summaryrefslogtreecommitdiff
path: root/include
AgeCommit message (Collapse)Author
2024-08-12net: nexthop: Increase weight to u16Petr Machata
In CLOS networks, as link failures occur at various points in the network, ECMP weights of the involved nodes are adjusted to compensate. With high fan-out of the involved nodes, and overall high number of nodes, a (non-)ECMP weight ratio that we would like to configure does not fit into 8 bits. Instead of, say, 255:254, we might like to configure something like 1000:999. For these deployments, the 8-bit weight may not be enough. To that end, in this patch increase the next hop weight from u8 to u16. Increasing the width of an integral type can be tricky, because while the code still compiles, the types may not check out anymore, and numerical errors come up. To prevent this, the conversion was done in two steps. First the type was changed from u8 to a single-member structure, which invalidated all uses of the field. This allowed going through them one by one and audit for type correctness. Then the structure was replaced with a vanilla u16 again. This should ensure that no place was missed. The UAPI for configuring nexthop group members is that an attribute NHA_GROUP carries an array of struct nexthop_grp entries: struct nexthop_grp { __u32 id; /* nexthop id - must exist */ __u8 weight; /* weight of this nexthop */ __u8 resvd1; __u16 resvd2; }; The field resvd1 is currently validated and required to be zero. We can lift this requirement and carry high-order bits of the weight in the reserved field: struct nexthop_grp { __u32 id; /* nexthop id - must exist */ __u8 weight; /* weight of this nexthop */ __u8 weight_high; __u16 resvd2; }; Keeping the fields split this way was chosen in case an existing userspace makes assumptions about the width of the weight field, and to sidestep any endianness issues. The weight field is currently encoded as the weight value minus one, because weight of 0 is invalid. This same trick is impossible for the new weight_high field, because zero must mean actual zero. With this in place: - Old userspace is guaranteed to carry weight_high of 0, therefore configuring 8-bit weights as appropriate. When dumping nexthops with 16-bit weight, it would only show the lower 8 bits. But configuring such nexthops implies existence of userspace aware of the extension in the first place. - New userspace talking to an old kernel will work as long as it only attempts to configure 8-bit weights, where the high-order bits are zero. Old kernel will bounce attempts at configuring >8-bit weights. Renaming reserved fields as they are allocated for some purpose is commonly done in Linux. Whoever touches a reserved field is doing so at their own risk. nexthop_grp::resvd1 in particular is currently used by at least strace, however they carry an own copy of UAPI headers, and the conversion should be trivial. A helper is provided for decoding the weight out of the two fields. Forcing a conversion seems preferable to bending backwards and introducing anonymous unions or whatever. Signed-off-by: Petr Machata <petrm@nvidia.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com> Link: https://patch.msgid.link/483e2fcf4beb0d9135d62e7d27b46fa2685479d4.1723036486.git.petrm@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-08-12net: nexthop: Add flag to assert that NHGRP reserved fields are zeroPetr Machata
There are many unpatched kernel versions out there that do not initialize the reserved fields of struct nexthop_grp. The issue with that is that if those fields were to be used for some end (i.e. stop being reserved), old kernels would still keep sending random data through the field, and a new userspace could not rely on the value. In this patch, use the existing NHA_OP_FLAGS, which is currently inbound only, to carry flags back to the userspace. Add a flag to indicate that the reserved fields in struct nexthop_grp are zeroed before dumping. This is reliant on the actual fix from commit 6d745cd0e972 ("net: nexthop: Initialize all fields in dumped nexthops"). Signed-off-by: Petr Machata <petrm@nvidia.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/21037748d4f9d8ff486151f4c09083bcf12d5df8.1723036486.git.petrm@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-08-12ipv6: eliminate ndisc_ops_is_useropt()Maciej Żenczykowski
as it doesn't seem to offer anything of value. There's only 1 trivial user: int lowpan_ndisc_is_useropt(u8 nd_opt_type) { return nd_opt_type == ND_OPT_6CO; } but there's no harm to always treating that as a useropt... Cc: David Ahern <dsahern@kernel.org> Cc: YOSHIFUJI Hideaki / 吉藤英明 <yoshfuji@linux-ipv6.org> Signed-off-by: Maciej Żenczykowski <maze@google.com> Link: https://patch.msgid.link/20240730003010.156977-1-maze@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-08-12ethtool: rss: support skipping contexts during dumpJakub Kicinski
Applications may want to deal with dynamic RSS contexts only. So dumping context 0 will be counter-productive for them. Support starting the dump from a given context ID. Alternative would be to implement a dump flag to skip just context 0, not sure which is better... Reviewed-by: Edward Cree <ecree.xilinx@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-08-12ethtool: rss: don't report key if device doesn't support itJakub Kicinski
