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It may happen that destination buffer memory overlaps with memory dynptr
points to. Hence, we must use memmove to correctly copy from dynptr to
destination buffer, or source buffer to dynptr.
This actually isn't a problem right now, as memcpy implementation falls
back to memmove on detecting overlap and warns about it, but we
shouldn't be relying on that.
Acked-by: Joanne Koong <joannelkoong@gmail.com>
Acked-by: David Vernet <void@manifault.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20221207204141.308952-7-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
After previous commit, we are minimizing helper specific assumptions
from check_func_arg_reg_off, making it generic, and offloading checks
for a specific argument type to their respective functions called after
check_func_arg_reg_off has been called.
This allows relying on a consistent set of guarantees after that call
and then relying on them in code that deals with registers for each
argument type later. This is in line with how process_spin_lock,
process_timer_func, process_kptr_func check reg->var_off to be constant.
The same reasoning is used here to move the alignment check into
process_dynptr_func. Note that it also needs to check for constant
var_off, and accumulate the constant var_off when computing the spi in
get_spi, but that fix will come in later changes.
Acked-by: Joanne Koong <joannelkoong@gmail.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20221207204141.308952-6-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
While check_func_arg_reg_off is the place which performs generic checks
needed by various candidates of reg->type, there is some handling for
special cases, like ARG_PTR_TO_DYNPTR, OBJ_RELEASE, and
ARG_PTR_TO_RINGBUF_MEM.
This commit aims to streamline these special cases and instead leave
other things up to argument type specific code to handle. The function
will be restrictive by default, and cover all possible cases when
OBJ_RELEASE is set, without having to update the function again (and
missing to do that being a bug).
This is done primarily for two reasons: associating back reg->type to
its argument leaves room for the list getting out of sync when a new
reg->type is supported by an arg_type.
The other case is ARG_PTR_TO_RINGBUF_MEM. The problem there is something
we already handle, whenever a release argument is expected, it should
be passed as the pointer that was received from the acquire function.
Hence zero fixed and variable offset.
There is nothing special about ARG_PTR_TO_RINGBUF_MEM, where technically
its target register type PTR_TO_MEM | MEM_RINGBUF can already be passed
with non-zero offset to other helper functions, which makes sense.
Hence, lift the arg_type_is_release check for reg->off and cover all
possible register types, instead of duplicating the same kind of check
twice for current OBJ_RELEASE arg_types (alloc_mem and ptr_to_btf_id).
For the release argument, arg_type_is_dynptr is the special case, where
we go to actual object being freed through the dynptr, so the offset of
the pointer still needs to allow fixed and variable offset and
process_dynptr_func will verify them later for the release argument case
as well.
This is not specific to ARG_PTR_TO_DYNPTR though, we will need to make
this exception for any future object on the stack that needs to be
released. In this sense, PTR_TO_STACK as a candidate for object on stack
argument is a special case for release offset checks, and they need to
be done by the helper releasing the object on stack.
Since the check has been lifted above all register type checks, remove
the duplicated check that is being done for PTR_TO_BTF_ID.
Acked-by: Joanne Koong <joannelkoong@gmail.com>
Acked-by: David Vernet <void@manifault.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20221207204141.308952-5-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Recently, user ringbuf support introduced a PTR_TO_DYNPTR register type
for use in callback state, because in case of user ringbuf helpers,
there is no dynptr on the stack that is passed into the callback. To
reflect such a state, a special register type was created.
However, some checks have been bypassed incorrectly during the addition
of this feature. First, for arg_type with MEM_UNINIT flag which
initialize a dynptr, they must be rejected for such register type.
Secondly, in the future, there are plans to add dynptr helpers that
operate on the dynptr itself and may change its offset and other
properties.
In all of these cases, PTR_TO_DYNPTR shouldn't be allowed to be passed
to such helpers, however the current code simply returns 0.
The rejection for helpers that release the dynptr is already handled.
