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The callback function that is used to create inodes and dentries is not
protected by anything and the data that is passed to it could become
stale. After eventfs_remove_dir() is called by the tracing system, it is
free to remove the events that are associated to that directory.
Unfortunately, that means the callbacks must not be called after that.
CPU0 CPU1
---- ----
eventfs_root_lookup() {
eventfs_remove_dir() {
mutex_lock(&event_mutex);
ei->is_freed = set;
mutex_unlock(&event_mutex);
}
kfree(event_call);
for (...) {
entry = &ei->entries[i];
r = entry->callback() {
call = data; // call == event_call above
if (call->flags ...)
[ USE AFTER FREE BUG ]
The safest way to protect this is to wrap the callback with:
mutex_lock(&eventfs_mutex);
if (!ei->is_freed)
r = entry->callback();
else
r = -1;
mutex_unlock(&eventfs_mutex);
This will make sure that the callback will not be called after it is
freed. But now it needs to be known that the callback is called while
holding internal eventfs locks, and that it must not call back into the
eventfs / tracefs system. There's no reason it should anyway, but document
that as well.
Link: https://lore.kernel.org/all/CA+G9fYu9GOEbD=rR5eMR-=HJ8H6rMsbzDC2ZY5=Y50WpWAE7_Q@mail.gmail.com/
Link: https://lkml.kernel.org/r/20231101172649.906696613@goodmis.org
Cc: Ajay Kaher <akaher@vmware.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Fixes: 5790b1fb3d672 ("eventfs: Remove eventfs_file and just use eventfs_inode")
Reported-by: Linux Kernel Functional Testing <lkft@linaro.org>
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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Now that inodes and dentries are created on the fly, they are also
reclaimed on memory pressure. Since the ownership and file mode are saved
in the inode, if they are freed, any changes to the ownership and mode
will be lost.
To counter this, if the user changes the permissions or ownership, save
them, and when creating the inodes again, restore those changes.
Link: https://lkml.kernel.org/r/20231101172649.691841445@goodmis.org
Cc: stable@vger.kernel.org
Cc: Ajay Kaher <akaher@vmware.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Fixes: 63940449555e7 ("eventfs: Implement eventfs lookup, read, open functions")
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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The eventfs_inode (ei) is protected by SRCU, but the ei->dentry is not. It
is protected by the eventfs_mutex. Anytime the eventfs_mutex is released,
and access to the ei->dentry needs to be done, it should first check if
ei->is_freed is set under the eventfs_mutex. If it is, then the ei->dentry
is invalid and must not be used. The ei->dentry must only be accessed
under the eventfs_mutex and after checking if ei->is_freed is set.
When the ei is being freed, it will (under the eventfs_mutex) set is_freed
and at the same time move the dentry to a free list to be cleared after
the eventfs_mutex is released. This means that any access to the
ei->dentry must check first if ei->is_freed is set, because if it is, then
the dentry is on its way to be freed.
Also add comments to describe this better.
Link: https://lore.kernel.org/all/CA+G9fYt6pY+tMZEOg=SoEywQOe19fGP3uR15SGowkdK+_X85Cg@mail.gmail.com/
Link: https://lore.kernel.org/all/CA+G9fYuDP3hVQ3t7FfrBAjd_WFVSurMgCepTxunSJf=MTe=6aA@mail.gmail.com/
Link: https://lkml.kernel.org/r/20231101172649.477608228@goodmis.org
Cc: Ajay Kaher <akaher@vmware.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Fixes: 5790b1fb3d672 ("eventfs: Remove eventfs_file and just use eventfs_inode")
Reported-by: Linux Kernel Functional Testing <lkft@linaro.org>
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Reported-by: Beau Belgrave <beaub@linux.microsoft.com>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Tested-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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As the eventfs_inode is freed in two different locations, make a helper
function free_ei() to make sure all the allocated fields of the
eventfs_inode is freed.
This requires renaming the existing free_ei() which is called by the srcu
handler to free_rcu_ei() and have free_ei() just do the freeing, where
free_rcu_ei() will call it.
Link: https://lkml.kernel.org/r/20231101172649.265214087@goodmis.org
Cc: Ajay Kaher <akaher@vmware.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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The eventfs_inode->is_freed was a union with the rcu_head with the
assumption that when it was on the srcu list the head would contain a
pointer which would make "is_freed" true. But that was a wrong assumption
as the rcu head is a single link list where the last element is NULL.
Instead, split the nr_entries integer so that "is_freed" is one bit and
the nr_entries is the next 31 bits. As there shouldn't be more than 10
(currently there's at most 5 to 7 depending on the config), this should
not be a problem.
Link: https://lkml.kernel.org/r/20231101172649.049758712@goodmis.org
Cc: stable@vger.kernel.org
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ajay Kaher <akaher@vmware.com>
Fixes: 63940449555e7 ("eventfs: Implement eventfs lookup, read, open functions")
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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The eventfs_remove_rec() had some missing parameters in the kerneldoc
comment above it. Also, rephrase the description a bit more to have a bit
more correct grammar.
Link: https://lore.kernel.org/linux-trace-kernel/20231030121523.0b2225a7@gandalf.local.home
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Fixes: 5790b1fb3d672 ("eventfs: Remove eventfs_file and just use eventfs_inode");
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202310052216.4SgqasWo-lkp@intel.com/
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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A synthetic event is created by the synthetic event interface that can
read both user or kernel address memory. In reality, it reads any
arbitrary memory location from within the kernel. If the address space is
in USER (where CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE is set) then
it uses strncpy_from_user_nofault() to copy strings otherwise it uses
strncpy_from_kernel_nofault().
But since both functions use the same variable there's no annotation to
what that variable is (ie. __user). This makes sparse complain.
Quiet sparse by typecasting the strncpy_from_user_nofault() variable to
a __user pointer.
Link: https://lore.kernel.org/linux-trace-kernel/20231031151033.73c42e23@gandalf.local.home
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Fixes: 0934ae9977c2 ("tracing: Fix reading strings from synthetic events");
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202311010013.fm8WTxa5-lkp@intel.com/
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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The creation of the top events directory does a dget() at the end of the
creation in eventfs_create_events_dir() with a comment saying the final
dput() will happen when it is removed. The problem is that a dget() is
already done on the dentry when it was created with tracefs_start_creating()!
The dget() now just causes a memory leak of that dentry.
Remove the extra dget() as the final dput() in the deletion of the events
directory actually matches the one in tracefs_start_creating().
Link: https://lore.kernel.org/linux-trace-kernel/20231031124229.4f2e3fa1@gandalf.local.home
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Fixes: 5790b1fb3d672 ("eventfs: Remove eventfs_file and just use eventfs_inode")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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The following can crash the kernel:
# cd /sys/kernel/tracing
# echo 'p:sched schedule' > kprobe_events
# exec 5>>events/kprobes/sched/enable
# > kprobe_events
# exec 5>&-
The above commands:
1. Change directory to the tracefs directory
2. Create a kprobe event (doesn't matter what one)
3. Open bash file descriptor 5 on the enable file of the kprobe event
4. Delete the kprobe event (removes the files too)
5. Close the bash file descriptor 5
The above causes a crash!
