28 Jul, 2020

1 commit

  • It's unusable from userland - it uses elf_gregset_t, which is not
    provided by exported headers. glibc has it in sys/procfs.h, but
    the same file defines struct elf_prstatus, so linux/elfcore.h can't
    be included once sys/procfs.h has been pulled. Same goes for uclibc
    and dietlibc simply doesn't have elf_gregset_t defined anywhere.

    IOW, no userland source is including that thing.

    Signed-off-by: Al Viro

    Al Viro
     

17 May, 2020

1 commit

  • bpfilter_umh is built for the default machine bit of the compiler,
    which may not match to the bit size of the kernel.

    This happens in the scenario below:

    You can use biarch GCC that defaults to 64-bit for building the 32-bit
    kernel. In this case, Kbuild passes -m32 to teach the compiler to
    produce 32-bit kernel space objects. However, it is missing when
    building bpfilter_umh. It is built as a 64-bit ELF, and then embedded
    into the 32-bit kernel.

    The 32-bit kernel and 64-bit umh is a bad combination.

    In theory, we can have 32-bit umh running on 64-bit kernel, but we do
    not have a good reason to support such a usecase.

    The best is to match the bit size between them.

    Pass -m32 or -m64 to the umh build command if it is found in
    $(KBUILD_CFLAGS). Evaluate CC_CAN_LINK against the kernel bit-size.

    Signed-off-by: Masahiro Yamada

    Masahiro Yamada
     

12 May, 2020

1 commit

  • This omits system headers from the generated header dependency.

    System headers are not updated unless you upgrade the compiler. Nor do
    they contain CONFIG options, so fixdep does not need to parse them.

    Having said that, the effect of this optimization will be quite small
    because the kernel code generally does not include system headers
    except . Host programs include a lot of system headers,
    but there are not so many in the kernel tree.

    At first, keeping system headers in .*.cmd files might be useful to
    detect the compiler update, but there is no guarantee that
    is included from every file. So, I implemented a more reliable way in
    the previous commit.

    Signed-off-by: Masahiro Yamada

    Masahiro Yamada
     

11 Apr, 2020

1 commit


25 Mar, 2020

1 commit


07 Jan, 2020

2 commits


09 Dec, 2019

1 commit

  • Since commit fcbb8461fd23 ("kbuild: remove header compile test"),
    'make clean' with O= option in the pristine source tree emits
    'No such file or directory' warning.

    $ git clean -d -f -x
    $ make O=foo clean
    make[1]: Entering directory '/home/masahiro/linux/foo'
    find: ‘usr/include’: No such file or directory
    make[1]: Leaving directory '/home/masahiro/linux/foo'

    Fixes: fcbb8461fd23 ("kbuild: remove header compile test")
    Reported-by: kbuild test robot
    Signed-off-by: Masahiro Yamada

    Masahiro Yamada
     

05 Dec, 2019

4 commits

  • Userspace cannot compile due to some missing type
    definitions. For example, building it for x86 fails as follows:

    CC usr/include/asm/sembuf.h.s
    In file included from :32:0:
    usr/include/asm/sembuf.h:17:20: error: field `sem_perm' has incomplete type
    struct ipc64_perm sem_perm; /* permissions .. see ipc.h */
    ^~~~~~~~
    usr/include/asm/sembuf.h:24:2: error: unknown type name `__kernel_time_t'
    __kernel_time_t sem_otime; /* last semop time */
    ^~~~~~~~~~~~~~~
    usr/include/asm/sembuf.h:25:2: error: unknown type name `__kernel_ulong_t'
    __kernel_ulong_t __unused1;
    ^~~~~~~~~~~~~~~~
    usr/include/asm/sembuf.h:26:2: error: unknown type name `__kernel_time_t'
    __kernel_time_t sem_ctime; /* last change time */
    ^~~~~~~~~~~~~~~
    usr/include/asm/sembuf.h:27:2: error: unknown type name `__kernel_ulong_t'
    __kernel_ulong_t __unused2;
    ^~~~~~~~~~~~~~~~
    usr/include/asm/sembuf.h:29:2: error: unknown type name `__kernel_ulong_t'
    __kernel_ulong_t sem_nsems; /* no. of semaphores in array */
    ^~~~~~~~~~~~~~~~
    usr/include/asm/sembuf.h:30:2: error: unknown type name `__kernel_ulong_t'
    __kernel_ulong_t __unused3;
    ^~~~~~~~~~~~~~~~
    usr/include/asm/sembuf.h:31:2: error: unknown type name `__kernel_ulong_t'
    __kernel_ulong_t __unused4;
    ^~~~~~~~~~~~~~~~

    It is just a matter of missing include directive.

