linux.git/kernel/bpf/preload, branch v6.12.80 Clone of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git bpf/preload: Don't select USERMODE_DRIVER 2025-08-15T10:13:48+00:00 Thomas Weißschuh thomas.weissschuh@linutronix.de 2025-07-21T09:04:41+00:00 87b34d935109b915956af28b98ad638c773477fc [ Upstream commit 2b03164eee20eac7ce0fe3aa4fbda7efc1e5427a ] The usermode driver framework is not used anymore by the BPF preload code. Fixes: cb80ddc67152 ("bpf: Convert bpf_preload.ko to use light skeleton.") Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/bpf/20250721-remove-usermode-driver-v1-1-0d0083334382@linutronix.de Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 2b03164eee20eac7ce0fe3aa4fbda7efc1e5427a ]

The usermode driver framework is not used anymore by the BPF
preload code.

Fixes: cb80ddc67152 ("bpf: Convert bpf_preload.ko to use light skeleton.")
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/bpf/20250721-remove-usermode-driver-v1-1-0d0083334382@linutronix.de
Signed-off-by: Sasha Levin <sashal@kernel.org>
bpf: Fix BPF_INTERNAL namespace import 2025-05-05T09:00:29+00:00 Xi Ruoyao xry111@xry111.site 2025-05-03T08:50:31+00:00 92c6f8c577a0ca52d779d3a4d42465bd81f854a1 The commit cdd30ebb1b9f ("module: Convert symbol namespace to string literal") makes the grammar of MODULE_IMPORT_NS and EXPORT_SYMBOL_NS different between the stable branches and the mainline. But when the commit 955f9ede52b8 ("bpf: Add namespace to BPF internal symbols") was backported from mainline, only EXPORT_SYMBOL_NS instances are adapted, leaving the MODULE_IMPORT_NS instance with the "new" grammar and causing the module fails to build: ERROR: modpost: module bpf_preload uses symbol bpf_link_get_from_fd from namespace BPF_INTERNAL, but does not import it. ERROR: modpost: module bpf_preload uses symbol kern_sys_bpf from namespace BPF_INTERNAL, but does not import it. Reported-by: Mingcong Bai <jeffbai@aosc.io> Reported-by: Alex Davis <alex47794@gmail.com> Closes: https://lore.kernel.org/all/CADiockBKBQTVqjA5G+RJ9LBwnEnZ8o0odYnL=LBZ_7QN=_SZ7A@mail.gmail.com/ Fixes: 955f9ede52b8 ("bpf: Add namespace to BPF internal symbols") Signed-off-by: Xi Ruoyao <xry111@xry111.site> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
The commit cdd30ebb1b9f ("module: Convert symbol namespace to string
literal") makes the grammar of MODULE_IMPORT_NS and EXPORT_SYMBOL_NS
different between the stable branches and the mainline.  But when
the commit 955f9ede52b8 ("bpf: Add namespace to BPF internal symbols")
was backported from mainline, only EXPORT_SYMBOL_NS instances are
adapted, leaving the MODULE_IMPORT_NS instance with the "new" grammar
and causing the module fails to build:

    ERROR: modpost: module bpf_preload uses symbol bpf_link_get_from_fd from namespace BPF_INTERNAL, but does not import it.
    ERROR: modpost: module bpf_preload uses symbol kern_sys_bpf from namespace BPF_INTERNAL, but does not import it.

Reported-by: Mingcong Bai <jeffbai@aosc.io>
Reported-by: Alex Davis <alex47794@gmail.com>
Closes: https://lore.kernel.org/all/CADiockBKBQTVqjA5G+RJ9LBwnEnZ8o0odYnL=LBZ_7QN=_SZ7A@mail.gmail.com/
Fixes: 955f9ede52b8 ("bpf: Add namespace to BPF internal symbols")
Signed-off-by: Xi Ruoyao <xry111@xry111.site>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
bpf: Add namespace to BPF internal symbols 2025-05-02T05:59:04+00:00 Alexei Starovoitov ast@kernel.org 2025-04-25T01:45:42+00:00 955f9ede52b8617e454fcfd4528f90bd23a30753 [ Upstream commit f88886de0927a2adf4c1b4c5c1f1d31d2023ef74 ] Add namespace to BPF internal symbols used by light skeleton to prevent abuse and document with the code their allowed usage. Fixes: b1d18a7574d0 ("bpf: Extend sys_bpf commands for bpf_syscall programs.") Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/bpf/20250425014542.62385-1-alexei.starovoitov@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit f88886de0927a2adf4c1b4c5c1f1d31d2023ef74 ]

Add namespace to BPF internal symbols used by light skeleton
to prevent abuse and document with the code their allowed usage.

