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2021-07-20rcu/nocb: Start moving nocb code to its own plugin fileFrederic Weisbecker3-1487/+1497
The kernel/rcu/tree_plugin.h file contains not only the plugins for preemptible RCU, but also many other features including rcu_nocbs callback offloading. This offloading has become large and complex, so it is time to put it in its own file. This commit starts that process. Suggested-by: Paul E. McKenney <[email protected]> Signed-off-by: Frederic Weisbecker <[email protected]> [ paulmck: Rename to tree_nocb.h, add Frederic as author. ] Signed-off-by: Paul E. McKenney <[email protected]>
2021-07-20Merge branch 'timers/urgent' of ↵Thomas Gleixner2-8/+10
git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks into timers/urgent Pull dyntick fixes from Frederic Weisbecker: - Fix a rearm race in the posix cpu timer code - Handle get_next_timer_interrupt() correctly when no timers are pending Link: https://lore.kernel.org/r/[email protected]
2021-07-19audit: add header protection to kernel/audit.hMaYuming1-0/+5
Protect kernel/audit.h against multiple #include's. Signed-off-by: MaYuming <[email protected]> [PM: rewrite subj/description] Signed-off-by: Paul Moore <[email protected]>
2021-07-19printk: Userspace format indexing supportChris Down4-5/+209
We have a number of systems industry-wide that have a subset of their functionality that works as follows: 1. Receive a message from local kmsg, serial console, or netconsole; 2. Apply a set of rules to classify the message; 3. Do something based on this classification (like scheduling a remediation for the machine), rinse, and repeat. As a couple of examples of places we have this implemented just inside Facebook, although this isn't a Facebook-specific problem, we have this inside our netconsole processing (for alarm classification), and as part of our machine health checking. We use these messages to determine fairly important metrics around production health, and it's important that we get them right. While for some kinds of issues we have counters, tracepoints, or metrics with a stable interface which can reliably indicate the issue, in order to react to production issues quickly we need to work with the interface which most kernel developers naturally use when developing: printk. Most production issues come from unexpected phenomena, and as such usually the code in question doesn't have easily usable tracepoints or other counters available for the specific problem being mitigated. We have a number of lines of monitoring defence against problems in production (host metrics, process metrics, service metrics, etc), and where it's not feasible to reliably monitor at another level, this kind of pragmatic netconsole monitoring is essential. As one would expect, monitoring using printk is rather brittle for a number of reasons -- most notably that the message might disappear entirely in a new version of the kernel, or that the message may change in some way that the regex or other classification methods start to silently fail. One factor that makes this even harder is that, under normal operation, many of these messages are never expected to be hit. For example, there may be a rare hardware bug which one wants to detect if it was to ever happen again, but its recurrence is not likely or anticipated. This precludes using something like checking whether the printk in question was printed somewhere fleetwide recently to determine whether the message in question is still present or not, since we don't anticipate that it should be printed anywhere, but still need to monitor for its future presence in the long-term. This class of issue has happened on a number of occasions, causing unhealthy machines with hardware issues to remain in production for longer than ideal. As a recent example, some monitoring around blk_update_request fell out of date and caused semi-broken machines to remain in production for longer than would be desirable. Searching through the codebase to find the message is also extremely fragile, because many of the messages are further constructed beyond their callsite (eg. btrfs_printk and other module-specific wrappers, each with their own functionality). Even if they aren't, guessing the format and formulation of the underlying message based on the aesthetics of the message emitted is not a recipe for success at scale, and our previous issues with fleetwide machine health checking demonstrate as much. This provides a solution to the issue of silently changed or deleted printks: we record pointers to all printk format strings known at compile time into a new .printk_index section, both in vmlinux and modules. At runtime, this can then be iterated by looking at <debugfs>/printk/index/<module>, which emits the following format, both readable by humans and able to be parsed by machines: $ head -1 vmlinux; shuf -n 5 vmlinux # <level[,flags]> filename:line function "format" <5> block/blk-settings.c:661 disk_stack_limits "%s: Warning: Device %s is misaligned\n" <4> kernel/trace/trace.c:8296 trace_create_file "Could not create tracefs '%s' entry\n" <6> arch/x86/kernel/hpet.c:144 _hpet_print_config "hpet: %s(%d):\n" <6> init/do_mounts.c:605 prepare_namespace "Waiting for root device %s...\n" <6> drivers/acpi/osl.c:1410 acpi_no_auto_serialize_setup "ACPI: auto-serialization disabled\n" This mitigates the majority of cases where we have a highly-specific printk which we want to match on, as we can now enumerate and check whether the format changed or the printk callsite disappeared entirely in userspace. This allows us to catch changes to printks we monitor earlier and decide what to do about it before it becomes problematic. There is no additional runtime cost for printk callers or printk itself, and the assembly generated is exactly the same. Signed-off-by: Chris Down <[email protected]> Cc: Petr Mladek <[email protected]> Cc: Jessica Yu <[email protected]> Cc: Sergey Senozhatsky <[email protected]> Cc: John Ogness <[email protected]> Cc: Steven Rostedt <[email protected]> Cc: Greg Kroah-Hartman <[email protected]> Cc: Johannes Weiner <[email protected]> Cc: Kees Cook <[email protected]> Reviewed-by: Petr Mladek <[email protected]> Tested-by: Petr Mladek <[email protected]> Reported-by: kernel test robot <[email protected]> Acked-by: Andy Shevchenko <[email protected]> Acked-by: Jessica Yu <[email protected]> # for module.{c,h} Signed-off-by: Petr Mladek <[email protected]> Link: https://lore.kernel.org/r/e42070983637ac5e384f17fbdbe86d19c7b212a5.1623775748.git.chris@chrisdown.name
2021-07-19printk: Rework parse_prefix into printk_parse_prefixChris Down2-4/+6
