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2022-12-09tracing: Add nohitcount option for suppressing display of raw hitcountMasami Hiramatsu (Google)2-8/+29
Add 'nohitcount' ('NOHC' for short) option for suppressing display of the raw hitcount column in the histogram. Note that you must specify at least one value except raw 'hitcount' when you specify this nohitcount option. # cd /sys/kernel/debug/tracing/ # echo hist:keys=pid:vals=runtime.percent,runtime.graph:sort=pid:NOHC > \ events/sched/sched_stat_runtime/trigger # sleep 10 # cat events/sched/sched_stat_runtime/hist # event histogram # # trigger info: hist:keys=pid:vals=runtime.percent,runtime.graph:sort=pid:size=2048:nohitcount [active] # { pid: 8 } runtime (%): 3.02 runtime: # { pid: 14 } runtime (%): 2.25 runtime: { pid: 16 } runtime (%): 2.25 runtime: { pid: 26 } runtime (%): 0.17 runtime: { pid: 61 } runtime (%): 11.52 runtime: #### { pid: 67 } runtime (%): 1.56 runtime: { pid: 68 } runtime (%): 0.84 runtime: { pid: 76 } runtime (%): 0.92 runtime: { pid: 117 } runtime (%): 2.50 runtime: # { pid: 146 } runtime (%): 49.88 runtime: #################### { pid: 157 } runtime (%): 16.63 runtime: ###### { pid: 158 } runtime (%): 8.38 runtime: ### Link: https://lore.kernel.org/linux-trace-kernel/166610814787.56030.4980636083486339906.stgit@devnote2 Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Reviewed-by: Tom Zanussi <zanussi@kernel.org> Tested-by: Tom Zanussi <zanussi@kernel.org>
2022-12-09tracing: Add .graph suffix option to histogram valueMasami Hiramatsu (Google)2-17/+63
Add the .graph suffix which shows the bar graph of the histogram value. For example, the below example shows that the bar graph of the histogram of the runtime for each tasks. ------ # cd /sys/kernel/debug/tracing/ # echo hist:keys=pid:vals=runtime.graph:sort=pid > \ events/sched/sched_stat_runtime/trigger # sleep 10 # cat events/sched/sched_stat_runtime/hist # event histogram # # trigger info: hist:keys=pid:vals=hitcount,runtime.graph:sort=pid:size=2048 [active] # { pid: 14 } hitcount: 2 runtime: { pid: 16 } hitcount: 8 runtime: { pid: 26 } hitcount: 1 runtime: { pid: 57 } hitcount: 3 runtime: { pid: 61 } hitcount: 20 runtime: ### { pid: 66 } hitcount: 2 runtime: { pid: 70 } hitcount: 3 runtime: { pid: 72 } hitcount: 2 runtime: { pid: 145 } hitcount: 14 runtime: #################### { pid: 152 } hitcount: 5 runtime: ####### { pid: 153 } hitcount: 2 runtime: #### Totals: Hits: 62 Entries: 11 Dropped: 0 ------- Link: https://lore.kernel.org/linux-trace-kernel/166610813953.56030.10944148382315789485.stgit@devnote2 Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Reviewed-by: Tom Zanussi <zanussi@kernel.org> Tested-by: Tom Zanussi <zanussi@kernel.org>
2022-12-09tracing: Add .percent suffix option to histogram valuesMasami Hiramatsu (Google)2-15/+78
Add .percent suffix option to show the histogram values in percentage. This feature is useful when we need yo undersntand the overall trend for the histograms of large values. E.g. this shows the runtime percentage for each tasks. ------ # cd /sys/kernel/debug/tracing/ # echo hist:keys=pid:vals=hitcount,runtime.percent:sort=pid > \ events/sched/sched_stat_runtime/trigger # sleep 10 # cat events/sched/sched_stat_runtime/hist # event histogram # # trigger info: hist:keys=pid:vals=hitcount,runtime.percent:sort=pid:size=2048 [active] # { pid: 8 } hitcount: 7 runtime (%): 4.14 { pid: 14 } hitcount: 5 runtime (%): 3.69 { pid: 16 } hitcount: 11 runtime (%): 3.41 { pid: 61 } hitcount: 41 runtime (%): 19.75 { pid: 65 } hitcount: 4 runtime (%): 1.48 { pid: 70 } hitcount: 6 runtime (%): 3.60 { pid: 72 } hitcount: 2 runtime (%): 1.10 { pid: 144 } hitcount: 10 runtime (%): 32.01 { pid: 151 } hitcount: 8 runtime (%): 22.66 { pid: 152 } hitcount: 2 runtime (%): 8.10 Totals: Hits: 96 Entries: 10 Dropped: 0 ----- Link: https://lore.kernel.org/linux-trace-kernel/166610813077.56030.4238090506973562347.stgit@devnote2 Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Reviewed-by: Tom Zanussi <zanussi@kernel.org> Tested-by: Tom Zanussi <zanussi@kernel.org>