BUG: kernel NULL pointer dereference, address: 0000000000000028
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT SMP PTI
CPU: 6 PID: 877 Comm: bash Not tainted 6.5.0-rc4-test-00008-g2c6b6b1029d4-dirty #186
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:tracing_release_file_tr+0xc/0x50
What happens here is that the kprobe event creates a trace_event_file
"file" descriptor that represents the file in tracefs to the event. It
maintains state of the event (is it enabled for the given instance?).
Opening the "enable" file gets a reference to the event "file" descriptor
via the open file descriptor. When the kprobe event is deleted, the file is
also deleted from the tracefs system which also frees the event "file"
descriptor.
But as the tracefs file is still opened by user space, it will not be
totally removed until the final dput() is called on it. But this is not
true with the event "file" descriptor that is already freed. If the user
does a write to or simply closes the file descriptor it will reference the
event "file" descriptor that was just freed, causing a use-after-free bug.
To solve this, add a ref count to the event "file" descriptor as well as a
new flag called "FREED". The "file" will not be freed until the last
reference is released. But the FREE flag will be set when the event is
removed to prevent any more modifications to that event from happening,
even if there's still a reference to the event "file" descriptor.
Link: https://lore.kernel.org/linux-trace-kernel/20231031000031.1e705592@gandalf.local.home/
Link: https://lore.kernel.org/linux-trace-kernel/20231031122453.7a48b923@gandalf.local.home
Cc: stable@vger.kernel.org
Cc: Mark Rutland <mark.rutland@arm.com>
Fixes: f5ca233e2e66d ("tracing: Increase trace array ref count on enable and filter files")
Reported-by: Beau Belgrave <beaub@linux.microsoft.com>
Tested-by: Beau Belgrave <beaub@linux.microsoft.com>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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Solve two ergonomic issues with struct seq_buf;
1) Too much boilerplate is required to initialize:
struct seq_buf s;
char buf[32];
seq_buf_init(s, buf, sizeof(buf));
Instead, we can build this directly on the stack. Provide
DECLARE_SEQ_BUF() macro to do this:
DECLARE_SEQ_BUF(s, 32);
2) %NUL termination is fragile and requires 2 steps to get a valid
C String (and is a layering violation exposing the "internals" of
seq_buf):
seq_buf_terminate(s);
do_something(s->buffer);
Instead, we can just return s->buffer directly after terminating it in
the refactored seq_buf_terminate(), now known as seq_buf_str():
do_something(seq_buf_str(s));
Link: https://lore.kernel.org/linux-trace-kernel/20231027155634.make.260-kees@kernel.org
Link: https://lore.kernel.org/linux-trace-kernel/20231026194033.it.702-kees@kernel.org/
Cc: Yosry Ahmed <yosryahmed@google.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Justin Stitt <justinstitt@google.com>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Yun Zhou <yun.zhou@windriver.com>
Cc: Jacob Keller <jacob.e.keller@intel.com>
Cc: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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It's eventfs_inode not eventfs_indoe. There's no deer involved!
Link: https://lore.kernel.org/linux-trace-kernel/20231024131024.5634c743@gandalf.local.home
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Fixes: 5790b1fb3d672 ("eventfs: Remove eventfs_file and just use eventfs_inode")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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As the comment right above a WARN_ON() in create_file_dentry() states:
* Note, with the mutex held, the e_dentry cannot have content
* and the ei->is_freed be true at the same time.
But the WARN_ON() only has:
WARN_ON_ONCE(ei->is_free);
Where to match the comment (and what it should actually do) is:
dentry = *e_dentry;
WARN_ON_ONCE(dentry && ei->is_free)
Also in that case, set dentry to NULL (although it should never happen).
Link: https://lore.kernel.org/linux-trace-kernel/20231024123628.62b88755@gandalf.local.home
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Fixes: 5790b1fb3d672 ("eventfs: Remove eventfs_file and just use eventfs_inode")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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While powerpc doesn't use the seq_buf readpos, it did explicitly
initialise it for no good reason.
Link: https://lore.kernel.org/linux-trace-kernel/20231024145600.739451-1-willy@infradead.org
Cc: Christoph Hellwig <hch@lst.de>
Cc: Justin Stitt <justinstitt@google.com>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Kees Cook <keescook@chromium.org>
Fixes: d0ed46b60396 ("tracing: Move readpos from seq_buf to trace_seq")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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Turn a kzalloc()+strcpy()+strncat() into an equivalent and less verbose
kasprintf().
Link: https://lore.kernel.org/linux-trace-kernel/30b6fb04dadc10a03cc1ad08f5d8a93ef623a167.1697899346.git.christophe.jaillet@wanadoo.fr
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Mukesh ojha <quic_mojha@quicinc.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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The comment for seq_buf_has_overflowed() says that an overflow condition is
marked by len == size, but that's not what the code is testing. Make the
comment match reality.
Link: https://lkml.kernel.org/r/87pm19kp0m.fsf@meer.lwn.net
Fixes: 8cd709ae7658a ("tracing: Have seq_buf use full buffer")
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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To make seq_buf more lightweight as a string buf, move the readpos member
from seq_buf to its container, trace_seq. That puts the responsibility
of maintaining the readpos entirely in the tracing code. If some future
users want to package up the readpos with a seq_buf, we can define a
new struct then.
Link: https://lore.kernel.org/linux-trace-kernel/20231020033545.2587554-2-willy@infradead.org
Cc: Kees Cook <keescook@chromium.org>
Cc: Justin Stitt <justinstitt@google.com>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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No functional modification involved.
fs/tracefs/event_inode.c:864: warning: expecting prototype for eventfs_remove(). Prototype was for eventfs_remove_dir() instead.
Link: https://lore.kernel.org/linux-trace-kernel/20231019031353.73846-1-jiapeng.chong@linux.alibaba.com
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=6939
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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The eventfs_create_dir() function returns error pointers, it never returns
NULL. Update the check to reflect that.
Link: https://lore.kernel.org/linux-trace-kernel/ff641474-84e2-46a7-9d7a-62b251a1050c@moroto.mountain
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Fixes: 5790b1fb3d67 ("eventfs: Remove eventfs_file and just use eventfs_inode")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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The failure path of allocating ei goes to a path that dereferences ei.
Add another label that skips over the ei dereferences to do the rest of
the clean up.
Link: https://lore.kernel.org/all/70e7bace-561c-95f-1117-706c2c220bc@inria.fr/
Link: https://lore.kernel.org/linux-trace-kernel/20231019204132.6662fef0@gandalf.local.home
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Fixes: 5790b1fb3d67 ("eventfs: Remove eventfs_file and just use eventfs_inode")
Reported-by: Julia Lawall <julia.lawall@inria.fr>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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When building with clang and CONFIG_RANDSTRUCT_FULL=y, there is an error
due to a cast in eventfs_create_events_dir():
fs/tracefs/event_inode.c:734:10: error: casting from randomized structure pointer type 'struct dentry *' to 'struct eventfs_inode *'
734 | return (struct eventfs_inode *)dentry;
| ^
1 error generated.
Use the ERR_CAST() function to resolve the error, as it was designed for
this exact situation (casting an error pointer to another type).
