Split up test_hash_init so that it calls each test more explicitly
insofar it is possible without rewriting the entire file. This aims at
improving readability.
Split tests performed on string_or as they don't interfere with those
performed in hash_or. Also separate pr_info calls about skipped tests
as they're not part of the tests themselves, but only warn about
(un)defined arch-specific hash functions.
Link: https://lkml.kernel.org/r/20211208183711.390454-4-isabbasso@riseup.net
Reviewed-by: David Gow <davidgow@google.com>
Tested-by: David Gow <davidgow@google.com>
Signed-off-by: Isabella Basso <isabbasso@riseup.net>
Cc: Augusto Durães Camargo <augusto.duraes33@gmail.com>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: Daniel Latypov <dlatypov@google.com>
Cc: Enzo Ferreira <ferreiraenzoa@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: kernel test robot <lkp@intel.com>
Cc: Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Split the test_int_hash function to keep its mainloop separate from
arch-specific chunks, which are only compiled as needed. This aims at
improving readability.
Link: https://lkml.kernel.org/r/20211208183711.390454-3-isabbasso@riseup.net
Reviewed-by: David Gow <davidgow@google.com>
Tested-by: David Gow <davidgow@google.com>
Signed-off-by: Isabella Basso <isabbasso@riseup.net>
Cc: Augusto Durães Camargo <augusto.duraes33@gmail.com>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: Daniel Latypov <dlatypov@google.com>
Cc: Enzo Ferreira <ferreiraenzoa@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: kernel test robot <lkp@intel.com>
Cc: Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "test_hash.c: refactor into KUnit", v3.
We refactored the lib/test_hash.c file into KUnit as part of the student
group LKCAMP [1] introductory hackathon for kernel development.
This test was pointed to our group by Daniel Latypov [2], so its full
conversion into a pure KUnit test was our goal in this patch series, but
we ran into many problems relating to it not being split as unit tests,
which complicated matters a bit, as the reasoning behind the original
tests is quite cryptic for those unfamiliar with hash implementations.
Some interesting developments we'd like to highlight are:
- In patch 1/5 we noticed that there was an unused define directive
that could be removed.
- In patch 4/5 we noticed how stringhash and hash tests are all under
the lib/test_hash.c file, which might cause some confusion, and we
also broke those kernel config entries up.
Overall KUnit developments have been made in the other patches in this
series:
In patches 2/5, 3/5 and 5/5 we refactored the lib/test_hash.c file so as
to make it more compatible with the KUnit style, whilst preserving the
original idea of the maintainer who designed it (i.e. George Spelvin),
which might be undesirable for unit tests, but we assume it is enough
for a first patch.
This patch (of 5):
Currently, there exist hash_32() and __hash_32() functions, which were
introduced in a patch [1] targeting architecture specific optimizations.
These functions can be overridden on a per-architecture basis to achieve
such optimizations. They must set their corresponding define directive
(HAVE_ARCH_HASH_32 and HAVE_ARCH__HASH_32, respectively) so that header
files can deal with these overrides properly.
As the supported 32-bit architectures that have their own hash function
implementation (i.e. m68k, Microblaze, H8/300, pa-risc) have only been
making use of the (more general) __hash_32() function (which only lacks
a right shift operation when compared to the hash_32() function), remove
the define directive corresponding to the arch-specific hash_32()
implementation.
[1] https://lore.kernel.org/lkml/20160525073311.5600.qmail@ns.sciencehorizons.net/
[akpm@linux-foundation.org: hash_32_generic() becomes hash_32()]
Link: https://lkml.kernel.org/r/20211208183711.390454-1-isabbasso@riseup.net
Link: https://lkml.kernel.org/r/20211208183711.390454-2-isabbasso@riseup.net
Reviewed-by: David Gow <davidgow@google.com>
Tested-by: David Gow <davidgow@google.com>
Co-developed-by: Augusto Durães Camargo <augusto.duraes33@gmail.com>
Signed-off-by: Augusto Durães Camargo <augusto.duraes33@gmail.com>
Co-developed-by: Enzo Ferreira <ferreiraenzoa@gmail.com>
Signed-off-by: Enzo Ferreira <ferreiraenzoa@gmail.com>
Signed-off-by: Isabella Basso <isabbasso@riseup.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: Daniel Latypov <dlatypov@google.com>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>
Cc: kernel test robot <lkp@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, the entry->prev and entry->next are considered to be valid as
long as they are not LIST_POISON{1|2}. However, the memory may be
corrupted. The prev->next is invalid probably because 'prev' is
invalid, not because prev->next's content is illegal.
Unfortunately, the printk and its subfunctions will modify the registers
that hold the 'prev' and 'next', and we don't see this valuable
information in the BUG context.
So print the contents of 'entry->prev' and 'entry->next'.
Here's an example:
list_del corruption. prev->next should be c0ecbf74, but was c08410dc
kernel BUG at lib/list_debug.c:53!