marvell/otx2 and mvpp2 do not support setting different keys for different RSS contexts. Contexts have separate indirection tables but key is shared with all other contexts. This is likely fine, indirection table is the most important piece. Don't report the key-related parameters from such drivers. This prevents driver-errors, e.g. otx2 always writes the main key, even when user asks to change per-context key. The second reason is that without this change tracking the keys by the core gets complicated. Even if the driver correctly reject setting key with rss_context != 0, change of the main key would have to be reflected in the XArray for all additional contexts. Since the additional contexts don't have their own keys not including the attributes (in Netlink speak) seems intuitive. ethtool CLI seems to deal with it just fine. Having to set the flag in majority of the drivers is a bit tedious but not reporting the key is a safer default. Reviewed-by: Edward Cree <ecree.xilinx@gmail.com> Reviewed-by: Joe Damato <jdamato@fastly.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-08-12ethtool: make ethtool_ops::cap_rss_ctx_supported optionalJakub Kicinski
cap_rss_ctx_supported was created because the API for creating and configuring additional contexts is mux'ed with the normal RSS API. Presence of ops does not imply driver can actually support rss_context != 0 (in fact drivers mostly ignore that field). cap_rss_ctx_supported lets core check that the driver is context-aware before calling it. Now that we have .create_rxfh_context, there is no such ambiguity. We can depend on presence of the op. Make setting the bit optional. Reviewed-by: Gal Pressman <gal@nvidia.com> Reviewed-by: Edward Cree <ecree.xilinx@gmail.com> Reviewed-by: Joe Damato <jdamato@fastly.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-08-11net: mii: constify advertising maskRussell King (Oracle)
Constify the advertising mask to linkmode functions that only read from the advertising mask. Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-08-08net: sungem_phy: Constify struct mii_phy_defChristophe JAILLET
'struct mii_phy_def' are not modified in this driver. Constifying these structures moves some data to a read-only section, so increase overall security. While at it fix the checkpatch warning related to this patch (some missing newlines and spaces around *) On a x86_64, with allmodconfig: Before: ====== 27709 928 0 28637 6fdd drivers/net/sungem_phy.o After: ===== text data bss dec hex filename 28157 476 0 28633 6fd9 drivers/net/sungem_phy.o Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Link: https://patch.msgid.link/54c3b30930f80f4895e6fa2f4234714fdea4ef4e.1723033266.git.christophe.jaillet@wanadoo.fr Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-08-08Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR. No conflicts or adjacent changes. Link: https://patch.msgid.link/20240808170148.3629934-1-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-08-08Merge tag 'net-6.11-rc3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net Pull networking fixes from Jakub Kicinski: "Including fixes from bluetooth. Current release - regressions: - eth: bnxt_en: fix memory out-of-bounds in bnxt_fill_hw_rss_tbl() on older chips Current release - new code bugs: - ethtool: fix off-by-one error / kdoc contradicting the code for max RSS context IDs - Bluetooth: hci_qca: - QCA6390: fix support on non-DT platforms - QCA6390: don't call pwrseq_power_off() twice - fix a NULL-pointer derefence at shutdown - eth: ice: fix incorrect assigns of FEC counters Previous releases - regressions: - mptcp: fix handling endpoints with both 'signal' and 'subflow' flags set - virtio-net: fix changing ring count when vq IRQ coalescing not supported - eth: gve: fix use of netif_carrier_ok() during reconfig / reset Previous releases - always broken: - eth: idpf: fix bugs in queue re-allocation on reconfig / reset - ethtool: fix context creation with no parameters Misc: - linkwatch: use system_unbound_wq to ease RTNL contention" * tag 'net-6.11-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (41 commits) net: dsa: microchip: disable EEE for KSZ8567/KSZ9567/KSZ9896/KSZ9897. ethtool: Fix context creation with no parameters net: ethtool: fix off-by-one error in max RSS context IDs net: pse-pd: tps23881: include missing bitfield.h header net: fec: Stop PPS on driver remove net: bcmgenet: Properly overlay PHY and MAC Wake-on-LAN capabilities l2tp: fix lockdep splat net: stmmac: dwmac4: fix PCS duplex mode decode idpf: fix UAFs when destroying the queues idpf: fix memleak in vport interrupt configuration idpf: fix memory leaks and crashes while performing a soft reset bnxt_en : Fix memory out-of-bounds in bnxt_fill_hw_rss_tbl() net: dsa: bcm_sf2: Fix a possible memory leak in bcm_sf2_mdio_register() net/smc: add the max value of fallback reason count Bluetooth: hci_sync: avoid dup filtering when passive scanning with adv monitor Bluetooth: l2cap: always unlock channel in l2cap_conless_channel() Bluetooth: hci_qca: fix a NULL-pointer derefence at shutdown Bluetooth: hci_qca: fix QCA6390 support on non-DT platforms Bluetooth: hci_qca: don't call pwrseq_power_off() twice for QCA6390 ice: Fix incorrect assigns of FEC counts ...