Link: https://lore.kernel.org/linux-trace-kernel/20231018-ftrace-fix-clang-randstruct-v1-1-338cb214abfb@kernel.org
Closes: https://github.com/ClangBuiltLinux/linux/issues/1947
Fixes: 5790b1fb3d67 ("eventfs: Remove eventfs_file and just use eventfs_inode")
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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The system_callback() function in trace_events.c is only used within that
file. The "static" annotation was missed.
Fixes: 5790b1fb3d672 ("eventfs: Remove eventfs_file and just use eventfs_inode")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202310051743.y9EobbUr-lkp@intel.com/
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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The update to removing the eventfs_file changed the way the events top
level directory was handled. Instead of returning a dentry, it now returns
the eventfs_inode. In this changed, the removing of the events top level
directory is not much different than removing any of the other
directories. Because of this, the removal just called eventfs_remove_dir()
instead of eventfs_remove_events_dir().
Although eventfs_remove_dir() does the clean up, it misses out on the
dget() of the ei->dentry done in eventfs_create_events_dir(). It makes
more sense to match eventfs_create_events_dir() with a specific function
eventfs_remove_events_dir() and this specific function can then perform
the dput() to the dentry that had the dget() when it was created.
Fixes: 5790b1fb3d67 ("eventfs: Remove eventfs_file and just use eventfs_inode")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202310051743.y9EobbUr-lkp@intel.com/
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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The function that the kprobe_args_char and kprobes_arg_string attaches to
for its test has changed its name once again. Now we need to check for
eventfs_create_dir(), and if it exists, use that, otherwise check for
eventfs_add_dir() and if that exists use that, otherwise use the original
tracefs_create_dir()!
Link: https://lore.kernel.org/linux-trace-kernel/20230914163535.487267410@goodmis.org
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ajay Kaher <akaher@vmware.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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Instead of having a descriptor for every file represented in the eventfs
directory, only have the directory itself represented. Change the API to
send in a list of entries that represent all the files in the directory
(but not other directories). The entry list contains a name and a callback
function that will be used to create the files when they are accessed.
struct eventfs_inode *eventfs_create_events_dir(const char *name, struct dentry *parent,
const struct eventfs_entry *entries,
int size, void *data);
is used for the top level eventfs directory, and returns an eventfs_inode
that will be used by:
struct eventfs_inode *eventfs_create_dir(const char *name, struct eventfs_inode *parent,
const struct eventfs_entry *entries,
int size, void *data);
where both of the above take an array of struct eventfs_entry entries for
every file that is in the directory.
The entries are defined by:
typedef int (*eventfs_callback)(const char *name, umode_t *mode, void **data,
const struct file_operations **fops);
struct eventfs_entry {
const char *name;
eventfs_callback callback;
};
Where the name is the name of the file and the callback gets called when
the file is being created. The callback passes in the name (in case the
same callback is used for multiple files), a pointer to the mode, data and
fops. The data will be pointing to the data that was passed in
eventfs_create_dir() or eventfs_create_events_dir() but may be overridden
to point to something else, as it will be used to point to the
inode->i_private that is created. The information passed back from the
callback is used to create the dentry/inode.
If the callback fills the data and the file should be created, it must
return a positive number. On zero or negative, the file is ignored.
This logic may also be used as a prototype to convert entire pseudo file
systems into just-in-time allocation.
The "show_events_dentry" file has been updated to show the directories,
and any files they have.
With just the eventfs_file allocations:
Before after deltas for meminfo (in kB):
MemFree: -14360
MemAvailable: -14260
Buffers: 40
Cached: 24
Active: 44
Inactive: 48
Inactive(anon): 28
Active(file): 44
Inactive(file): 20
Dirty: -4
AnonPages: 28
Mapped: 4
KReclaimable: 132
Slab: 1604
SReclaimable: 132
SUnreclaim: 1472
Committed_AS: 12
Before after deltas for slabinfo:
<slab>: <objects> [ * <size> = <total>]
ext4_inode_cache 27 [* 1184 = 31968 ]
extent_status 102 [* 40 = 4080 ]
tracefs_inode_cache 144 [* 656 = 94464 ]
buffer_head 39 [* 104 = 4056 ]
shmem_inode_cache 49 [* 800 = 39200 ]
filp -53 [* 256 = -13568 ]
dentry 251 [* 192 = 48192 ]
lsm_file_cache 277 [* 32 = 8864 ]
vm_area_struct -14 [* 184 = -2576 ]
trace_event_file 1748 [* 88 = 153824 ]
kmalloc-1k 35 [* 1024 = 35840 ]
kmalloc-256 49 [* 256 = 12544 ]
kmalloc-192 -28 [* 192 = -5376 ]
kmalloc-128 -30 [* 128 = -3840 ]
kmalloc-96 10581 [* 96 = 1015776 ]
kmalloc-64 3056 [* 64 = 195584 ]
kmalloc-32 1291 [* 32 = 41312 ]
kmalloc-16 2310 [* 16 = 36960 ]
kmalloc-8 9216 [* 8 = 73728 ]
Free memory dropped by 14,360 kB
Available memory dropped by 14,260 kB
Total slab additions in size: 1,771,032 bytes
With this change:
Before after deltas for meminfo (in kB):
MemFree: -12084
MemAvailable: -11976
Buffers: 32
Cached: 32
Active: 72
Inactive: 168
Inactive(anon): 176
Active(file): 72
Inactive(file): -8
Dirty: 24
AnonPages: 196
Mapped: 8
KReclaimable: 148
Slab: 836
SReclaimable: 148
SUnreclaim: 688
Committed_AS: 324
Before after deltas for slabinfo:
<slab>: <objects> [ * <size> = <total>]
tracefs_inode_cache 144 [* 656 = 94464 ]
shmem_inode_cache -23 [* 800 = -18400 ]
filp -92 [* 256 = -23552 ]
dentry 179 [* 192 = 34368 ]
lsm_file_cache -3 [* 32 = -96 ]
vm_area_struct -13 [* 184 = -2392 ]
trace_event_file 1748 [* 88 = 153824 ]
kmalloc-1k -49 [* 1024 = -50176 ]
kmalloc-256 -27 [* 256 = -6912 ]
kmalloc-128 1864 [* 128 = 238592 ]
kmalloc-64 4685 [* 64 = 299840 ]
kmalloc-32 -72 [* 32 = -2304 ]
kmalloc-16 256 [* 16 = 4096 ]
total = 721352
Free memory dropped by 12,084 kB
Available memory dropped by 11,976 kB
Total slab additions in size: 721,352 bytes
That's over 2 MB in savings per instance for free and available memory,
and over 1 MB in savings per instance of slab memory.
Link: https://lore.kernel.org/linux-trace-kernel/20231003184059.4924468e@gandalf.local.home
Link: https://lore.kernel.org/linux-trace-kernel/20231004165007.43d79161@gandalf.local.home
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ajay Kaher <akaher@vmware.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
Users need to know how to make events persist now that we allow for
that. We also now allow the dynamic_events file to create events by
utilizing the persist flag during event register.
Add back in to documentation how /sys/kernel/tracing/dynamic_events can
be used to create persistent user_events. Add a section under registering
for the currently supported flags (USER_EVENT_REG_PERSIST) and the
required permissions. Add a note under deleting that deleting a
persistent event also requires sufficient permission.