    Include to make it self-contained, and add it to
    the compile-test coverage.

    Link: http://lkml.kernel.org/r/20191030063855.9989-3-yamada.masahiro@socionext.com
    Signed-off-by: Masahiro Yamada
    Cc: Arnd Bergmann
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Masahiro Yamada
     
  • Userspace cannot compile due to some missing type
    definitions. For example, building it for x86 fails as follows:

    CC usr/include/asm/msgbuf.h.s
    In file included from usr/include/asm/msgbuf.h:6:0,
    from :32:
    usr/include/asm-generic/msgbuf.h:25:20: error: field `msg_perm' has incomplete type
    struct ipc64_perm msg_perm;
    ^~~~~~~~
    usr/include/asm-generic/msgbuf.h:27:2: error: unknown type name `__kernel_time_t'
    __kernel_time_t msg_stime; /* last msgsnd time */
    ^~~~~~~~~~~~~~~
    usr/include/asm-generic/msgbuf.h:28:2: error: unknown type name `__kernel_time_t'
    __kernel_time_t msg_rtime; /* last msgrcv time */
    ^~~~~~~~~~~~~~~
    usr/include/asm-generic/msgbuf.h:29:2: error: unknown type name `__kernel_time_t'
    __kernel_time_t msg_ctime; /* last change time */
    ^~~~~~~~~~~~~~~
    usr/include/asm-generic/msgbuf.h:41:2: error: unknown type name `__kernel_pid_t'
    __kernel_pid_t msg_lspid; /* pid of last msgsnd */
    ^~~~~~~~~~~~~~
    usr/include/asm-generic/msgbuf.h:42:2: error: unknown type name `__kernel_pid_t'
    __kernel_pid_t msg_lrpid; /* last receive pid */
    ^~~~~~~~~~~~~~

    It is just a matter of missing include directive.

    Include to make it self-contained, and add it to
    the compile-test coverage.

    Link: http://lkml.kernel.org/r/20191030063855.9989-2-yamada.masahiro@socionext.com
    Signed-off-by: Masahiro Yamada
    Cc: Arnd Bergmann
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Masahiro Yamada
     
  • Userspace cannot compile due to some missing type
    definitions. For example, building it for x86 fails as follows:

    CC usr/include/asm/ipcbuf.h.s
    In file included from usr/include/asm/ipcbuf.h:1:0,
    from :32:
    usr/include/asm-generic/ipcbuf.h:21:2: error: unknown type name `__kernel_key_t'
    __kernel_key_t key;
    ^~~~~~~~~~~~~~
    usr/include/asm-generic/ipcbuf.h:22:2: error: unknown type name `__kernel_uid32_t'
    __kernel_uid32_t uid;
    ^~~~~~~~~~~~~~~~
    usr/include/asm-generic/ipcbuf.h:23:2: error: unknown type name `__kernel_gid32_t'
    __kernel_gid32_t gid;
    ^~~~~~~~~~~~~~~~
    usr/include/asm-generic/ipcbuf.h:24:2: error: unknown type name `__kernel_uid32_t'
    __kernel_uid32_t cuid;
    ^~~~~~~~~~~~~~~~
    usr/include/asm-generic/ipcbuf.h:25:2: error: unknown type name `__kernel_gid32_t'
    __kernel_gid32_t cgid;
    ^~~~~~~~~~~~~~~~
    usr/include/asm-generic/ipcbuf.h:26:2: error: unknown type name `__kernel_mode_t'
    __kernel_mode_t mode;
    ^~~~~~~~~~~~~~~
    usr/include/asm-generic/ipcbuf.h:28:35: error: `__kernel_mode_t' undeclared here (not in a function)
    unsigned char __pad1[4 - sizeof(__kernel_mode_t)];
    ^~~~~~~~~~~~~~~
    usr/include/asm-generic/ipcbuf.h:31:2: error: unknown type name `__kernel_ulong_t'
    __kernel_ulong_t __unused1;
    ^~~~~~~~~~~~~~~~
    usr/include/asm-generic/ipcbuf.h:32:2: error: unknown type name `__kernel_ulong_t'
    __kernel_ulong_t __unused2;
    ^~~~~~~~~~~~~~~~

    It is just a matter of missing include directive.

