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linux/kernel/bpf
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Jordan Rome b8e3a87a62 bpf: Add crosstask check to __bpf_get_stack 
Currently get_perf_callchain only supports user stack walking for
the current task. Passing the correct *crosstask* param will return
0 frames if the task passed to __bpf_get_stack isn't the current
one instead of a single incorrect frame/address. This change
passes the correct *crosstask* param but also does a preemptive
check in __bpf_get_stack if the task is current and returns
-EOPNOTSUPP if it is not.

This issue was found using bpf_get_task_stack inside a BPF
iterator ("iter/task"), which iterates over all tasks.
bpf_get_task_stack works fine for fetching kernel stacks
but because get_perf_callchain relies on the caller to know
if the requested *task* is the current one (via *crosstask*)
it was failing in a confusing way.

It might be possible to get user stacks for all tasks utilizing
something like access_process_vm but that requires the bpf
program calling bpf_get_task_stack to be sleepable and would
therefore be a breaking change.

Fixes: fa28dcb82a38 ("bpf: Introduce helper bpf_get_task_stack()")
Signed-off-by: Jordan Rome <jordalgo@meta.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20231108112334.3433136-1-jordalgo@meta.com
2023-11-10 11:06:10 -08:00
..
preload
bpf: make preloaded map iterators to display map elements count
2023-07-06 12:42:25 -07:00
arraymap.c
bpf: return long from bpf_map_ops funcs
2023-03-22 15:11:30 -07:00
bloom_filter.c
bpf: Centralize permissions checks for all BPF map types
2023-06-19 14:04:04 +02:00
bpf_cgrp_storage.c
bpf: Teach verifier that certain helpers accept NULL pointer.
2023-04-04 16:57:16 -07:00
bpf_inode_storage.c
Networking changes for 6.4.
2023-04-26 16:07:23 -07:00
bpf_iter.c
bpf: Add __bpf_kfunc_{start,end}_defs macros
2023-11-01 22:33:53 -07:00
bpf_local_storage.c
bpf: bpf_sk_storage: Fix the missing uncharge in sk_omem_alloc
2023-09-06 11:08:14 +02:00
bpf_lru_list.c
bpf: Address KCSAN report on bpf_lru_list
2023-05-12 12:01:03 -07:00
bpf_lru_list.h
bpf: lru: Remove unused declaration bpf_lru_promote()
2023-08-08 17:21:42 -07:00
bpf_lsm.c
bpf: Fix the kernel crash caused by bpf_setsockopt().
2023-01-26 23:26:40 -08:00
bpf_struct_ops_types.h
bpf: Add dummy BPF STRUCT_OPS for test purpose
2021-11-01 14:10:00 -07:00
bpf_struct_ops.c
bpf: Charge modmem for struct_ops trampoline
2023-09-14 15:30:45 -07:00
bpf_task_storage.c
bpf: Teach verifier that certain helpers accept NULL pointer.
2023-04-04 16:57:16 -07:00
btf.c
bpf: Move GRAPH_{ROOT,NODE}_MASK macros into btf_field_type enum
2023-11-09 19:07:51 -08:00
cgroup_iter.c
bpf: Let verifier consider {task,cgroup} is trusted in bpf_iter_reg
2023-11-07 15:24:25 -08:00
cgroup.c
for-6.7/io_uring-sockopt-2023-10-30
2023-11-01 11:16:34 -10:00
core.c
Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
2023-09-17 15:12:06 +01:00
cpumap.c
net, bpf: Add a warning if NAPI cb missed xdp_do_flush().
2023-10-17 15:02:03 +02:00
cpumask.c
bpf: Add __bpf_kfunc_{start,end}_defs macros
2023-11-01 22:33:53 -07:00
devmap.c