For fixing this, we take a step back and rework existing code in a way
that will allow fitting in all classes of helpers and have a coherent
model for dealing with the variety of use cases in which dynptr is used.
First, for ARG_PTR_TO_DYNPTR, it can either be set alone or together
with a DYNPTR_TYPE_* constant that denotes the only type it accepts.
Next, helpers which initialize a dynptr use MEM_UNINIT to indicate this
fact. To make the distinction clear, use MEM_RDONLY flag to indicate
that the helper only operates on the memory pointed to by the dynptr,
not the dynptr itself. In C parlance, it would be equivalent to taking
the dynptr as a point to const argument.
When either of these flags are not present, the helper is allowed to
mutate both the dynptr itself and also the memory it points to.
Currently, the read only status of the memory is not tracked in the
dynptr, but it would be trivial to add this support inside dynptr state
of the register.
With these changes and renaming PTR_TO_DYNPTR to CONST_PTR_TO_DYNPTR to
better reflect its usage, it can no longer be passed to helpers that
initialize a dynptr, i.e. bpf_dynptr_from_mem, bpf_ringbuf_reserve_dynptr.
A note to reviewers is that in code that does mark_stack_slots_dynptr,
and unmark_stack_slots_dynptr, we implicitly rely on the fact that
PTR_TO_STACK reg is the only case that can reach that code path, as one
cannot pass CONST_PTR_TO_DYNPTR to helpers that don't set MEM_RDONLY. In
both cases such helpers won't be setting that flag.
The next patch will add a couple of selftest cases to make sure this
doesn't break.
Fixes: 205715673844 ("bpf: Add bpf_user_ringbuf_drain() helper")
Acked-by: Joanne Koong <joannelkoong@gmail.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20221207204141.308952-4-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
ARG_PTR_TO_DYNPTR is akin to ARG_PTR_TO_TIMER, ARG_PTR_TO_KPTR, where
the underlying register type is subjected to more special checks to
determine the type of object represented by the pointer and its state
consistency.
Move dynptr checks to their own 'process_dynptr_func' function so that
is consistent and in-line with existing code. This also makes it easier
to reuse this code for kfunc handling.
Then, reuse this consolidated function in kfunc dynptr handling too.
Note that for kfuncs, the arg_type constraint of DYNPTR_TYPE_LOCAL has
been lifted.
Acked-by: David Vernet <void@manifault.com>
Acked-by: Joanne Koong <joannelkoong@gmail.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20221207204141.308952-2-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
If there are pending rcu callback, free_mem_alloc() will use
rcu_barrier_tasks_trace() and rcu_barrier() to wait for the pending
__free_rcu_tasks_trace() and __free_rcu() callback.
If rcu_trace_implies_rcu_gp() is true, there will be no pending
__free_rcu(), so it will be OK to skip rcu_barrier() as well.
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20221209010947.3130477-3-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
When there are batched freeing operations on a specific CPU, part of
the freed elements ((high_watermark - lower_watermark) / 2 + 1) will be
indirectly moved into waiting_for_gp list through free_by_rcu list.
After call_rcu_in_progress becomes false again, the remaining elements
in free_by_rcu list will be moved to waiting_for_gp list by the next
invocation of free_bulk(). However if the expiration of RCU tasks trace
grace period is relatively slow, none element in free_by_rcu list will
be moved.
So instead of invoking __alloc_percpu_gfp() or kmalloc_node() to
allocate a new object, in alloc_bulk() just check whether or not there is
freed element in free_by_rcu list and reuse it if available.
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20221209010947.3130477-2-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
memcg_write_event_control() accesses the dentry->d_name of the specified
control fd to route the write call. As a cgroup interface file can't be
renamed, it's safe to access d_name as long as the specified file is a
regular cgroup file. Also, as these cgroup interface files can't be
removed before the directory, it's safe to access the parent too.
