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6a2f786e69
The BPF selftest global_func10 in progs/test_global_func10.c contains:
struct Small {
long x;
};
struct Big {
long x;
long y;
};
[...]
__noinline int foo(const struct Big *big)
{
if (!big)
return 0;
return bpf_get_prandom_u32() < big->y;
}
[...]
SEC("cgroup_skb/ingress")
__failure __msg("invalid indirect access to stack")
int global_func10(struct __sk_buff *skb)
{
const struct Small small = {.x = skb->len };
return foo((struct Big *)&small) ? 1 : 0;
}
GCC emits a "maybe uninitialized" warning for the code above, because
it knows `foo' accesses `big->y'.
Since the purpose of this selftest is to check that the verifier will
fail on this sort of invalid memory access, this patch just silences
the compiler warning.
Tested in bpf-next master.
No regressions.
Signed-off-by: Jose E. Marchesi <jose.marchesi@oracle.com>
Cc: david.faust@oracle.com
Cc: cupertino.miranda@oracle.com
Cc: Yonghong Song <yonghong.song@linux.dev>
Cc: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20240511212349.23549-1-jose.marchesi@oracle.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.