net, bpf: Add a warning if NAPI cb missed xdp_do_flush().
2023-10-17 15:02:03 +02:00
disasm.c
bpf: change bpf_alu_sign_string and bpf_movsx_string to static
2023-08-04 16:15:50 -07:00
disasm.h
bpf: Relicense disassembler as GPL-2.0-only OR BSD-2-Clause
2021-09-02 14:49:23 +02:00
dispatcher.c
bpf: Synchronize dispatcher update with bpf_dispatcher_xdp_func
2022-12-14 12:02:14 -08:00
hashtab.c
bpf: Fix unnecessary -EBUSY from htab_lock_bucket
2023-10-24 14:25:55 +02:00
helpers.c
bpf: Use bpf_mem_free_rcu when bpf_obj_dropping non-refcounted nodes
2023-11-09 19:07:51 -08:00
inode.c
bpf: convert to new timestamp accessors
2023-10-18 14:08:30 +02:00
Kconfig
bpf: Add fd-based tcx multi-prog infra with link support
2023-07-19 10:07:27 -07:00
link_iter.c
bpf: Add bpf_link iterator
2022-05-10 11:20:45 -07:00
local_storage.c
cgroup changes for v6.4-rc1
2023-04-29 10:05:22 -07:00
log.c
bpf: drop unnecessary user-triggerable WARN_ONCE in verifierl log
2023-05-16 22:34:50 -07:00
lpm_trie.c
bpf, lpm: Fix check prefixlen before walking trie
2023-11-09 19:07:38 -08:00
Makefile
bpf: Add fd-based tcx multi-prog infra with link support
2023-07-19 10:07:27 -07:00
map_in_map.c
bpf: Fix elem_size not being set for inner maps
2023-06-02 16:22:12 -07:00
map_in_map.h
bpf: Add map_meta_equal map ops
2020-08-28 15:41:30 +02:00
map_iter.c
bpf: Add __bpf_kfunc_{start,end}_defs macros
2023-11-01 22:33:53 -07:00
memalloc.c
bpf: Add more WARN_ON_ONCE checks for mismatched alloc and free
2023-10-26 14:23:33 +02:00
mmap_unlock_work.h
bpf: Introduce helper bpf_find_vma
2021-11-07 11:54:51 -08:00
mprog.c
bpf: Handle bpf_mprog_query with NULL entry
2023-10-06 17:11:20 -07:00
net_namespace.c
net: Add includes masked by netdevice.h including uapi/bpf.h
2021-12-29 20:03:05 -08:00
offload.c
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
2023-09-21 21:49:45 +02:00
percpu_freelist.c
bpf: Initialize same number of free nodes for each pcpu_freelist
2022-11-11 12:05:14 -08:00
percpu_freelist.h
bpf: Use raw_spin_trylock() for pcpu_freelist_push/pop in NMI
2020-10-06 00:04:11 +02:00
prog_iter.c
bpf: Refactor bpf_iter_reg to have separate seq_info member
2020-07-25 20:16:32 -07:00
queue_stack_maps.c
bpf: Avoid deadlock when using queue and stack maps from NMI
2023-09-11 19:04:49 -07:00
reuseport_array.c
bpf: Centralize permissions checks for all BPF map types
2023-06-19 14:04:04 +02:00
ringbuf.c
bpf: Fold smp_mb__before_atomic() into atomic_set_release()
2023-10-24 14:26:07 +02:00
stackmap.c
bpf: Add crosstask check to __bpf_get_stack
2023-11-10 11:06:10 -08:00
syscall.c
netkit, bpf: Add bpf programmable net device
2023-10-24 16:06:03 -07:00
sysfs_btf.c
bpf: Load and verify kernel module BTFs
2020-11-10 15:25:53 -08:00
task_iter.c
bpf: Let verifier consider {task,cgroup} is trusted in bpf_iter_reg
2023-11-07 15:24:25 -08:00
tcx.c
bpf, tcx: Get rid of tcx_link_const
2023-10-23 15:01:53 -07:00
tnum.c
bpf, tnums: Provably sound, faster, and more precise algorithm for tnum_mul
2021-06-01 13:34:15 +02:00
trampoline.c
bpf, x64: Fix tailcall infinite loop
2023-09-12 13:06:12 -07:00
verifier.c
bpf: Mark direct ld of stashed bpf_{rb,list}_node as non-owning ref
2023-11-09 19:07:51 -08:00