Prior to 347c4a874710 ("memcg: remove cgroup_event->cft"), there was a
call to __file_cft() which verified that the specified file is a regular
cgroupfs file before further accesses. The cftype pointer returned from
__file_cft() was no longer necessary and the commit inadvertently
dropped the file type check with it allowing any file to slip through.
With the invarients broken, the d_name and parent accesses can now race
against renames and removals of arbitrary files and cause
use-after-free's.
Fix the bug by resurrecting the file type check in __file_cft(). Now
that cgroupfs is implemented through kernfs, checking the file
operations needs to go through a layer of indirection. Instead, let's
check the superblock and dentry type.
Signed-off-by: Tejun Heo <tj@kernel.org>
Fixes: 347c4a874710 ("memcg: remove cgroup_event->cft")
Cc: stable@kernel.org # v3.14+
Reported-by: Jann Horn <jannh@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
insn->imm for kfunc is the relative address of __bpf_call_base,
instead of __bpf_base_call, Fix the comment error.
Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
Link: https://lore.kernel.org/r/20221208013724.257848-1-yangjihong1@huawei.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
In BPF all global functions, and BPF helpers return a 64-bit
value. For kfunc calls, this is not the case, and they can return
e.g. 32-bit values.
The return register R0 for kfuncs calls can therefore be marked as
subreg_def != DEF_NOT_SUBREG. In general, if a register is marked with
subreg_def != DEF_NOT_SUBREG, some archs (where bpf_jit_needs_zext()
returns true) require the verifier to insert explicit zero-extension
instructions.
For kfuncs calls, however, the caller should do sign/zero extension
for return values. In other words, the compiler is responsible to
insert proper instructions, not the verifier.
An example, provided by Yonghong Song:
$ cat t.c
extern unsigned foo(void);
unsigned bar1(void) {
return foo();
}
unsigned bar2(void) {
if (foo()) return 10; else return 20;
}
$ clang -target bpf -mcpu=v3 -O2 -c t.c && llvm-objdump -d t.o
t.o: file format elf64-bpf
Disassembly of section .text:
0000000000000000 <bar1>:
0: 85 10 00 00 ff ff ff ff call -0x1
1: 95 00 00 00 00 00 00 00 exit
0000000000000010 <bar2>:
2: 85 10 00 00 ff ff ff ff call -0x1
3: bc 01 00 00 00 00 00 00 w1 = w0
4: b4 00 00 00 14 00 00 00 w0 = 0x14
5: 16 01 01 00 00 00 00 00 if w1 == 0x0 goto +0x1 <LBB1_2>
6: b4 00 00 00 0a 00 00 00 w0 = 0xa
0000000000000038 <LBB1_2>:
7: 95 00 00 00 00 00 00 00 exit
If the return value of 'foo()' is used in the BPF program, the proper
zero-extension will be done.
Currently, the verifier correctly marks, say, a 32-bit return value as
subreg_def != DEF_NOT_SUBREG, but will fail performing the actual
zero-extension, due to a verifier bug in
opt_subreg_zext_lo32_rnd_hi32(). load_reg is not properly set to R0,
and the following path will be taken:
if (WARN_ON(load_reg == -1)) {
verbose(env, "verifier bug. zext_dst is set, but no reg is defined\n");
return -EFAULT;
}
A longer discussion from v1 can be found in the link below.
Correct the verifier by avoiding doing explicit zero-extension of R0
for kfunc calls. Note that R0 will still be marked as a sub-register
for return values smaller than 64-bit.
Fixes: 83a2881903f3 ("bpf: Account for BPF_FETCH in insn_has_def32()")
Link: https://lore.kernel.org/bpf/20221202103620.1915679-1-bjorn@kernel.org/
Suggested-by: Yonghong Song <yhs@meta.com>
Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20221207103540.396496-1-bjorn@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
When the blk_classic option is enabled, non-blktrace events must be
filtered out. Otherwise, events of other types are output in the blktrace
classic format, which is unexpected.