parse_prefix is needed externally by later patches, so move it into a context where it can be used as such. Also give it the printk_ prefix to reduce the chance of collisions. Signed-off-by: Chris Down <[email protected]> Cc: Petr Mladek <[email protected]> Reviewed-by: Petr Mladek <[email protected]> Acked-by: Andy Shevchenko <[email protected]> Signed-off-by: Petr Mladek <[email protected]> Link: https://lore.kernel.org/r/b22ba314a860e5c7f887958f1eab2649f9bd1d06.1623775748.git.chris@chrisdown.name
2021-07-19printk: Straighten out log_flags into printk_info_flagsChris Down2-23/+26
In the past, `enum log_flags` was part of `struct log`, hence the name. `struct log` has since been reworked and now this struct is stored inside `struct printk_info`. However, the name was never updated, which is somewhat confusing -- especially since these flags operate at the record level rather than at the level of an abstract log. printk_info_flags also joins its other metadata struct friends in printk_ringbuffer.h. Signed-off-by: Chris Down <[email protected]> Reviewed-by: Petr Mladek <[email protected]> Acked-by: Andy Shevchenko <[email protected]> Signed-off-by: Petr Mladek <[email protected]> Link: https://lore.kernel.org/r/3dd801982f02603e6e3aa4f8bc4f5ebb830a4949.1623775748.git.chris@chrisdown.name
2021-07-17Merge tag 'trace-v5.14-5' of ↵Linus Torvalds1-3/+3
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing fix from Steven Rostedt: "Fix the histogram logic from possibly crashing the kernel Working on the histogram code, I found that if you dereference a char pointer in a trace event that happens to point to user space, it can crash the kernel, as it does no checks of that pointer. I have code coming that will do this better, so just remove this ability to treat character pointers in trace events as stings in the histogram" * tag 'trace-v5.14-5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Do not reference char * as a string in histograms
2021-07-16bpf: Add ambient BPF runtime context stored in currentAndrii Nakryiko3-14/+6
b910eaaaa4b8 ("bpf: Fix NULL pointer dereference in bpf_get_local_storage() helper") fixed the problem with cgroup-local storage use in BPF by pre-allocating per-CPU array of 8 cgroup storage pointers to accommodate possible BPF program preemptions and nested executions. While this seems to work good in practice, it introduces new and unnecessary failure mode in which not all BPF programs might be executed if we fail to find an unused slot for cgroup storage, however unlikely it is. It might also not be so unlikely when/if we allow sleepable cgroup BPF programs in the future. Further, the way that cgroup storage is implemented as ambiently-available property during entire BPF program execution is a convenient way to pass extra information to BPF program and helpers without requiring user code to pass around extra arguments explicitly. So it would be good to have a generic solution that can allow implementing this without arbitrary restrictions. Ideally, such solution would work for both preemptable and sleepable BPF programs in exactly the same way. This patch introduces such solution, bpf_run_ctx. It adds one pointer field (bpf_ctx) to task_struct. This field is maintained by BPF_PROG_RUN family of macros in such a way that it always stays valid throughout BPF program execution. BPF program preemption is handled by remembering previous current->bpf_ctx value locally while executing nested BPF program and restoring old value after nested BPF program finishes. This is handled by two helper functions, bpf_set_run_ctx() and bpf_reset_run_ctx(), which are supposed to be used before and after BPF program runs, respectively. Restoring old value of the pointer handles preemption, while bpf_run_ctx pointer being a property of current task_struct naturally solves this problem for sleepable BPF programs by "following" BPF program execution as it is scheduled in and out of CPU. It would even allow CPU migration of BPF programs, even though it's not currently allowed by BPF infra. This patch cleans up cgroup local storage handling as a first application. The design itself is generic, though, with bpf_run_ctx being an empty struct that is supposed to be embedded into a specific struct for a given BPF program type (bpf_cg_run_ctx in this case). Follow up patches are planned that will expand this mechanism for other uses within tracing BPF programs. To verify that this change doesn't revert the fix to the original cgroup storage issue, I ran the same repro as in the original report ([0]) and didn't get any problems. Replacing bpf_reset_run_ctx(old_run_ctx) with bpf_reset_run_ctx(NULL) triggers the issue pretty quickly (so repro does work). [0] https://lore.kernel.org/bpf/YEEvBUiJl2pJkxTd@krava/ Fixes: b910eaaaa4b8 ("bpf: Fix NULL pointer dereference in bpf_get_local_storage() helper") Signed-off-by: Andrii Nakryiko <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Acked-by: Yonghong Song <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-07-16Merge branch 'urgent' of ↵Linus Torvalds4-12/+10
git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu Pull RCU fixes from Paul McKenney: - fix regressions induced by a merge-window change in scheduler semantics, which means that smp_processor_id() can no longer be used in kthreads using simple affinity to bind themselves to a specific CPU. - fix a bug in Tasks Trace RCU that was thought to be strictly theoretical. However, production workloads have started hitting this, so these fixes need to be merged sooner rather than later. - fix a minor printk()-format-mismatch issue introduced during the merge window. * 'urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu: rcu: Fix pr_info() formats and values in show_rcu_gp_kthreads() rcu-tasks: Don't delete holdouts within trc_wait_for_one_reader() rcu-tasks: Don't delete holdouts within trc_inspect_reader() refscale: Avoid false-positive warnings in ref_scale_reader() scftorture: Avoid false-positive warnings in scftorture_invoker()
2021-07-16locking/rwsem: Remove an unused parameter of rwsem_wake()xuyehan1-3/+3
The 2nd parameter 'count' is not used in this function. The places where the function is called are also modified. Signed-off-by: xuyehan <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Acked-by: Waiman Long <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2021-07-16perf: Refactor permissions check into perf_check_permission()Marco Elver1-26/+32
Refactor the permission check in perf_event_open() into a helper perf_check_permission(). This makes the permission check logic more readable (because we no longer have a negated disjunction). Add a comment mentioning the ptrace check also checks the uid. No functional change intended. Signed-off-by: Marco Elver <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Reviewed-by: Dmitry Vyukov <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2021-07-16perf: Fix required permissions if sigtrap is requestedMarco Elver1-1/+24
