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authorKees Cook <kees+treewide@kernel.org>2026-09-02 15:31:14 -0700
committerKees Cook <kees@kernel.org>2026-09-04 21:37:00 -0700
commit3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d (patch)
treec65086f9bdcd48c6360fb7cb4598bca084da1f32 /tools/memory-model/lock.cat
downloadlinux-stable-3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d.tar.gz
linux-stable-3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d.zip
treewide: refresh kmalloc_obj() conversionsgrafted
This is another run of the Coccinelle script for converting kmalloc() family of allocations to kmalloc_obj() via the existing rules in scripts/coccinelle/api/kmalloc_objs.cocci This catches both the set of kmalloc() uses added since the first kmalloc_obj() conversions in v7.0 and adds a large group missed in the first pass due to Coccinelle not interacting well with the cleanup.h scoped_...() family of macros[1]. I worked around this with spatch's "--macro-file" argument to a file with all the scoped_...() macros mapped to Coccinelle's YACFE_ITERATOR[2] as that was the closest viable control flow indicator I could find. Build tested allmodconfig on x86, arm64, arm, loongarch, mips, powerpc, riscv, and s390 with no new warnings. Link: https://lore.kernel.org/lkml/202609021314.8A9C0B8@keescook/ [1] Link: https://github.com/coccinelle/coccinelle/blob/master/standard.h [2] Signed-off-by: Kees Cook <kees+treewide@kernel.org>
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+// SPDX-License-Identifier: GPL-2.0+
+(*
+ * Copyright (C) 2016 Luc Maranget <luc.maranget@inria.fr> for Inria
+ * Copyright (C) 2017 Alan Stern <stern@rowland.harvard.edu>
+ *)
+
+(*
+ * Generate coherence orders and handle lock operations
+ *)
+
+include "cross.cat"
+
+(*
+ * The lock-related events generated by herd7 are as follows:
+ *
+ * LKR Lock-Read: the read part of a spin_lock() or successful
+ * spin_trylock() read-modify-write event pair
+ * LKW Lock-Write: the write part of a spin_lock() or successful
+ * spin_trylock() RMW event pair
+ * UL Unlock: a spin_unlock() event
+ * LF Lock-Fail: a failed spin_trylock() event
+ * RL Read-Locked: a spin_is_locked() event which returns True
+ * RU Read-Unlocked: a spin_is_locked() event which returns False
+ *
+ * LKR and LKW events always come paired, like all RMW event sequences.
+ *
+ * LKR, LF, RL, and RU are read events; LKR has Acquire ordering.
+ * LKW and UL are write events; UL has Release ordering.
+ * LKW, LF, RL, and RU have no ordering properties.
+ *)
+
+(* Backward compatibility *)
+let RL = try RL with emptyset
+let RU = try RU with emptyset
+
+(* Treat RL as a kind of LF: a read with no ordering properties *)
+let LF = LF | RL
+
+(* There should be no ordinary R or W accesses to spinlocks or SRCU structs *)
+let ALL-LOCKS = LKR | LKW | UL | LF | RU | Srcu-lock | Srcu-unlock | Sync-srcu
+flag ~empty [M \ IW \ ALL-LOCKS] ; loc ; [ALL-LOCKS] as mixed-lock-accesses
+
+(* Link Lock-Reads to their RMW-partner Lock-Writes *)
+let lk-rmw = ([LKR] ; po-loc ; [LKW]) \ (po ; po)
+let rmw = rmw | lk-rmw
+
+(* The litmus test is invalid if an LKR/LKW event is not part of an RMW pair *)
+flag ~empty LKW \ range(lk-rmw) as unpaired-LKW
+flag ~empty LKR \ domain(lk-rmw) as unpaired-LKR
+
+(*
+ * An LKR must always see an unlocked value; spin_lock() calls nested
+ * inside a critical section (for the same lock) always deadlock.
+ *)
+empty ([LKW] ; po-loc ; [LKR]) \ (po-loc ; [UL] ; po-loc) as lock-nest
+
+(*
+ * In the same way, spin_is_locked() inside a critical section must always
+ * return True (no RU events can be in a critical section for the same lock).