... ...
PC is at __list_del_entry_valid+0x58/0x98
LR is at __list_del_entry_valid+0x58/0x98
psr: 60000093
sp : c0ecbf30 ip : 00000000 fp : 00000001
r10: c08410d0 r9 : 00000001 r8 : c0825e0c
r7 : 20000013 r6 : c08410d0 r5 : c0ecbf74 r4 : c0ecbf74
r3 : c0825d08 r2 : 00000000 r1 : df7ce6f4 r0 : 00000044
... ...
Stack: (0xc0ecbf30 to 0xc0ecc000)
bf20: c0ecbf74 c0164fd0 c0ecbf70 c0165170
bf40: c0eca000 c0840c00 c0840c00 c0824500 c0825e0c c0189bbc c088f404 60000013
bf60: 60000013 c0e85100 000004ec 00000000 c0ebcdc0 c0ecbf74 c0ecbf74 c0825d08
bf80: c0e807c0 c018965c 00000000 c013f2a0 c0e807c0 c013f154 00000000 00000000
bfa0: 00000000 00000000 00000000 c01001b0 00000000 00000000 00000000 00000000
bfc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
bfe0: 00000000 00000000 00000000 00000000 00000013 00000000 00000000 00000000
(__list_del_entry_valid) from (__list_del_entry+0xc/0x20)
(__list_del_entry) from (finish_swait+0x60/0x7c)
(finish_swait) from (rcu_gp_kthread+0x560/0xa20)
(rcu_gp_kthread) from (kthread+0x14c/0x15c)
(kthread) from (ret_from_fork+0x14/0x24)
At first, I thought prev->next was overwritten. Later, I carefully
analyzed the RCU code and the disassembly code. The error occurred when
deleting a node from the list rcu_state.gp_wq. The System.map shows
that the address of rcu_state is c0840c00. Then I use gdb to obtain the
offset of rcu_state.gp_wq.task_list.
(gdb) p &((struct rcu_state *)0)->gp_wq.task_list
$1 = (struct list_head *) 0x4dc
Again:
list_del corruption. prev->next should be c0ecbf74, but was c08410dc
c08410dc = c0840c00 + 0x4dc = &rcu_state.gp_wq.task_list
Because rcu_state.gp_wq has at most one node, so I can guess that "prev
= &rcu_state.gp_wq.task_list". But for other scenes, maybe I wasn't so
lucky, I cannot figure out the value of 'prev'.
Link: https://lkml.kernel.org/r/20211207025835.1909-1-thunder.leizhen@huawei.com
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Introduce list_is_head() in the similar (*) way as it's done for
list_entry_is_head(). Make use of it in the list.h.
*) it's done as inliner and not a macro to be aligned with other
list_is_*() APIs; while at it, make all three to have the same
style.
Link: https://lkml.kernel.org/r/20211201141824.81400-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When --nogit is used with scripts/get_maintainer.pl, the script spews 4
lines of unnecessary information (noise). Do not print those lines when
--nogit is specified.
This change removes the printing of these 4 lines:
./scripts/get_maintainer.pl: No supported VCS found. Add --nogit to options?
Using a git repository produces better results.
Try Linus Torvalds' latest git repository using:
git clone git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Link: https://lkml.kernel.org/r/20220102031424.3328-1-rdunlap@infradead.org
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
PRIO_PGRP needs the tasklist_lock mainly to serialize vs setpgid(2), to
protect against any concurrent change_pid(PIDTYPE_PGID) that can move
the task from one hlist to another while iterating.
However, the remaining can only rely only on RCU:
PRIO_PROCESS only does the task lookup and never iterates over tasklist
and we already have an rcu-aware stable pointer.
PRIO_USER is already racy vs setuid(2) so with creds being rcu
protected, we can end up seeing stale data. When removing the
tasklist_lock there can be a race with (i) fork but this is benign as
the child's nice is inherited and the new task is not observable by the
user yet either, hence the return semantics do not differ. And (ii) a
race with exit, which is a small window and can cause us to miss a task
which was removed from the list and it had the highest nice.
Similarly change the buggy do_each_thread/while_each_thread combo in
PRIO_USER for the rcu-safe for_each_process_thread flavor, which doesn't
make use of next_thread/p->thread_group.
[akpm@linux-foundation.org: coding style fixes]
Link: https://lkml.kernel.org/r/20211210182250.43734-1-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When I was implementing a new per-cpu kthread cfs_migration, I found the
comm of it "cfs_migration/%u" is truncated due to the limitation of
TASK_COMM_LEN. For example, the comm of the percpu thread on CPU10~19
all have the same name "cfs_migration/1", which will confuse the user.