If perf_event_open() is called with another task as target and perf_event_attr::sigtrap is set, and the target task's user does not match the calling user, also require the CAP_KILL capability or PTRACE_MODE_ATTACH permissions. Otherwise, with the CAP_PERFMON capability alone it would be possible for a user to send SIGTRAP signals via perf events to another user's tasks. This could potentially result in those tasks being terminated if they cannot handle SIGTRAP signals. Note: The check complements the existing capability check, but is not supposed to supersede the ptrace_may_access() check. At a high level we now have: capable of CAP_PERFMON and (CAP_KILL if sigtrap) OR ptrace_may_access(...) // also checks for same thread-group and uid Fixes: 97ba62b27867 ("perf: Add support for SIGTRAP on perf events") Reported-by: Dmitry Vyukov <[email protected]> Signed-off-by: Marco Elver <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Acked-by: Dmitry Vyukov <[email protected]> Cc: <[email protected]> # 5.13+ Link: https://lore.kernel.org/r/[email protected]
2021-07-16cgroup: remove cgroup_mount from commentszhaoxiaoqiang111-1/+0
Git rid of an outdated comment. Since cgroup was fully switched to fs_context, cgroup_mount() is gone and it's confusing to mention in comments of cgroup_kill_sb(). Delete it. Signed-off-by: zhaoxiaoqiang11 <[email protected]> Signed-off-by: Tejun Heo <[email protected]>
2021-07-16bpf: Fix pointer arithmetic mask tightening under state pruningDaniel Borkmann1-10/+17
In 7fedb63a8307 ("bpf: Tighten speculative pointer arithmetic mask") we narrowed the offset mask for unprivileged pointer arithmetic in order to mitigate a corner case where in the speculative domain it is possible to advance, for example, the map value pointer by up to value_size-1 out-of- bounds in order to leak kernel memory via side-channel to user space. The verifier's state pruning for scalars leaves one corner case open where in the first verification path R_x holds an unknown scalar with an aux->alu_limit of e.g. 7, and in a second verification path that same register R_x, here denoted as R_x', holds an unknown scalar which has tighter bounds and would thus satisfy range_within(R_x, R_x') as well as tnum_in(R_x, R_x') for state pruning, yielding an aux->alu_limit of 3: Given the second path fits the register constraints for pruning, the final generated mask from aux->alu_limit will remain at 7. While technically not wrong for the non-speculative domain, it would however be possible to craft similar cases where the mask would be too wide as in 7fedb63a8307. One way to fix it is to detect the presence of unknown scalar map pointer arithmetic and force a deeper search on unknown scalars to ensure that we do not run into a masking mismatch. Signed-off-by: Daniel Borkmann <[email protected]> Acked-by: Alexei Starovoitov <[email protected]>
2021-07-16bpf: Remove superfluous aux sanitation on subprog rejectionDaniel Borkmann1-34/+0
Follow-up to fe9a5ca7e370 ("bpf: Do not mark insn as seen under speculative path verification"). The sanitize_insn_aux_data() helper does not serve a particular purpose in today's code. The original intention for the helper was that if function-by-function verification fails, a given program would be cleared from temporary insn_aux_data[], and then its verification would be re-attempted in the context of the main program a second time. However, a failure in do_check_subprogs() will skip do_check_main() and propagate the error to the user instead, thus such situation can never occur. Given its interaction is not compatible to the Spectre v1 mitigation (due to comparing aux->seen with env->pass_cnt), just remove sanitize_insn_aux_data() to avoid future bugs in this area. Signed-off-by: Daniel Borkmann <[email protected]> Acked-by: Alexei Starovoitov <[email protected]>
2021-07-16dma-mapping: handle vmalloc addresses in dma_common_{mmap,get_sgtable}Roman Skakun1-2/+10
xen-swiotlb can use vmalloc backed addresses for dma coherent allocations and uses the common helpers. Properly handle them to unbreak Xen on ARM platforms. Fixes: 1b65c4e5a9af ("swiotlb-xen: use xen_alloc/free_coherent_pages") Signed-off-by: Roman Skakun <[email protected]> Reviewed-by: Andrii Anisov <[email protected]> [hch: split the patch, renamed the helpers] Signed-off-by: Christoph Hellwig <[email protected]>
2021-07-15Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller13-94/+1105
Alexei Starovoitov says: ==================== pull-request: bpf-next 2021-07-15 The following pull-request contains BPF updates for your *net-next* tree. We've added 45 non-merge commits during the last 15 day(s) which contain a total of 52 files changed, 3122 insertions(+), 384 deletions(-). The main changes are: 1) Introduce bpf timers, from Alexei. 2) Add sockmap support for unix datagram socket, from Cong. 3) Fix potential memleak and UAF in the verifier, from He. 4) Add bpf_get_func_ip helper, from Jiri. 5) Improvements to generic XDP mode, from Kumar. 6) Support for passing xdp_md to XDP programs in bpf_prog_run, from Zvi. =================== Signed-off-by: David S. Miller <[email protected]>
2021-07-15sock_map: Relax config dependency to CONFIG_NETCong Wang1-1/+1
Currently sock_map still has Kconfig dependency on CONFIG_INET, but there is no actual functional dependency on it after we introduce ->psock_update_sk_prot(). We have to extend it to CONFIG_NET now as we are going to support AF_UNIX. Signed-off-by: Cong Wang <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-07-15bpf: Add bpf_get_func_ip helper for kprobe programsJiri Olsa2-0/+18
Adding bpf_get_func_ip helper for BPF_PROG_TYPE_KPROBE programs, so it's now possible to call bpf_get_func_ip from both kprobe and kretprobe programs. Taking the caller's address from 'struct kprobe::addr', which is defined for both kprobe and kretprobe. Signed-off-by: Jiri Olsa <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Reviewed-by: Masami Hiramatsu <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-07-15bpf: Add bpf_get_func_ip helper for tracing programsJiri Olsa2-0/+58
Adding bpf_get_func_ip helper for BPF_PROG_TYPE_TRACING programs, specifically for all trampoline attach types. The trampoline's caller IP address is stored in (ctx - 8) address. so there's no reason to actually call the helper, but rather fixup the call instruction and return [ctx - 8] value directly. Signed-off-by: Jiri Olsa <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-07-15bpf: Enable BPF_TRAMP_F_IP_ARG for trampolines with call_get_func_ipJiri Olsa1-3/+9