The problem can be triggered in the following ways:
# echo 1 > /sys/kernel/debug/tracing/options/blk_classic
# echo 1 > /sys/kernel/debug/tracing/events/enable
# echo blk > /sys/kernel/debug/tracing/current_tracer
# cat /sys/kernel/debug/tracing/trace_pipe
Fixes: c71a89615411 ("blktrace: add ftrace plugin")
Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
Link: https://lore.kernel.org/r/20221122040410.85113-1-yangjihong1@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
bpf_cgroup_acquire(), bpf_cgroup_release(), bpf_cgroup_kptr_get(), and
bpf_cgroup_ancestor(), are kfuncs that were recently added to
kernel/bpf/helpers.c. These are "core" kfuncs in that they're available
for use in any tracepoint or struct_ops BPF program. Though they have no
ABI stability guarantees, we should still document them. This patch adds
a struct cgroup * subsection to the Core kfuncs section which describes
each of these kfuncs.
Signed-off-by: David Vernet <void@manifault.com>
Link: https://lore.kernel.org/r/20221207204911.873646-3-void@manifault.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
bpf_task_acquire(), bpf_task_release(), and bpf_task_from_pid() are
kfuncs that were recently added to kernel/bpf/helpers.c. These are
"core" kfuncs in that they're available for use for any tracepoint or
struct_ops BPF program. Though they have no ABI stability guarantees, we
should still document them. This patch adds a new Core kfuncs section to
the BPF kfuncs doc, and adds entries for all of these task kfuncs.
Note that bpf_task_kptr_get() is not documented, as it still returns
NULL while we're working to resolve how it can use RCU to ensure struct
task_struct * lifetime.
Signed-off-by: David Vernet <void@manifault.com>
Link: https://lore.kernel.org/r/20221207204911.873646-2-void@manifault.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Number of total instructions in BPF program (including subprogs) can and
is accessed from env->prog->len. visit_func_call_insn() doesn't do any
checks against insn_cnt anymore, relying on push_insn() to do this check
internally. So remove unnecessary insn_cnt input argument from
visit_func_call_insn() and visit_insn() functions.
Suggested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20221207195534.2866030-1-andrii@kernel.org
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Merge "do not rely on ALLOW_ERROR_INJECTION for fmod_ret" into bpf-next
Merge commit 5b481acab4ce ("bpf: do not rely on ALLOW_ERROR_INJECTION for fmod_ret")
from hid tree into bpf-next.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add support for zstd compressed modules to the in-kernel decompression
code. This allows zstd compressed modules to be decompressed by the
kernel, similar to the existing support for gzip and xz compressed
modules.
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Piotr Gorski <lucjan.lucjanov@gmail.com>
Cc: Nick Terrell <terrelln@fb.com>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Reviewed-by: Piotr Gorski <lucjan.lucjanov@gmail.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
The current way of expressing that a non-bpf kernel component is willing
to accept that bpf programs can be attached to it and that they can change
the return value is to abuse ALLOW_ERROR_INJECTION.
This is debated in the link below, and the result is that it is not a
reasonable thing to do.
Reuse the kfunc declaration structure to also tag the kernel functions
we want to be fmodret. This way we can control from any subsystem which
functions are being modified by bpf without touching the verifier.
Link: https://lore.kernel.org/all/20221121104403.1545f9b5@gandalf.local.home/
Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/r/20221206145936.922196-2-benjamin.tissoires@redhat.com
Don't mark some instructions as jump points when there are actually no
jumps and instructions are just processed sequentially. Such case is
handled naturally by precision backtracking logic without the need to
update jump history. See get_prev_insn_idx(). It goes back linearly by
one instruction, unless current top of jmp_history is pointing to
current instruction. In such case we use `st->jmp_history[cnt - 1].prev_idx`
to find instruction from which we jumped to the current instruction
non-linearly.