Link: https://lkml.kernel.org/r/20230912180704.1284-4-beaub@linux.microsoft.com
Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
Now that we have exposed USER_EVENT_REG_PERSIST events can persist both
via the ABI and in the /sys/kernel/tracing/dynamic_events file.
Ensure both the ABI and DYN cases work by calling both during the parse
tests. Add new flags test that ensures only USER_EVENT_REG_PERSIST is
honored and any other flag is invalid.
Link: https://lkml.kernel.org/r/20230912180704.1284-3-beaub@linux.microsoft.com
Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
There are several scenarios that have come up where having a user_event
persist even if the process that registered it exits. The main one is
having a daemon create events on bootup that shouldn't get deleted if
the daemon has to exit or reload. Another is within OpenTelemetry
exporters, they wish to potentially check if a user_event exists on the
system to determine if exporting the data out should occur. The
user_event in this case must exist even in the absence of the owning
process running (such as the above daemon case).
Expose the previously internal flag USER_EVENT_REG_PERSIST to user
processes. Upon register or delete of events with this flag, ensure the
user is perfmon_capable to prevent random user processes with access to
tracefs from creating events that persist after exit.
Link: https://lkml.kernel.org/r/20230912180704.1284-2-beaub@linux.microsoft.com
Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
Use try_cmpxchg instead of cmpxchg (*ptr, old, new) == old in
rb_insert_pages. x86 CMPXCHG instruction returns success in ZF flag,
so this change saves a compare after cmpxchg (and related move
instruction in front of cmpxchg).
No functional change intended.
Link: https://lore.kernel.org/linux-trace-kernel/20230914163420.12923-1-ubizjak@gmail.com
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
The ring buffer of global_trace is set to the minimum size in
order to save memory on boot up and then it will be expand when
some trace feature enabled.
However currently operations under an instance can also cause
global_trace ring buffer being expanded, and the expanded memory
would be wasted if global_trace then not being used.
See following case, we enable 'sched_switch' event in instance 'A', then
ring buffer of global_trace is unexpectedly expanded to be 1410KB, also
the '(expanded: 1408)' from 'buffer_size_kb' of instance is confusing.
# cd /sys/kernel/tracing
# mkdir instances/A
# cat buffer_size_kb
7 (expanded: 1408)
# cat instances/A/buffer_size_kb
1410 (expanded: 1408)
# echo sched:sched_switch > instances/A/set_event
# cat buffer_size_kb
1410
# cat instances/A/buffer_size_kb
1410
To fix it, we can:
- Make 'ring_buffer_expanded' as a member of 'struct trace_array';
- Make 'ring_buffer_expanded' of instance is defaultly true,
global_trace is defaultly false;
- In order not to expose 'global_trace' outside of file
'kernel/trace/trace.c', introduce trace_set_ring_buffer_expanded()
to set 'ring_buffer_expanded' as 'true';
- Pass the expected trace_array to tracing_update_buffers().
Link: https://lore.kernel.org/linux-trace-kernel/20230906091837.3998020-1-zhengyejian1@huawei.com
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
|
|
Since commit d8131c2965d5 ("kbuild: remove $(MODLIB)/source symlink"),
modules_install does not create the 'source' symlink.
Remove the stale code from builddeb and kernel.spec.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
|
|
Drivers must not reference functions marked with __exit as these likely
are not available when the code is built-in.
There are few creative offenders uncovered for example in ARCH=amd64
allmodconfig builds. So only trigger the section mismatch warning for
W=1 builds.
The dual rule that drivers must not reference .init.* is implemented
since commit 0db252452378 ("modpost: don't allow *driver to reference
.init.*") which however missed that .exit.* should be handled in the
same way.
Thanks to Masahiro Yamada and Arnd Bergmann who gave valuable hints to
find this improvement.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
|
|
Remove the left-over of commit e24f6628811e ("modpost: remove all
traces of cpuinit/cpuexit sections").
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Paul Gortmaker <paul.gortmaker@windriver.com>
|
|
Without this 'else' statement, an "usb" name goes into two handlers:
the first/previous 'if' statement _AND_ the for-loop over 'devtable',
but the latter is useless as it has no 'usb' device_id entry anyway.
Tested with allmodconfig before/after patch; no changes to *.mod.c:
git checkout v6.6-rc3
make -j$(nproc) allmodconfig
make -j$(nproc) olddefconfig
make -j$(nproc)
find . -name '*.mod.c' | cpio -pd /tmp/before
# apply patch
make -j$(nproc)
find . -name '*.mod.c' | cpio -pd /tmp/after
diff -r /tmp/before/ /tmp/after/
# no difference
Fixes: acbef7b76629 ("modpost: fix module autoloading for OF devices with generic compatible property")
Signed-off-by: Mauricio Faria de Oliveira <mfo@canonical.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
|
|
The dcache_dir_open_wrapper() could be called when a dynamic event is
being deleted leaving a dentry with no children. In this case the
dlist->dentries array will never be allocated. This needs to be checked
for in eventfs_release(), otherwise it will trigger a NULL pointer
dereference.
Link: https://lore.kernel.org/linux-trace-kernel/20230930090106.1c3164e9@rorschach.local.home
Cc: Mark Rutland <mark.rutland@arm.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Fixes: ef36b4f92868 ("eventfs: Remember what dentries were created on dir open")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
All architectures should use a long aligned address passed to set_bit().
User processes can pass either a 32-bit or 64-bit sized value to be
updated when tracing is enabled when on a 64-bit kernel. Both cases are
ensured to be naturally aligned, however, that is not enough. The
address must be long aligned without affecting checks on the value
within the user process which require different adjustments for the bit
for little and big endian CPUs.
Add a compat flag to user_event_enabler that indicates when a 32-bit
value is being used on a 64-bit kernel. Long align addresses and correct
the bit to be used by set_bit() to account for this alignment. Ensure
compat flags are copied during forks and used during deletion clears.
Link: https://lore.kernel.org/linux-trace-kernel/20230925230829.341-2-beaub@linux.microsoft.com
Link: https://lore.kernel.org/linux-trace-kernel/20230914131102.179100-1-cleger@rivosinc.com/
Cc: stable@vger.kernel.org
Fixes: 7235759084a4 ("tracing/user_events: Use remote writes for event enablement")
Reported-by: Clément Léger <cleger@rivosinc.com>
Suggested-by: Clément Léger <cleger@rivosinc.com>
Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
When kernel is compiled without preemption, the eval_map_work_func()
(which calls trace_event_eval_update()) will not be preempted up to its
complete execution. This can actually cause a problem since if another
CPU call stop_machine(), the call will have to wait for the
eval_map_work_func() function to finish executing in the workqueue
before being able to be scheduled. This problem was observe on a SMP
system at boot time, when the CPU calling the initcalls executed
clocksource_done_booting() which in the end calls stop_machine(). We
observed a 1 second delay because one CPU was executing
eval_map_work_func() and was not preempted by the stop_machine() task.
Adding a call to cond_resched() in trace_event_eval_update() allows
other tasks to be executed and thus continue working asynchronously
like before without blocking any pending task at boot time.