Enabling BPF_TRAMP_F_IP_ARG for trampolines that actually need it. The BPF_TRAMP_F_IP_ARG adds extra 3 instructions to trampoline code and is used only by programs with bpf_get_func_ip helper, which is added in following patch and sets call_get_func_ip bit. This patch ensures that BPF_TRAMP_F_IP_ARG flag is used only for trampolines that have programs with call_get_func_ip set. Signed-off-by: Jiri Olsa <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-07-15Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpfDavid S. Miller1-0/+2
Andrii Nakryiko says: ==================== pull-request: bpf 2021-07-15 The following pull-request contains BPF updates for your *net* tree. We've added 9 non-merge commits during the last 5 day(s) which contain a total of 9 files changed, 37 insertions(+), 15 deletions(-). The main changes are: 1) Fix NULL pointer dereference in BPF_TEST_RUN for BPF_XDP_DEVMAP and BPF_XDP_CPUMAP programs, from Xuan Zhuo. 2) Fix use-after-free of net_device in XDP bpf_link, from Xuan Zhuo. 3) Follow-up fix to subprog poke descriptor use-after-free problem, from Daniel Borkmann and John Fastabend. 4) Fix out-of-range array access in s390 BPF JIT backend, from Colin Ian King. 5) Fix memory leak in BPF sockmap, from John Fastabend. 6) Fix for sockmap to prevent proc stats reporting bug, from John Fastabend and Jakub Sitnicki. 7) Fix NULL pointer dereference in bpftool, from Tobias Klauser. 8) AF_XDP documentation fixes, from Baruch Siach. ==================== Signed-off-by: David S. Miller <[email protected]>
2021-07-15tracing: Do not reference char * as a string in histogramsSteven Rostedt (VMware)1-3/+3
The histogram logic was allowing events with char * pointers to be used as normal strings. But it was easy to crash the kernel with: # echo 'hist:keys=filename' > events/syscalls/sys_enter_openat/trigger And open some files, and boom! BUG: unable to handle page fault for address: 00007f2ced0c3280 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 1173fa067 P4D 1173fa067 PUD 1171b6067 PMD 1171dd067 PTE 0 Oops: 0000 [#1] PREEMPT SMP CPU: 6 PID: 1810 Comm: cat Not tainted 5.13.0-rc5-test+ #61 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v03.03 07/14/2016 RIP: 0010:strlen+0x0/0x20 Code: f6 82 80 2a 0b a9 20 74 11 0f b6 50 01 48 83 c0 01 f6 82 80 2a 0b a9 20 75 ef c3 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 <80> 3f 00 74 10 48 89 f8 48 83 c0 01 80 38 00 75 f7 48 29 f8 c3 RSP: 0018:ffffbdbf81567b50 EFLAGS: 00010246 RAX: 0000000000000003 RBX: ffff93815cdb3800 RCX: ffff9382401a22d0 RDX: 0000000000000100 RSI: 0000000000000000 RDI: 00007f2ced0c3280 RBP: 0000000000000100 R08: ffff9382409ff074 R09: ffffbdbf81567c98 R10: ffff9382409ff074 R11: 0000000000000000 R12: ffff9382409ff074 R13: 0000000000000001 R14: ffff93815a744f00 R15: 00007f2ced0c3280 FS: 00007f2ced0f8580(0000) GS:ffff93825a800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2ced0c3280 CR3: 0000000107069005 CR4: 00000000001706e0 Call Trace: event_hist_trigger+0x463/0x5f0 ? find_held_lock+0x32/0x90 ? sched_clock_cpu+0xe/0xd0 ? lock_release+0x155/0x440 ? kernel_init_free_pages+0x6d/0x90 ? preempt_count_sub+0x9b/0xd0 ? kernel_init_free_pages+0x6d/0x90 ? get_page_from_freelist+0x12c4/0x1680 ? __rb_reserve_next+0xe5/0x460 ? ring_buffer_lock_reserve+0x12a/0x3f0 event_triggers_call+0x52/0xe0 ftrace_syscall_enter+0x264/0x2c0 syscall_trace_enter.constprop.0+0x1ee/0x210 do_syscall_64+0x1c/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae Where it triggered a fault on strlen(key) where key was the filename. The reason is that filename is a char * to user space, and the histogram code just blindly dereferenced it, with obvious bad results. I originally tried to use strncpy_from_user/kernel_nofault() but found that there's other places that its dereferenced and not worth the effort. Just do not allow "char *" to act like strings. Link: https://lkml.kernel.org/r/[email protected] Cc: Ingo Molnar <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Masami Hiramatsu <[email protected]> Cc: Tzvetomir Stoyanov <[email protected]> Cc: [email protected] Acked-by: Namhyung Kim <[email protected]> Acked-by: Tom Zanussi <[email protected]> Fixes: 79e577cbce4c4 ("tracing: Support string type key properly") Fixes: 5967bd5c4239 ("tracing: Let filter_assign_type() detect FILTER_PTR_STRING") Signed-off-by: Steven Rostedt (VMware) <[email protected]>
2021-07-15Merge tag 'Wimplicit-fallthrough-clang-5.14-rc2' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux Pull fallthrough fixes from Gustavo Silva: "This fixes many fall-through warnings when building with Clang and -Wimplicit-fallthrough, and also enables -Wimplicit-fallthrough for Clang, globally. It's also important to notice that since we have adopted the use of the pseudo-keyword macro fallthrough, we also want to avoid having more /* fall through */ comments being introduced. Contrary to GCC, Clang doesn't recognize any comments as implicit fall-through markings when the -Wimplicit-fallthrough option is enabled. So, in order to avoid having more comments being introduced, we use the option -Wimplicit-fallthrough=5 for GCC, which similar to Clang, will cause a warning in case a code comment is intended to be used as a fall-through marking. The patch for Makefile also enforces this. We had almost 4,000 of these issues for Clang in the beginning, and there might be a couple more out there when building some architectures with certain configurations. However, with the recent fixes I think we are in good shape and it is now possible to enable the warning for Clang" * tag 'Wimplicit-fallthrough-clang-5.14-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux: (27 commits) Makefile: Enable -Wimplicit-fallthrough for Clang powerpc/smp: Fix fall-through warning for Clang dmaengine: mpc512x: Fix fall-through warning for Clang usb: gadget: fsl_qe_udc: Fix fall-through warning for Clang powerpc/powernv: Fix fall-through warning for Clang MIPS: Fix unreachable code issue MIPS: Fix fall-through warnings for Clang ASoC: Mediatek: MT8183: Fix fall-through warning for Clang power: supply: Fix fall-through warnings for Clang dmaengine: ti: k3-udma: Fix fall-through warning for Clang s390: Fix fall-through warnings for Clang dmaengine: ipu: Fix fall-through warning for Clang iommu/arm-smmu-v3: Fix fall-through warning for Clang mmc: jz4740: Fix fall-through warning for Clang PCI: Fix fall-through warning for Clang scsi: libsas: Fix fall-through warning for Clang video: fbdev: Fix fall-through warning for Clang math-emu: Fix fall-through warning cpufreq: Fix fall-through warning for Clang drm/msm: Fix fall-through warning in msm_gem_new_impl() ...
