linux.git/tools/lib/bpf/btf.c, branch for-next

libbpf: Change hash_combine parameters from long to unsigned long

2024-11-16T19:01:38+00:00

The hash_combine() could be trapped when compiled with sanitizer like "zig cc"
or clang with signed-integer-overflow option. This patch parameters and return
type to unsigned long to remove the potential overflow.

Signed-off-by: Sidong Yang 
Acked-by: Yonghong Song 
Link: https://lore.kernel.org/r/20241116081054.65195-1-sidong.yang@furiosa.ai
Signed-off-by: Alexei Starovoitov

libbpf: Stringify errno in log messages in btf*.c

2024-11-12T04:29:45+00:00

Convert numeric error codes into the string representations in log
messages in btf.c and btf_dump.c.

Signed-off-by: Mykyta Yatsenko 
Signed-off-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/20241111212919.368971-4-mykyta.yatsenko5@gmail.com

libbpf: Support BTF.ext loading and output in either endianness

2024-10-04T00:47:36+00:00

Support for handling BTF data of either endianness was added in [1], but
did not include BTF.ext data for lack of use cases. Later, support for
static linking [2] provided a use case, but this feature and later ones
were restricted to native-endian usage.

Add support for BTF.ext handling in either endianness. Convert BTF.ext data
to native endianness when read into memory for further processing, and
support raw data access that restores the original byte-order for output.
Add internal header functions for byte-swapping func, line, and core info
records.

Add new API functions btf_ext__endianness() and btf_ext__set_endianness()
for query and setting byte-order, as already exist for BTF data.

[1] 3289959b97ca ("libbpf: Support BTF loading and raw data output in both endianness")
[2] 8fd27bf69b86 ("libbpf: Add BPF static linker BTF and BTF.ext support")

Signed-off-by: Tony Ambardar 
Signed-off-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/133407ab20e0dd5c07cab2a6fa7879dee1ffa4bc.1726475448.git.tony.ambardar@gmail.com
Signed-off-by: Alexei Starovoitov

libbpf: Improve log message formatting

2024-10-04T00:47:36+00:00

Fix missing newlines and extraneous terminal spaces in messages.

Signed-off-by: Tony Ambardar 
Signed-off-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/086884b7cbf87e524d584f9bf87f7a580e378b2b.1726475448.git.tony.ambardar@gmail.com
Signed-off-by: Alexei Starovoitov

libbpf: Fix some typos in comments

2024-09-09T23:05:40+00:00

Fix some spelling errors in the code comments of libbpf:

betwen -> between
paremeters -> parameters
knowning -> knowing
definiton -> definition
compatiblity -> compatibility
overriden -> overridden
occured -> occurred
proccess -> process
managment -> management
nessary -> necessary

Signed-off-by: Yusheng Zheng 
Signed-off-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/20240909225952.30324-1-yunwei356@gmail.com

libbpf: fix some typos in libbpf

2024-09-05T20:07:47+00:00

Hi, fix some spelling errors in libbpf, the details are as follows:

-in the code comments:
	termintaing->terminating
	architecutre->architecture
	requring->requiring
	recored->recoded
	sanitise->sanities
	allowd->allowed
	abover->above
	see bpf_udst_arg()->see bpf_usdt_arg()

Signed-off-by: Lin Yikai 
Link: https://lore.kernel.org/r/20240905110354.3274546-3-yikai.lin@vivo.com
Signed-off-by: Alexei Starovoitov

libbpf: Ensure new BTF objects inherit input endianness

2024-08-30T17:41:01+00:00

New split BTF needs to preserve base's endianness. Similarly, when
creating a distilled BTF, we need to preserve original endianness.

Fix by updating libbpf's btf__distill_base() and btf_new_empty() to retain
the byte order of any source BTF objects when creating new ones.

Fixes: ba451366bf44 ("libbpf: Implement basic split BTF support")
Fixes: 58e185a0dc35 ("libbpf: Add btf__distill_base() creating split BTF with distilled base BTF")
Reported-by: Song Liu 
Reported-by: Eduard Zingerman 
Suggested-by: Eduard Zingerman 
Signed-off-by: Tony Ambardar 
Signed-off-by: Andrii Nakryiko 
Tested-by: Alan Maguire 
Acked-by: Eduard Zingerman 
Link: https://lore.kernel.org/bpf/6358db36c5f68b07873a0a5be2d062b1af5ea5f8.camel@gmail.com/
Link: https://lore.kernel.org/bpf/20240830095150.278881-1-tony.ambardar@gmail.com

libbpf: Fix error handling in btf__distill_base()

2024-07-01T15:05:08+00:00

Coverity points out that after calling btf__new_empty_split() the wrong
value is checked for error.

Fixes: 58e185a0dc35 ("libbpf: Add btf__distill_base() creating split BTF with distilled base BTF")
Reported-by: Andrii Nakryiko 
Signed-off-by: Alan Maguire 
Signed-off-by: Daniel Borkmann 
Link: https://lore.kernel.org/bpf/20240629100058.2866763-1-alan.maguire@oracle.com

libbpf: Skip base btf sanity checks

2024-06-24T16:19:42+00:00

When upgrading to libbpf 1.3 we noticed a big performance hit while
loading programs using CORE on non base-BTF symbols. This was tracked
down to the new BTF sanity check logic. The issue is the base BTF
definitions are checked first for the base BTF and then again for every
module BTF.

Loading 5 dummy programs (using libbpf-rs) that are using CORE on a
non-base BTF symbol on my system:
- Before this fix: 3s.
- With this fix: 0.1s.

Fix this by only checking the types starting at the BTF start id. This
should ensure the base BTF is still checked as expected but only once
(btf->start_id == 1 when creating the base BTF), and then only
additional types are checked for each module BTF.

Fixes: 3903802bb99a ("libbpf: Add basic BTF sanity validation")
Signed-off-by: Antoine Tenart 
Signed-off-by: Andrii Nakryiko 
Reviewed-by: Alan Maguire 
Link: https://lore.kernel.org/bpf/20240624090908.171231-1-atenart@kernel.org

libbpf: Split field iter code into its own file kernel

2024-06-21T21:45:07+00:00

This will allow it to be shared with the kernel.  No functional change.

Suggested-by: Andrii Nakryiko 
Signed-off-by: Alan Maguire 
Signed-off-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/20240620091733.1967885-4-alan.maguire@oracle.com