    Include to make it self-contained, and add it to
    the compile-test coverage.

    Link: http://lkml.kernel.org/r/20191030063855.9989-1-yamada.masahiro@socionext.com
    Signed-off-by: Masahiro Yamada
    Cc: Arnd Bergmann
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Masahiro Yamada
     
  • Userspace cannot compile

    CC usr/include/linux/scc.h.s
    In file included from :32:0:
    usr/include/linux/scc.h:20:20: error: `SIOCDEVPRIVATE' undeclared here (not in a function)
    SIOCSCCRESERVED = SIOCDEVPRIVATE,
    ^~~~~~~~~~~~~~

    Include to make it self-contained, and add it to the
    compile-test coverage.

    Link: http://lkml.kernel.org/r/20191108055809.26969-1-yamada.masahiro@socionext.com
    Signed-off-by: Masahiro Yamada
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Masahiro Yamada
     

14 Nov, 2019

2 commits

  • Currently, some sanity checks for uapi headers are done by
    scripts/headers_check.pl, which is wired up to the 'headers_check'
    target in the top Makefile.

    It is true compiling headers has better test coverage, but there
    are still several headers excluded from the compile test. I like
    to keep headers_check.pl for a while, but we can delete a lot of
    code by moving the build rule to usr/include/Makefile.

    Signed-off-by: Masahiro Yamada

    Masahiro Yamada
     
  • There are both positive and negative options about this feature.
    At first, I thought it was a good idea, but actually Linus stated a
    negative opinion (https://lkml.org/lkml/2019/9/29/227). I admit it
    is ugly and annoying.

    The baseline I'd like to keep is the compile-test of uapi headers.
    (Otherwise, kernel developers have no way to ensure the correctness
    of the exported headers.)

    I will maintain a small build rule in usr/include/Makefile.
    Remove the other header test functionality.

    Signed-off-by: Masahiro Yamada

    Masahiro Yamada
     

11 Nov, 2019

1 commit


05 Oct, 2019

1 commit


29 Sep, 2019

1 commit

  • Pull networking fixes from David Miller:

    1) Sanity check URB networking device parameters to avoid divide by
    zero, from Oliver Neukum.

    2) Disable global multicast filter in NCSI, otherwise LLDP and IPV6
    don't work properly. Longer term this needs a better fix tho. From
    Vijay Khemka.

    3) Small fixes to selftests (use ping when ping6 is not present, etc.)
    from David Ahern.

    4) Bring back rt_uses_gateway member of struct rtable, it's semantics
    were not well understood and trying to remove it broke things. From
    David Ahern.

    5) Move usbnet snaity checking, ignore endpoints with invalid
    wMaxPacketSize. From Bjørn Mork.

    6) Missing Kconfig deps for sja1105 driver, from Mao Wenan.

    7) Various small fixes to the mlx5 DR steering code, from Alaa Hleihel,
    Alex Vesker, and Yevgeny Kliteynik

    8) Missing CAP_NET_RAW checks in various places, from Ori Nimron.

    9) Fix crash when removing sch_cbs entry while offloading is enabled,
    from Vinicius Costa Gomes.

    10) Signedness bug fixes, generally in looking at the result given by
    of_get_phy_mode() and friends. From Dan Crapenter.

    11) Disable preemption around BPF_PROG_RUN() calls, from Eric Dumazet.

    12) Don't create VRF ipv6 rules if ipv6 is disabled, from David Ahern.

    13) Fix quantization code in tcp_bbr, from Kevin Yang.