Also remove both jump and prune point marking for instruction right
after unconditional jumps, as program flow can get to the instruction
right after unconditional jump instruction only if there is a jump to
that instruction from somewhere else in the program. In such case we'll
mark such instruction as prune/jump point because it's a destination of
a jump.
This change has no changes in terms of number of instructions or states
processes across Cilium and selftests programs.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/r/20221206233345.438540-4-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Jump history updating and state equivalence checks are conceptually
independent, so move push_jmp_history() out of is_state_visited(). Also
make a decision whether to perform state equivalence checks or not one
layer higher in do_check(), keeping is_state_visited() unconditionally
performing state checks.
push_jmp_history() should be performed after state checks. There is just
one small non-uniformity. When is_state_visited() finds already
validated equivalent state, it propagates precision marks to current
state's parent chain. For this to work correctly, jump history has to be
updated, so is_state_visited() is doing that internally.
But if no equivalent verified state is found, jump history has to be
updated in a newly cloned child state, so is_jmp_point()
+ push_jmp_history() is performed after is_state_visited() exited with
zero result, which means "proceed with validation".
This change has no functional changes. It's not strictly necessary, but
feels right to decouple these two processes.
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20221206233345.438540-3-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
BPF verifier marks some instructions as prune points. Currently these
prune points serve two purposes.
It's a point where verifier tries to find previously verified state and
check current state's equivalence to short circuit verification for
current code path.
But also currently it's a point where jump history, used for precision
backtracking, is updated. This is done so that non-linear flow of
execution could be properly backtracked.
Such coupling is coincidental and unnecessary. Some prune points are not
part of some non-linear jump path, so don't need update of jump history.
On the other hand, not all instructions which have to be recorded in
jump history necessarily are good prune points.
This patch splits prune and jump points into independent flags.
Currently all prune points are marked as jump points to minimize amount
of changes in this patch, but next patch will perform some optimization
of prune vs jmp point placement.
No functional changes are intended.
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20221206233345.438540-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
btf->struct_meta_tab is populated by btf_parse_struct_metas in btf.c.
There, a BTF record is created for any type containing a spin_lock or
any next-gen datastructure node/head.
Currently, for non-MAP_VALUE types, reg_btf_record will only search for
a record using struct_meta_tab if the reg->type exactly matches
(PTR_TO_BTF_ID | MEM_ALLOC). This exact match is too strict: an
"allocated obj" type - returned from bpf_obj_new - might pick up other
flags while working its way through the program.
Loosen the check to be exact for base_type and just use MEM_ALLOC mask
for type_flag.
This patch is marked Fixes as the original intent of reg_btf_record was
unlikely to have been to fail finding btf_record for valid alloc obj
types with additional flags, some of which (e.g. PTR_UNTRUSTED)
are valid register type states for alloc obj independent of this series.
However, I didn't find a specific broken repro case outside of this
series' added functionality, so it's possible that nothing was
triggering this logic error before.
Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
cc: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Fixes: 4e814da0d599 ("bpf: Allow locking bpf_spin_lock in allocated objects")
Link: https://lore.kernel.org/r/20221206231000.3180914-2-davemarchevsky@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
A series of prior patches added some kfuncs that allow struct
task_struct * objects to be used as kptrs. These kfuncs leveraged the
'refcount_t rcu_users' field of the task for performing refcounting.
This field was used instead of 'refcount_t usage', as we wanted to
leverage the safety provided by RCU for ensuring a task's lifetime.
A struct task_struct is refcounted by two different refcount_t fields:
1. p->usage: The "true" refcount field which task lifetime. The
task is freed as soon as this refcount drops to 0.
2. p->rcu_users: An "RCU users" refcount field which is statically
initialized to 2, and is co-located in a union with
a struct rcu_head field (p->rcu). p->rcu_users
essentially encapsulates a single p->usage
refcount, and when p->rcu_users goes to 0, an RCU
callback is scheduled on the struct rcu_head which
decrements the p->usage refcount.