This issue is not critical, because we can get the corresponding CPU
from the task's Cpus_allowed. But for kthreads corresponding to other
hardware devices, it is not easy to get the detailed device info from
task comm, for example,
jbd2/nvme0n1p2-
xfs-reclaim/sdf
Currently there are so many truncated kthreads:
rcu_tasks_kthre
rcu_tasks_rude_
rcu_tasks_trace
poll_mpt3sas0_s
ext4-rsv-conver
xfs-reclaim/sd{a, b, c, ...}
xfs-blockgc/sd{a, b, c, ...}
xfs-inodegc/sd{a, b, c, ...}
audit_send_repl
ecryptfs-kthrea
vfio-irqfd-clea
jbd2/nvme0n1p2-
...
We can shorten these names to work around this problem, but it may be
not applied to all of the truncated kthreads. Take 'jbd2/nvme0n1p2-'
for example, it is a nice name, and it is not a good idea to shorten it.
One possible way to fix this issue is extending the task comm size, but
as task->comm is used in lots of places, that may cause some potential
buffer overflows. Another more conservative approach is introducing a
new pointer to store kthread's full name if it is truncated, which won't
introduce too much overhead as it is in the non-critical path. Finally
we make a dicision to use the second approach. See also the discussions
in this thread:
https://lore.kernel.org/lkml/20211101060419.4682-1-laoar.shao@gmail.com/
After this change, the full name of these truncated kthreads will be
displayed via /proc/[pid]/comm:
rcu_tasks_kthread
rcu_tasks_rude_kthread
rcu_tasks_trace_kthread
poll_mpt3sas0_statu
ext4-rsv-conversion
xfs-reclaim/sdf1
xfs-blockgc/sdf1
xfs-inodegc/sdf1
audit_send_reply
ecryptfs-kthread
vfio-irqfd-cleanup
jbd2/nvme0n1p2-8
Link: https://lkml.kernel.org/r/20211120112850.46047-1-laoar.shao@gmail.com
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Suggested-by: Petr Mladek <pmladek@suse.com>
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: Michal Miroslaw <mirq-linux@rere.qmqm.pl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As the sched:sched_switch tracepoint args are derived from the kernel,
we'd better make it same with the kernel. So the macro TASK_COMM_LEN is
converted to type enum, then all the BPF programs can get it through
BTF.
The BPF program which wants to use TASK_COMM_LEN should include the
header vmlinux.h. Regarding the test_stacktrace_map and
test_tracepoint, as the type defined in linux/bpf.h are also defined in
vmlinux.h, so we don't need to include linux/bpf.h again.
Link: https://lkml.kernel.org/r/20211120112738.45980-8-laoar.shao@gmail.com
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com>
Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: Michal Miroslaw <mirq-linux@rere.qmqm.pl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Kees Cook <keescook@chromium.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
bpf_probe_read_kernel_str() will add a nul terminator to the dst, then
we don't care about if the dst size is big enough.
Link: https://lkml.kernel.org/r/20211120112738.45980-7-laoar.shao@gmail.com
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: Michal Miroslaw <mirq-linux@rere.qmqm.pl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Kees Cook <keescook@chromium.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
bpf_probe_read_kernel_str() will add a nul terminator to the dst, then
we don't care about if the dst size is big enough. This patch also
replaces the hard-coded 16 with TASK_COMM_LEN to make it grepable.
Link: https://lkml.kernel.org/r/20211120112738.45980-6-laoar.shao@gmail.com
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: Michal Miroslaw <mirq-linux@rere.qmqm.pl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Kees Cook <keescook@chromium.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We'd better use the helper get_task_comm() rather than the open-coded
strlcpy() to get task comm. As the comment above the hard-coded 16, we
can replace it with TASK_COMM_LEN.
Link: https://lkml.kernel.org/r/20211120112738.45980-4-laoar.shao@gmail.com
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: Michal Miroslaw <mirq-linux@rere.qmqm.pl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Kees Cook <keescook@chromium.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If the dest buffer size is smaller than sizeof(tsk->comm), the buffer
will be without null ternimator, that may cause problem. Using
strscpy_pad() instead of strncpy() in __get_task_comm() can make the
string always nul ternimated and zero padded.
Link: https://lkml.kernel.org/r/20211120112738.45980-3-laoar.shao@gmail.com
Suggested-by: Kees Cook <keescook@chromium.org>
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: Michal Miroslaw <mirq-linux@rere.qmqm.pl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Kees Cook <keescook@chromium.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "task comm cleanups", v2.
This patchset is part of the patchset "extend task comm from 16 to
24"[1]. Now we have different opinion that dynamically allocates memory
to store kthread's long name into a separate pointer, so I decide to
take the useful cleanups apart from the original patchset and send it
separately[2].
These useful cleanups can make the usage around task comm less
error-prone. Furthermore, it will be useful if we want to extend task
comm in the future.