Link: https://lore.kernel.org/linux-trace-kernel/20230929191637.416931-1-cleger@rivosinc.com
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Clément Léger <cleger@rivosinc.com>
Tested-by: Atish Patra <atishp@rivosinc.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
It was discovered that the ring buffer polling was incorrectly stating
that read would not block, but that's because polling did not take into
account that reads will block if the "buffer-percent" was set. Instead,
the ring buffer polling would say reads would not block if there was any
data in the ring buffer. This was incorrect behavior from a user space
point of view. This was fixed by commit 42fb0a1e84ff by having the polling
code check if the ring buffer had more data than what the user specified
"buffer percent" had.
The problem now is that the polling code did not register itself to the
writer that it wanted to wait for a specific "full" value of the ring
buffer. The result was that the writer would wake the polling waiter
whenever there was a new event. The polling waiter would then wake up, see
that there's not enough data in the ring buffer to notify user space and
then go back to sleep. The next event would wake it up again.
Before the polling fix was added, the code would wake up around 100 times
for a hackbench 30 benchmark. After the "fix", due to the constant waking
of the writer, it would wake up over 11,0000 times! It would never leave
the kernel, so the user space behavior was still "correct", but this
definitely is not the desired effect.
To fix this, have the polling code add what it's waiting for to the
"shortest_full" variable, to tell the writer not to wake it up if the
buffer is not as full as it expects to be.
Note, after this fix, it appears that the waiter is now woken up around 2x
the times it was before (~200). This is a tremendous improvement from the
11,000 times, but I will need to spend some time to see why polling is
more aggressive in its wakeups than the read blocking code.
Link: https://lore.kernel.org/linux-trace-kernel/20230929180113.01c2cae3@rorschach.local.home
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Fixes: 42fb0a1e84ff ("tracing/ring-buffer: Have polling block on watermark")
Reported-by: Julia Lawall <julia.lawall@inria.fr>
Tested-by: Julia Lawall <julia.lawall@inria.fr>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
Eric reported that handling corresponding crash hotplug event can be
failed easily when many memory hotplug event are notified in a short
period. They failed because failing to take __kexec_lock.
=======
[ 78.714569] Fallback order for Node 0: 0
[ 78.714575] Built 1 zonelists, mobility grouping on. Total pages: 1817886
[ 78.717133] Policy zone: Normal
[ 78.724423] crash hp: kexec_trylock() failed, elfcorehdr may be inaccurate
[ 78.727207] crash hp: kexec_trylock() failed, elfcorehdr may be inaccurate
[ 80.056643] PEFILE: Unsigned PE binary
=======
The memory hotplug events are notified very quickly and very many, while
the handling of crash hotplug is much slower relatively. So the atomic
variable __kexec_lock and kexec_trylock() can't guarantee the
serialization of crash hotplug handling.
Here, add a new mutex lock __crash_hotplug_lock to serialize crash hotplug
handling specifically. This doesn't impact the usage of __kexec_lock.
Link: https://lkml.kernel.org/r/20230926120905.392903-1-bhe@redhat.com
Fixes: 247262756121 ("crash: add generic infrastructure for crash hotplug support")
Signed-off-by: Baoquan He <bhe@redhat.com>
Tested-by: Eric DeVolder <eric.devolder@oracle.com>
Reviewed-by: Eric DeVolder <eric.devolder@oracle.com>
Reviewed-by: Valentin Schneider <vschneid@redhat.com>
Cc: Sourabh Jain <sourabhjain@linux.ibm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
hugetlb_reparenting_test.sh that may cause error
According to the awk manual, the -e option does not need to be specified
in front of 'program' (unless you need to mix program-file).
The redundant -e option can cause error when users use awk tools other
than gawk (for example, mawk does not support the -e option).
Error Example:
awk: not an option: -e
Link: https://lkml.kernel.org/r/VI1P193MB075228810591AF2FDD7D42C599C3A@VI1P193MB0752.EURP193.PROD.OUTLOOK.COM
Signed-off-by: Juntong Deng <juntong.deng@outlook.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
specified
When calling mbind() with MPOL_MF_{MOVE|MOVEALL} | MPOL_MF_STRICT, kernel
should attempt to migrate all existing pages, and return -EIO if there is
misplaced or unmovable page. Then commit 6f4576e3687b ("mempolicy: apply
page table walker on queue_pages_range()") messed up the return value and
didn't break VMA scan early ianymore when MPOL_MF_STRICT alone. The
return value problem was fixed by commit a7f40cfe3b7a ("mm: mempolicy:
make mbind() return -EIO when MPOL_MF_STRICT is specified"), but it broke
the VMA walk early if unmovable page is met, it may cause some pages are
not migrated as expected.
The code should conceptually do:
if (MPOL_MF_MOVE|MOVEALL)
scan all vmas
try to migrate the existing pages
return success
else if (MPOL_MF_MOVE* | MPOL_MF_STRICT)
scan all vmas
try to migrate the existing pages
return -EIO if unmovable or migration failed
else /* MPOL_MF_STRICT alone */
break early if meets unmovable and don't call mbind_range() at all
else /* none of those flags */
check the ranges in test_walk, EFAULT without mbind_range() if discontig.
Fixed the behavior.
Link: https://lkml.kernel.org/r/20230920223242.3425775-1-yang@os.amperecomputing.com
Fixes: a7f40cfe3b7a ("mm: mempolicy: make mbind() return -EIO when MPOL_MF_STRICT is specified")
Signed-off-by: Yang Shi <yang@os.amperecomputing.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Rafael Aquini <aquini@redhat.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: David Rientjes <rientjes@google.com>
Cc: <stable@vger.kernel.org> [4.9+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
When CONFIG_DAMON_VADDR_KUNIT_TEST=y and making CONFIG_DEBUG_KMEMLEAK=y
and CONFIG_DEBUG_KMEMLEAK_AUTO_SCAN=y, the below memory leak is detected.
Since commit 9f86d624292c ("mm/damon/vaddr-test: remove unnecessary
variables"), the damon_destroy_ctx() is removed, but still call
damon_new_target() and damon_new_region(), the damon_region which is
allocated by kmem_cache_alloc() in damon_new_region() and the damon_target
which is allocated by kmalloc in damon_new_target() are not freed. And
the damon_region which is allocated in damon_new_region() in
damon_set_regions() is also not freed.
So use damon_destroy_target to free all the damon_regions and damon_target.
unreferenced object 0xffff888107c9a940 (size 64):
comm "kunit_try_catch", pid 1069, jiffies 4294670592 (age 732.761s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 06 00 00 00 6b 6b 6b 6b ............kkkk
60 c7 9c 07 81 88 ff ff f8 cb 9c 07 81 88 ff ff `...............
backtrace:
[<ffffffff817e0167>] kmalloc_trace+0x27/0xa0
[<ffffffff819c11cf>] damon_new_target+0x3f/0x1b0
[<ffffffff819c7d55>] damon_do_test_apply_three_regions.constprop.0+0x95/0x3e0
[<ffffffff819c82be>] damon_test_apply_three_regions1+0x21e/0x260
[<ffffffff829fce6a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
[<ffffffff81237cf6>] kthread+0x2b6/0x380
[<ffffffff81097add>] ret_from_fork+0x2d/0x70
[<ffffffff81003791>] ret_from_fork_asm+0x11/0x20
unreferenced object 0xffff8881079cc740 (size 56):
comm "kunit_try_catch", pid 1069, jiffies 4294670592 (age 732.761s)
hex dump (first 32 bytes):
05 00 00 00 00 00 00 00 14 00 00 00 00 00 00 00 ................