Our logic was that by using p->rcu_users, we would be able to use RCU to
safely issue refcount_inc_not_zero() a task's rcu_users field to
determine if a task could still be acquired, or was exiting.
Unfortunately, this does not work due to p->rcu_users and p->rcu sharing
a union. When p->rcu_users goes to 0, an RCU callback is scheduled to
drop a single p->usage refcount, and because the fields share a union,
the refcount immediately becomes nonzero again after the callback is
scheduled.
If we were to split the fields out of the union, this wouldn't be a
problem. Doing so should also be rather non-controversial, as there are
a number of places in struct task_struct that have padding which we
could use to avoid growing the structure by splitting up the fields.
For now, so as to fix the kfuncs to be correct, this patch instead
updates bpf_task_acquire() and bpf_task_release() to use the p->usage
field for refcounting via the get_task_struct() and put_task_struct()
functions. Because we can no longer rely on RCU, the change also guts
the bpf_task_acquire_not_zero() and bpf_task_kptr_get() functions
pending a resolution on the above problem.
In addition, the task fixes the kfunc and rcu_read_lock selftests to
expect this new behavior.
Fixes: 90660309b0c7 ("bpf: Add kfuncs for storing struct task_struct * as a kptr")
Fixes: fca1aa75518c ("bpf: Handle MEM_RCU type properly")
Reported-by: Matus Jokay <matus.jokay@stuba.sk>
Signed-off-by: David Vernet <void@manifault.com>
Link: https://lore.kernel.org/r/20221206210538.597606-1-void@manifault.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
A previous change amended try_to_freeze_tasks() with the "what"
variable pointing to a string describing the group of tasks subject to
the freezing which may be used in the error message in there too, so
make that happen.
Accordingly, update sleepgraph.py to catch the modified error message
as appropriate.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Using pr_cont() in the tasks freezing code related to system-wide
suspend and hibernation is problematic, because the continuation
messages printed there are susceptible to interspersing with other
unrelated messages which results in output that is hard to
understand.
Address this issue by modifying try_to_freeze_tasks() to print
messages that don't require continuations and adjusting its
callers accordingly.
Reported-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
For supporting post MSI-X enable allocations and for the upcoming PCI/IMS
support a separate interface is required which allows not only the
allocation of a specific index, but also the allocation of any, i.e. the
next free index. The latter is especially required for IMS because IMS
completely does away with index to functionality mappings which are
often found in MSI/MSI-X implementation.
But even with MSI-X there are devices where only the first few indices have
a fixed functionality and the rest is freely assignable by software,
e.g. to queues.
msi_domain_alloc_irq_at() is also different from the range based interfaces
as it always enforces that the MSI descriptor is allocated by the core code
and not preallocated by the caller like the PCI/MSI[-X] enable code path
does.
msi_domain_alloc_irq_at() can be invoked with the index argument set to
MSI_ANY_INDEX which makes the core code pick the next free index. The irq
domain can provide a prepare_desc() operation callback in it's
msi_domain_ops to do domain specific post allocation initialization before
the actual Linux interrupt and the associated interrupt descriptor and
hierarchy alloccations are conducted.
The function also takes an optional @icookie argument which is of type
union msi_instance_cookie. This cookie is not used by the core code and is
stored in the allocated msi_desc::data::icookie. The meaning of the cookie
is completely implementation defined. In case of IMS this might be a PASID
or a pointer to a device queue, but for the MSI core it's opaque and not
used in any way.
The function returns a struct msi_map which on success contains the
allocated index number and the Linux interrupt number so the caller can
spare the index to Linux interrupt number lookup.
On failure map::index contains the error code and map::virq is 0.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221124232326.501359457@linutronix.de
The existing MSI domain ops msi_prepare() and set_desc() turned out to be
unsuitable for implementing IMS support.
msi_prepare() does not operate on the MSI descriptors. set_desc() lacks
an irq_domain pointer and has a completely different purpose.
