kernel_optimize_test/samples
Yonghong Song 9618bde489 samples/bpf: Change Makefile to cope with latest llvm
With latest llvm trunk, bpf programs under samples/bpf
directory, if using CORE, may experience the following
errors:

LLVM ERROR: Cannot select: intrinsic %llvm.preserve.struct.access.index
PLEASE submit a bug report to https://bugs.llvm.org/ and include the crash backtrace.
Stack dump:
0.      Program arguments: llc -march=bpf -filetype=obj -o samples/bpf/test_probe_write_user_kern.o
1.      Running pass 'Function Pass Manager' on module '<stdin>'.
2.      Running pass 'BPF DAG->DAG Pattern Instruction Selection' on function '@bpf_prog1'
 #0 0x000000000183c26c llvm::sys::PrintStackTrace(llvm::raw_ostream&, int)
    (/data/users/yhs/work/llvm-project/llvm/build.cur/install/bin/llc+0x183c26c)
...
 #7 0x00000000017c375e (/data/users/yhs/work/llvm-project/llvm/build.cur/install/bin/llc+0x17c375e)
 #8 0x00000000016a75c5 llvm::SelectionDAGISel::CannotYetSelect(llvm::SDNode*)
    (/data/users/yhs/work/llvm-project/llvm/build.cur/install/bin/llc+0x16a75c5)
 #9 0x00000000016ab4f8 llvm::SelectionDAGISel::SelectCodeCommon(llvm::SDNode*, unsigned char const*,
    unsigned int) (/data/users/yhs/work/llvm-project/llvm/build.cur/install/bin/llc+0x16ab4f8)
...
Aborted (core dumped) | llc -march=bpf -filetype=obj -o samples/bpf/test_probe_write_user_kern.o

The reason is due to llvm change https://reviews.llvm.org/D87153
where the CORE relocation global generation is moved from the beginning
of target dependent optimization (llc) to the beginning
of target independent optimization (opt).

Since samples/bpf programs did not use vmlinux.h and its clang compilation
uses native architecture, we need to adjust arch triple at opt level
to do CORE relocation global generation properly. Otherwise, the above
error will appear.

This patch fixed the issue by introduce opt and llvm-dis to compilation chain,
which will do proper CORE relocation global generation as well as O2 level
optimization. Tested with llvm10, llvm11 and trunk/llvm12.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20201006043427.1891742-1-yhs@fb.com
2020-10-06 11:45:03 -07:00
..
auxdisplay kbuild: introduce hostprogs-always-y and userprogs-always-y 2020-08-10 01:32:59 +09:00
binderfs kbuild: introduce hostprogs-always-y and userprogs-always-y 2020-08-10 01:32:59 +09:00
bpf samples/bpf: Change Makefile to cope with latest llvm 2020-10-06 11:45:03 -07:00
configfs
connector kbuild: introduce hostprogs-always-y and userprogs-always-y 2020-08-10 01:32:59 +09:00
ftrace sample-trace-array: Remove trace_array 'sample-instance' 2020-06-16 21:21:02 -04:00
hidraw kbuild: introduce hostprogs-always-y and userprogs-always-y 2020-08-10 01:32:59 +09:00
hw_breakpoint samples/hw_breakpoint: drop use of kallsyms_lookup_name() 2020-04-07 10:43:44 -07:00
kdb
kfifo proc: convert everything to "struct proc_ops" 2020-02-04 03:05:26 +00:00
kobject
kprobes docs: move remaining stuff under Documentation/*.txt to Documentation/staging 2020-06-19 14:17:05 -06:00
livepatch livepatch: Handle allocation failure in the sample of shadow variable API 2020-01-17 11:12:06 +01:00
mei kbuild: introduce hostprogs-always-y and userprogs-always-y 2020-08-10 01:32:59 +09:00
mic/mpssd .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
pidfd kbuild: introduce hostprogs-always-y and userprogs-always-y 2020-08-10 01:32:59 +09:00
pktgen docs: networking: convert pktgen.txt to ReST 2020-04-30 12:56:37 -07:00
qmi
rpmsg
seccomp kbuild: introduce hostprogs-always-y and userprogs-always-y 2020-08-10 01:32:59 +09:00
timers kbuild: introduce hostprogs-always-y and userprogs-always-y 2020-08-10 01:32:59 +09:00
trace_events tracing: Fix doc mistakes in trace sample 2020-05-07 13:32:57 -04:00
trace_printk samples/trace_printk: Wait for IRQ work to finish 2019-12-21 16:08:22 -05:00
uhid kbuild: introduce hostprogs-always-y and userprogs-always-y 2020-08-10 01:32:59 +09:00
v4l media: rename VFL_TYPE_GRABBER to _VIDEO 2020-02-24 16:52:39 +01:00
vfio-mdev PCI: Move PCI_VENDOR_ID_REDHAT definition to pci_ids.h 2020-07-09 17:00:47 -05:00
vfs kbuild: introduce hostprogs-always-y and userprogs-always-y 2020-08-10 01:32:59 +09:00
watch_queue kbuild: introduce hostprogs-always-y and userprogs-always-y 2020-08-10 01:32:59 +09:00
watchdog kbuild: introduce hostprogs-always-y and userprogs-always-y 2020-08-10 01:32:59 +09:00
Kconfig samples: watch_queue: build sample program for target architecture 2020-06-22 01:56:09 +09:00
Makefile Kbuild updates for v5.8 (2nd) 2020-06-13 13:29:16 -07:00