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author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-06-09 09:54:46 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-06-09 09:54:46 -0700 |
commit | a5ad5742f671de906adbf29fbedf0a04705cebad (patch) | |
tree | 88d1a4c18e2025a5a8335dbbc9dea8bebeba5789 /kernel/bpf/stackmap.c | |
parent | 013b2deba9a6b80ca02f4fafd7dedf875e9b4450 (diff) | |
parent | 4fa7252338a56fbc90220e6330f136a379175a7a (diff) | |
download | linux-a5ad5742f671de906adbf29fbedf0a04705cebad.tar.gz linux-a5ad5742f671de906adbf29fbedf0a04705cebad.tar.bz2 linux-a5ad5742f671de906adbf29fbedf0a04705cebad.zip |
Merge branch 'akpm' (patches from Andrew)
Merge even more updates from Andrew Morton:
- a kernel-wide sweep of show_stack()
- pagetable cleanups
- abstract out accesses to mmap_sem - prep for mmap_sem scalability work
- hch's user acess work
Subsystems affected by this patch series: debug, mm/pagemap, mm/maccess,
mm/documentation.
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (93 commits)
include/linux/cache.h: expand documentation over __read_mostly
maccess: return -ERANGE when probe_kernel_read() fails
x86: use non-set_fs based maccess routines
maccess: allow architectures to provide kernel probing directly
maccess: move user access routines together
maccess: always use strict semantics for probe_kernel_read
maccess: remove strncpy_from_unsafe
tracing/kprobes: handle mixed kernel/userspace probes better
bpf: rework the compat kernel probe handling
bpf:bpf_seq_printf(): handle potentially unsafe format string better
bpf: handle the compat string in bpf_trace_copy_string better
bpf: factor out a bpf_trace_copy_string helper
maccess: unify the probe kernel arch hooks
maccess: remove probe_read_common and probe_write_common
maccess: rename strnlen_unsafe_user to strnlen_user_nofault
maccess: rename strncpy_from_unsafe_strict to strncpy_from_kernel_nofault
maccess: rename strncpy_from_unsafe_user to strncpy_from_user_nofault
maccess: update the top of file comment
maccess: clarify kerneldoc comments
maccess: remove duplicate kerneldoc comments
...
Diffstat (limited to 'kernel/bpf/stackmap.c')
-rw-r--r-- | kernel/bpf/stackmap.c | 17 |
1 files changed, 5 insertions, 12 deletions
diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c index 7b8381ce40a0..599488f25e40 100644 --- a/kernel/bpf/stackmap.c +++ b/kernel/bpf/stackmap.c @@ -33,7 +33,7 @@ struct bpf_stack_map { /* irq_work to run up_read() for build_id lookup in nmi context */ struct stack_map_irq_work { struct irq_work irq_work; - struct rw_semaphore *sem; + struct mm_struct *mm; }; static void do_up_read(struct irq_work *entry) @@ -44,8 +44,7 @@ static void do_up_read(struct irq_work *entry) return; work = container_of(entry, struct stack_map_irq_work, irq_work); - up_read_non_owner(work->sem); - work->sem = NULL; + mmap_read_unlock_non_owner(work->mm); } static DEFINE_PER_CPU(struct stack_map_irq_work, up_read_work); @@ -317,7 +316,7 @@ static void stack_map_get_build_id_offset(struct bpf_stack_build_id *id_offs, * with build_id. */ if (!user || !current || !current->mm || irq_work_busy || - down_read_trylock(¤t->mm->mmap_sem) == 0) { + !mmap_read_trylock_non_owner(current->mm)) { /* cannot access current->mm, fall back to ips */ for (i = 0; i < trace_nr; i++) { id_offs[i].status = BPF_STACK_BUILD_ID_IP; @@ -342,16 +341,10 @@ static void stack_map_get_build_id_offset(struct bpf_stack_build_id *id_offs, } if (!work) { - up_read(¤t->mm->mmap_sem); + mmap_read_unlock_non_owner(current->mm); } else { - work->sem = ¤t->mm->mmap_sem; + work->mm = current->mm; irq_work_queue(&work->irq_work); - /* - * The irq_work will release the mmap_sem with - * up_read_non_owner(). The rwsem_release() is called - * here to release the lock from lockdep's perspective. - */ - rwsem_release(¤t->mm->mmap_sem.dep_map, _RET_IP_); } } |