Fixes: b1d18a7574d0 ("bpf: Extend sys_bpf commands for bpf_syscall programs.")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/bpf/20250425014542.62385-1-alexei.starovoitov@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
bpf: make preloaded map iterators to display map elements count 2023-07-06T19:42:25+00:00 Anton Protopopov aspsk@isovalent.com 2023-07-06T13:39:31+00:00 515ee52b2224f73f63ac031cbf400cd513d2f45b Add another column to the /sys/fs/bpf/maps.debug iterator to display cur_entries, the current number of entries in the map as is returned by the bpf_map_sum_elem_count kfunc. Also fix formatting. Example: # cat /sys/fs/bpf/maps.debug id name max_entries cur_entries 2 iterator.rodata 1 0 125 cilium_auth_map 524288 666 126 cilium_runtime_ 256 0 127 cilium_signals 32 0 128 cilium_node_map 16384 1344 129 cilium_events 32 0 ... Signed-off-by: Anton Protopopov <aspsk@isovalent.com> Link: https://lore.kernel.org/r/20230706133932.45883-5-aspsk@isovalent.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> 
Add another column to the /sys/fs/bpf/maps.debug iterator to display
cur_entries, the current number of entries in the map as is returned
by the bpf_map_sum_elem_count kfunc. Also fix formatting.

Example:

    # cat /sys/fs/bpf/maps.debug
      id name             max_entries  cur_entries
       2 iterator.rodata            1            0
     125 cilium_auth_map       524288          666
     126 cilium_runtime_          256            0
     127 cilium_signals            32            0
     128 cilium_node_map        16384         1344
     129 cilium_events             32            0
     ...

Signed-off-by: Anton Protopopov <aspsk@isovalent.com>
Link: https://lore.kernel.org/r/20230706133932.45883-5-aspsk@isovalent.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
bpf: Replace deprecated -target with --target= for Clang 2023-06-29T13:46:17+00:00 Fangrui Song maskray@google.com 2023-06-24T00:18:56+00:00 bbaf1ff06af49e856501024abbe161d96c1f0d66 The -target option has been deprecated since clang 3.4 in 2013. Therefore, use the preferred --target=bpf form instead. This also matches how we use --target= in scripts/Makefile.clang. Signed-off-by: Fangrui Song <maskray@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: Quentin Monnet <quentin@isovalent.com> Link: https://github.com/llvm/llvm-project/commit/274b6f0c87a6a1798de0a68135afc7f95def6277 Link: https://lore.kernel.org/bpf/20230624001856.1903733-1-maskray@google.com 
The -target option has been deprecated since clang 3.4 in 2013. Therefore, use
the preferred --target=bpf form instead. This also matches how we use --target=
in scripts/Makefile.clang.

Signed-off-by: Fangrui Song <maskray@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Quentin Monnet <quentin@isovalent.com>
Link: https://github.com/llvm/llvm-project/commit/274b6f0c87a6a1798de0a68135afc7f95def6277
Link: https://lore.kernel.org/bpf/20230624001856.1903733-1-maskray@google.com
bpf: Replace all non-returning strlcpy with strscpy 2023-05-31T11:04:20+00:00 Azeem Shaikh azeemshaikh38@gmail.com 2023-05-30T15:56:59+00:00 ffadc372529e268b54c5b98f56da07d8024fa1cb strlcpy() reads the entire source buffer first. This read may exceed the destination size limit. This is both inefficient and can lead to linear read overflows if a source string is not NUL-terminated [1]. This is not the case here, however, in an effort to remove strlcpy() completely [2], lets replace strlcpy() here with strscpy(). No return values were used, so a direct replacement is safe. [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy [2] https://github.com/KSPP/linux/issues/89 Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/bpf/20230530155659.309657-1-azeemshaikh38@gmail.com 
strlcpy() reads the entire source buffer first. This read may exceed the
destination size limit. This is both inefficient and can lead to linear
read overflows if a source string is not NUL-terminated [1]. This is not
the case here, however, in an effort to remove strlcpy() completely [2],
lets replace strlcpy() here with strscpy(). No return values were used,
so a direct replacement is safe.

  [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
  [2] https://github.com/KSPP/linux/issues/89

Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/bpf/20230530155659.309657-1-azeemshaikh38@gmail.com
bpf: iterators: Split iterators.lskel.h into little- and big- endian versions 2023-01-28T20:45:15+00:00 Ilya Leoshkevich iii@linux.ibm.com 2023-01-28T00:06:43+00:00 0f0e5f5bd5066c9ffaa006e26fc7d092b04d4088 iterators.lskel.h is little-endian, therefore bpf iterator is currently broken on big-endian systems. Introduce a big-endian version and add instructions regarding its generation. Unfortunately bpftool's cross-endianness capabilities are limited to BTF right now, so the procedure requires access to a big-endian machine or a configured emulator. Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Link: https://lore.kernel.org/r/20230128000650.1516334-25-iii@linux.ibm.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> 
iterators.lskel.h is little-endian, therefore bpf iterator is currently
broken on big-endian systems. Introduce a big-endian version and add
instructions regarding its generation. Unfortunately bpftool's
cross-endianness capabilities are limited to BTF right now, so the
procedure requires access to a big-endian machine or a configured
emulator.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Link: https://lore.kernel.org/r/20230128000650.1516334-25-iii@linux.ibm.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
bpf: iterators: Build and use lightweight bootstrap version of bpftool 2022-07-15T19:01:30+00:00 Pu Lehui pulehui@huawei.com 2022-07-14T02:46:12+00:00 3848636b4a88f0706f9ce48d532163244abadd43 kernel/bpf/preload/iterators use bpftool for vmlinux.h, skeleton, and static linking only. So we can use lightweight bootstrap version of bpftool to handle these, and it will be faster. Suggested-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Pu Lehui <pulehui@huawei.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220714024612.944071-4-pulehui@huawei.com 
kernel/bpf/preload/iterators use bpftool for vmlinux.h, skeleton, and
static linking only. So we can use lightweight bootstrap version of
bpftool to handle these, and it will be faster.

Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Pu Lehui <pulehui@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220714024612.944071-4-pulehui@huawei.com
bpf: Remove redundant slash 2022-03-08T06:19:32+00:00 Yuntao Wang ytcoode@gmail.com 2022-03-05T16:10:13+00:00 4989135a85334337ac8b7e42e7ee1a569ad5f7f5 The trailing slash of LIBBPF_SRCS is redundant, remove it. Also inline it as its only used in LIBBPF_INCLUDE. Signed-off-by: Yuntao Wang <ytcoode@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220305161013.361646-1-ytcoode@gmail.com 
The trailing slash of LIBBPF_SRCS is redundant, remove it. Also inline
it as its only used in LIBBPF_INCLUDE.

Signed-off-by: Yuntao Wang <ytcoode@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220305161013.361646-1-ytcoode@gmail.com
bpf: Fix issue with bpf preload module taking over stdout/stdin of kernel. 2022-02-25T20:48:35+00:00 Yucong Sun fallentree@fb.com 2022-02-25T18:59:24+00:00 80bebebdac935473568c27d4f1349dc8f9809bf7 In cb80ddc67152 ("bpf: Convert bpf_preload.ko to use light skeleton.") BPF preload was switched from user mode process to use in-kernel light skeleton instead. However, in the kernel context, early in the boot sequence, the first available FD can start from 0, instead of normally 3 for user mode process. So FDs 0 and 1 are then used for loaded BPF programs and prevent init process from setting up stdin/stdout/stderr on FD 0, 1, and 2 as expected. Before the fix: ls -lah /proc/1/fd/* lrwx------1 root root 64 Feb 23 17:20 /proc/1/fd/0 -> /dev/null lrwx------ 1 root root 64 Feb 23 17:20 /proc/1/fd/1 -> /dev/null lrwx------ 1 root root 64 Feb 23 17:20 /proc/1/fd/2 -> /dev/console lrwx------ 1 root root 64 Feb 23 17:20 /proc/1/fd/6 -> /dev/console lrwx------ 1 root root 64 Feb 23 17:20 /proc/1/fd/7 -> /dev/console After the fix: ls -lah /proc/1/fd/* lrwx------ 1 root root 64 Feb 24 21:23 /proc/1/fd/0 -> /dev/console lrwx------ 1 root root 64 Feb 24 21:23 /proc/1/fd/1 -> /dev/console lrwx------ 1 root root 64 Feb 24 21:23 /proc/1/fd/2 -> /dev/console Fix by closing prog FDs after initialization. struct bpf_prog's themselves are kept alive through direct kernel references taken with bpf_link_get_from_fd(). Fixes: cb80ddc67152 ("bpf: Convert bpf_preload.ko to use light skeleton.") Signed-off-by: Yucong Sun <fallentree@fb.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220225185923.2535519-1-fallentree@fb.com 
In cb80ddc67152 ("bpf: Convert bpf_preload.ko to use light skeleton.")
BPF preload was switched from user mode process to use in-kernel light
skeleton instead. However, in the kernel context, early in the boot
sequence, the first available FD can start from 0, instead of normally
3 for user mode process. So FDs 0 and 1 are then used for loaded BPF
programs and prevent init process from setting up stdin/stdout/stderr on
FD 0, 1, and 2 as expected.

Before the fix:

ls -lah /proc/1/fd/*

lrwx------1 root root 64 Feb 23 17:20 /proc/1/fd/0 -> /dev/null
lrwx------ 1 root root 64 Feb 23 17:20 /proc/1/fd/1 -> /dev/null
lrwx------ 1 root root 64 Feb 23 17:20 /proc/1/fd/2 -> /dev/console
lrwx------ 1 root root 64 Feb 23 17:20 /proc/1/fd/6 -> /dev/console
lrwx------ 1 root root 64 Feb 23 17:20 /proc/1/fd/7 -> /dev/console

After the fix:

ls -lah /proc/1/fd/*

lrwx------ 1 root root 64 Feb 24 21:23 /proc/1/fd/0 -> /dev/console
lrwx------ 1 root root 64 Feb 24 21:23 /proc/1/fd/1 -> /dev/console
lrwx------ 1 root root 64 Feb 24 21:23 /proc/1/fd/2 -> /dev/console

Fix by closing prog FDs after initialization. struct bpf_prog's
themselves are kept alive through direct kernel references taken with
bpf_link_get_from_fd().

Fixes: cb80ddc67152 ("bpf: Convert bpf_preload.ko to use light skeleton.")
Signed-off-by: Yucong Sun <fallentree@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220225185923.2535519-1-fallentree@fb.com