Introduce a prepare_desc() op which allows IMS implementations to amend an
MSI descriptor which was allocated by the core code, e.g. by adjusting the
iomem base or adding some data based on the allocated index. This is way
better than requiring that all IMS domain implementations preallocate the
MSI descriptor and then allocate the interrupt.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221124232326.444560717@linutronix.de
Provide new bus tokens for the upcoming per device PCI/MSI and PCI/MSIX
interrupt domains.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221124232325.917219885@linutronix.de
Per device domains provide the real domain size to the core code. This
allows range checking on insertion of MSI descriptors and also paves the
way for dynamic index allocations which are required e.g. for IMS. This
avoids external mechanisms like bitmaps on the device side and just
utilizes the core internal MSI descriptor storxe for it.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221124232325.798556374@linutronix.de
proc_skip_spaces() seems to think it is working on C strings, and ends
up being just a wrapper around skip_spaces() with a really odd calling
convention.
Instead of basing it on skip_spaces(), it should have looked more like
proc_skip_char(), which really is the exact same function (except it
skips a particular character, rather than whitespace). So use that as
inspiration, odd coding and all.
Now the calling convention actually makes sense and works for the
intended purpose.
Reported-and-tested-by: Kyle Zeng <zengyhkyle@gmail.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
proc_get_long() is passed a size_t, but then assigns it to an 'int'
variable for the length. Let's not do that, even if our IO paths are
limited to MAX_RW_COUNT (exactly because of these kinds of type errors).
So do the proper test in the rigth type.
Reported-by: Kyle Zeng <zengyhkyle@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Provide an interface to match a per device domain bus token. This allows to
query which type of domain is installed for a particular domain id. Will be
used for PCI to avoid frequent create/remove cycles for the MSI resp. MSI-X
domains.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221124232325.738047902@linutronix.de
Now that all prerequsites are in place, provide the actual interfaces for
creating and removing per device interrupt domains.
MSI device interrupt domains are created from the provided
msi_domain_template which is duplicated so that it can be modified for the
particular device.
The name of the domain and the name of the interrupt chip are composed by
"$(PREFIX)$(CHIPNAME)-$(DEVNAME)"
$PREFIX: The optional prefix provided by the underlying MSI parent domain
via msi_parent_ops::prefix.
$CHIPNAME: The name of the irq_chip in the template
$DEVNAME: The name of the device
The domain is further initialized through a MSI parent domain callback which
fills in the required functionality for the parent domain or domains further
down the hierarchy. This initialization can fail, e.g. when the requested
feature or MSI domain type cannot be supported.
The domain pointer is stored in the pointer array inside of msi_device_data
which is attached to the domain.
The domain can be removed via the API or left for disposal via devres when
the device is torn down. The API removal is useful e.g. for PCI to have
seperate domains for MSI and MSI-X, which are mutually exclusive and always
occupy the default domain id slot.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221124232325.678838546@linutronix.de
Split the functionality of msi_create_irq_domain() so it can
be reused for creating per device irq domains.
No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221124232325.559086358@linutronix.de
To allow proper range checking especially for dynamic allocations add a
size field to struct msi_domain_info. If the field is 0 then the size is
unknown or unlimited (up to MSI_MAX_INDEX) to provide backwards
compability.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221124232325.501144862@linutronix.de
MSI parent domains must have some control over the MSI domains which are
built on top. On domain creation they need to fill in e.g. architecture
specific chip callbacks or msi domain ops to make the outermost domain
parent agnostic which is obviously required for architecture independence
etc.
The structure contains:
1) A bitfield which exposes the supported functional features. This
allows to check for features and is also used in the initialization
callback to mask out unsupported features when the actual domain
implementation requests a broader range, e.g. on x86 PCI multi-MSI
is only supported by remapping domains but not by the underlying
vector domain. The PCI/MSI code can then always request multi-MSI
support, but the resulting feature set after creation might not
have it set.