[1]. https://lore.kernel.org/lkml/20211101060419.4682-1-laoar.shao@gmail.com/
[2]. https://lore.kernel.org/lkml/CALOAHbAx55AUo3bm8ZepZSZnw7A08cvKPdPyNTf=E_tPqmw5hw@mail.gmail.com/
This patch (of 7):
strlcpy() can trigger out-of-bound reads on the source string[1], we'd
better use strscpy() instead. To make it be robust against full tsk->comm
copies that got noticed in other places, we should make sure it's zero
padded.
[1] https://github.com/KSPP/linux/issues/89
Link: https://lkml.kernel.org/r/20211120112738.45980-1-laoar.shao@gmail.com
Link: https://lkml.kernel.org/r/20211120112738.45980-2-laoar.shao@gmail.com
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: Michal Miroslaw <mirq-linux@rere.qmqm.pl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Kees Cook <keescook@chromium.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Include a note at the top to discourage people from including it in
headers.
Link: https://lkml.kernel.org/r/20211209150803.4473-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When kernel.h is used in the headers it adds a lot into dependency hell,
especially when there are circular dependencies are involved.
Replace kernel.h inclusion with the list of what is really being used.
The rest of the changes are induced by the above and may not be split.
Link: https://lkml.kernel.org/r/20211209123823.20425-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Arend van Spriel <arend.vanspriel@broadcom.com> [brcmfmac]
Acked-by: Kalle Valo <kvalo@kernel.org>
Cc: Arend van Spriel <aspriel@gmail.com>
Cc: Franky Lin <franky.lin@broadcom.com>
Cc: Hante Meuleman <hante.meuleman@broadcom.com>
Cc: Chi-hsien Lin <chi-hsien.lin@infineon.com>
Cc: Wright Feng <wright.feng@infineon.com>
Cc: Chung-hsien Hsu <chung-hsien.hsu@infineon.com>
Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Subsequent if judgments will assign new values to ret, so the statement
here should be deleted
The clang_analyzer complains as follows:
fs/proc/proc_sysctl.c:
Value stored to 'ret' is never read
Link: https://lkml.kernel.org/r/20211230063622.586360-1-luo.penghao@zte.com.cn
Signed-off-by: luo penghao <luo.penghao@zte.com.cn>
Reported-by: Zeal Robot <zealci@zte.com.cn>
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
sysctl_print_dir() always terminates the printed path name with a slash,
so printing a slash before the file part causes a duplicate like in
sysctl duplicate entry: /kernel//perf_user_access
Fix this by dropping the extra slash.
Link: https://lkml.kernel.org/r/e3054d605dc56f83971e4b6d2f5fa63a978720ad.1641551872.git.geert+renesas@glider.be
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Cc: Iurii Zaikin <yzaikin@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Convert return type of proc_fd_access_allowed() and the 'allowed' in it
to be boolean since the return type of ptrace_may_access() is boolean.
Link: https://lkml.kernel.org/r/20211219024404.29779-1-zhengqi.arch@bytedance.com
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Change the proc_create[_data]() stubs which are used when CONFIG_PROC_FS
is not set from #defines to a static inline stubs.
This should fix clang -Werror builds failing due to errors like this:
drivers/platform/x86/thinkpad_acpi.c:918:30: error: unused variable
'dispatch_proc_ops' [-Werror,-Wunused-const-variable]
Fixing this in include/linux/proc_fs.h should ensure that the same issue
is also fixed in any other drivers hitting the same -Werror issue.
[akpm@linux-foundation.org: fix CONFIG_PROC_FS=n]
[akpm@linux-foundation.org: fix arch/sparc/kernel/led.c]
[akpm@linux-foundation.org: fix build]
Link: https://lkml.kernel.org/r/20211116131112.508304-1-hdegoede@redhat.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reported-by: kernel test robot <lkp@intel.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In commit cc5f2704c9 ("proc/vmcore: convert oldmem_pfn_is_ram callback
to more generic vmcore callbacks"), we added detection of surprise
vmcore_cb unregistration after the vmcore was already opened. Once
detected, we warn the user and simulate reading zeroes from that point
on when accessing the vmcore.
The basic reason was that unexpected unregistration, for example, by
manually unbinding a driver from a device after opening the vmcore, is
not supported and could result in reading oldmem the vmcore_cb would
have actually prohibited while registered. However, something like that
can similarly be trigger by a user that's really looking for trouble
simply by unbinding the relevant driver before opening the vmcore -- or
by disallowing loading the driver in the first place. So it's actually
of limited help.
Currently, unregistration can only be triggered via virtio-mem when
manually unbinding the driver from the device inside the VM; there is no
way to trigger it from the hypervisor, as hypervisors don't allow for
unplugging virtio-mem devices -- ripping out system RAM from a VM
without coordination with the guest is usually not a good idea.
The important part is that unbinding the driver and unregistering the
vmcore_cb while concurrently reading the vmcore won't crash the system,
and that is handled by the rwsem.