2022-12-09tracing: Allow multiple hitcount values in histogramsTom Zanussi1-3/+9
The hitcount is treated specially in the histograms - since it's always expected to be there regardless of whether the user specified anything or not, it's always added as the first histogram value. Currently the code doesn't allow it to be added more than once as a value, which is inconsistent with all the other possible values. It would seem to be a pointless thing to want to do, but other features being added such as percent and graph modifiers don't work properly with the current hitcount restrictions. Fix this by allowing multiple hitcounts to be added. Link: https://lore.kernel.org/linux-trace-kernel/166610812248.56030.16754785928712505251.stgit@devnote2 Signed-off-by: Tom Zanussi <zanussi@kernel.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Tested-by: Tom Zanussi <zanussi@kernel.org>
2022-12-09Merge branch 'mm-hotfixes-stable' into mm-stableAndrew Morton1-1/+0
2022-12-09memcg: fix possible use-after-free in memcg_write_event_control()Tejun Heo1-1/+0
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. Link: https://lkml.kernel.org/r/Y5FRm/cfcKPGzWwl@slm.duckdns.org Fixes: 347c4a874710 ("memcg: remove cgroup_event->cft") Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Jann Horn <jannh@google.com> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: <stable@vger.kernel.org> [3.14+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-12-08bpf: Use memmove for bpf_dynptr_{read,write}Kumar Kartikeya Dwivedi1-2/+10
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>
2022-12-08bpf: Move PTR_TO_STACK alignment check to process_dynptr_funcKumar Kartikeya Dwivedi1-5/+8
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>
2022-12-08bpf: Rework check_func_arg_reg_offKumar Kartikeya Dwivedi1-25/+38
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>
2022-12-08bpf: Rework process_dynptr_funcKumar Kartikeya Dwivedi2-67/+178
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>
2022-12-08bpf: Propagate errors from process_* checks in check_func_argKumar Kartikeya Dwivedi1-10/+15
Currently, we simply ignore the errors in process_spin_lock, process_timer_func, process_kptr_func, process_dynptr_func. Instead, bubble up the error by storing and checking err variable. Acked-by: Joanne Koong <joannelkoong@gmail.com> Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20221207204141.308952-3-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-12-08bpf: Refactor ARG_PTR_TO_DYNPTR checks into process_dynptr_funcKumar Kartikeya Dwivedi1-64/+70
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>
2022-12-08Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski3-20/+28
No conflicts. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-12-08bpf: Skip rcu_barrier() if rcu_trace_implies_rcu_gp() is trueHou Tao1-1/+9
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>
2022-12-08bpf: Reuse freed element in free_by_rcu during allocationHou Tao1-3/+18
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>
2022-12-08memcg: Fix possible use-after-free in memcg_write_event_control()Tejun Heo1-1/+0
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>
2022-12-08bpf: Fix comment error in fixup_kfunc_call functionYang Jihong1-1/+1
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>
2022-12-08bpf: Do not zero-extend kfunc return valuesBjörn Töpel1-0/+4
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>
2022-12-08blktrace: Fix output non-blktrace event when blk_classic option enabledYang Jihong1-1/+2
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>
2022-12-08Merge branch 'topic/objtool' into nextMichael Ellerman1-0/+7
Merge the powerpc objtool support, which we were keeping in a topic branch in case of any merge conflicts.