2021-07-15bpf: Teach stack depth check about async callbacks.Alexei Starovoitov1-3/+15
Teach max stack depth checking algorithm about async callbacks that don't increase bpf program stack size. Also add sanity check that bpf_tail_call didn't sneak into async cb. It's impossible, since PTR_TO_CTX is not available in async cb, hence the program cannot contain bpf_tail_call(ctx,...); Signed-off-by: Alexei Starovoitov <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Acked-by: Andrii Nakryiko <[email protected]> Acked-by: Toke Høiland-Jørgensen <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-07-15bpf: Implement verifier support for validation of async callbacks.Alexei Starovoitov2-8/+123
bpf_for_each_map_elem() and bpf_timer_set_callback() helpers are relying on PTR_TO_FUNC infra in the verifier to validate addresses to subprograms and pass them into the helpers as function callbacks. In case of bpf_for_each_map_elem() the callback is invoked synchronously and the verifier treats it as a normal subprogram call by adding another bpf_func_state and new frame in __check_func_call(). bpf_timer_set_callback() doesn't invoke the callback directly. The subprogram will be called asynchronously from bpf_timer_cb(). Teach the verifier to validate such async callbacks as special kind of jump by pushing verifier state into stack and let pop_stack() process it. Special care needs to be taken during state pruning. The call insn doing bpf_timer_set_callback has to be a prune_point. Otherwise short timer callbacks might not have prune points in front of bpf_timer_set_callback() which means is_state_visited() will be called after this call insn is processed in __check_func_call(). Which means that another async_cb state will be pushed to be walked later and the verifier will eventually hit BPF_COMPLEXITY_LIMIT_JMP_SEQ limit. Since push_async_cb() looks like another push_stack() branch the infinite loop detection will trigger false positive. To recognize this case mark such states as in_async_callback_fn. To distinguish infinite loop in async callback vs the same callback called with different arguments for different map and timer add async_entry_cnt to bpf_func_state. Enforce return zero from async callbacks. Signed-off-by: Alexei Starovoitov <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Acked-by: Andrii Nakryiko <[email protected]> Acked-by: Toke Høiland-Jørgensen <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-07-15bpf: Relax verifier recursion check.Alexei Starovoitov1-2/+6
In the following bpf subprogram: static int timer_cb(void *map, void *key, void *value) { bpf_timer_set_callback(.., timer_cb); } the 'timer_cb' is a pointer to a function. ld_imm64 insn is used to carry this pointer. bpf_pseudo_func() returns true for such ld_imm64 insn. Unlike bpf_for_each_map_elem() the bpf_timer_set_callback() is asynchronous. Relax control flow check to allow such "recursion" that is seen as an infinite loop by check_cfg(). The distinction between bpf_for_each_map_elem() the bpf_timer_set_callback() is done in the follow up patch. Signed-off-by: Alexei Starovoitov <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Acked-by: Andrii Nakryiko <[email protected]> Acked-by: Toke Høiland-Jørgensen <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-07-15bpf: Remember BTF of inner maps.Alexei Starovoitov1-0/+6
BTF is required for 'struct bpf_timer' to be recognized inside map value. The bpf timers are supported inside inner maps. Remember 'struct btf *' in inner_map_meta to make it available to the verifier in the sequence: struct bpf_map *inner_map = bpf_map_lookup_elem(&outer_map, ...); if (inner_map) timer = bpf_map_lookup_elem(&inner_map, ...); Signed-off-by: Alexei Starovoitov <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Acked-by: Yonghong Song <[email protected]> Acked-by: Martin KaFai Lau <[email protected]> Acked-by: Andrii Nakryiko <[email protected]> Acked-by: Toke Høiland-Jørgensen <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-07-15bpf: Prevent pointer mismatch in bpf_timer_init.Alexei Starovoitov1-3/+28
bpf_timer_init() arguments are: 1. pointer to a timer (which is embedded in map element). 2. pointer to a map. Make sure that pointer to a timer actually belongs to that map. Use map_uid (which is unique id of inner map) to reject: inner_map1 = bpf_map_lookup_elem(outer_map, key1) inner_map2 = bpf_map_lookup_elem(outer_map, key2) if (inner_map1 && inner_map2) { timer = bpf_map_lookup_elem(inner_map1); if (timer) // mismatch would have been allowed bpf_timer_init(timer, inner_map2); } Signed-off-by: Alexei Starovoitov <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Acked-by: Martin KaFai Lau <[email protected]> Acked-by: Andrii Nakryiko <[email protected]> Acked-by: Toke Høiland-Jørgensen <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-07-15bpf: Add map side support for bpf timers.Alexei Starovoitov7-35/+225
Restrict bpf timers to array, hash (both preallocated and kmalloced), and lru map types. The per-cpu maps with timers don't make sense, since 'struct bpf_timer' is a part of map value. bpf timers in per-cpu maps would mean that the number of timers depends on number of possible cpus and timers would not be accessible from all cpus. lpm map support can be added in the future. The timers in inner maps are supported. The bpf_map_update/delete_elem() helpers and sys_bpf commands cancel and free bpf_timer in a given map element. Similar to 'struct bpf_spin_lock' BTF is required and it is used to validate that map element indeed contains 'struct bpf_timer'. Make check_and_init_map_value() init both bpf_spin_lock and bpf_timer when map element data is reused in preallocated htab and lru maps. Teach copy_map_value() to support both bpf_spin_lock and bpf_timer in a single map element. There could be one of each, but not more than one. Due to 'one bpf_timer in one element' restriction do not support timers in global data, since global data is a map of single element, but from bpf program side it's seen as many global variables and restriction of single global timer would be odd. The sys_bpf map_freeze and sys_mmap syscalls are not allowed on maps with timers, since user space could have corrupted mmap element and crashed the kernel. The maps with timers cannot be readonly. Due to these restrictions search for bpf_timer in datasec BTF in case it was placed in the global data to report clear error. The previous patch allowed 'struct bpf_timer' as a first field in a map element only. Relax this restriction. Refactor lru map to s/bpf_lru_push_free/htab_lru_push_free/ to cancel and free the timer when lru map deletes an element as a part of it eviction algorithm. Make sure that bpf program cannot access 'struct bpf_timer' via direct load/store. The timer operation are done through helpers only. This is similar to 'struct bpf_spin_lock'. Signed-off-by: Alexei Starovoitov <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Acked-by: Yonghong Song <[email protected]> Acked-by: Martin KaFai Lau <[email protected]> Acked-by: Andrii Nakryiko <[email protected]> Acked-by: Toke Høiland-Jørgensen <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-07-15bpf: Introduce bpf timers.Alexei Starovoitov3-1/+434
