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s390/bpf: Fix multiple tail calls #31

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33 changes: 33 additions & 0 deletions .travis.yml
Original file line number Diff line number Diff line change
@@ -0,0 +1,33 @@
sudo: required
language: bash
dist: bionic
services:
- docker

env:
global:
- PROJECT_NAME='libbpf'
- AUTHOR_EMAIL="$(git log -1 --pretty=\"%aE\")"
- REPO_ROOT="$TRAVIS_BUILD_DIR"
- CI_ROOT="$REPO_ROOT/travis-ci"
- VMTEST_ROOT="$CI_ROOT/vmtest"

addons:
apt:
packages:
- qemu-kvm
- zstd
- binutils-dev
- elfutils
- libcap-dev
- libelf-dev
- libdw-dev
- python3-docutils

jobs:
include:
- stage: Builds & Tests
name: Kernel LATEST + selftests
language: bash
env: KERNEL=LATEST
script: $CI_ROOT/vmtest/run_vmtest.sh || travis_terminate 1
61 changes: 27 additions & 34 deletions arch/s390/net/bpf_jit_comp.c
Original file line number Diff line number Diff line change
Expand Up @@ -50,7 +50,6 @@ struct bpf_jit {
int r14_thunk_ip; /* Address of expoline thunk for 'br %r14' */
int tail_call_start; /* Tail call start offset */
int excnt; /* Number of exception table entries */
int labels[1]; /* Labels for local jumps */
};

#define SEEN_MEM BIT(0) /* use mem[] for temporary storage */
Expand Down Expand Up @@ -229,18 +228,18 @@ static inline void reg_set_seen(struct bpf_jit *jit, u32 b1)
REG_SET_SEEN(b3); \
})

#define EMIT6_PCREL_LABEL(op1, op2, b1, b2, label, mask) \
#define EMIT6_PCREL_RIEB(op1, op2, b1, b2, mask, target) \
({ \
int rel = (jit->labels[label] - jit->prg) >> 1; \
unsigned int rel = (int)((target) - jit->prg) / 2; \
_EMIT6((op1) | reg(b1, b2) << 16 | (rel & 0xffff), \
(op2) | (mask) << 12); \
REG_SET_SEEN(b1); \
REG_SET_SEEN(b2); \
})

#define EMIT6_PCREL_IMM_LABEL(op1, op2, b1, imm, label, mask) \
#define EMIT6_PCREL_RIEC(op1, op2, b1, imm, mask, target) \
({ \
int rel = (jit->labels[label] - jit->prg) >> 1; \
unsigned int rel = (int)((target) - jit->prg) / 2; \
_EMIT6((op1) | (reg_high(b1) | (mask)) << 16 | \
(rel & 0xffff), (op2) | ((imm) & 0xff) << 8); \
REG_SET_SEEN(b1); \
Expand Down Expand Up @@ -1282,7 +1281,9 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp,
EMIT4(0xb9040000, BPF_REG_0, REG_2);
break;
}
case BPF_JMP | BPF_TAIL_CALL:
case BPF_JMP | BPF_TAIL_CALL: {
int patch_1_clrj, patch_2_clij, patch_3_brc;

/*
* Implicit input:
* B1: pointer to ctx
Expand All @@ -1300,16 +1301,10 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp,
EMIT6_DISP_LH(0xe3000000, 0x0016, REG_W1, REG_0, BPF_REG_2,
offsetof(struct bpf_array, map.max_entries));
/* if ((u32)%b3 >= (u32)%w1) goto out; */
if (!is_first_pass(jit) && can_use_rel(jit, jit->labels[0])) {
/* clrj %b3,%w1,0xa,label0 */
EMIT6_PCREL_LABEL(0xec000000, 0x0077, BPF_REG_3,
REG_W1, 0, 0xa);
} else {
/* clr %b3,%w1 */
EMIT2(0x1500, BPF_REG_3, REG_W1);
/* brcl 0xa,label0 */
EMIT6_PCREL_RILC(0xc0040000, 0xa, jit->labels[0]);
}
/* clrj %b3,%w1,0xa,out */
patch_1_clrj = jit->prg;
EMIT6_PCREL_RIEB(0xec000000, 0x0077, BPF_REG_3, REG_W1, 0xa,
jit->prg);