+ *)
+empty ([LKW] ; po-loc ; [RU]) \ (po-loc ; [UL] ; po-loc) as nested-is-locked
+
+(* The final value of a spinlock should not be tested *)
+flag ~empty [FW] ; loc ; [ALL-LOCKS] as lock-final
+
+(*
+ * Put lock operations in their appropriate classes, but leave UL out of W
+ * until after the co relation has been generated.
+ *)
+let R = R | LKR | LF | RU
+let W = W | LKW
+
+let Release = Release | UL
+let Acquire = Acquire | LKR
+
+(* Match LKW events to their corresponding UL events *)
+let critical = ([LKW] ; po-loc ; [UL]) \ (po-loc ; [LKW | UL] ; po-loc)
+
+flag ~empty UL \ range(critical) as unmatched-unlock
+
+(* Allow up to one unmatched LKW per location; more must deadlock *)
+let UNMATCHED-LKW = LKW \ domain(critical)
+empty ([UNMATCHED-LKW] ; loc ; [UNMATCHED-LKW]) \ id as unmatched-locks
+
+(* rfi for LF events: link each LKW to the LF events in its critical section *)
+let rfi-lf = ([LKW] ; po-loc ; [LF]) \ ([LKW] ; po-loc ; [UL] ; po-loc)
+
+(* Utility macro to convert a single pair to a single-edge relation *)
+let pair-to-relation p = p ++ 0
+
+(*
+ * If a given LF event e is outside a critical section, it cannot read
+ * internally but it may read from an LKW event in another thread.
+ * Compute the relation containing these possible edges.
+ *)
+let possible-rfe-noncrit-lf e = (LKW * {e}) & loc & ext
+
+(* Compute set of sets of possible rfe edges for LF events *)
+let all-possible-rfe-lf =
+ (*
+ * Convert the possible-rfe-noncrit-lf relation for e
+ * to a set of single edges
+ *)
+ let set-of-singleton-rfe-lf e =
+ map pair-to-relation (possible-rfe-noncrit-lf e)
+ (* Do this for each LF event e that isn't in rfi-lf *)
+ in map set-of-singleton-rfe-lf (LF \ range(rfi-lf))
+
+(* Generate all rf relations for LF events *)
+with rfe-lf from cross(all-possible-rfe-lf)
+let rf-lf = rfe-lf | rfi-lf
+
+(*
+ * A given RU event e may read internally from the last po-previous UL,
+ * or it may read from a UL event in another thread or the initial write.
+ * Compute the relation containing these possible edges.
+ *)
+let possible-rf-ru e = (((UL * {e}) & po-loc) \
+ ([UL] ; po-loc ; [UL] ; po-loc)) |
+ (((UL | IW) * {e}) & loc & ext)
+
+(* Compute set of sets of possible rf edges for RU events *)
+let all-possible-rf-ru =
+ (* Convert the possible-rf-ru relation for e to a set of single edges *)
+ let set-of-singleton-rf-ru e =
+ map pair-to-relation (possible-rf-ru e)
+ (* Do this for each RU event e *)
+ in map set-of-singleton-rf-ru RU
+
+(* Generate all rf relations for RU events *)
+with rf-ru from cross(all-possible-rf-ru)
+
+(* Final rf relation *)
+let rf = rf | rf-lf | rf-ru
+
+(* Generate all co relations, including LKW events but not UL *)
+let co0 = co0 | ([IW] ; loc ; [LKW]) |
+ (([LKW] ; loc ; [UNMATCHED-LKW]) \ [UNMATCHED-LKW])
+include "cos-opt.cat"
+let W = W | UL
+let M = R | W
+
+(* Merge UL events into co *)
+let co = (co | critical | (critical^-1 ; co))+
+let coe = co & ext
+let coi = co & int
+
+(* Merge LKR events into rf *)
+let rf = rf | ([IW | UL] ; singlestep(co) ; lk-rmw^-1)
+let rfe = rf & ext
+let rfi = rf & int
+
+let fr = rf^-1 ; co
+let fre = fr & ext
+let fri = fr & int
+
+show co,rf,fr