Introduce 'struct bpf_timer { __u64 :64; __u64 :64; };' that can be embedded in hash/array/lru maps as a regular field and helpers to operate on it: // Initialize the timer. // First 4 bits of 'flags' specify clockid. // Only CLOCK_MONOTONIC, CLOCK_REALTIME, CLOCK_BOOTTIME are allowed. long bpf_timer_init(struct bpf_timer *timer, struct bpf_map *map, int flags); // Configure the timer to call 'callback_fn' static function. long bpf_timer_set_callback(struct bpf_timer *timer, void *callback_fn); // Arm the timer to expire 'nsec' nanoseconds from the current time. long bpf_timer_start(struct bpf_timer *timer, u64 nsec, u64 flags); // Cancel the timer and wait for callback_fn to finish if it was running. long bpf_timer_cancel(struct bpf_timer *timer); Here is how BPF program might look like: struct map_elem { int counter; struct bpf_timer timer; }; struct { __uint(type, BPF_MAP_TYPE_HASH); __uint(max_entries, 1000); __type(key, int); __type(value, struct map_elem); } hmap SEC(".maps"); static int timer_cb(void *map, int *key, struct map_elem *val); /* val points to particular map element that contains bpf_timer. */ SEC("fentry/bpf_fentry_test1") int BPF_PROG(test1, int a) { struct map_elem *val; int key = 0; val = bpf_map_lookup_elem(&hmap, &key); if (val) { bpf_timer_init(&val->timer, &hmap, CLOCK_REALTIME); bpf_timer_set_callback(&val->timer, timer_cb); bpf_timer_start(&val->timer, 1000 /* call timer_cb2 in 1 usec */, 0); } } This patch adds helper implementations that rely on hrtimers to call bpf functions as timers expire. The following patches add necessary safety checks. Only programs with CAP_BPF are allowed to use bpf_timer. The amount of timers used by the program is constrained by the memcg recorded at map creation time. The bpf_timer_init() helper needs explicit 'map' argument because inner maps are dynamic and not known at load time. While the bpf_timer_set_callback() is receiving hidden 'aux->prog' argument supplied by the verifier. The prog pointer is needed to do refcnting of bpf program to make sure that program doesn't get freed while the timer is armed. This approach relies on "user refcnt" scheme used in prog_array that stores bpf programs for bpf_tail_call. The bpf_timer_set_callback() will increment the prog refcnt which is paired with bpf_timer_cancel() that will drop the prog refcnt. The ops->map_release_uref is responsible for cancelling the timers and dropping prog refcnt when user space reference to a map reaches zero. This uref approach is done to make sure that Ctrl-C of user space process will not leave timers running forever unless the user space explicitly pinned a map that contained timers in bpffs. bpf_timer_init() and bpf_timer_set_callback() will return -EPERM if map doesn't have user references (is not held by open file descriptor from user space and not pinned in bpffs). The bpf_map_delete_elem() and bpf_map_update_elem() operations cancel and free the timer if given map element had it allocated. "bpftool map update" command can be used to cancel timers. The 'struct bpf_timer' is explicitly __attribute__((aligned(8))) because '__u64 :64' has 1 byte alignment of 8 byte padding. Signed-off-by: Alexei Starovoitov <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Acked-by: Martin KaFai Lau <[email protected]> Acked-by: Andrii Nakryiko <[email protected]> Acked-by: Toke Høiland-Jørgensen <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-07-15bpf: Factor out bpf_spin_lock into helpers.Alexei Starovoitov1-4/+14
Move ____bpf_spin_lock/unlock into helpers to make it more clear that quadruple underscore bpf_spin_lock/unlock are irqsave/restore variants. Signed-off-by: Alexei Starovoitov <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Acked-by: Martin KaFai Lau <[email protected]> Acked-by: Andrii Nakryiko <[email protected]> Acked-by: Toke Høiland-Jørgensen <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-07-15bpf: Prepare bpf_prog_put() to be called from irq context.Alexei Starovoitov1-6/+26
Currently bpf_prog_put() is called from the task context only. With addition of bpf timers the timer related helpers will start calling bpf_prog_put() from irq-saved region and in rare cases might drop the refcnt to zero. To address this case, first, convert bpf_prog_free_id() to be irq-save (this is similar to bpf_map_free_id), and, second, defer non irq appropriate calls into work queue. For example: bpf_audit_prog() is calling kmalloc and wake_up_interruptible, bpf_prog_kallsyms_del_all()->bpf_ksym_del()->spin_unlock_bh(). They are not safe with irqs disabled. Signed-off-by: Alexei Starovoitov <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Acked-by: Martin KaFai Lau <[email protected]> Acked-by: Andrii Nakryiko <[email protected]> Acked-by: Toke Høiland-Jørgensen <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-07-14bpf: Fix potential memleak and UAF in the verifier.He Fengqing1-11/+16
In bpf_patch_insn_data(), we first use the bpf_patch_insn_single() to insert new instructions, then use adjust_insn_aux_data() to adjust insn_aux_data. If the old env->prog have no enough room for new inserted instructions, we use bpf_prog_realloc to construct new_prog and free the old env->prog. There have two errors here. First, if adjust_insn_aux_data() return ENOMEM, we should free the new_prog. Second, if adjust_insn_aux_data() return ENOMEM, bpf_patch_insn_data() will return NULL, and env->prog has been freed in bpf_prog_realloc, but we will use it in bpf_check(). So in this patch, we make the adjust_insn_aux_data() never fails. In bpf_patch_insn_data(), we first pre-malloc memory for the new insn_aux_data, then call bpf_patch_insn_single() to insert new instructions, at last call adjust_insn_aux_data() to adjust insn_aux_data. Fixes: 8041902dae52 ("bpf: adjust insn_aux_data when patching insns") Signed-off-by: He Fengqing <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: Song Liu <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-07-15timers: Fix get_next_timer_interrupt() with no timers pendingNicolas Saenz Julienne1-3/+5
31cd0e119d50 ("timers: Recalculate next timer interrupt only when necessary") subtly altered get_next_timer_interrupt()'s behaviour. The function no longer consistently returns KTIME_MAX with no timers pending. In order to decide if there are any timers pending we check whether the next expiry will happen NEXT_TIMER_MAX_DELTA jiffies from now. Unfortunately, the next expiry time and the timer base clock are no longer updated in unison. The former changes upon certain timer operations (enqueue, expire, detach), whereas the latter keeps track of jiffies as they move forward. Ultimately breaking the logic above. A simplified example: - Upon entering get_next_timer_interrupt() with: jiffies = 1 base->clk = 0; base->next_expiry = NEXT_TIMER_MAX_DELTA; 'base->next_expiry == base->clk + NEXT_TIMER_MAX_DELTA', the function returns KTIME_MAX. - 'base->clk' is updated to the jiffies value. - The next time we enter get_next_timer_interrupt(), taking into account no timer operations happened: base->clk = 1; base->next_expiry = NEXT_TIMER_MAX_DELTA; 'base->next_expiry != base->clk + NEXT_TIMER_MAX_DELTA', the function returns a valid expire time, which is incorrect. This ultimately might unnecessarily rearm sched's timer on nohz_full setups, and add latency to the system[1]. So, introduce 'base->timers_pending'[2], update it every time 'base->next_expiry' changes, and use it in get_next_timer_interrupt(). [1] See tick_nohz_stop_tick(). [2] A quick pahole check on x86_64 and arm64 shows it doesn't make 'struct timer_base' any bigger. Fixes: 31cd0e119d50 ("timers: Recalculate next timer interrupt only when necessary") Signed-off-by: Nicolas Saenz Julienne <[email protected]> Signed-off-by: Frederic Weisbecker <[email protected]>