To make the mechanism more future proof, let's remove the "read zero"
part, but leave the warning in place. For example, we could have a
future driver (like virtio-balloon) that will contact the hypervisor to
figure out if we already populated a page for a given PFN.
Hotunplugging such a device and consequently unregistering the vmcore_cb
could be triggered from the hypervisor without harming the system even
while kdump is running. In that case, we don't want to silently end up
with a vmcore that contains wrong data, because the user inside the VM
might be unaware of the hypervisor action and might easily miss the
warning in the log.
Link: https://lkml.kernel.org/r/20211111192243.22002-1-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Philipp Rudo <prudo@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
With NEED_PER_CPU_PAGE_FIRST_CHUNK enabled, we need a function to
populate pte, this patch adds a generic pcpu populate pte function,
pcpu_populate_pte(), which is marked __weak and used on most
architectures, but it is overridden on x86, which has its own
implementation.
Link: https://lkml.kernel.org/r/20211216112359.103822-5-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
With the previous patch, we could add a generic pcpu first chunk
allocate and free function to cleanup the duplicated definations on each
architecture.
Link: https://lkml.kernel.org/r/20211216112359.103822-4-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add pcpu_fc_cpu_to_node_fn_t and pass it into pcpu_fc_alloc_fn_t, pcpu
first chunk allocation will call it to alloc memblock on the
corresponding node by it, this is prepare for the next patch.
Link: https://lkml.kernel.org/r/20211216112359.103822-3-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "mm: percpu: Cleanup percpu first chunk function".
When supporting page mapping percpu first chunk allocator on arm64, we
found there are lots of duplicated codes in percpu embed/page first chunk
allocator. This patchset is aimed to cleanup them and should no function
change.
The currently supported status about 'embed' and 'page' in Archs shows
below,
embed: NEED_PER_CPU_PAGE_FIRST_CHUNK
page: NEED_PER_CPU_EMBED_FIRST_CHUNK
embed page
------------------------
arm64 Y Y
mips Y N
powerpc Y Y
riscv Y N
sparc Y Y
x86 Y Y
------------------------
There are two interfaces about percpu first chunk allocator,
extern int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size,
size_t atom_size,
pcpu_fc_cpu_distance_fn_t cpu_distance_fn,
- pcpu_fc_alloc_fn_t alloc_fn,
- pcpu_fc_free_fn_t free_fn);
+ pcpu_fc_cpu_to_node_fn_t cpu_to_nd_fn);
extern int __init pcpu_page_first_chunk(size_t reserved_size,
- pcpu_fc_alloc_fn_t alloc_fn,
- pcpu_fc_free_fn_t free_fn,
- pcpu_fc_populate_pte_fn_t populate_pte_fn);
+ pcpu_fc_cpu_to_node_fn_t cpu_to_nd_fn);
The pcpu_fc_alloc_fn_t/pcpu_fc_free_fn_t is killed, we provide generic
pcpu_fc_alloc() and pcpu_fc_free() function, which are called in the
pcpu_embed/page_first_chunk().
1) For pcpu_embed_first_chunk(), pcpu_fc_cpu_to_node_fn_t is needed to be
provided when archs supported NUMA.
2) For pcpu_page_first_chunk(), the pcpu_fc_populate_pte_fn_t is killed too,
a generic pcpu_populate_pte() which marked '__weak' is provided, if you
need a different function to populate pte on the arch(like x86), please
provide its own implementation.
[1] https://github.com/kevin78/linux.git percpu-cleanup
This patch (of 4):
The HAVE_SETUP_PER_CPU_AREA/NEED_PER_CPU_EMBED_FIRST_CHUNK/
NEED_PER_CPU_PAGE_FIRST_CHUNK/USE_PERCPU_NUMA_NODE_ID configs, which have
duplicate definitions on platforms that subscribe it.
Move them into mm, drop these redundant definitions and instead just
select it on applicable platforms.
Link: https://lkml.kernel.org/r/20211216112359.103822-1-wangkefeng.wang@huawei.com
Link: https://lkml.kernel.org/r/20211216112359.103822-2-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com> [arm64]
Cc: Will Deacon <will@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
For improved debugging it can be helpful to send version information
as other clients do during NTLMSSP negotiation. See protocol document
MS-NLMP section 2.2.1.1
Set the major and minor versions based on the kernel version, and the
BuildNumber based on the internal cifs.ko module version number,
and following the recommendation in the protocol documentation
(MS-NLMP section 2.2.10) we set the NTLMRevisionCurrent field to 15.
Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
arch/riscv/mm/init.c:48:11-16: WARNING: conversion to bool not needed here
Remove unneeded conversion to bool
Semantic patch information:
Relational and logical operators evaluate to bool,
explicit conversion is overly verbose and unneeded.
Generated by: scripts/coccinelle/misc/boolconv.cocci
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: kernel test robot <lkp@intel.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
This patchset allows to have a single kernel for sv39 and sv48 without
being relocatable.