2024-08-08net: ethtool: fix off-by-one error in max RSS context IDsEdward Cree
Both ethtool_ops.rxfh_max_context_id and the default value used when it's not specified are supposed to be exclusive maxima (the former is documented as such; the latter, U32_MAX, cannot be used as an ID since it equals ETH_RXFH_CONTEXT_ALLOC), but xa_alloc() expects an inclusive maximum. Subtract one from 'limit' to produce an inclusive maximum, and pass that to xa_alloc(). Increase bnxt's max by one to prevent a (very minor) regression, as BNXT_MAX_ETH_RSS_CTX is an inclusive max. This is safe since bnxt is not actually hard-limited; BNXT_MAX_ETH_RSS_CTX is just a leftover from old driver code that managed context IDs itself. Rename rxfh_max_context_id to rxfh_max_num_contexts to make its semantics (hopefully) more obvious. Fixes: 847a8ab18676 ("net: ethtool: let the core choose RSS context IDs") Signed-off-by: Edward Cree <ecree.xilinx@gmail.com> Link: https://patch.msgid.link/5a2d11a599aa5b0cc6141072c01accfb7758650c.1723045898.git.ecree.xilinx@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-08-07ring-buffer: Remove unused function ring_buffer_nr_pages()Jianhui Zhou
Because ring_buffer_nr_pages() is not an inline function and user accesses buffer->buffers[cpu]->nr_pages directly, the function ring_buffer_nr_pages is removed. Signed-off-by: Jianhui Zhou <912460177@qq.com> Link: https://lore.kernel.org/tencent_F4A7E9AB337F44E0F4B858D07D19EF460708@qq.com Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-08-07tracing: Use refcount for trace_event_file reference counterSteven Rostedt
Instead of using an atomic counter for the trace_event_file reference counter, use the refcount interface. It has various checks to make sure the reference counting is correct, and will warn if it detects an error (like refcount_inc() on '0'). Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/20240726144208.687cce24@rorschach.local.home Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-08-07tcp: rstreason: introduce SK_RST_REASON_TCP_DISCONNECT_WITH_DATA for active ↵Jason Xing
reset When user tries to disconnect a socket and there are more data written into tcp write queue, we should tell users about this reset reason. Signed-off-by: Jason Xing <kernelxing@tencent.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-08-07tcp: rstreason: introduce SK_RST_REASON_TCP_KEEPALIVE_TIMEOUT for active resetJason Xing
Introducing this to show the users the reason of keepalive timeout. Signed-off-by: Jason Xing <kernelxing@tencent.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-08-07tcp: rstreason: introduce SK_RST_REASON_TCP_STATE for active resetJason Xing
Introducing a new type TCP_STATE to handle some reset conditions appearing in RFC 793 due to its socket state. Actually, we can look into RFC 9293 which has no discrepancy about this part. Signed-off-by: Jason Xing <kernelxing@tencent.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-08-07tcp: rstreason: introduce SK_RST_REASON_TCP_ABORT_ON_MEMORY for active resetJason Xing
Introducing a new type TCP_ABORT_ON_MEMORY for tcp reset reason to handle out of memory case. Signed-off-by: Jason Xing <kernelxing@tencent.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-08-07tcp: rstreason: introduce SK_RST_REASON_TCP_ABORT_ON_LINGER for active resetJason Xing
Introducing a new type TCP_ABORT_ON_LINGER for tcp reset reason to handle negative linger value case. Signed-off-by: Jason Xing <kernelxing@tencent.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-08-07tcp: rstreason: introduce SK_RST_REASON_TCP_ABORT_ON_CLOSE for active resetJason Xing
Introducing a new type TCP_ABORT_ON_CLOSE for tcp reset reason to handle the case where more data is unread in closing phase. Signed-off-by: Jason Xing <kernelxing@tencent.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-08-05net/mlx5: Add support for MTPTM and MTCTR registersRahul Rameshbabu
Make Management Precision Time Measurement (MTPTM) register and Management Cross Timestamp (MTCTR) register usable in mlx5 driver. Signed-off-by: Rahul Rameshbabu <rrameshbabu@nvidia.com> Signed-off-by: Tariq Toukan <tariqt@nvidia.com> Reviewed-by: Wojciech Drewek <wojciech.drewek@intel.com> Tested-by: Vadim Fedorenko <vadim.fedorenko@linux.dev> Link: https://patch.msgid.link/20240730134055.1835261-2-tariqt@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-08-05ipv6: udp: constify 'struct net' parameter of socket lookupsEric Dumazet
Following helpers do not touch their 'struct net' argument. - udp6_lib_lookup() - __udp6_lib_lookup() Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/20240802134029.3748005-6-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-08-05inet6: constify 'struct net' parameter of various lookup helpersEric Dumazet
Following helpers do not touch their struct net argument: - bpf_sk_lookup_run_v6() - __inet6_lookup_established() - inet6_lookup_reuseport() - inet6_lookup_listener() - inet6_lookup_run_sk_lookup() - __inet6_lookup() - inet6_lookup() Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/20240802134029.3748005-5-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-08-05udp: constify 'struct net' parameter of socket lookupsEric Dumazet
Following helpers do not touch their 'struct net' argument. - udp_sk_bound_dev_eq() - udp4_lib_lookup() - __udp4_lib_lookup() Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/20240802134029.3748005-4-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-08-05inet: constify 'struct net' parameter of various lookup helpersEric Dumazet
Following helpers do not touch their struct net argument: - bpf_sk_lookup_run_v4() - inet_lookup_reuseport() - inet_lhash2_lookup() - inet_lookup_run_sk_lookup() - __inet_lookup_listener() - __inet_lookup_established() Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/20240802134029.3748005-3-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-08-05inet: constify inet_sk_bound_dev_eq() net parameterEric Dumazet