2021-07-15posix-cpu-timers: Fix rearm racing against process tickFrederic Weisbecker1-5/+5
Since the process wide cputime counter is started locklessly from posix_cpu_timer_rearm(), it can be concurrently stopped by operations on other timers from the same thread group, such as in the following unlucky scenario: CPU 0 CPU 1 ----- ----- timer_settime(TIMER B) posix_cpu_timer_rearm(TIMER A) cpu_clock_sample_group() (pct->timers_active already true) handle_posix_cpu_timers() check_process_timers() stop_process_timers() pct->timers_active = false arm_timer(TIMER A) tick -> run_posix_cpu_timers() // sees !pct->timers_active, ignore // our TIMER A Fix this with simply locking process wide cputime counting start and timer arm in the same block. Acked-by: Peter Zijlstra (Intel) <[email protected]> Signed-off-by: Frederic Weisbecker <[email protected]> Fixes: 60f2ceaa8111 ("posix-cpu-timers: Remove unnecessary locking around cpu_clock_sample_group") Cc: [email protected] Cc: Oleg Nesterov <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Eric W. Biederman <[email protected]>
2021-07-14Merge tag 'net-5.14-rc2' of ↵Linus Torvalds3-42/+32
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net Pull networking fixes from Jakub Kicinski. "Including fixes from bpf and netfilter. Current release - regressions: - sock: fix parameter order in sock_setsockopt() Current release - new code bugs: - netfilter: nft_last: - fix incorrect arithmetic when restoring last used - honor NFTA_LAST_SET on restoration Previous releases - regressions: - udp: properly flush normal packet at GRO time - sfc: ensure correct number of XDP queues; don't allow enabling the feature if there isn't sufficient resources to Tx from any CPU - dsa: sja1105: fix address learning getting disabled on the CPU port - mptcp: addresses a rmem accounting issue that could keep packets in subflow receive buffers longer than necessary, delaying MPTCP-level ACKs - ip_tunnel: fix mtu calculation for ETHER tunnel devices - do not reuse skbs allocated from skbuff_fclone_cache in the napi skb cache, we'd try to return them to the wrong slab cache - tcp: consistently disable header prediction for mptcp Previous releases - always broken: - bpf: fix subprog poke descriptor tracking use-after-free - ipv6: - allocate enough headroom in ip6_finish_output2() in case iptables TEE is used - tcp: drop silly ICMPv6 packet too big messages to avoid expensive and pointless lookups (which may serve as a DDOS vector) - make sure fwmark is copied in SYNACK packets - fix 'disable_policy' for forwarded packets (align with IPv4) - netfilter: conntrack: - do not renew entry stuck in tcp SYN_SENT state - do not mark RST in the reply direction coming after SYN packet for an out-of-sync entry - mptcp: cleanly handle error conditions with MP_JOIN and syncookies - mptcp: fix double free when rejecting a join due to port mismatch - validate lwtstate->data before returning from skb_tunnel_info() - tcp: call sk_wmem_schedule before sk_mem_charge in zerocopy path - mt76: mt7921: continue to probe driver when fw already downloaded - bonding: fix multiple issues with offloading IPsec to (thru?) bond - stmmac: ptp: fix issues around Qbv support and setting time back - bcmgenet: always clear wake-up based on energy detection Misc: - sctp: move 198 addresses from unusable to private scope - ptp: support virtual clocks and timestamping - openvswitch: optimize operation for key comparison" * tag 'net-5.14-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (158 commits) net: dsa: properly check for the bridge_leave methods in dsa_switch_bridge_leave() sfc: add logs explaining XDP_TX/REDIRECT is not available sfc: ensure correct number of XDP queues sfc: fix lack of XDP TX queues - error XDP TX failed (-22) net: fddi: fix UAF in fza_probe net: dsa: sja1105: fix address learning getting disabled on the CPU port net: ocelot: fix switchdev objects synced for wrong netdev with LAG offload net: Use nlmsg_unicast() instead of netlink_unicast() octeontx2-pf: Fix uninitialized boolean variable pps ipv6: allocate enough headroom in ip6_finish_output2() net: hdlc: rename 'mod_init' & 'mod_exit' functions to be module-specific net: bridge: multicast: fix MRD advertisement router port marking race net: bridge: multicast: fix PIM hello router port marking race net: phy: marvell10g: fix differentiation of 88X3310 from 88X3340 dsa: fix for_each_child.cocci warnings virtio_net: check virtqueue_add_sgs() return value mptcp: properly account bulk freed memory selftests: mptcp: fix case multiple subflows limited by server mptcp: avoid processing packet if a subflow reset mptcp: fix syncookie process if mptcp can not_accept new subflow ...
2021-07-14fs: add vfs_parse_fs_param_source() helperChristian Brauner1-9/+5
Add a simple helper that filesystems can use in their parameter parser to parse the "source" parameter. A few places open-coded this function and that already caused a bug in the cgroup v1 parser that we fixed. Let's make it harder to get this wrong by introducing a helper which performs all necessary checks. Link: https://syzkaller.appspot.com/bug?id=6312526aba5beae046fdae8f00399f87aab48b12 Cc: Christoph Hellwig <[email protected]> Cc: Alexander Viro <[email protected]> Cc: Dmitry Vyukov <[email protected]> Signed-off-by: Christian Brauner <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2021-07-14cgroup: verify that source is a stringChristian Brauner1-0/+2
The following sequence can be used to trigger a UAF: int fscontext_fd = fsopen("cgroup"); int fd_null = open("/dev/null, O_RDONLY); int fsconfig(fscontext_fd, FSCONFIG_SET_FD, "source", fd_null); close_range(3, ~0U, 0); The cgroup v1 specific fs parser expects a string for the "source" parameter. However, it is perfectly legitimate to e.g. specify a file descriptor for the "source" parameter. The fs parser doesn't know what a filesystem allows there. So it's a bug to assume that "source" is always of type fs_value_is_string when it can reasonably also be fs_value_is_file. This assumption in the cgroup code causes a UAF because struct fs_parameter uses a union for the actual value. Access to that union is guarded by the param->type member. Since the cgroup paramter parser didn't check param->type but unconditionally moved param->string into fc->source a close on the fscontext_fd would trigger a UAF during put_fs_context() which frees fc->source thereby freeing the file stashed in param->file causing a UAF during a close of the fd_null. Fix this by verifying that param->type is actually a string and report an error if not. In follow up patches I'll add a new generic helper that can be used here and by other filesystems instead of this error-prone copy-pasta fix. But fixing it in here first makes backporting a it to stable a lot easier. Fixes: 8d2451f4994f ("cgroup1: switch to option-by-option parsing") Reported-by: [email protected] Cc: Christoph Hellwig <[email protected]> Cc: Alexander Viro <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: <[email protected]> Cc: syzkaller-bugs <[email protected]> Signed-off-by: Christian Brauner <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2021-07-13swiotlb: add overflow checks to swiotlb_bounceDominique Martinet1-3/+17