/*
* if (tail_call_cnt++ > MAX_TAIL_CALL_CNT)
Expand All @@ -1324,16 +1319,10 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp,
EMIT4_IMM(0xa7080000, REG_W0, 1);
/* laal %w1,%w0,off(%r15) */
EMIT6_DISP_LH(0xeb000000, 0x00fa, REG_W1, REG_W0, REG_15, off);
if (!is_first_pass(jit) && can_use_rel(jit, jit->labels[0])) {
/* clij %w1,MAX_TAIL_CALL_CNT,0x2,label0 */
EMIT6_PCREL_IMM_LABEL(0xec000000, 0x007f, REG_W1,
MAX_TAIL_CALL_CNT, 0, 0x2);
} else {
/* clfi %w1,MAX_TAIL_CALL_CNT */
EMIT6_IMM(0xc20f0000, REG_W1, MAX_TAIL_CALL_CNT);
/* brcl 0x2,label0 */
EMIT6_PCREL_RILC(0xc0040000, 0x2, jit->labels[0]);
}
/* clij %w1,MAX_TAIL_CALL_CNT,0x2,out */
patch_2_clij = jit->prg;
EMIT6_PCREL_RIEC(0xec000000, 0x007f, REG_W1, MAX_TAIL_CALL_CNT,
2, jit->prg);

/*
* prog = array->ptrs[index];
Expand All @@ -1348,13 +1337,9 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp,
/* ltg %r1,prog(%b2,%r1) */
EMIT6_DISP_LH(0xe3000000, 0x0002, REG_1, BPF_REG_2,
REG_1, offsetof(struct bpf_array, ptrs));
if (!is_first_pass(jit) && can_use_rel(jit, jit->labels[0])) {
/* brc 0x8,label0 */
EMIT4_PCREL_RIC(0xa7040000, 0x8, jit->labels[0]);
} else {
/* brcl 0x8,label0 */
EMIT6_PCREL_RILC(0xc0040000, 0x8, jit->labels[0]);
}
/* brc 0x8,out */
patch_3_brc = jit->prg;
EMIT4_PCREL_RIC(0xa7040000, 8, jit->prg);

/*
* Restore registers before calling function
Expand All @@ -1371,8 +1356,16 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp,
/* bc 0xf,tail_call_start(%r1) */
_EMIT4(0x47f01000 + jit->tail_call_start);
/* out: */
jit->labels[0] = jit->prg;
if (jit->prg_buf) {
*(u16 *)(jit->prg_buf + patch_1_clrj + 2) =
(jit->prg - patch_1_clrj) >> 1;
*(u16 *)(jit->prg_buf + patch_2_clij + 2) =
(jit->prg - patch_2_clij) >> 1;
*(u16 *)(jit->prg_buf + patch_3_brc + 2) =
(jit->prg - patch_3_brc) >> 1;
}
break;
}
case BPF_JMP | BPF_EXIT: /* return b0 */
last = (i == fp->len - 1) ? 1 : 0;
if (last)
Expand Down
84 changes: 84 additions & 0 deletions travis-ci/managers/debian.sh
Original file line number Diff line number Diff line change
@@ -0,0 +1,84 @@
#!/bin/bash

PHASES=(${@:-SETUP RUN RUN_ASAN CLEANUP})
DEBIAN_RELEASE="${DEBIAN_RELEASE:-testing}"
CONT_NAME="${CONT_NAME:-libbpf-debian-$DEBIAN_RELEASE}"
ENV_VARS="${ENV_VARS:-}"
DOCKER_RUN="${DOCKER_RUN:-docker run}"
REPO_ROOT="${REPO_ROOT:-$PWD}"
ADDITIONAL_DEPS=(clang pkg-config gcc-8)
CFLAGS="-g -O2 -Werror -Wall"

function info() {
echo -e "\033[33;1m$1\033[0m"
}

function error() {
echo -e "\033[31;1m$1\033[0m"
}

function docker_exec() {
docker exec $ENV_VARS -it $CONT_NAME "$@"
}

set -e

source "$(dirname $0)/travis_wait.bash"