2022-12-08Merge branch 'rework/console-list-lock' into for-linusPetr Mladek82-964/+2732
2022-12-07bpf/docs: Document struct cgroup * kfuncsDavid Vernet1-1/+1
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>
2022-12-07bpf/docs: Document struct task_struct * kfuncsDavid Vernet1-1/+1
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>
2022-12-07bpf: Remove unused insn_cnt argument from visit_[func_call_]insn()Andrii Nakryiko1-6/+5
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
2022-12-07Merge "do not rely on ALLOW_ERROR_INJECTION for fmod_ret" into bpf-nextAlexei Starovoitov2-7/+40
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>
2022-12-07module/decompress: Support zstd in-kernel decompressionStephen Boyd2-3/+92
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>
2022-12-07bpf: do not rely on ALLOW_ERROR_INJECTION for fmod_retBenjamin Tissoires2-7/+40
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
2022-12-06bpf: remove unnecessary prune and jump pointsAndrii Nakryiko1-24/+10
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>
2022-12-06bpf: mostly decouple jump history management from is_state_visited()Andrii Nakryiko1-23/+26
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>
2022-12-06bpf: decouple prune and jump pointsAndrii Nakryiko1-14/+43
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>
2022-12-06bpf: Loosen alloc obj test in verifier's reg_btf_recordDave Marchevsky1-1/+6
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>
2022-12-06bpf: Don't use rcu_users to refcount in task kfuncsDavid Vernet1-28/+48
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>
2022-12-06Merge branch 'for-next/ftrace' into for-next/coreWill Deacon3-6/+5
* for-next/ftrace: ftrace: arm64: remove static ftrace ftrace: arm64: move from REGS to ARGS ftrace: abstract DYNAMIC_FTRACE_WITH_ARGS accesses ftrace: rename ftrace_instruction_pointer_set() -> ftrace_regs_set_instruction_pointer() ftrace: pass fregs to arch_ftrace_set_direct_caller()
2022-12-06PM: sleep: Refine error message in try_to_freeze_tasks()Rafael J. Wysocki1-2/+2
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>
2022-12-06PM: sleep: Avoid using pr_cont() in the tasks freezing codeRafael J. Wysocki1-13/+8
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>
2022-12-05genirq/msi: Provide msi_domain_alloc_irq_at()Thomas Gleixner1-10/+95
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
2022-12-05genirq/msi: Provide msi_domain_ops:: Prepare_desc()Thomas Gleixner1-0/+3
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
2022-12-05genirq/msi: Provide BUS_DEVICE_PCI_MSI[X]Thomas Gleixner1-0/+4
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
2022-12-05genirq/msi: Add range checking to msi_insert_desc()Thomas Gleixner1-10/+43
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
2022-12-05proc: proc_skip_spaces() shouldn't think it is working on C stringsLinus Torvalds1-12/+13
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>
2022-12-05proc: avoid integer type confusion in get_proc_longLinus Torvalds1-3/+2
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>
2022-12-05genirq/msi: Provide msi_match_device_domain()Thomas Gleixner1-0/+25
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
2022-12-05genirq/msi: Provide msi_create/free_device_irq_domain()Thomas Gleixner1-0/+138
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
2022-12-05genirq/msi: Split msi_create_irq_domain()Thomas Gleixner1-12/+20
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
2022-12-05genirq/msi: Add size info to struct msi_domain_infoThomas Gleixner1-0/+11
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
2022-12-05genirq/msi: Provide struct msi_parent_opsThomas Gleixner1-0/+41
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
2022-12-05genirq/msi: Remove unused alloc/free interfacesThomas Gleixner1-73/+0
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
2022-12-05genirq/msi: Provide new domain id allocation functionsThomas Gleixner1-39/+136
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
2022-12-05genirq/msi: Provide new domain id based interfaces for freeing interruptsThomas Gleixner1-22/+120
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
2022-12-05genirq/msi: Make msi_add_simple_msi_descs() device domain awareThomas Gleixner1-41/+57
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