The idea comes from Arnd Bergmann who suggested to do the same as x86,
that is mapping the kernel to the end of the address space, which allows
the kernel to be linked at the same address for both sv39 and sv48 and
then does not require to be relocated at runtime.
This implements sv48 support at runtime. The kernel will try to boot
with 4-level page table and will fallback to 3-level if the HW does not
support it. Folding the 4th level into a 3-level page table has almost
no cost at runtime.
Note that kasan region had to be moved to the end of the address space
since its location must be known at compile-time and then be valid for
both sv39 and sv48 (and sv57 that is coming).
* riscv-sv48-v3:
riscv: Explicit comment about user virtual address space size
riscv: Use pgtable_l4_enabled to output mmu_type in cpuinfo
riscv: Implement sv48 support
asm-generic: Prepare for riscv use of pud_alloc_one and pud_free
riscv: Allow to dynamically define VA_BITS
riscv: Introduce functions to switch pt_ops
riscv: Split early kasan mapping to prepare sv48 introduction
riscv: Move KASAN mapping next to the kernel mapping
riscv: Get rid of MAXPHYSMEM configs
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Define precisely the size of the user accessible virtual space size
for sv32/39/48 mmu types and explain why the whole virtual address
space is split into 2 equal chunks between kernel and user space.
Signed-off-by: Alexandre Ghiti <alexandre.ghiti@canonical.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Now that the mmu type is determined at runtime using SATP
characteristic, use the global variable pgtable_l4_enabled to output
mmu type of the processor through /proc/cpuinfo instead of relying on
device tree infos.
Signed-off-by: Alexandre Ghiti <alexandre.ghiti@canonical.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
By adding a new 4th level of page table, give the possibility to 64bit
kernel to address 2^48 bytes of virtual address: in practice, that offers
128TB of virtual address space to userspace and allows up to 64TB of
physical memory.
If the underlying hardware does not support sv48, we will automatically
fallback to a standard 3-level page table by folding the new PUD level into
PGDIR level. In order to detect HW capabilities at runtime, we
use SATP feature that ignores writes with an unsupported mode.
Signed-off-by: Alexandre Ghiti <alexandre.ghiti@canonical.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
In the following commits, riscv will almost use the generic versions of
pud_alloc_one and pud_free but an additional check is required since those
functions are only relevant when using at least a 4-level page table, which
will be determined at runtime on riscv.
So move the content of those functions into other functions that riscv
can use without duplicating code.
Signed-off-by: Alexandre Ghiti <alexandre.ghiti@canonical.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
With 4-level page table folding at runtime, we don't know at compile time
the size of the virtual address space so we must set VA_BITS dynamically
so that sparsemem reserves the right amount of memory for struct pages.
Signed-off-by: Alexandre Ghiti <alexandre.ghiti@canonical.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
This simply gathers the different pt_ops initialization in functions
where a comment was added to explain why the page table operations must
be changed along the boot process.
Signed-off-by: Alexandre Ghiti <alexandre.ghiti@canonical.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Now that kasan shadow region is next to the kernel, for sv48, this
region won't be aligned on PGDIR_SIZE and then when populating this
region, we'll need to get down to lower levels of the page table. So
instead of reimplementing the page table walk for the early population,
take advantage of the existing functions used for the final population.
Note that kasan swapper initialization must also be split since memblock
is not initialized at this point and as the last PGD is shared with the
kernel, we'd need to allocate a PUD so postpone the kasan final
population after the kernel population is done.
Signed-off-by: Alexandre Ghiti <alexandre.ghiti@canonical.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Now that KASAN_SHADOW_OFFSET is defined at compile time as a config,
this value must remain constant whatever the size of the virtual address
space, which is only possible by pushing this region at the end of the
address space next to the kernel mapping.
Signed-off-by: Alexandre Ghiti <alexandre.ghiti@canonical.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
CONFIG_MAXPHYSMEM_* are actually never used, even the nommu defconfigs
selecting the MAXPHYSMEM_2GB had no effects on PAGE_OFFSET since it was
preempted by !MMU case right before.
In addition, the move of the kernel mapping at the end of the address
space broke the use of MAXPHYSMEM_2G with MMU since it defines PAGE_OFFSET
at the same address as the kernel mapping.
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Fixes: 2bfc6cd81b ("riscv: Move kernel mapping outside of linear mapping")
Signed-off-by: Alexandre Ghiti <alexandre.ghiti@canonical.com>
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: Conor Dooley <Conor.Dooley@microchip.com>
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
The xfs_inodegc_stop() helper performs a high level flush of pending
work on the percpu queues and then runs a cancel_work_sync() on each
of the percpu work tasks to ensure all work has completed before
returning. While cancel_work_sync() waits for wq tasks to complete,
it does not guarantee work tasks have started. This means that the
_stop() helper can queue and instantly cancel a wq task without
having completed the associated work. This can be observed by
tracepoint inspection of a simple "rm -f <file>; fsfreeze -f <mnt>"
test:
xfs_destroy_inode: ... ino 0x83 ...
xfs_inode_set_need_inactive: ... ino 0x83 ...
xfs_inodegc_stop: ...