    * git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (127 commits)
    net: tap: clean up an indentation issue
    nfp: abm: fix memory leak in nfp_abm_u32_knode_replace
    tcp: better handle TCP_USER_TIMEOUT in SYN_SENT state
    sk_buff: drop all skb extensions on free and skb scrubbing
    tcp_bbr: fix quantization code to not raise cwnd if not probing bandwidth
    mlxsw: spectrum_flower: Fail in case user specifies multiple mirror actions
    Documentation: Clarify trap's description
    mlxsw: spectrum: Clear VLAN filters during port initialization
    net: ena: clean up indentation issue
    NFC: st95hf: clean up indentation issue
    net: phy: micrel: add Asym Pause workaround for KSZ9021
    net: socionext: ave: Avoid using netdev_err() before calling register_netdev()
    ptp: correctly disable flags on old ioctls
    lib: dimlib: fix help text typos
    net: dsa: microchip: Always set regmap stride to 1
    nfp: flower: fix memory leak in nfp_flower_spawn_vnic_reprs
    nfp: flower: prevent memory leak in nfp_flower_spawn_phy_reprs
    net/sched: Set default of CONFIG_NET_TC_SKB_EXT to N
    vrf: Do not attempt to create IPv6 mcast rule if IPv6 is disabled
    net: sched: sch_sfb: don't call qdisc_put() while holding tree lock
    ...

    Linus Torvalds
     

25 Sep, 2019

1 commit

  • When CONFIG_UAPI_HEADER_TEST=y, exported headers are compile-tested to
    make sure they can be included from user-space.

    Currently, linux/netfilter_bridge/ebtables.h is excluded from the test
    coverage. To make it join the compile-test, we need to fix the build
    errors attached below.

    For a case like this, we decided to use __u{8,16,32,64} variable types
    in this discussion:

    https://lkml.org/lkml/2019/6/5/18

    Build log:

    CC usr/include/linux/netfilter_bridge/ebtables.h.s
    In file included from :32:0:
    ./usr/include/linux/netfilter_bridge/ebtables.h:126:4: error: unknown type name ‘uint8_t’
    uint8_t revision;
    ^~~~~~~
    ./usr/include/linux/netfilter_bridge/ebtables.h:139:4: error: unknown type name ‘uint8_t’
    uint8_t revision;
    ^~~~~~~
    ./usr/include/linux/netfilter_bridge/ebtables.h:152:4: error: unknown type name ‘uint8_t’
    uint8_t revision;
    ^~~~~~~

    Signed-off-by: Masahiro Yamada
    Signed-off-by: Pablo Neira Ayuso

    Masahiro Yamada
     

29 Aug, 2019

1 commit


23 Jul, 2019

1 commit


20 Jul, 2019

1 commit

  • - Some headers graduated from the blacklist

    - hyperv_timer.h joined the header-test when CONFIG_X86=y

    - nf_tables*.h joined the header-test when CONFIG_NF_TABLES is
    enabled.

    - The entry for nf_tables_offload.h was added to fix build error for
    the combination of CONFIG_NF_TABLES=n and CONFIG_KERNEL_HEADER_TEST=y.

    - The entry for iomap.h was added because this header is supposed to
    be included only when CONFIG_BLOCK=y

    Signed-off-by: Masahiro Yamada

    Masahiro Yamada
     

08 Jul, 2019

1 commit

  • Multiple people have suggested compile-testing UAPI headers to ensure
    they can be really included from user-space. "make headers_check" is
    obviously not enough to catch bugs, and we often leak unresolved
    references to user-space.

    Use the new header-test-y syntax to implement it. Please note exported
    headers are compile-tested with a completely different set of compiler
    flags. The header search path is set to $(objtree)/usr/include since
    exported headers should not include unexported ones.

    We use -std=gnu89 for the kernel space since the kernel code highly
    depends on GNU extensions. On the other hand, UAPI headers should be
    written in more standardized C, so they are compiled with -std=c90.
    This will emit errors if C++ style comments, the keyword 'inline', etc.
    are used. Please use C style comments (/* ... */), '__inline__', etc.
    in UAPI headers.

    There is additional compiler requirement to enable this test because
    many of UAPI headers include , , ,
    etc. directly or indirectly. You cannot use kernel.org pre-built
    toolchains [1] since they lack .

    I reused CONFIG_CC_CAN_LINK to check the system header availability.
    The intention is slightly different, but a compiler that can link
    userspace programs provide system headers.

    For now, a lot of headers need to be excluded because they cannot
    be compiled standalone, but this is a good start point.

    [1] https://mirrors.edge.kernel.org/pub/tools/crosstool/index.html

    Signed-off-by: Masahiro Yamada
    Reviewed-by: Sam Ravnborg

    Masahiro Yamada