From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops There's some internal state that ftrace_ops needs to have set, but since it can be declared outside of the ftrace.c code, it calls ftrace_ops_init() on the ops in every global function. The issue is that if two tasks call it on the same ops at the same time it is possible to have the initialization of one corrupt the initialization of the other call. Create a ops_mutex to use to synchronize every initialization of the ftrace_ops. The mutex is taken within checking the ftrace_ops flag that states it was initializied but the flag is checked again after the mutex has been taken. Checking first outside the mutex allows it to shortcut having to take the mutex. But then the check needs to be done again after the mute is taken in case of races. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock") Reported-by: sashiko-bot@kernel.org Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/ Signed-off-by: Steven Rostedt --- scripts/coccinelle/api/kvmalloc.cocci | 256 ++++++++++++++++++++++++++++++++++ 1 file changed, 256 insertions(+) create mode 100644 scripts/coccinelle/api/kvmalloc.cocci (limited to 'scripts/coccinelle/api/kvmalloc.cocci') diff --git a/scripts/coccinelle/api/kvmalloc.cocci b/scripts/coccinelle/api/kvmalloc.cocci new file mode 100644 index 000000000..5ddcb76b7 --- /dev/null +++ b/scripts/coccinelle/api/kvmalloc.cocci @@ -0,0 +1,256 @@ +// SPDX-License-Identifier: GPL-2.0-only +/// +/// Find if/else condition with kmalloc/vmalloc calls. +/// Suggest to use kvmalloc instead. Same for kvfree. +/// +// Confidence: High +// Copyright: (C) 2020 Denis Efremov ISPRAS +// Options: --no-includes --include-headers +// + +virtual patch +virtual report +virtual org +virtual context + +@initialize:python@ +@@ +filter = frozenset(['kvfree']) + +def relevant(p): + return not (filter & {el.current_element for el in p}) + +@kvmalloc depends on !patch@ +expression E, E1, size; +identifier flags; +binary operator cmp = {<=, <, ==, >, >=}; +identifier x; +type T; +position p; +@@ + +( +* if (size cmp E1 || ...)@p { + ... +* E = \(kmalloc\|kzalloc\|kcalloc\|kmalloc_node\|kzalloc_node\| +* kmalloc_array\|kmalloc_array_node\|kcalloc_node\) +* (..., size, \(flags\|GFP_KERNEL\|\(GFP_KERNEL\|flags\)|__GFP_NOWARN\), ...) + ... + } else { + ... +* E = \(vmalloc\|vzalloc\|vmalloc_node\|vzalloc_node\)(..., size, ...) + ... + } +| +* E = \(kmalloc\|kzalloc\|kcalloc\|kmalloc_node\|kzalloc_node\| +* kmalloc_array\|kmalloc_array_node\|kcalloc_node\) +* (..., size, \(flags\|GFP_KERNEL\|\(GFP_KERNEL\|flags\)|__GFP_NOWARN\), ...) + ... when != E = E1 + when != size = E1 + when any +* if (E == NULL)@p { + ... +* E = \(vmalloc\|vzalloc\|vmalloc_node\|vzalloc_node\)(..., size, ...) + ... + } +| +* T x = \(kmalloc\|kzalloc\|kcalloc\|kmalloc_node\|kzalloc_node\| +* kmalloc_array\|kmalloc_array_node\|kcalloc_node\) +* (..., size, \(flags\|GFP_KERNEL\|\(GFP_KERNEL\|flags\)|__GFP_NOWARN\), ...); + ... when != x = E1 + when != size = E1 + when any +* if (x == NULL)@p { + ... +* x = \(vmalloc\|vzalloc\|vmalloc_node\|vzalloc_node\)(..., size, ...) + ... + } +) + +@kvfree depends on !patch@ +expression E; +position p : script:python() { relevant(p) }; +@@ + +* if (is_vmalloc_addr(E))@p { + ... +* vfree(E) + ... + } else { + ... when != krealloc(E, ...) + when any +* \(kfree\|kfree_sensitive\)(E) + ... + } + +@depends on patch@ +expression E, E1, size, node; +binary operator cmp = {<=, <, ==, >, >=}; +identifier flags, x; +type T; +@@ + +( +- if (size cmp E1) +- E = kmalloc(size, flags); +- else +- E = vmalloc(size); ++ E = kvmalloc(size, flags); +| +- if (size cmp E1) +- E = kmalloc(size, \(GFP_KERNEL\|GFP_KERNEL|__GFP_NOWARN\)); +- else +- E = vmalloc(size); ++ E = kvmalloc(size, GFP_KERNEL); +| +- E = kmalloc(size, flags | __GFP_NOWARN); +- if (E == NULL) +- E = vmalloc(size); ++ E = kvmalloc(size, flags); +| +- E = kmalloc(size, \(GFP_KERNEL\|GFP_KERNEL|__GFP_NOWARN\)); +- if (E == NULL) +- E = vmalloc(size); ++ E = kvmalloc(size, GFP_KERNEL); +| +- T x = kmalloc(size, flags | __GFP_NOWARN); +- if (x == NULL) +- x = vmalloc(size); ++ T x = kvmalloc(size, flags); +| +- T x = kmalloc(size, \(GFP_KERNEL\|GFP_KERNEL|__GFP_NOWARN\)); +- if (x == NULL) +- x = vmalloc(size); ++ T x = kvmalloc(size, GFP_KERNEL); +| +- if (size cmp E1) +- E = kzalloc(size, flags); +- else +- E = vzalloc(size); ++ E = kvzalloc(size, flags); +| +- if (size cmp E1) +- E = kzalloc(size, \(GFP_KERNEL\|GFP_KERNEL|__GFP_NOWARN\)); +- else +- E = vzalloc(size); ++ E = kvzalloc(size, GFP_KERNEL); +| +- E = kzalloc(size, flags | __GFP_NOWARN); +- if (E == NULL) +- E = vzalloc(size); ++ E = kvzalloc(size, flags); +| +- E = kzalloc(size, \(GFP_KERNEL\|GFP_KERNEL|__GFP_NOWARN\)); +- if (E == NULL) +- E = vzalloc(size); ++ E = kvzalloc(size, GFP_KERNEL); +| +- T x = kzalloc(size, flags | __GFP_NOWARN); +- if (x == NULL) +- x = vzalloc(size); ++ T x = kvzalloc(size, flags); +| +- T x = kzalloc(size, \(GFP_KERNEL\|GFP_KERNEL|__GFP_NOWARN\)); +- if (x == NULL) +- x = vzalloc(size); ++ T x = kvzalloc(size, GFP_KERNEL); +| +- if (size cmp E1) +- E = kmalloc_node(size, flags, node); +- else +- E = vmalloc_node(size, node); ++ E = kvmalloc_node(size, flags, node); +| +- if (size cmp E1) +- E = kmalloc_node(size, \(GFP_KERNEL\|GFP_KERNEL|__GFP_NOWARN\), node); +- else +- E = vmalloc_node(size, node); ++ E = kvmalloc_node(size, GFP_KERNEL, node); +| +- E = kmalloc_node(size, flags | __GFP_NOWARN, node); +- if (E == NULL) +- E = vmalloc_node(size, node); ++ E = kvmalloc_node(size, flags, node); +| +- E = kmalloc_node(size, \(GFP_KERNEL\|GFP_KERNEL|__GFP_NOWARN\), node); +- if (E == NULL) +- E = vmalloc_node(size, node); ++ E = kvmalloc_node(size, GFP_KERNEL, node); +| +- T x = kmalloc_node(size, flags | __GFP_NOWARN, node); +- if (x == NULL) +- x = vmalloc_node(size, node); ++ T x = kvmalloc_node(size, flags, node); +| +- T x = kmalloc_node(size, \(GFP_KERNEL\|GFP_KERNEL|__GFP_NOWARN\), node); +- if (x == NULL) +- x = vmalloc_node(size, node); ++ T x = kvmalloc_node(size, GFP_KERNEL, node); +| +- if (size cmp E1) +- E = kvzalloc_node(size, flags, node); +- else +- E = vzalloc_node(size, node); ++ E = kvzalloc_node(size, flags, node); +| +- if (size cmp E1) +- E = kvzalloc_node(size, \(GFP_KERNEL\|GFP_KERNEL|__GFP_NOWARN\), node); +- else +- E = vzalloc_node(size, node); ++ E = kvzalloc_node(size, GFP_KERNEL, node); +| +- E = kvzalloc_node(size, flags | __GFP_NOWARN, node); +- if (E == NULL) +- E = vzalloc_node(size, node); ++ E = kvzalloc_node(size, flags, node); +| +- E = kvzalloc_node(size, \(GFP_KERNEL\|GFP_KERNEL|__GFP_NOWARN\), node); +- if (E == NULL) +- E = vzalloc_node(size, node); ++ E = kvzalloc_node(size, GFP_KERNEL, node); +| +- T x = kvzalloc_node(size, flags | __GFP_NOWARN, node); +- if (x == NULL) +- x = vzalloc_node(size, node); ++ T x = kvzalloc_node(size, flags, node); +| +- T x = kvzalloc_node(size, \(GFP_KERNEL\|GFP_KERNEL|__GFP_NOWARN\), node); +- if (x == NULL) +- x = vzalloc_node(size, node); ++ T x = kvzalloc_node(size, GFP_KERNEL, node); +) + +@depends on patch@ +expression E; +position p : script:python() { relevant(p) }; +@@ + +- if (is_vmalloc_addr(E))@p +- vfree(E); +- else +- kfree(E); ++ kvfree(E); + +@script: python depends on report@ +p << kvmalloc.p; +@@ + +coccilib.report.print_report(p[0], "WARNING opportunity for kvmalloc") + +@script: python depends on org@ +p << kvmalloc.p; +@@ + +coccilib.org.print_todo(p[0], "WARNING opportunity for kvmalloc") + +@script: python depends on report@ +p << kvfree.p; +@@ + +coccilib.report.print_report(p[0], "WARNING opportunity for kvfree") + +@script: python depends on org@ +p << kvfree.p; +@@ + +coccilib.org.print_todo(p[0], "WARNING opportunity for kvfree") -- cgit v1.3.1