...
xfs_inodegc_start: ...
xfs_inodegc_worker: ...
xfs_inode_inactivating: ... ino 0x83 ...
The first few lines show that the inode is removed and need inactive
state set, but the inactivation work has not completed before the
inodegc mechanism stops. The inactivation doesn't actually occur
until the fs is unfrozen and the gc mechanism starts back up. Note
that this test requires fsfreeze to reproduce because xfs_freeze
indirectly invokes xfs_fs_statfs(), which calls xfs_inodegc_flush().
When this occurs, the workqueue try_to_grab_pending() logic first
tries to steal the pending bit, which does not succeed because the
bit has been set by queue_work_on(). Subsequently, it checks for
association of a pool workqueue from the work item under the pool
lock. This association is set at the point a work item is queued and
cleared when dequeued for processing. If the association exists, the
work item is removed from the queue and cancel_work_sync() returns
true. If the pwq association is cleared, the remove attempt assumes
the task is busy and retries (eventually returning false to the
caller after waiting for the work task to complete).
To avoid this race, we can flush each work item explicitly before
cancel. However, since the _queue_all() already schedules each
underlying work item, the workqueue level helpers are sufficient to
achieve the same ordering effect. E.g., the inodegc enabled flag
prevents scheduling any further work in the _stop() case. Use the
drain_workqueue() helper in this particular case to make the intent
a bit more self explanatory.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
YiFei Zhu says:
====================
Right now, most cgroup hooks are best used for permission checks. They
can only reject a syscall with -EPERM, so a cause of a rejection, if
the rejected by eBPF cgroup hooks, is ambiguous to userspace.
Additionally, if the syscalls are implemented in eBPF, all permission
checks and the implementation has to happen within the same filter,
as programs executed later in the series of progs are unaware of the
return values return by the previous progs.
This patch series adds two helpers, bpf_get_retval and bpf_set_retval,
that allows hooks to get/set the return value of syscall to userspace.
This also allows later progs to retrieve retval set by previous progs.
For legacy programs that rejects a syscall without setting the retval,
for backwards compatibility, if a prog rejects without itself or a
prior prog setting retval to an -err, the retval is set by the kernel
to -EPERM.
For getsockopt hooks that has ctx->retval, this variable mirrors that
that accessed by the helpers.
Additionally, the following user-visible behavior for getsockopt
hooks has changed:
- If a prior filter rejected the syscall, it will be visible
in ctx->retval.
- Attempting to change the retval arbitrarily is now allowed and
will not cause an -EFAULT.
- If kernel rejects a getsockopt syscall before running the hooks,
the error will be visible in ctx->retval. Returning 0 from the
prog will not overwrite the error to -EPERM unless there is an
explicit call of bpf_set_retval(-EPERM)
Tests have been added in this series to test the behavior of the helper
with cgroup setsockopt getsockopt hooks.
Patch 1 changes the API of macros to prepare for the next patch and
should be a no-op.
Patch 2 moves ctx->retval to a struct pointed to by current
task_struct.
Patch 3 implements the helpers.
Patch 4 tests the behaviors of the helpers.
Patch 5 updates a test after the test broke due to the visible changes.
v1 -> v2:
- errno -> retval
- split one helper to get & set helpers
- allow retval to be set arbitrarily in the general case
- made the helper retval and context retval mirror each other
====================
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The tests would break without this patch, because at one point it calls
getsockopt(fd, SOL_TCP, TCP_ZEROCOPY_RECEIVE, &buf, &optlen)
This getsockopt receives the kernel-set -EINVAL. Prior to this patch
series, the eBPF getsockopt hook's -EPERM would override kernel's
-EINVAL, however, after this patch series, return 0's automatic
-EPERM will not; the eBPF prog has to explicitly bpf_set_retval(-EPERM)
if that is wanted.
I also removed the explicit mentions of EPERM in the comments in the
prog.
Signed-off-by: YiFei Zhu <zhuyifei@google.com>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/4f20b77cb46812dbc2bdcd7e3fa87c7573bde55e.1639619851.git.zhuyifei@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The tests checks how different ways of interacting with the helpers
(getting retval, setting EUNATCH, EISCONN, and legacy reject
returning 0 without setting retval), produce different results in
both the setsockopt syscall and the retval returned by the helper.
A few more tests verify the interaction between the retval of the
helper and the retval in getsockopt context.