for phase in "${PHASES[@]}"; do
case $phase in
SETUP)
info "Setup phase"
info "Using Debian $DEBIAN_RELEASE"

sudo apt-get -y -o Dpkg::Options::="--force-confnew" install docker-ce
docker --version

docker pull debian:$DEBIAN_RELEASE
info "Starting container $CONT_NAME"
$DOCKER_RUN -v $REPO_ROOT:/build:rw \
-w /build --privileged=true --name $CONT_NAME \
-dit --net=host debian:$DEBIAN_RELEASE /bin/bash
docker_exec bash -c "echo deb-src http://deb.debian.org/debian $DEBIAN_RELEASE main >>/etc/apt/sources.list"
docker_exec apt-get -y update
docker_exec apt-get -y build-dep libelf-dev
docker_exec apt-get -y install libelf-dev
docker_exec apt-get -y install "${ADDITIONAL_DEPS[@]}"
;;
RUN|RUN_CLANG|RUN_GCC8|RUN_ASAN|RUN_CLANG_ASAN|RUN_GCC8_ASAN)
if [[ "$phase" = *"CLANG"* ]]; then
ENV_VARS="-e CC=clang -e CXX=clang++"
CC="clang"
elif [[ "$phase" = *"GCC8"* ]]; then
ENV_VARS="-e CC=gcc-8 -e CXX=g++-8"
CC="gcc-8"
else
CFLAGS="${CFLAGS} -Wno-stringop-truncation"
fi
if [[ "$phase" = *"ASAN"* ]]; then
CFLAGS="${CFLAGS} -fsanitize=address,undefined"
fi
docker_exec mkdir build install
docker_exec ${CC:-cc} --version
info "build"
docker_exec make -j$((4*$(nproc))) CFLAGS="${CFLAGS}" -C ./src -B OBJDIR=../build
info "ldd build/libbpf.so:"
docker_exec ldd build/libbpf.so
if ! docker_exec ldd build/libbpf.so | grep -q libelf; then
error "No reference to libelf.so in libbpf.so!"
exit 1
fi
info "install"
docker_exec make -j$((4*$(nproc))) -C src OBJDIR=../build DESTDIR=../install install
docker_exec rm -rf build install
;;
CLEANUP)
info "Cleanup phase"
docker stop $CONT_NAME
docker rm -f $CONT_NAME
;;
*)
echo >&2 "Unknown phase '$phase'"
exit 1
esac
done
61 changes: 61 additions & 0 deletions travis-ci/managers/travis_wait.bash
Original file line number Diff line number Diff line change
@@ -0,0 +1,61 @@
# This was borrowed from https://github.com/travis-ci/travis-build/tree/master/lib/travis/build/bash
# to get around https://github.com/travis-ci/travis-ci/issues/9979. It should probably be removed
# as soon as Travis CI has started to provide an easy way to export the functions to bash scripts.

travis_jigger() {
local cmd_pid="${1}"
shift
local timeout="${1}"
shift
local count=0

echo -e "\\n"

while [[ "${count}" -lt "${timeout}" ]]; do
count="$((count + 1))"
echo -ne "Still running (${count} of ${timeout}): ${*}\\r"
sleep 60
done

echo -e "\\n${ANSI_RED}Timeout (${timeout} minutes) reached. Terminating \"${*}\"${ANSI_RESET}\\n"
kill -9 "${cmd_pid}"
}

travis_wait() {
local timeout="${1}"

if [[ "${timeout}" =~ ^[0-9]+$ ]]; then
shift
else
timeout=20
fi

local cmd=("${@}")
local log_file="travis_wait_${$}.log"

"${cmd[@]}" &>"${log_file}" &
local cmd_pid="${!}"

travis_jigger "${!}" "${timeout}" "${cmd[@]}" &
local jigger_pid="${!}"
local result

