linux/kernel/bpf, branch v5.10

bpf: Fix enum names for bpf_this_cpu_ptr() and bpf_per_cpu_ptr() helpers

2020-12-11T22:19:07Z

Remove bpf_ prefix, which causes these helpers to be reported in verifier dump as bpf_bpf_this_cpu_ptr() and bpf_bpf_per_cpu_ptr(), respectively. Lets fix it as long as it is still possible before UAPI freezes on these helpers. Fixes: eaa6bcb71ef6 ("bpf: Introduce bpf_per_cpu_ptr()") Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Signed-off-by: Daniel Borkmann Signed-off-by: Linus Torvalds

bpf: Fix propagation of 32-bit signed bounds from 64-bit bounds.

2020-12-10T21:02:53Z

The 64-bit signed bounds should not affect 32-bit signed bounds unless the verifier knows that upper 32-bits are either all 1s or all 0s. For example the register with smin_value==1 doesn't mean that s32_min_value is also equal to 1, since smax_value could be larger than 32-bit subregister can hold. The verifier refines the smax/s32_max return value from certain helpers in do_refine_retval_range(). Teach the verifier to recognize that smin/s32_min value is also bounded. When both smin and smax bounds fit into 32-bit subregister the verifier can propagate those bounds. Fixes: 3f50f132d840 ("bpf: Verifier, do explicit ALU32 bounds tracking") Reported-by: Jean-Philippe Brucker Acked-by: John Fastabend Signed-off-by: Alexei Starovoitov

bpf: Relax return code check for subprograms

2020-11-14T16:17:27Z

Currently verifier enforces return code checks for subprograms in the same manner as it does for program entry points. This prevents returning arbitrary scalar values from subprograms. Scalar type of returned values is checked by btf_prepare_func_args() and hence it should be safe to allow only scalars for now. Relax return code checks for subprograms and allow any correct scalar values. Fixes: 51c39bb1d5d10 (bpf: Introduce function-by-function verification) Signed-off-by: Dmitrii Banshchikov Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20201113171756.90594-1-me@ubique.spb.ru

bpf: Fix unsigned 'datasec_id' compared with zero in check_pseudo_btf_id

2020-11-11T09:50:22Z

The unsigned variable datasec_id is assigned a return value from the call to check_pseudo_btf_id(), which may return negative error code. This fixes the following coccicheck warning: ./kernel/bpf/verifier.c:9616:5-15: WARNING: Unsigned expression compared with zero: datasec_id > 0 Fixes: eaa6bcb71ef6 ("bpf: Introduce bpf_per_cpu_ptr()") Reported-by: Tosk Robot Signed-off-by: Kaixu Xia Signed-off-by: Daniel Borkmann Acked-by: Andrii Nakryiko Acked-by: John Fastabend Cc: Hao Luo Link: https://lore.kernel.org/bpf/1605071026-25906-1-git-send-email-kaixuxia@tencent.com

bpf: Update verification logic for LSM programs

2020-11-06T21:15:21Z

The current logic checks if the name of the BTF type passed in attach_btf_id starts with "bpf_lsm_", this is not sufficient as it also allows attachment to non-LSM hooks like the very function that performs this check, i.e. bpf_lsm_verify_prog. In order to ensure that this verification logic allows attachment to only LSM hooks, the LSM_HOOK definitions in lsm_hook_defs.h are used to generate a BTF_ID set. Upon verification, the attach_btf_id of the program being attached is checked for presence in this set. Fixes: 9e4e01dfd325 ("bpf: lsm: Implement attach, detach and execution") Signed-off-by: KP Singh Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20201105230651.2621917-1-kpsingh@chromium.org

bpf: Zero-fill re-used per-cpu map element

2020-11-06T03:55:57Z

Zero-fill element values for all other cpus than current, just as when not using prealloc. This is the only way the bpf program can ensure known initial values for all cpus ('onallcpus' cannot be set when coming from the bpf program). The scenario is: bpf program inserts some elements in a per-cpu map, then deletes some (or userspace does). When later adding new elements using bpf_map_update_elem(), the bpf program can only set the value of the new elements for the current cpu. When prealloc is enabled, previously deleted elements are re-used. Without the fix, values for other cpus remain whatever they were when the re-used entry was previously freed. A selftest is added to validate correct operation in above scenario as well as in case of LRU per-cpu map element re-use. Fixes: 6c9059817432 ("bpf: pre-allocate hash map elements") Signed-off-by: David Verbeiren Signed-off-by: Alexei Starovoitov Acked-by: Matthieu Baerts Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20201104112332.15191-1-david.verbeiren@tessares.net

bpf: BPF_PRELOAD depends on BPF_SYSCALL

2020-11-06T02:49:29Z

Fix build error when BPF_SYSCALL is not set/enabled but BPF_PRELOAD is by making BPF_PRELOAD depend on BPF_SYSCALL. ERROR: modpost: "bpf_preload_ops" [kernel/bpf/preload/bpf_preload.ko] undefined! Reported-by: kernel test robot Reported-by: Randy Dunlap Signed-off-by: Randy Dunlap Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20201105195109.26232-1-rdunlap@infradead.org