inet_sk_bound_dev_eq() and its callers do not modify the net structure. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/20240802134029.3748005-2-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-08-04profiling: remove profile=sleep supportTetsuo Handa
The kernel sleep profile is no longer working due to a recursive locking bug introduced by commit 42a20f86dc19 ("sched: Add wrapper for get_wchan() to keep task blocked") Booting with the 'profile=sleep' kernel command line option added or executing # echo -n sleep > /sys/kernel/profiling after boot causes the system to lock up. Lockdep reports kthreadd/3 is trying to acquire lock: ffff93ac82e08d58 (&p->pi_lock){....}-{2:2}, at: get_wchan+0x32/0x70 but task is already holding lock: ffff93ac82e08d58 (&p->pi_lock){....}-{2:2}, at: try_to_wake_up+0x53/0x370 with the call trace being lock_acquire+0xc8/0x2f0 get_wchan+0x32/0x70 __update_stats_enqueue_sleeper+0x151/0x430 enqueue_entity+0x4b0/0x520 enqueue_task_fair+0x92/0x6b0 ttwu_do_activate+0x73/0x140 try_to_wake_up+0x213/0x370 swake_up_locked+0x20/0x50 complete+0x2f/0x40 kthread+0xfb/0x180 However, since nobody noticed this regression for more than two years, let's remove 'profile=sleep' support based on the assumption that nobody needs this functionality. Fixes: 42a20f86dc19 ("sched: Add wrapper for get_wchan() to keep task blocked") Cc: stable@vger.kernel.org # v5.16+ Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-08-03Merge tag 'scsi-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi Pull SCSI fixes from James Bottomley: "One core change that reverts the double message print patch in sd.c (it was causing regressions on embedded systems). The rest are driver fixes in ufs, mpt3sas and mpi3mr" * tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: scsi: ufs: exynos: Don't resume FMP when crypto support is disabled scsi: mpt3sas: Avoid IOMMU page faults on REPORT ZONES scsi: mpi3mr: Avoid IOMMU page faults on REPORT ZONES scsi: ufs: core: Do not set link to OFF state while waking up from hibernation scsi: Revert "scsi: sd: Do not repeat the starting disk message" scsi: ufs: core: Fix deadlock during RTC update scsi: ufs: core: Bypass quick recovery if force reset is needed scsi: ufs: core: Check LSDBS cap when !mcq
2024-08-03net: Don't register pernet_operations if only one of id or size is specified.Kuniyuki Iwashima
We can allocate per-netns memory for struct pernet_operations by specifying id and size. register_pernet_operations() assigns an id to pernet_operations and later ops_init() allocates the specified size of memory as net->gen->ptr[id]. If id is missing, no memory is allocated. If size is not specified, pernet_operations just wastes an entry of net->gen->ptr[] for every netns. net_generic is available only when both id and size are specified, so let's ensure that. While we are at it, we add const to both fields. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-08-03runtime constants: deal with old decrepit linkersLinus Torvalds
The runtime constants linker script depended on documented linker behavior [1]: "If an output section’s name is the same as the input section’s name and is representable as a C identifier, then the linker will automatically PROVIDE two symbols: __start_SECNAME and __stop_SECNAME, where SECNAME is the name of the section. These indicate the start address and end address of the output section respectively" to just automatically define the symbol names for the bounds of the runtime constant arrays. It turns out that this isn't actually something we can rely on, with old linkers not generating these automatic symbols. It looks to have been introduced in binutils-2.29 back in 2017, and we still support building with versions all the way back to binutils-2.25 (from 2015). And yes, Oleg actually seems to be using such ancient versions of binutils. So instead of depending on the implicit symbols from "section names match and are representable C identifiers", just do this all manually. It's not like it causes us any extra pain, we already have to do that for all the other sections that we use that often have special characters in them. Reported-and-tested-by: Oleg Nesterov <oleg@redhat.com> Link: https://sourceware.org/binutils/docs/ld/Input-Section-Example.html [1] Link: https://lore.kernel.org/all/20240802114518.GA20924@redhat.com/ Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-08-02net: core: annotate socks of struct sock_reuseport with __counted_byDmitry Antipov
According to '__reuseport_alloc()', annotate flexible array member 'sock' of 'struct sock_reuseport' with '__counted_by()' and use convenient 'struct_size()' to simplify the math used in 'kzalloc()'. Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru> Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20240801142311.42837-1-dmantipov@yandex.ru Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-08-02linkmode: Change return type of linkmode_andnot to boolSimon Horman
linkmode_andnot() simply returns the result of bitmap_andnot(). And the return type of bitmap_andnot() is bool. So it makes sense for the return type of linkmode_andnot() to also be bool. I checked all call-sites and they either ignore the return value or treat it as a bool. Compile tested only. Link: https://lore.kernel.org/netdev/68088998-4486-4930-90a4-96a32f08c490@lunn.ch/ Signed-off-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/20240801-linkfield-bowl-v1-1-d58f68967802@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-08-02net: remove IFF_* re-definitionJakub Kicinski
