[ Upstream commit cedc12c5b57f7efa6dbebfb2b140e8675f5a2616 ]
In the current state, an erroneous call to
bpf_object__find_map_by_name(NULL, ...) leads to a segmentation
fault through the following call chain:
bpf_object__find_map_by_name(obj = NULL, ...)
-> bpf_object__for_each_map(pos, obj = NULL)
-> bpf_object__next_map((obj = NULL), NULL)
-> return (obj = NULL)->maps
While calling bpf_object__find_map_by_name with obj = NULL is
obviously incorrect, this should not lead to a segmentation
fault but rather be handled gracefully.
As __bpf_map__iter already handles this situation correctly, we
can delegate the check for the regular case there and only add
a check in case the prev or next parameter is NULL.
Signed-off-by: Andreas Ziegler <ziegler.andreas@siemens.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240703083436.505124-1-ziegler.andreas@siemens.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 189f1a976e426011e6a5588f1d3ceedf71fe2965 ]
For all these years libbpf's BTF dumper has been emitting not strictly
valid syntax for function prototypes that have no input arguments.
Instead of `int (*blah)()` we should emit `int (*blah)(void)`.
This is not normally a problem, but it manifests when we get kfuncs in
vmlinux.h that have no input arguments. Due to compiler internal
specifics, we get no BTF information for such kfuncs, if they are not
declared with proper `(void)`.
The fix is trivial. We also need to adjust a few ancient tests that
happily assumed `()` is correct.
Fixes: 351131b51c7a ("libbpf: add btf_dump API for BTF-to-C conversion")
Reported-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://lore.kernel.org/bpf/20240712224442.282823-1-andrii@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 009367099eb61a4fc2af44d4eb06b6b4de7de6db ]
[Changes from V1:
- Use a default branch in the switch statement to initialize `val'.]
GCC warns that `val' may be used uninitialized in the
BPF_CRE_READ_BITFIELD macro, defined in bpf_core_read.h as:
[...]
unsigned long long val; \
[...] \
switch (__CORE_RELO(s, field, BYTE_SIZE)) { \
case 1: val = *(const unsigned char *)p; break; \
case 2: val = *(const unsigned short *)p; break; \
case 4: val = *(const unsigned int *)p; break; \
case 8: val = *(const unsigned long long *)p; break; \
} \
[...]
val; \
} \
This patch adds a default entry in the switch statement that sets
`val' to zero in order to avoid the warning, and random values to be
used in case __builtin_preserve_field_info returns unexpected values
for BPF_FIELD_BYTE_SIZE.
Tested in bpf-next master.
No regressions.
Signed-off-by: Jose E. Marchesi <jose.marchesi@oracle.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240508101313.16662-1-jose.marchesi@oracle.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
