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6f9aba7f0d
While running 'perf test' for bpf, observed that "BPF prologue
generation" test case fails to compile with clang. Logs below from
powerpc:
<stdin>:33:2: error: use of undeclared identifier 'fmode_t'
fmode_t f_mode = (fmode_t)_f_mode;
^
<stdin>:37:6: error: use of undeclared identifier 'f_mode'; did you mean '_f_mode'?
if (f_mode & FMODE_WRITE)
^~~~~~
_f_mode
<stdin>:30:60: note: '_f_mode' declared here
int bpf_func__null_lseek(void *ctx, int err, unsigned long _f_mode,
^
2 errors generated.
The test code tests/bpf-script-test-prologue.c uses fmode_t. And the
error above is for "fmode_t" which is defined in include/linux/types.h
as part of kernel build directory: "/lib/modules/<kernel_version>/build"
that comes from kernel devel [ soft link to /usr/src/<kernel_version> ].
Clang picks this header file from "-working-directory" build option that
specifies this build folder.
But the commit 14e4b9f428 ("perf trace: Raw augmented syscalls fix
libbpf 1.0+ compatibility") changed the include directory to use:
"/usr/include".
Post this change, types.h from /usr/include/ is getting picked upwhich
doesn’t contain definition of "fmode_t" and hence fails to compile.
Compilation command before this commit:
/usr/bin/clang -D__KERNEL__ -D__NR_CPUS__=72 -DLINUX_VERSION_CODE=0x50e00 -xc -I/root/lib/perf/include/bpf -nostdinc -I./arch/powerpc/include -I./arch/powerpc/include/generated -I./include -I./arch/powerpc/include/uapi -I./arch/powerpc/include/generated/uapi -I./include/uapi -I./include/generated/uapi -include ./include/linux/compiler-version.h -include ./include/linux/kconfig.h -Wno-unused-value -Wno-pointer-sign -working-directory /lib/modules/<ver>/build -c - -target bpf -g -O2 -o -
Compilation command after this commit:
/usr/bin/clang -D__KERNEL__ -D__NR_CPUS__=72 -DLINUX_VERSION_CODE=0x50e00 -xc -I/usr/include/ -nostdinc -I./arch/powerpc/include -I./arch/powerpc/include/generated -I./include -I./arch/powerpc/include/uapi -I./arch/powerpc/include/generated/uapi -I./include/uapi -I./include/generated/uapi -include ./include/linux/compiler-version.h -include ./include/linux/kconfig.h -Wno-unused-value -Wno-pointer-sign -working-directory /lib/modules/<ver>/build -c - -target bpf -g -O2 -o -
The difference is addition of -I/usr/include/ in the first line which
is causing the error. Fix this by adding typedef for "fmode_t" in the
testcase to solve the compile issue.
Fixes: 14e4b9f428 ("perf trace: Raw augmented syscalls fix libbpf 1.0+ compatibility")
Signed-off-by: Athira Jajeev <atrajeev@linux.vnet.ibm.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Disha Goel <disgoel@linux.ibm.com>
Cc: Ian Rogers <irogers@google.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nageswara R Sastry <rnsastry@linux.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/linux-perf-users/20230105120436.92051-1-atrajeev@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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.