We re-define values of enum netdev_priv_flags as preprocessor macros with the same name. I guess this was done to avoid breaking out of tree modules which may use #ifdef X for kernel compatibility? Commit 7aa98047df95 ("net: move net_device priv_flags out from UAPI") which added the enum doesn't say. In any case, the flags with defines are quite old now, and defines for new flags don't get added. OOT drivers have to resort to code greps for compat detection, anyway. Let's delete these defines, save LoC, help LXR link to the right place. Reviewed-by: Simon Horman <horms@kernel.org> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Link: https://patch.msgid.link/20240801163401.378723-1-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-08-02Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull kvm updates from Paolo Bonzini: "The bulk of the changes here is a largish change to guest_memfd, delaying the clearing and encryption of guest-private pages until they are actually added to guest page tables. This started as "let's make it impossible to misuse the API" for SEV-SNP; but then it ballooned a bit. The new logic is generally simpler and more ready for hugepage support in guest_memfd. Summary: - fix latent bug in how usage of large pages is determined for confidential VMs - fix "underline too short" in docs - eliminate log spam from limited APIC timer periods - disallow pre-faulting of memory before SEV-SNP VMs are initialized - delay clearing and encrypting private memory until it is added to guest page tables - this change also enables another small cleanup: the checks in SNP_LAUNCH_UPDATE that limit it to non-populated, private pages can now be moved in the common kvm_gmem_populate() function - fix compilation error that the RISC-V merge introduced in selftests" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: x86/mmu: fix determination of max NPT mapping level for private pages KVM: riscv: selftests: Fix compile error KVM: guest_memfd: abstract how prepared folios are recorded KVM: guest_memfd: let kvm_gmem_populate() operate only on private gfns KVM: extend kvm_range_has_memory_attributes() to check subset of attributes KVM: cleanup and add shortcuts to kvm_range_has_memory_attributes() KVM: guest_memfd: move check for already-populated page to common code KVM: remove kvm_arch_gmem_prepare_needed() KVM: guest_memfd: make kvm_gmem_prepare_folio() operate on a single struct kvm KVM: guest_memfd: delay kvm_gmem_prepare_folio() until the memory is passed to the guest KVM: guest_memfd: return locked folio from __kvm_gmem_get_pfn KVM: rename CONFIG_HAVE_KVM_GMEM_* to CONFIG_HAVE_KVM_ARCH_GMEM_* KVM: guest_memfd: do not go through struct page KVM: guest_memfd: delay folio_mark_uptodate() until after successful preparation KVM: guest_memfd: return folio from __kvm_gmem_get_pfn() KVM: x86: disallow pre-fault for SNP VMs before initialization KVM: Documentation: Fix title underline too short warning KVM: x86: Eliminate log spam from limited APIC timer periods
2024-08-02Merge branch 'kvm-fixes' into HEADPaolo Bonzini
* fix latent bug in how usage of large pages is determined for confidential VMs * fix "underline too short" in docs * eliminate log spam from limited APIC timer periods * disallow pre-faulting of memory before SEV-SNP VMs are initialized * delay clearing and encrypting private memory until it is added to guest page tables * this change also enables another small cleanup: the checks in SNP_LAUNCH_UPDATE that limit it to non-populated, private pages can now be moved in the common kvm_gmem_populate() function
2024-08-02Merge tag 'riscv-for-linus-6.11-rc2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux Pull RISC-V fixes from Palmer Dabbelt: - A fix to avoid dropping some of the internal pseudo-extensions, which breaks *envcfg dependency parsing - The kernel entry address is now aligned in purgatory, which avoids a misaligned load that can lead to crash on systems that don't support misaligned accesses early in boot - The FW_SFENCE_VMA_RECEIVED perf event was duplicated in a handful of perf JSON configurations, one of them been updated to FW_SFENCE_VMA_ASID_SENT - The starfive cache driver is now restricted to 64-bit systems, as it isn't 32-bit clean - A fix for to avoid aliasing legacy-mode perf counters with software perf counters - VM_FAULT_SIGSEGV is now handled in the page fault code - A fix for stalls during CPU hotplug due to IPIs being disabled - A fix for memblock bounds checking. This manifests as a crash on systems with discontinuous memory maps that have regions that don't fit in the linear map * tag 'riscv-for-linus-6.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: riscv: Fix linear mapping checks for non-contiguous memory regions RISC-V: Enable the IPI before workqueue_online_cpu() riscv/mm: Add handling for VM_FAULT_SIGSEGV in mm_fault_error() perf: riscv: Fix selecting counters in legacy mode cache: StarFive: Require a 64-bit system perf arch events: Fix duplicate RISC-V SBI firmware event name riscv/purgatory: align riscv_kernel_entry riscv: cpufeature: Do not drop Linux-internal extensions
2024-08-02Merge tag 'asm-generic-fixes-6.11-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic Pull asm-generic fixes from Arnd Bergmann: "These are three important bug fixes for the cross-architecture tree, fixing a regression with the new syscall.tbl file, the inconsistent numbering for the new uretprobe syscall and a bug with iowrite64be on alpha" * tag 'asm-generic-fixes-6.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: syscalls: fix syscall macros for newfstat/newfstatat uretprobe: change syscall number, again alpha: fix ioread64be()/iowrite64be() helpers
2024-08-02Merge tag 'sound-6.11-rc2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound Pull sound fixes from Takashi Iwai: "A small collection of fixes: - Revert of FireWire changes that caused a long-time regression - Another long-time regression fix for AMD HDMI - MIDI2 UMP fixes - HD-audio Conexant codec fixes and a quirk" * tag 'sound-6.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: ALSA: hda: Conditionally use snooping for AMD HDMI ALSA: usb-audio: Correct surround channels in UAC1 channel map ALSA: seq: ump: Explicitly reset RPN with Null RPN ALSA: seq: ump: Transmit RPN/NRPN message at each MSB/LSB data reception ALSA: seq: ump: Use the common RPN/bank conversion context ALSA: ump: Explicitly reset RPN with Null RPN ALSA: ump: Transmit RPN/NRPN message at each MSB/LSB data reception Revert "ALSA: firewire-lib: operate for period elapse event in process context" Revert "ALSA: firewire-lib: obsolete workqueue for period update" ALSA: hda/realtek: Add quirk for Acer Aspire E5-574G ALSA: seq: ump: Optimize conversions from SysEx to UMP ALSA: hda/conexant: Mute speakers at suspend / shutdown ALSA: hda/generic: Add a helper to mute speakers at suspend/shutdown ALSA: hda: conexant: Fix headset auto detect fail in the polling mode