bpf: Don't rely on GCC attribute((optimize)) to disable GCSE

2020-10-30T03:01:46Z

Commit 3193c0836 ("bpf: Disable GCC -fgcse optimization for ___bpf_prog_run()") introduced a __no_fgcse macro that expands to a function scope __attribute__((optimize("-fno-gcse"))), to disable a GCC specific optimization that was causing trouble on x86 builds, and was not expected to have any positive effect in the first place. However, as the GCC manual documents, __attribute__((optimize)) is not for production use, and results in all other optimization options to be forgotten for the function in question. This can cause all kinds of trouble, but in one particular reported case, it causes -fno-asynchronous-unwind-tables to be disregarded, resulting in .eh_frame info to be emitted for the function. This reverts commit 3193c0836, and instead, it disables the -fgcse optimization for the entire source file, but only when building for X86 using GCC with CONFIG_BPF_JIT_ALWAYS_ON disabled. Note that the original commit states that CONFIG_RETPOLINE=n triggers the issue, whereas CONFIG_RETPOLINE=y performs better without the optimization, so it is kept disabled in both cases. Fixes: 3193c0836f20 ("bpf: Disable GCC -fgcse optimization for ___bpf_prog_run()") Signed-off-by: Ard Biesheuvel Signed-off-by: Alexei Starovoitov Tested-by: Geert Uytterhoeven Reviewed-by: Nick Desaulniers Link: https://lore.kernel.org/lkml/CAMuHMdUg0WJHEcq6to0-eODpXPOywLot6UD2=GFHpzoj_hCoBQ@mail.gmail.com/ Link: https://lore.kernel.org/bpf/20201028171506.15682-2-ardb@kernel.org

Merge tag 'net-5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2020-10-23T19:05:49Z

Pull networking fixes from Jakub Kicinski: "Cross-tree/merge window issues: - rtl8150: don't incorrectly assign random MAC addresses; fix late in the 5.9 cycle started depending on a return code from a function which changed with the 5.10 PR from the usb subsystem Current release regressions: - Revert "virtio-net: ethtool configurable RXCSUM", it was causing crashes at probe when control vq was not negotiated/available Previous release regressions: - ixgbe: fix probing of multi-port 10 Gigabit Intel NICs with an MDIO bus, only first device would be probed correctly - nexthop: Fix performance regression in nexthop deletion by effectively switching from recently added synchronize_rcu() to synchronize_rcu_expedited() - netsec: ignore 'phy-mode' device property on ACPI systems; the property is not populated correctly by the firmware, but firmware configures the PHY so just keep boot settings Previous releases - always broken: - tcp: fix to update snd_wl1 in bulk receiver fast path, addressing bulk transfers getting "stuck" - icmp: randomize the global rate limiter to prevent attackers from getting useful signal - r8169: fix operation under forced interrupt threading, make the driver always use hard irqs, even on RT, given the handler is light and only wants to schedule napi (and do so through a _irqoff() variant, preferably) - bpf: Enforce pointer id generation for all may-be-null register type to avoid pointers erroneously getting marked as null-checked - tipc: re-configure queue limit for broadcast link - net/sched: act_tunnel_key: fix OOB write in case of IPv6 ERSPAN tunnels - fix various issues in chelsio inline tls driver Misc: - bpf: improve just-added bpf_redirect_neigh() helper api to support supplying nexthop by the caller - in case BPF program has already done a lookup we can avoid doing another one - remove unnecessary break statements - make MCTCP not select IPV6, but rather depend on it" * tag 'net-5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (62 commits) tcp: fix to update snd_wl1 in bulk receiver fast path net: Properly typecast int values to set sk_max_pacing_rate netfilter: nf_fwd_netdev: clear timestamp in forwarding path ibmvnic: save changed mac address to adapter->mac_addr selftests: mptcp: depends on built-in IPv6 Revert "virtio-net: ethtool configurable RXCSUM" rtnetlink: fix data overflow in rtnl_calcit() net: ethernet: mtk-star-emac: select REGMAP_MMIO net: hdlc_raw_eth: Clear the IFF_TX_SKB_SHARING flag after calling ether_setup net: hdlc: In hdlc_rcv, check to make sure dev is an HDLC device bpf, libbpf: Guard bpf inline asm from bpf_tail_call_static bpf, selftests: Extend test_tc_redirect to use modified bpf_redirect_neigh() bpf: Fix bpf_redirect_neigh helper api to support supplying nexthop mptcp: depends on IPV6 but not as a module sfc: move initialisation of efx->filter_sem to efx_init_struct() mpls: load mpls_gso after mpls_iptunnel net/sched: act_tunnel_key: fix OOB write in case of IPv6 ERSPAN tunnels net/sched: act_gate: Unlock ->tcfa_lock in tc_setup_flow_action() net: dsa: bcm_sf2: make const array static, makes object smaller mptcp: MPTCP_IPV6 should depend on IPV6 instead of selecting it ...

Merge branch 'work.set_fs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2020-10-22T16:59:21Z

Pull initial set_fs() removal from Al Viro: "Christoph's set_fs base series + fixups" * 'work.set_fs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fs: Allow a NULL pos pointer to __kernel_read fs: Allow a NULL pos pointer to __kernel_write powerpc: remove address space overrides using set_fs() powerpc: use non-set_fs based maccess routines x86: remove address space overrides using set_fs() x86: make TASK_SIZE_MAX usable from assembly code x86: move PAGE_OFFSET, TASK_SIZE & friends to page_{32,64}_types.h lkdtm: remove set_fs-based tests test_bitmap: remove user bitmap tests uaccess: add infrastructure for kernel builds with set_fs() fs: don't allow splice read/write without explicit ops fs: don't allow kernel reads and writes without iter ops sysctl: Convert to iter interfaces proc: add a read_iter method to proc proc_ops proc: cleanup the compat vs no compat file ops proc: remove a level of indentation in proc_get_inode