Signed-off-by: YiFei Zhu <zhuyifei@google.com>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/43ec60d679ae3f4f6fd2460559c28b63cb93cd12.1639619851.git.zhuyifei@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The helpers continue to use int for retval because all the hooks
are int-returning rather than long-returning. The return value of
bpf_set_retval is int for future-proofing, in case in the future
there may be errors trying to set the retval.
After the previous patch, if a program rejects a syscall by
returning 0, an -EPERM will be generated no matter if the retval
is already set to -err. This patch change it being forced only if
retval is not -err. This is because we want to support, for
example, invoking bpf_set_retval(-EINVAL) and return 0, and have
the syscall return value be -EINVAL not -EPERM.
For BPF_PROG_CGROUP_INET_EGRESS_RUN_ARRAY, the prior behavior is
that, if the return value is NET_XMIT_DROP, the packet is silently
dropped. We preserve this behavior for backward compatibility
reasons, so even if an errno is set, the errno does not return to
caller. However, setting a non-err to retval cannot propagate so
this is not allowed and we return a -EFAULT in that case.
Signed-off-by: YiFei Zhu <zhuyifei@google.com>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/b4013fd5d16bed0b01977c1fafdeae12e1de61fb.1639619851.git.zhuyifei@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The retval value is moved to struct bpf_cg_run_ctx for ease of access
in different prog types with different context structs layouts. The
helper implementation (to be added in a later patch in the series) can
simply perform a container_of from current->bpf_ctx to retrieve
bpf_cg_run_ctx.
Unfortunately, there is no easy way to access the current task_struct
via the verifier BPF bytecode rewrite, aside from possibly calling a
helper, so a pointer to current task is added to struct bpf_sockopt_kern
so that the rewritten BPF bytecode can access struct bpf_cg_run_ctx with
an indirection.
For backward compatibility, if a getsockopt program rejects a syscall
by returning 0, an -EPERM will be generated, by having the
BPF_PROG_RUN_ARRAY_CG family macros automatically set the retval to
-EPERM. Unlike prior to this patch, this -EPERM will be visible to
ctx->retval for any other hooks down the line in the prog array.
Additionally, the restriction that getsockopt filters can only set
the retval to 0 is removed, considering that certain getsockopt
implementations may return optlen. Filters are now able to set the
value arbitrarily.
Signed-off-by: YiFei Zhu <zhuyifei@google.com>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/73b0325f5c29912ccea7ea57ec1ed4d388fc1d37.1639619851.git.zhuyifei@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Right now BPF_PROG_RUN_ARRAY and related macros return 1 or 0
for whether the prog array allows or rejects whatever is being
hooked. The caller of these macros then return -EPERM or continue
processing based on thw macro's return value. Unforunately this is
inflexible, since -EPERM is the only err that can be returned.
This patch should be a no-op; it prepares for the next patch. The
returning of the -EPERM is moved to inside the macros, so the outer
functions are directly returning what the macros returned if they
are non-zero.
Signed-off-by: YiFei Zhu <zhuyifei@google.com>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/788abcdca55886d1f43274c918eaa9f792a9f33b.1639619851.git.zhuyifei@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
We used to have more code around the work loop, but now the goto and
lock juggling just makes it less readable than it should. Get rid of it.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The previous mt7986 clock drivers were incorrectly marked as GPL-1.0.
This patch changes the driver to the standard GPL-2.0 license.
Signed-off-by: Sam Shih <sam.shih@mediatek.com>
Link: https://lore.kernel.org/r/20220119123658.10095-2-sam.shih@mediatek.com
Reported-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Add a hashmap to map the string offsets from a source btf to the
string offsets from a target btf to reduce overheads.
btf__add_btf() calls btf__add_str() to add strings from a source to a
target btf. It causes many string comparisons, and it is a major
hotspot when adding a big btf. btf__add_str() uses strcmp() to check
if a hash entry is the right one. The extra hashmap here compares
offsets of strings, that are much cheaper. It remembers the results
of btf__add_str() for later uses to reduce the cost.
We are parallelizing BTF encoding for pahole by creating separated btf
instances for worker threads. These per-thread btf instances will be
added to the btf instance of the main thread by calling btf__add_str()
to deduplicate and write out. With this patch and -j4, the running
time of pahole drops to about 6.0s from 6.6s.
The following lines are the summary of 'perf stat' w/o the change.
6.668126396 seconds time elapsed
13.451054000 seconds user
0.715520000 seconds sys
The following lines are the summary w/ the change.
5.986973919 seconds time elapsed
12.939903000 seconds user
0.724152000 seconds sys
V4 fixes a bug of error checking against the pointer returned by
hashmap__new().
[v3] https://lore.kernel.org/bpf/20220118232053.2113139-1-kuifeng@fb.com/
[v2] https://lore.kernel.org/bpf/20220114193713.461349-1-kuifeng@fb.com/
Signed-off-by: Kui-Feng Lee <kuifeng@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220119180214.255634-1-kuifeng@fb.com