2024-08-02uretprobe: change syscall number, againArnd Bergmann
Despite multiple attempts to get the syscall number assignment right for the newly added uretprobe syscall, we ended up with a bit of a mess: - The number is defined as 467 based on the assumption that the xattrat family of syscalls would use 463 through 466, but those did not make it into 6.11. - The include/uapi/asm-generic/unistd.h file still lists the number 463, but the new scripts/syscall.tbl that was supposed to have the same data lists 467 instead as the number for arc, arm64, csky, hexagon, loongarch, nios2, openrisc and riscv. None of these architectures actually provide a uretprobe syscall. - All the other architectures (powerpc, arm, mips, ...) don't list this syscall at all. There are two ways to make it consistent again: either list it with the same syscall number on all architectures, or only list it on x86 but not in scripts/syscall.tbl and asm-generic/unistd.h. Based on the most recent discussion, it seems like we won't need it anywhere else, so just remove the inconsistent assignment and instead move the x86 number to the next available one in the architecture specific range, which is 335. Fixes: 5c28424e9a34 ("syscalls: Fix to add sys_uretprobe to syscall.tbl") Fixes: 190fec72df4a ("uprobe: Wire up uretprobe system call") Fixes: 63ded110979b ("uprobe: Change uretprobe syscall scope and number") Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Reviewed-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2024-08-02vsock/virtio: add SIOCOUTQ support for all virtio based transportsLuigi Leonardi
Introduce support for virtio_transport_unsent_bytes ioctl for virtio_transport, vhost_vsock and vsock_loopback. For all transports the unsent bytes counter is incremented in virtio_transport_get_credit. In virtio_transport (G2H) and in vhost-vsock (H2G) the counter is decremented when the skbuff is consumed. In vsock_loopback the same skbuff is passed from the transmitter to the receiver, so the counter is decremented before queuing the skbuff to the receiver. Signed-off-by: Luigi Leonardi <luigi.leonardi@outlook.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-08-02vsock: add support for SIOCOUTQ ioctlLuigi Leonardi
Add support for ioctl(s) in AF_VSOCK. The only ioctl available is SIOCOUTQ/TIOCOUTQ, which returns the number of unsent bytes in the socket. This information is transport-specific and is delegated to them using a callback. Suggested-by: Daan De Meyer <daan.j.demeyer@gmail.com> Signed-off-by: Luigi Leonardi <luigi.leonardi@outlook.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-08-01Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR. No conflicts or adjacent changes. Link: https://patch.msgid.link/20240801131917.34494-1-pabeni@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-08-01Merge tag 'net-6.11-rc2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net Pull networking fixes from Paolo Abeni: "Including fixes from wireless, bleutooth, BPF and netfilter. Current release - regressions: - core: drop bad gso csum_start and offset in virtio_net_hdr - wifi: mt76: fix null pointer access in mt792x_mac_link_bss_remove - eth: tun: add missing bpf_net_ctx_clear() in do_xdp_generic() - phy: aquantia: only poll GLOBAL_CFG regs on aqr113, aqr113c and aqr115c Current release - new code bugs: - smc: prevent UAF in inet_create() - bluetooth: btmtk: fix kernel crash when entering btmtk_usb_suspend - eth: bnxt: reject unsupported hash functions Previous releases - regressions: - sched: act_ct: take care of padding in struct zones_ht_key - netfilter: fix null-ptr-deref in iptable_nat_table_init(). - tcp: adjust clamping window for applications specifying SO_RCVBUF Previous releases - always broken: - ethtool: rss: small fixes to spec and GET - mptcp: - fix signal endpoint re-add - pm: fix backup support in signal endpoints - wifi: ath12k: fix soft lockup on suspend - eth: bnxt_en: fix RSS logic in __bnxt_reserve_rings() - eth: ice: fix AF_XDP ZC timeout and concurrency issues - eth: mlx5: - fix missing lock on sync reset reload - fix error handling in irq_pool_request_irq" * tag 'net-6.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (76 commits) mptcp: fix duplicate data handling mptcp: fix bad RCVPRUNED mib accounting ipv6: fix ndisc_is_useropt() handling for PIO igc: Fix double reset adapter triggered from a single taprio cmd net: MAINTAINERS: Demote Qualcomm IPA to "maintained" net: wan: fsl_qmc_hdlc: Discard received CRC net: wan: fsl_qmc_hdlc: Convert carrier_lock spinlock to a mutex net/mlx5e: Add a check for the return value from mlx5_port_set_eth_ptys net/mlx5e: Fix CT entry update leaks of modify header context net/mlx5e: Require mlx5 tc classifier action support for IPsec prio capability net/mlx5: Fix missing lock on sync reset reload net/mlx5: Lag, don't use the hardcoded value of the first port net/mlx5: DR, Fix 'stack guard page was hit' error in dr_rule net/mlx5: Fix error handling in irq_pool_request_irq net/mlx5: Always drain health in shutdown callback net: Add skbuff.h to MAINTAINERS r8169: don't increment tx_dropped in case of NETDEV_TX_BUSY netfilter: iptables: Fix potential null-ptr-deref in ip6table_nat_table_init(). netfilter: iptables: Fix null-ptr-deref in iptable_nat_table_init(). net: drop bad gso csum_start and offset in virtio_net_hdr ...