2) An optional string prefix which is put in front of domain and chip
names during creation of the MSI domain. That allows to keep the
naming schemes e.g. on x86 where PCI-MSI domains have a IR- prefix
when interrupt remapping is enabled.
3) An initialization callback to sanity check the domain info of
the to be created MSI domain, to restrict features and to
apply changes in MSI ops and interrupt chip callbacks to
accomodate to the particular MSI parent implementation and/or
the underlying hierarchy.
Add a conveniance function to delegate the initialization from the
MSI parent domain to an underlying domain in the hierarchy.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221124232325.382485843@linutronix.de
Now that all users are converted remove the old interfaces.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221124230314.694291814@linutronix.de
Provide two sorts of interfaces to handle the different use cases:
- msi_domain_alloc_irqs_range():
Handles a caller defined precise range
- msi_domain_alloc_irqs_all():
Allocates all interrupts associated to a domain by scanning the
allocated MSI descriptors
The latter is useful for the existing PCI/MSI support which does not have
range information available.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221124230314.396497163@linutronix.de
Provide two sorts of interfaces to handle the different use cases:
- msi_domain_free_irqs_range():
Handles a caller defined precise range
- msi_domain_free_irqs_all():
Frees all interrupts associated to a domain
The latter is useful for device teardown and to handle the legacy MSI support
which does not have any range information available.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221124230314.337844751@linutronix.de
Allocating simple interrupt descriptors in the core code has to be multi
device irqdomain aware for the upcoming PCI/IMS support.
Change the interfaces to take a domain id into account. Use the internal
control struct for transport of arguments.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221124230314.279112474@linutronix.de
Change the descriptor free functions to take a domain id to prepare for the
upcoming multi MSI domain per device support.
To avoid changing and extending the interfaces over and over use an core
internal control struct and hand the pointer through the various functions.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221124230314.220788011@linutronix.de
Change the descriptor allocation and insertion functions to take a domain
id to prepare for the upcoming multi MSI domain per device support.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221124230314.163043028@linutronix.de
This reflects the functionality better. No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221124230314.103554618@linutronix.de
In preparation of the upcoming per device multi MSI domain support, change
the interface to support lookups based on domain id and zero based index
within the domain.
Signed-off-by: Ahmed S. Darwish <darwi@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221124230314.044613697@linutronix.de
To support multiple MSI interrupt domains per device it is necessary to
segment the xarray MSI descriptor storage. Each domain gets up to
MSI_MAX_INDEX entries.
Change the iterators so they operate with domain ids and take the domain
offsets into account.
The publicly available iterators which are mostly used in legacy
implementations and the PCI/MSI core default to MSI_DEFAULT_DOMAIN (0)
which is the id for the existing "global" domains.
No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221124230313.985498981@linutronix.de
With the upcoming per device MSI interrupt domain support it is necessary
to store the domain pointers per device.
Instead of delegating that storage to device drivers or subsystems add a
domain pointer to the msi_dev_domain array in struct msi_device_data.
This pointer is also used to take care of tearing down the irq domains when
msi_device_data is cleaned up via devres.
The interfaces into the MSI core will be changed from irqdomain pointer
based interfaces to domain id based interfaces to support multiple MSI
domains on a single device (e.g. PCI/MSI[-X] and PCI/IMS.
Once the per device domain support is complete the irq domain pointer in
struct device::msi.domain will not longer contain a pointer to the "global"
MSI domain. It will contain a pointer to the MSI parent domain instead.
It would be a horrible maze of conditionals to evaluate all over the place
which domain pointer should be used, i.e. the "global" one in
device::msi::domain or one from the internal pointer array.
To avoid this evaluate in msi_setup_device_data() whether the irq domain
which is associated to a device is a "global" or a parent MSI domain. If it
is global then copy the pointer into the first entry of the msi_dev_domain
array.
This allows to convert interfaces and implementation to domain ids while
keeping everything existing working.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221124230313.923860399@linutronix.de