This is a follow-up on 5f89468e2f06 ("swiotlb: manipulate orig_addr when tlb_addr has offset") which fixed unaligned dma mappings, making sure the following overflows are caught: - offset of the start of the slot within the device bigger than requested address' offset, in other words if the base address given in swiotlb_tbl_map_single to create the mapping (orig_addr) was after the requested address for the sync (tlb_offset) in the same block: |------------------------------------------| block <----------------------------> mapped part of the block ^ orig_addr ^ invalid tlb_addr for sync - if the resulting offset was bigger than the allocation size this one could happen if the mapping was not until the end. e.g. |------------------------------------------| block <---------------------> mapped part of the block ^ ^ orig_addr invalid tlb_addr Both should never happen so print a warning and bail out without trying to adjust the sizes/offsets: the first one could try to sync from orig_addr to whatever is left of the requested size, but the later really has nothing to sync there... Signed-off-by: Dominique Martinet <[email protected]> Cc: Konrad Rzeszutek Wilk <[email protected]> Reviewed-by: Bumyong Lee <[email protected] Cc: Chanho Park <[email protected]> Cc: Christoph Hellwig <[email protected]> Signed-off-by: Konrad Rzeszutek Wilk <[email protected]>
2021-07-13swiotlb: fix implicit debugfs declarationsClaire Chang1-5/+16
Factor out the debugfs bits from rmem_swiotlb_device_init() into a separate rmem_swiotlb_debugfs_init() to fix the implicit debugfs declarations. Fixes: 461021875c50 ("swiotlb: Add restricted DMA pool initialization") Reported-by: kernel test robot <[email protected]> Signed-off-by: Claire Chang <[email protected]> Signed-off-by: Konrad Rzeszutek Wilk <[email protected]>
2021-07-13swiotlb: Add restricted DMA pool initializationClaire Chang2-0/+90
Add the initialization function to create restricted DMA pools from matching reserved-memory nodes. Regardless of swiotlb setting, the restricted DMA pool is preferred if available. The restricted DMA pools provide a basic level of protection against the DMA overwriting buffer contents at unexpected times. However, to protect against general data leakage and system memory corruption, the system needs to provide a way to lock down the memory access, e.g., MPU. Signed-off-by: Claire Chang <[email protected]> Reviewed-by: Christoph Hellwig <[email protected]> Tested-by: Stefano Stabellini <[email protected]> Tested-by: Will Deacon <[email protected]> Signed-off-by: Konrad Rzeszutek Wilk <[email protected]>
2021-07-13swiotlb: Add restricted DMA alloc/free supportClaire Chang2-14/+73
Add the functions, swiotlb_{alloc,free} and is_swiotlb_for_alloc to support the memory allocation from restricted DMA pool. The restricted DMA pool is preferred if available. Note that since coherent allocation needs remapping, one must set up another device coherent pool by shared-dma-pool and use dma_alloc_from_dev_coherent instead for atomic coherent allocation. Signed-off-by: Claire Chang <[email protected]> Reviewed-by: Christoph Hellwig <[email protected]> Tested-by: Stefano Stabellini <[email protected]> Tested-by: Will Deacon <[email protected]> Acked-by: Stefano Stabellini <[email protected]> Signed-off-by: Konrad Rzeszutek Wilk <[email protected]>
2021-07-13swiotlb: Refactor swiotlb_tbl_unmap_singleClaire Chang1-15/+20
Add a new function, swiotlb_release_slots, to make the code reusable for supporting different bounce buffer pools. Signed-off-by: Claire Chang <[email protected]> Reviewed-by: Christoph Hellwig <[email protected]> Tested-by: Stefano Stabellini <[email protected]> Tested-by: Will Deacon <[email protected]> Signed-off-by: Konrad Rzeszutek Wilk <[email protected]>
2021-07-13swiotlb: Move alloc_size to swiotlb_find_slotsClaire Chang1-8/+9
Rename find_slots to swiotlb_find_slots and move the maintenance of alloc_size to it for better code reusability later. Signed-off-by: Claire Chang <[email protected]> Reviewed-by: Christoph Hellwig <[email protected]> Tested-by: Stefano Stabellini <[email protected]> Tested-by: Will Deacon <[email protected]> Signed-off-by: Konrad Rzeszutek Wilk <[email protected]>
2021-07-13swiotlb: Use is_swiotlb_force_bounce for swiotlb data bouncingClaire Chang3-2/+6
Propagate the swiotlb_force into io_tlb_default_mem->force_bounce and use it to determine whether to bounce the data or not. This will be useful later to allow for different pools. Signed-off-by: Claire Chang <[email protected]> Reviewed-by: Christoph Hellwig <[email protected]> Tested-by: Stefano Stabellini <[email protected]> Tested-by: Will Deacon <[email protected]> Acked-by: Stefano Stabellini <[email protected]> Signed-off-by: Konrad Rzeszutek Wilk <[email protected]> [v2: Includes Will's fix]
2021-07-13swiotlb: Update is_swiotlb_active to add a struct device argumentClaire Chang2-3/+3
Update is_swiotlb_active to add a struct device argument. This will be useful later to allow for different pools. Signed-off-by: Claire Chang <[email protected]> Reviewed-by: Christoph Hellwig <[email protected]> Tested-by: Stefano Stabellini <[email protected]> Tested-by: Will Deacon <[email protected]> Acked-by: Stefano Stabellini <[email protected]> Signed-off-by: Konrad Rzeszutek Wilk <[email protected]>
2021-07-13swiotlb: Update is_swiotlb_buffer to add a struct device argumentClaire Chang2-6/+6
Update is_swiotlb_buffer to add a struct device argument. This will be useful later to allow for different pools. Signed-off-by: Claire Chang <[email protected]> Reviewed-by: Christoph Hellwig <[email protected]> Tested-by: Stefano Stabellini <[email protected]> Tested-by: Will Deacon <[email protected]> Acked-by: Stefano Stabellini <[email protected]> Signed-off-by: Konrad Rzeszutek Wilk <[email protected]>
2021-07-13swiotlb: Set dev->dma_io_tlb_mem to the swiotlb pool usedClaire Chang1-4/+4
Always have the pointer to the swiotlb pool used in struct device. This could help simplify the code for other pools. Signed-off-by: Claire Chang <[email protected]> Reviewed-by: Christoph Hellwig <[email protected]> Tested-by: Stefano Stabellini <[email protected]> Tested-by: Will Deacon <[email protected]> Acked-by: Stefano Stabellini <[email protected]> Signed-off-by: Konrad Rzeszutek Wilk <[email protected]>
2021-07-13swiotlb: Refactor swiotlb_create_debugfsClaire Chang1-7/+14
Split the debugfs creation to make the code reusable for supporting different bounce buffer pools. Signed-off-by: Claire Chang <[email protected]> Reviewed-by: Christoph Hellwig <[email protected]> Tested-by: Stefano Stabellini <[email protected]> Tested-by: Will Deacon <[email protected]> Signed-off-by: Konrad Rzeszutek Wilk <[email protected]>