2024-08-01RISC-V: Enable the IPI before workqueue_online_cpu()Nick Hu
Sometimes the hotplug cpu stalls at the arch_cpu_idle() for a while after workqueue_online_cpu(). When cpu stalls at the idle loop, the reschedule IPI is pending. However the enable bit is not enabled yet so the cpu stalls at WFI until watchdog timeout. Therefore enable the IPI before the workqueue_online_cpu() to fix the issue. Fixes: 63c5484e7495 ("workqueue: Add multiple affinity scopes and interface to select them") Signed-off-by: Nick Hu <nick.hu@sifive.com> Reviewed-by: Anup Patel <anup@brainfault.org> Link: https://lore.kernel.org/r/20240717031714.1946036-1-nick.hu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-08-01net: skbuff: Skip early return in skb_unref when debuggingBreno Leitao
This patch modifies the skb_unref function to skip the early return optimization when CONFIG_DEBUG_NET is enabled. The change ensures that the reference count decrement always occurs in debug builds, allowing for more thorough checking of SKB reference counting. Previously, when the SKB's reference count was 1 and CONFIG_DEBUG_NET was not set, the function would return early after a memory barrier (smp_rmb()) without decrementing the reference count. This optimization assumes it's safe to proceed with freeing the SKB without the overhead of an atomic decrement from 1 to 0. With this change: - In non-debug builds (CONFIG_DEBUG_NET not set), behavior remains unchanged, preserving the performance optimization. - In debug builds (CONFIG_DEBUG_NET set), the reference count is always decremented, even when it's 1, allowing for consistent behavior and potentially catching subtle SKB management bugs. This modification enhances debugging capabilities for networking code without impacting performance in production kernels. It helps kernel developers identify and diagnose issues related to SKB management and reference counting in the network stack. Cc: Chris Mason <clm@fb.com> Suggested-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Breno Leitao <leitao@debian.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20240729104741.370327-1-leitao@debian.org Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-07-31minmax: fix up min3() and max3() tooLinus Torvalds
David Laight pointed out that we should deal with the min3() and max3() mess too, which still does excessive expansion. And our current macros are actually rather broken. In particular, the macros did this: #define min3(x, y, z) min((typeof(x))min(x, y), z) #define max3(x, y, z) max((typeof(x))max(x, y), z) and that not only is a nested expansion of possibly very complex arguments with all that involves, the typing with that "typeof()" cast is completely wrong. For example, imagine what happens in max3() if 'x' happens to be a 'unsigned char', but 'y' and 'z' are 'unsigned long'. The types are compatible, and there's no warning - but the result is just random garbage. No, I don't think we've ever hit that issue in practice, but since we now have sane infrastructure for doing this right, let's just use it. It fixes any excessive expansion, and also avoids these kinds of broken type issues. Requested-by: David Laight <David.Laight@aculab.com> Acked-by: Arnd Bergmann <arnd@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-07-31ALSA: ump: Transmit RPN/NRPN message at each MSB/LSB data receptionTakashi Iwai
The UMP 1.1 spec says that an RPN/NRPN should be sent when one of the following occurs: * a CC 38 is received * a subsequent CC 6 is received * a CC 98, 99, 100, and 101 is received, indicating the last RPN/NRPN message has ended and a new one has started That said, we should send a partial data even if it's not fully filled. Let's change the UMP conversion helper code to follow that rule. Link: https://patch.msgid.link/20240731130528.12600-2-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2024-07-31Add support for PIO p flagPatrick Rohr
draft-ietf-6man-pio-pflag is adding a new flag to the Prefix Information Option to signal that the network can allocate a unique IPv6 prefix per client via DHCPv6-PD (see draft-ietf-v6ops-dhcp-pd-per-device). When ra_honor_pio_pflag is enabled, the presence of a P-flag causes SLAAC autoconfiguration to be disabled for that particular PIO. An automated test has been added in Android (r.android.com/3195335) to go along with this change. Cc: Maciej Żenczykowski <maze@google.com> Cc: Lorenzo Colitti <lorenzo@google.com> Cc: David Lamparter <equinox@opensourcerouting.org> Cc: Simon Horman <horms@kernel.org> Signed-off-by: Patrick Rohr <prohr@google.com> Reviewed-by: Maciej Żenczykowski <maze@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-07-30Merge tag 'for-6.11-rc1-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fixes from David Sterba: - fix regression in extent map rework when handling insertion of overlapping compressed extent - fix unexpected file length when appending to a file using direct io and buffer not faulted in - in zoned mode, fix accounting of unusable space when flipping read-only block group back to read-write - fix page locking when COWing an inline range, assertion failure found by syzbot - fix calculation of space info in debugging print - tree-checker, add validation of data reference item - fix a few -Wmaybe-uninitialized build warnings * tag 'for-6.11-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: initialize location to fix -Wmaybe-uninitialized in btrfs_lookup_dentry() btrfs: fix corruption after buffer fault in during direct IO append write btrfs: zoned: fix zone_unusable accounting on making block group read-write again btrfs: do not subtract delalloc from avail bytes btrfs: make cow_file_range_inline() honor locked_page on error btrfs: fix corrupt read due to bad offset of a compressed extent map btrfs: tree-checker: validate dref root and objectid
