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Eduard Zingerman
63bb645b9d
In order to express test cases that use bpf_tail_call() intrinsic it
is necessary to have several programs to be loaded at a time.
This commit adds __auxiliary annotation to the set of annotations
supported by test_loader.c. Programs marked as auxiliary are always
loaded but are not treated as a separate test.
For example:
void dummy_prog1(void);
struct {
__uint(type, BPF_MAP_TYPE_PROG_ARRAY);
__uint(max_entries, 4);
__uint(key_size, sizeof(int));
__array(values, void (void));
} prog_map SEC(".maps") = {
.values = {
[0] = (void *) &dummy_prog1,
},
};
SEC("tc")
__auxiliary
__naked void dummy_prog1(void) {
asm volatile ("r0 = 42; exit;");
}
SEC("tc")
__description("reference tracking: check reference or tail call")
__success __retval(0)
__naked void check_reference_or_tail_call(void)
{
asm volatile (
"r2 = %[prog_map] ll;"
"r3 = 0;"
"call %[bpf_tail_call];"
"r0 = 0;"
"exit;"
:: __imm(bpf_tail_call),
: __clobber_all);
}
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20230421174234.2391278-2-eddyz87@gmail.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 Restructured Text 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.