicname="${atomic}_${pfx}${name}${sfx}${order}"
+	local atomicname="${arch}${atomic}_${pfx}${name}${sfx}${order}"
 
 	local ret="$(gen_ret_type "${meta}" "${int}")"
 	local retstmt="$(gen_ret_stmt "${meta}")"
@@ -32,7 +34,7 @@ gen_template_fallback()
 	fi
 }
 
-#gen_proto_fallback(meta, pfx, name, sfx, order, atomic, int, args...)
+#gen_proto_fallback(meta, pfx, name, sfx, order, arch, atomic, int, args...)
 gen_proto_fallback()
 {
 	local meta="$1"; shift
@@ -56,16 +58,17 @@ cat << EOF
 EOF
 }
 
-#gen_proto_order_variants(meta, pfx, name, sfx, atomic, int, args...)
+#gen_proto_order_variants(meta, pfx, name, sfx, arch, atomic, int, args...)
 gen_proto_order_variants()
 {
 	local meta="$1"; shift
 	local pfx="$1"; shift
 	local name="$1"; shift
 	local sfx="$1"; shift
-	local atomic="$1"
+	local arch="$1"
+	local atomic="$2"
 
-	local basename="${atomic}_${pfx}${name}${sfx}"
+	local basename="${arch}${atomic}_${pfx}${name}${sfx}"
 
 	local template="$(find_fallback_template "${pfx}" "${name}" "${sfx}" "${order}")"
 
@@ -94,7 +97,7 @@ gen_proto_order_variants()
 	gen_basic_fallbacks "${basename}"
 
 	if [ ! -z "${template}" ]; then
-		printf "#endif /* ${atomic}_${pfx}${name}${sfx} */\n\n"
+		printf "#endif /* ${arch}${atomic}_${pfx}${name}${sfx} */\n\n"
 		gen_proto_fallback "${meta}" "${pfx}" "${name}" "${sfx}" "" "$@"
 		gen_proto_fallback "${meta}" "${pfx}" "${name}" "${sfx}" "_acquire" "$@"
 		gen_proto_fallback "${meta}" "${pfx}" "${name}" "${sfx}" "_release" "$@"
@@ -149,20 +152,19 @@ cat << EOF
 #ifndef _LINUX_ATOMIC_FALLBACK_H
 #define _LINUX_ATOMIC_FALLBACK_H
 
+#include <linux/compiler.h>
+
 EOF
 
-for xchg in "xchg" "cmpxchg" "cmpxchg64"; do
+for xchg in "${ARCH}xchg" "${ARCH}cmpxchg" "${ARCH}cmpxchg64"; do
 	gen_xchg_fallbacks "${xchg}"
 done
 
 grep '^[a-z]' "$1" | while read name meta args; do
-	gen_proto "${meta}" "${name}" "atomic" "int" ${args}
+	gen_proto "${meta}" "${name}" "${ARCH}" "atomic" "int" ${args}
 done
 
 cat <<EOF
-#define atomic_cond_read_acquire(v, c) smp_cond_load_acquire(&(v)->counter, (c))
-#define atomic_cond_read_relaxed(v, c) smp_cond_load_relaxed(&(v)->counter, (c))
-
 #ifdef CONFIG_GENERIC_ATOMIC64
 #include <asm-generic/atomic64.h>
 #endif
@@ -170,12 +172,9 @@ cat <<EOF
 EOF
 
 grep '^[a-z]' "$1" | while read name meta args; do
-	gen_proto "${meta}" "${name}" "atomic64" "s64" ${args}
+	gen_proto "${meta}" "${name}" "${ARCH}" "atomic64" "s64" ${args}
 done
 
 cat <<EOF
-#define atomic64_cond_read_acquire(v, c) smp_cond_load_acquire(&(v)->counter, (c))
-#define atomic64_cond_read_relaxed(v, c) smp_cond_load_relaxed(&(v)->counter, (c))
-
 #endif /* _LINUX_ATOMIC_FALLBACK_H */
 EOF
diff --git a/scripts/atomic/gen-atomics.sh b/scripts/atomic/gen-atomics.sh
index 000dc6437893..d29e159ef489 100644
--- a/scripts/atomic/gen-atomics.sh
+++ b/scripts/atomic/gen-atomics.sh
@@ -10,10 +10,11 @@ LINUXDIR=${ATOMICDIR}/../..
 cat <<EOF |
 gen-atomic-instrumented.sh      asm-generic/atomic-instrumented.h
 gen-atomic-long.sh              asm-generic/atomic-long.h
+gen-atomic-fallback.sh          linux/atomic-arch-fallback.h		arch_
 gen-atomic-fallback.sh          linux/atomic-fallback.h
 EOF
-while read script header; do
-	/bin/sh ${ATOMICDIR}/${script} ${ATOMICTBL} > ${LINUXDIR}/include/${header}
+while read script header args; do
+	/bin/sh ${ATOMICDIR}/${script} ${ATOMICTBL} ${args} > ${LINUXDIR}/include/${header}
 	HASH="$(sha1sum ${LINUXDIR}/include/${header})"
 	HASH="${HASH%% *}"
 	printf "// %s\n" "${HASH}" >> ${LINUXDIR}/include/${header}