2024-07-30net: drop bad gso csum_start and offset in virtio_net_hdrWillem de Bruijn
Tighten csum_start and csum_offset checks in virtio_net_hdr_to_skb for GSO packets. The function already checks that a checksum requested with VIRTIO_NET_HDR_F_NEEDS_CSUM is in skb linear. But for GSO packets this might not hold for segs after segmentation. Syzkaller demonstrated to reach this warning in skb_checksum_help offset = skb_checksum_start_offset(skb); ret = -EINVAL; if (WARN_ON_ONCE(offset >= skb_headlen(skb))) By injecting a TSO packet: WARNING: CPU: 1 PID: 3539 at net/core/dev.c:3284 skb_checksum_help+0x3d0/0x5b0 ip_do_fragment+0x209/0x1b20 net/ipv4/ip_output.c:774 ip_finish_output_gso net/ipv4/ip_output.c:279 [inline] __ip_finish_output+0x2bd/0x4b0 net/ipv4/ip_output.c:301 iptunnel_xmit+0x50c/0x930 net/ipv4/ip_tunnel_core.c:82 ip_tunnel_xmit+0x2296/0x2c70 net/ipv4/ip_tunnel.c:813 __gre_xmit net/ipv4/ip_gre.c:469 [inline] ipgre_xmit+0x759/0xa60 net/ipv4/ip_gre.c:661 __netdev_start_xmit include/linux/netdevice.h:4850 [inline] netdev_start_xmit include/linux/netdevice.h:4864 [inline] xmit_one net/core/dev.c:3595 [inline] dev_hard_start_xmit+0x261/0x8c0 net/core/dev.c:3611 __dev_queue_xmit+0x1b97/0x3c90 net/core/dev.c:4261 packet_snd net/packet/af_packet.c:3073 [inline] The geometry of the bad input packet at tcp_gso_segment: [ 52.003050][ T8403] skb len=12202 headroom=244 headlen=12093 tailroom=0 [ 52.003050][ T8403] mac=(168,24) mac_len=24 net=(192,52) trans=244 [ 52.003050][ T8403] shinfo(txflags=0 nr_frags=1 gso(size=1552 type=3 segs=0)) [ 52.003050][ T8403] csum(0x60000c7 start=199 offset=1536 ip_summed=3 complete_sw=0 valid=0 level=0) Mitigate with stricter input validation. csum_offset: for GSO packets, deduce the correct value from gso_type. This is already done for USO. Extend it to TSO. Let UFO be: udp[46]_ufo_fragment ignores these fields and always computes the checksum in software. csum_start: finding the real offset requires parsing to the transport header. Do not add a parser, use existing segmentation parsing. Thanks to SKB_GSO_DODGY, that also catches bad packets that are hw offloaded. Again test both TSO and USO. Do not test UFO for the above reason, and do not test UDP tunnel offload. GSO packet are almost always CHECKSUM_PARTIAL. USO packets may be CHECKSUM_NONE since commit 10154dbded6d6 ("udp: Allow GSO transmit from devices with no checksum offload"), but then still these fields are initialized correctly in udp4_hwcsum/udp6_hwcsum_outgoing. So no need to test for ip_summed == CHECKSUM_PARTIAL first. This revises an existing fix mentioned in the Fixes tag, which broke small packets with GSO offload, as detected by kselftests. Link: https://syzkaller.appspot.com/bug?extid=e1db31216c789f552871 Link: https://lore.kernel.org/netdev/20240723223109.2196886-1-kuba@kernel.org Fixes: e269d79c7d35 ("net: missing check virtio") Cc: stable@vger.kernel.org Signed-off-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20240729201108.1615114-1-willemdebruijn.kernel@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-07-30minmax: improve macro expansion and type checkingLinus Torvalds
This clarifies the rules for min()/max()/clamp() type checking and makes them a much more efficient macro expansion. In particular, we now look at the type and range of the inputs to see whether they work together, generating a mask of acceptable comparisons, and then just verifying that the inputs have a shared case: - an expression with a signed type can be used for (1) signed comparisons (2) unsigned comparisons if it is statically known to have a non-negative value - an expression with an unsigned type can be used for (3) unsigned comparison (4) signed comparisons if the type is smaller than 'int' and thus the C integer promotion rules will make it signed anyway Here rule (1) and (3) are obvious, and rule (2) is important in order to allow obvious trivial constants to be used together with unsigned values. Rule (4) is not necessarily a good idea, but matches what we used to do, and we have extant cases of this situation in the kernel. Notably with bcachefs having an expression like min(bch2_bucket_sectors_dirty(a), ca->mi.bucket_size) where bch2_bucket_sectors_dirty() returns an 's64', and 'ca->mi.bucket_size' is of type 'u16'. Technically that bcachefs comparison is clearly sensible on a C type level, because the 'u16' will go through the normal C integer promotion, and become 'int', and then we're comparing two signed values and everything looks sane. However, it's not entirely clear that a 'min(s64,u16)' operation makes a lot of conceptual sense, and it's possible that we will remove rule (4). After all, the _reason_ we have these complicated type checks is exactly that the C type promotion rules are not very intuitive. But at least for now the rule is in place for backwards compatibility. Also note that rule (2) existed before, but is hugely relaxed by this commit. It used to be true only for the simplest compile-time non-negative integer constants. The new macro model will allow cases where the compiler can trivially see that an expression is non-negative even if it isn't necessarily a constant. For example, the amdgpu driver does min_t(size_t, sizeof(fru_info->serial), pia[addr] & 0x3F)); because our old 'min()' macro would see that 'pia[addr] & 0x3F' is of type 'int' and clearly not a C constant expression, so doing a 'min()' with a 'size_t' is a signedness violation. Our new 'min()' macro still sees that 'pia[addr] & 0x3F' is of type 'int', but is smart enough to also see that it is clearly non-negative, and thus would allow that case without any complaints. Cc: Arnd Bergmann <arnd@kernel.org> Cc: David Laight <David.Laight@aculab.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>