6b 6b 6b 6b 6b 6b 6b 6b 00 00 00 00 6b 6b 6b 6b kkkkkkkk....kkkk
backtrace:
[<ffffffff819bc492>] damon_new_region+0x22/0x1c0
[<ffffffff819c7d91>] damon_do_test_apply_three_regions.constprop.0+0xd1/0x3e0
[<ffffffff819c82be>] damon_test_apply_three_regions1+0x21e/0x260
[<ffffffff829fce6a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
[<ffffffff81237cf6>] kthread+0x2b6/0x380
[<ffffffff81097add>] ret_from_fork+0x2d/0x70
[<ffffffff81003791>] ret_from_fork_asm+0x11/0x20
unreferenced object 0xffff888107c9ac40 (size 64):
comm "kunit_try_catch", pid 1071, jiffies 4294670595 (age 732.843s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 06 00 00 00 6b 6b 6b 6b ............kkkk
a0 cc 9c 07 81 88 ff ff 78 a1 76 07 81 88 ff ff ........x.v.....
backtrace:
[<ffffffff817e0167>] kmalloc_trace+0x27/0xa0
[<ffffffff819c11cf>] damon_new_target+0x3f/0x1b0
[<ffffffff819c7d55>] damon_do_test_apply_three_regions.constprop.0+0x95/0x3e0
[<ffffffff819c851e>] damon_test_apply_three_regions2+0x21e/0x260
[<ffffffff829fce6a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
[<ffffffff81237cf6>] kthread+0x2b6/0x380
[<ffffffff81097add>] ret_from_fork+0x2d/0x70
[<ffffffff81003791>] ret_from_fork_asm+0x11/0x20
unreferenced object 0xffff8881079ccc80 (size 56):
comm "kunit_try_catch", pid 1071, jiffies 4294670595 (age 732.843s)
hex dump (first 32 bytes):
05 00 00 00 00 00 00 00 14 00 00 00 00 00 00 00 ................
6b 6b 6b 6b 6b 6b 6b 6b 00 00 00 00 6b 6b 6b 6b kkkkkkkk....kkkk
backtrace:
[<ffffffff819bc492>] damon_new_region+0x22/0x1c0
[<ffffffff819c7d91>] damon_do_test_apply_three_regions.constprop.0+0xd1/0x3e0
[<ffffffff819c851e>] damon_test_apply_three_regions2+0x21e/0x260
[<ffffffff829fce6a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
[<ffffffff81237cf6>] kthread+0x2b6/0x380
[<ffffffff81097add>] ret_from_fork+0x2d/0x70
[<ffffffff81003791>] ret_from_fork_asm+0x11/0x20
unreferenced object 0xffff888107c9af40 (size 64):
comm "kunit_try_catch", pid 1073, jiffies 4294670597 (age 733.011s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 06 00 00 00 6b 6b 6b 6b ............kkkk
20 a2 76 07 81 88 ff ff b8 a6 76 07 81 88 ff ff .v.......v.....
backtrace:
[<ffffffff817e0167>] kmalloc_trace+0x27/0xa0
[<ffffffff819c11cf>] damon_new_target+0x3f/0x1b0
[<ffffffff819c7d55>] damon_do_test_apply_three_regions.constprop.0+0x95/0x3e0
[<ffffffff819c877e>] damon_test_apply_three_regions3+0x21e/0x260
[<ffffffff829fce6a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
[<ffffffff81237cf6>] kthread+0x2b6/0x380
[<ffffffff81097add>] ret_from_fork+0x2d/0x70
[<ffffffff81003791>] ret_from_fork_asm+0x11/0x20
unreferenced object 0xffff88810776a200 (size 56):
comm "kunit_try_catch", pid 1073, jiffies 4294670597 (age 733.011s)
hex dump (first 32 bytes):
05 00 00 00 00 00 00 00 14 00 00 00 00 00 00 00 ................
6b 6b 6b 6b 6b 6b 6b 6b 00 00 00 00 6b 6b 6b 6b kkkkkkkk....kkkk
backtrace:
[<ffffffff819bc492>] damon_new_region+0x22/0x1c0
[<ffffffff819c7d91>] damon_do_test_apply_three_regions.constprop.0+0xd1/0x3e0
[<ffffffff819c877e>] damon_test_apply_three_regions3+0x21e/0x260
[<ffffffff829fce6a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
[<ffffffff81237cf6>] kthread+0x2b6/0x380
[<ffffffff81097add>] ret_from_fork+0x2d/0x70
[<ffffffff81003791>] ret_from_fork_asm+0x11/0x20
unreferenced object 0xffff88810776a740 (size 56):
comm "kunit_try_catch", pid 1073, jiffies 4294670597 (age 733.025s)
hex dump (first 32 bytes):
3d 00 00 00 00 00 00 00 3f 00 00 00 00 00 00 00 =.......?.......
6b 6b 6b 6b 6b 6b 6b 6b 00 00 00 00 6b 6b 6b 6b kkkkkkkk....kkkk
backtrace:
[<ffffffff819bc492>] damon_new_region+0x22/0x1c0
[<ffffffff819bfcc2>] damon_set_regions+0x4c2/0x8e0
[<ffffffff819c7dbb>] damon_do_test_apply_three_regions.constprop.0+0xfb/0x3e0
[<ffffffff819c877e>] damon_test_apply_three_regions3+0x21e/0x260
[<ffffffff829fce6a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
[<ffffffff81237cf6>] kthread+0x2b6/0x380
[<ffffffff81097add>] ret_from_fork+0x2d/0x70
[<ffffffff81003791>] ret_from_fork_asm+0x11/0x20
unreferenced object 0xffff888108038240 (size 64):
comm "kunit_try_catch", pid 1075, jiffies 4294670600 (age 733.022s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 03 00 00 00 6b 6b 6b 6b ............kkkk
48 ad 76 07 81 88 ff ff 98 ae 76 07 81 88 ff ff H.v.......v.....
backtrace:
[<ffffffff817e0167>] kmalloc_trace+0x27/0xa0
[<ffffffff819c11cf>] damon_new_target+0x3f/0x1b0
[<ffffffff819c7d55>] damon_do_test_apply_three_regions.constprop.0+0x95/0x3e0
[<ffffffff819c898d>] damon_test_apply_three_regions4+0x1cd/0x210
[<ffffffff829fce6a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
[<ffffffff81237cf6>] kthread+0x2b6/0x380
[<ffffffff81097add>] ret_from_fork+0x2d/0x70
[<ffffffff81003791>] ret_from_fork_asm+0x11/0x20
unreferenced object 0xffff88810776ad28 (size 56):
comm "kunit_try_catch", pid 1075, jiffies 4294670600 (age 733.022s)
hex dump (first 32 bytes):
05 00 00 00 00 00 00 00 07 00 00 00 00 00 00 00 ................