{
set +e
wait "${cmd_pid}" 2>/dev/null
result="${?}"
ps -p"${jigger_pid}" &>/dev/null && kill "${jigger_pid}"
set -e
}

if [[ "${result}" -eq 0 ]]; then
echo -e "\\n${ANSI_GREEN}The command ${cmd[*]} exited with ${result}.${ANSI_RESET}"
else
echo -e "\\n${ANSI_RED}The command ${cmd[*]} exited with ${result}.${ANSI_RESET}"
fi

echo -e "\\n${ANSI_GREEN}Log:${ANSI_RESET}\\n"
cat "${log_file}"

return "${result}"
}
27 changes: 27 additions & 0 deletions travis-ci/managers/ubuntu.sh
Original file line number Diff line number Diff line change
@@ -0,0 +1,27 @@
#!/bin/bash
set -e
set -x

RELEASE="bionic"

echo "deb-src http://archive.ubuntu.com/ubuntu/ $RELEASE main restricted universe multiverse" >>/etc/apt/sources.list

apt-get update
apt-get -y build-dep libelf-dev
apt-get install -y libelf-dev pkg-config

source "$(dirname $0)/travis_wait.bash"

cd $REPO_ROOT

CFLAGS="-g -O2 -Werror -Wall -fsanitize=address,undefined"
mkdir build install
cc --version
make -j$((4*$(nproc))) CFLAGS="${CFLAGS}" -C ./src -B OBJDIR=../build
ldd build/libbpf.so
if ! ldd build/libbpf.so | grep -q libelf; then
echo "FAIL: No reference to libelf.so in libbpf.so!"
exit 1
fi
make -j$((4*$(nproc))) -C src OBJDIR=../build DESTDIR=../install install
rm -rf build install
30 changes: 30 additions & 0 deletions travis-ci/vmtest/build_pahole.sh
Original file line number Diff line number Diff line change
@@ -0,0 +1,30 @@
#!/bin/bash

set -eu

source $(cd $(dirname $0) && pwd)/helpers.sh

travis_fold start build_pahole "Building pahole"

CWD=$(pwd)
REPO_PATH=$1
PAHOLE_ORIGIN=https://git.kernel.org/pub/scm/devel/pahole/pahole.git

mkdir -p ${REPO_PATH}
cd ${REPO_PATH}
git init
git remote add origin ${PAHOLE_ORIGIN}
git fetch origin
git checkout master

mkdir -p build
cd build
cmake -DCMAKE_BUILD_TYPE=RelWithDebInfo -D__LIB=lib ..
make -j$((4*$(nproc))) all
sudo make install

export LD_LIBRARY_PATH=${LD_LIBRARY_PATH:-}:/usr/local/lib
ldd $(which pahole)
pahole --version

travis_fold end build_pahole
40 changes: 40 additions & 0 deletions travis-ci/vmtest/build_selftests.sh
Original file line number Diff line number Diff line change
@@ -0,0 +1,40 @@
#!/bin/bash

set -euo pipefail

source $(cd $(dirname $0) && pwd)/helpers.sh

travis_fold start prepare_selftests "Building selftests"

LLVM_VER=12
LIBBPF_PATH="${REPO_ROOT}"

PREPARE_SELFTESTS_SCRIPT=${VMTEST_ROOT}/prepare_selftests-${KERNEL}.sh
if [ -f "${PREPARE_SELFTESTS_SCRIPT}" ]; then
(cd "${REPO_ROOT}/tools/testing/selftests/bpf" && ${PREPARE_SELFTESTS_SCRIPT})
fi

if [[ "${KERNEL}" = 'LATEST' ]]; then
VMLINUX_H=
else
VMLINUX_H=${VMTEST_ROOT}/vmlinux.h
fi

make \
CLANG=clang-${LLVM_VER} \
LLC=llc-${LLVM_VER} \
LLVM_STRIP=llvm-strip-${LLVM_VER} \
VMLINUX_BTF="${VMLINUX_BTF}" \
VMLINUX_H=${VMLINUX_H} \
-C "${REPO_ROOT}/tools/testing/selftests/bpf" \
-j $((2*$(nproc)))
mkdir ${LIBBPF_PATH}/selftests
cp -R "${REPO_ROOT}/tools/testing/selftests/bpf" \
${LIBBPF_PATH}/selftests
cd ${LIBBPF_PATH}
rm selftests/bpf/.gitignore
git add selftests

git add "${VMTEST_ROOT}/configs/blacklist"

travis_fold end prepare_selftests
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