6b 6b 6b 6b 6b 6b 6b 6b 00 00 00 00 6b 6b 6b 6b kkkkkkkk....kkkk
backtrace:
[<ffffffff819bc492>] damon_new_region+0x22/0x1c0
[<ffffffff819bfcc2>] damon_set_regions+0x4c2/0x8e0
[<ffffffff819c7dbb>] damon_do_test_apply_three_regions.constprop.0+0xfb/0x3e0
[<ffffffff819c898d>] damon_test_apply_three_regions4+0x1cd/0x210
[<ffffffff829fce6a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
[<ffffffff81237cf6>] kthread+0x2b6/0x380
[<ffffffff81097add>] ret_from_fork+0x2d/0x70
[<ffffffff81003791>] ret_from_fork_asm+0x11/0x20
Link: https://lkml.kernel.org/r/20230925072100.3725620-1-ruanjinjie@huawei.com
Fixes: 9f86d624292c ("mm/damon/vaddr-test: remove unnecessary variables")
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
This reverts commits 86327e8eb94c ("memcg: drop kmem.limit_in_bytes") and
partially reverts 58056f77502f ("memcg, kmem: further deprecate
kmem.limit_in_bytes") which have incrementally removed support for the
kernel memory accounting hard limit. Unfortunately it has turned out that
there is still userspace depending on the existence of
memory.kmem.limit_in_bytes [1]. The underlying functionality is not
really required but the non-existent file just confuses the userspace
which fails in the result. The patch to fix this on the userspace side
has been submitted but it is hard to predict how it will propagate through
the maze of 3rd party consumers of the software.
Now, reverting alone 86327e8eb94c is not an option because there is
another set of userspace which cannot cope with ENOTSUPP returned when
writing to the file. Therefore we have to go and revisit 58056f77502f as
well. There are two ways to go ahead. Either we give up on the
deprecation and fully revert 58056f77502f as well or we can keep
kmem.limit_in_bytes but make the write a noop and warn about the fact.
This should work for both known breaking workloads which depend on the
existence but do not depend on the hard limit enforcement.
Note to backporters to stable trees. a8c49af3be5f ("memcg: add per-memcg
total kernel memory stat") introduced in 4.18 has added memcg_account_kmem
so the accounting is not done by obj_cgroup_charge_pages directly for v1
anymore. Prior kernels need to add it explicitly (thanks to Johannes for
pointing this out).
[akpm@linux-foundation.org: fix build - remove unused local]
Link: http://lkml.kernel.org/r/20230920081101.GA12096@linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net [1]
Link: https://lkml.kernel.org/r/ZRE5VJozPZt9bRPy@dhcp22.suse.cz
Fixes: 86327e8eb94c ("memcg: drop kmem.limit_in_bytes")
Fixes: 58056f77502f ("memcg, kmem: further deprecate kmem.limit_in_bytes")
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jeremi Piotrowski <jpiotrowski@linux.microsoft.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Tejun heo <tj@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
While stress-testing zswap a memory corruption was happening when writing
back pages. __frontswap_store used to check for duplicate entries before
attempting to store a page in zswap, this was because if the store fails
the old entry isn't removed from the tree. This change removes duplicate
entries in zswap_store before the actual attempt.
[cerasuolodomenico@gmail.com: add a warning and a comment, per Johannes]
Link: https://lkml.kernel.org/r/20230925130002.1929369-1-cerasuolodomenico@gmail.com
Link: https://lkml.kernel.org/r/20230922172211.1704917-1-cerasuolodomenico@gmail.com
Fixes: 42c06a0e8ebe ("mm: kill frontswap")
Signed-off-by: Domenico Cerasuolo <cerasuolodomenico@gmail.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Nhat Pham <nphamcs@gmail.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
When called with a swap entry that does not embed a PFN (e.g.
PTE_MARKER_POISONED or PTE_MARKER_UFFD_WP), the previous implementation of
set_huge_pte_at() would either cause a BUG() to fire (if CONFIG_DEBUG_VM
is enabled) or cause a dereference of an invalid address and subsequent
panic.
arm64's huge pte implementation supports multiple huge page sizes, some of
which are implemented in the page table with multiple contiguous entries.
So set_huge_pte_at() needs to work out how big the logical pte is, so that
it can also work out how many physical ptes (or pmds) need to be written.
It previously did this by grabbing the folio out of the pte and querying
its size.
However, there are cases when the pte being set is actually a swap entry.
But this also used to work fine, because for huge ptes, we only ever saw
migration entries and hwpoison entries. And both of these types of swap
entries have a PFN embedded, so the code would grab that and everything
still worked out.
But over time, more calls to set_huge_pte_at() have been added that set
swap entry types that do not embed a PFN. And this causes the code to go
bang. The triggering case is for the uffd poison test, commit
99aa77215ad0 ("selftests/mm: add uffd unit test for UFFDIO_POISON"), which
causes a PTE_MARKER_POISONED swap entry to be set, coutesey of commit
8a13897fb0da ("mm: userfaultfd: support UFFDIO_POISON for hugetlbfs") -
added in v6.5-rc7. Although review shows that there are other call sites
that set PTE_MARKER_UFFD_WP (which also has no PFN), these don't trigger
on arm64 because arm64 doesn't support UFFD WP.
Arguably, the root cause is really due to commit 18f3962953e4 ("mm:
hugetlb: kill set_huge_swap_pte_at()"), which aimed to simplify the
interface to the core code by removing set_huge_swap_pte_at() (which took
a page size parameter) and replacing it with calls to set_huge_pte_at()
where the size was inferred from the folio, as descibed above. While that
commit didn't break anything at the time, it did break the interface
because it couldn't handle swap entries without PFNs. And since then new
callers have come along which rely on this working. But given the
brokeness is only observable after commit 8a13897fb0da ("mm: userfaultfd:
support UFFDIO_POISON for hugetlbfs"), that one gets the Fixes tag.
Now that we have modified the set_huge_pte_at() interface to pass the huge
page size in the previous patch, we can trivially fix this issue.
Link: https://lkml.kernel.org/r/20230922115804.2043771-3-ryan.roberts@arm.com
Fixes: 8a13897fb0da ("mm: userfaultfd: support UFFDIO_POISON for hugetlbfs")
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Reviewed-by: Axel Rasmussen <axelrasmussen@google.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Cc: <stable@vger.kernel.org> [6.5+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Patch series "Fix set_huge_pte_at() panic on arm64", v2.
This series fixes a bug in arm64's implementation of set_huge_pte_at(),
which can result in an unprivileged user causing a kernel panic. The
problem was triggered when running the new uffd poison mm selftest for
HUGETLB memory. This test (and the uffd poison feature) was merged for
v6.5-rc7.
Ideally, I'd like to get this fix in for v6.6 and I've cc'ed stable
(correctly this time) to get it backported to v6.5, where the issue first
showed up.
Description of Bug
==================
arm64's huge pte implementation supports multiple huge page sizes, some of
which are implemented in the page table with multiple contiguous entries.
So set_huge_pte_at() needs to work out how big the logical pte is, so that
it can also work out how many physical ptes (or pmds) need to be written.
It previously did this by grabbing the folio out of the pte and querying
its size.
However, there are cases when the pte being set is actually a swap entry.
But this also used to work fine, because for huge ptes, we only ever saw
migration entries and hwpoison entries. And both of these types of swap
entries have a PFN embedded, so the code would grab that and everything
still worked out.
But over time, more calls to set_huge_pte_at() have been added that set
swap entry types that do not embed a PFN. And this causes the code to go
bang. The triggering case is for the uffd poison test, commit
99aa77215ad0 ("selftests/mm: add uffd unit test for UFFDIO_POISON"), which
causes a PTE_MARKER_POISONED swap entry to be set, coutesey of commit
8a13897fb0da ("mm: userfaultfd: support UFFDIO_POISON for hugetlbfs") -
added in v6.5-rc7. Although review shows that there are other call sites
that set PTE_MARKER_UFFD_WP (which also has no PFN), these don't trigger
on arm64 because arm64 doesn't support UFFD WP.
If CONFIG_DEBUG_VM is enabled, we do at least get a BUG(), but otherwise,
it will dereference a bad pointer in page_folio():
static inline struct folio *hugetlb_swap_entry_to_folio(swp_entry_t entry)
{
VM_BUG_ON(!is_migration_entry(entry) && !is_hwpoison_entry(entry));
return page_folio(pfn_to_page(swp_offset_pfn(entry)));
}
Fix
===
The simplest fix would have been to revert the dodgy cleanup commit
18f3962953e4 ("mm: hugetlb: kill set_huge_swap_pte_at()"), but since
things have moved on, this would have required an audit of all the new
set_huge_pte_at() call sites to see if they should be converted to
set_huge_swap_pte_at(). As per the original intent of the change, it
would also leave us open to future bugs when people invariably get it
wrong and call the wrong helper.
So instead, I've added a huge page size parameter to set_huge_pte_at().
This means that the arm64 code has the size in all cases. It's a bigger
change, due to needing to touch the arches that implement the function,
but it is entirely mechanical, so in my view, low risk.
I've compile-tested all touched arches; arm64, parisc, powerpc, riscv,
s390, sparc (and additionally x86_64). I've additionally booted and run
mm selftests against arm64, where I observe the uffd poison test is fixed,
and there are no other regressions.
This patch (of 2):
In order to fix a bug, arm64 needs to be told the size of the huge page
for which the pte is being set in set_huge_pte_at(). Provide for this by
adding an `unsigned long sz` parameter to the function. This follows the
same pattern as huge_pte_clear().
This commit makes the required interface modifications to the core mm as
well as all arches that implement this function (arm64, parisc, powerpc,
riscv, s390, sparc). The actual arm64 bug will be fixed in a separate
commit.
No behavioral changes intended.
Link: https://lkml.kernel.org/r/20230922115804.2043771-1-ryan.roberts@arm.com
Link: https://lkml.kernel.org/r/20230922115804.2043771-2-ryan.roberts@arm.com
Fixes: 8a13897fb0da ("mm: userfaultfd: support UFFDIO_POISON for hugetlbfs")
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> [powerpc 8xx]
Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com> [vmalloc change]
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Cc: <stable@vger.kernel.org> [6.5+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
When updating the maple tree iterator to avoid rewalks, an issue was
introduced when shifting beyond the limits. This can be seen by trying to
go to the previous address of 0, which would set the maple node to
MAS_NONE and keep the range as the last entry.
Subsequent calls to mas_find() would then search upwards from mas->last
and skip the value at mas->index/mas->last. This showed up as a bug in
mprotect which skips the actual VMA at the current range after attempting
to go to the previous VMA from 0.
Since MAS_NONE may already be set when searching for a value that isn't
contained within a node, changing the handling of MAS_NONE in mas_find()
would make the code more complicated and error prone. Furthermore, there
was no way to tell which limit was hit, and thus which action to take
(next or the entry at the current range).
This solution is to add two states to track what happened with the
previous iterator action. This allows for the expected behaviour of the
next command to return the correct item (either the item at the range
requested, or the next/previous).
Tests are also added and updated accordingly.
Link: https://lkml.kernel.org/r/20230921181236.509072-3-Liam.Howlett@oracle.com
Link: https://gist.github.com/heatd/85d2971fae1501b55b6ea401fbbe485b
Link: https://lore.kernel.org/linux-mm/20230921181236.509072-1-Liam.Howlett@oracle.com/
Fixes: 39193685d585 ("maple_tree: try harder to keep active node with mas_prev()")
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reported-by: Pedro Falcato <pedro.falcato@gmail.com>
Closes: https://gist.github.com/heatd/85d2971fae1501b55b6ea401fbbe485b
Closes: https://bugs.archlinux.org/task/79656
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Patch series "maple_tree: Fix mas_prev() state regression".
Pedro Falcato retported an mprotect regression [1] which was bisected back
to the iterator changes for maple tree. Root cause analysis showed the
mas_prev() running off the end of the VMA space (previous from 0) followed
by mas_find(), would skip the first value.
This patchset introduces maple state underflow/overflow so the sequence of
calls on the maple state will return what the user expects.
Users who encounter this bug may see mprotect(), userfaultfd_register(),
and mlock() fail on VMAs mapped with address 0.
This patch (of 2):
Instead of constantly checking each possibility of the maple state,
create a fast path that will skip over checking unlikely states.
Link: https://lkml.kernel.org/r/20230921181236.509072-1-Liam.Howlett@oracle.com
Link: https://lkml.kernel.org/r/20230921181236.509072-2-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Pedro Falcato <pedro.falcato@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
In nilfs_gccache_submit_read_data(), brelse(bh) is called to drop the
reference count of bh when the call to nilfs_dat_translate() fails. If
the reference count hits 0 and its owner page gets unlocked, bh may be
freed. However, bh->b_page is dereferenced to put the page after that,
which may result in a use-after-free bug. This patch moves the release
operation after unlocking and putting the page.
NOTE: The function in question is only called in GC, and in combination
with current userland tools, address translation using DAT does not occur
in that function, so the code path that causes this issue will not be
executed. However, it is possible to run that code path by intentionally
modifying the userland GC library or by calling the GC ioctl directly.
[konishi.ryusuke@gmail.com: NOTE added to the commit log]
Link: https://lkml.kernel.org/r/1543201709-53191-1-git-send-email-bianpan2016@163.com
Link: https://lkml.kernel.org/r/20230921141731.10073-1-konishi.ryusuke@gmail.com
Fixes: a3d93f709e89 ("nilfs2: block cache for garbage collection")
Signed-off-by: Pan Bian <bianpan2016@163.com>
Reported-by: Ferry Meng <mengferry@linux.alibaba.com>
Closes: https://lkml.kernel.org/r/20230818092022.111054-1-mengferry@linux.alibaba.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
In order to fix the L1TF vulnerability, x86 can invert the PTE bits for
PROT_NONE VMAs, which means we cannot move from one PTE to the next by
adding 1 to the PFN field of the PTE. This results in the BUG reported at
[1].
Abstract advancing the PTE to the next PFN through a pte_next_pfn()
function/macro.
Link: https://lkml.kernel.org/r/20230920040958.866520-1-willy@infradead.org
Fixes: bcc6cc832573 ("mm: add default definition of set_ptes()")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reported-by: syzbot+55cc72f8cc3a549119df@syzkaller.appspotmail.com
Closes: https://lkml.kernel.org/r/000000000000d099fa0604f03351@google.com [1]
Reviewed-by: Yin Fengwei <fengwei.yin@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
