From 119e9db233ad0f4cbd4cfb9f9385a7bca378b37d Mon Sep 17 00:00:00 2001 From: Zeng Chi Date: Mon, 21 Sep 2026 18:24:42 +0800 Subject: KVM: Don't pre-reserve xarray entries when storing empty/NULL attributes Skip the xarray reservation loop when clearing all memory attributes, as storing NULL only erases the entry and never needs to allocate, so no reservation (and no cleanup of a failed one) is required in that case. Suggested-by: Sean Christopherson Cc: David Ballesteros Signed-off-by: Zeng Chi Link: https://patch.msgid.link/20260921102442.1232375-1-zeng_chi911@163.com [sean: split to separate patch] Signed-off-by: Sean Christopherson --- tools/testing/selftests/kcmp/.gitignore | 3 + tools/testing/selftests/kcmp/Makefile | 9 ++ tools/testing/selftests/kcmp/kcmp_test.c | 168 +++++++++++++++++++++++++++++++ 3 files changed, 180 insertions(+) create mode 100644 tools/testing/selftests/kcmp/.gitignore create mode 100644 tools/testing/selftests/kcmp/Makefile create mode 100644 tools/testing/selftests/kcmp/kcmp_test.c (limited to 'tools/testing/selftests/kcmp') diff --git a/tools/testing/selftests/kcmp/.gitignore b/tools/testing/selftests/kcmp/.gitignore new file mode 100644 index 000000000..38ccdfe80 --- /dev/null +++ b/tools/testing/selftests/kcmp/.gitignore @@ -0,0 +1,3 @@ +# SPDX-License-Identifier: GPL-2.0-only +kcmp_test +kcmp-test-file diff --git a/tools/testing/selftests/kcmp/Makefile b/tools/testing/selftests/kcmp/Makefile new file mode 100644 index 000000000..59a1e5379 --- /dev/null +++ b/tools/testing/selftests/kcmp/Makefile @@ -0,0 +1,9 @@ +# SPDX-License-Identifier: GPL-2.0-only +CFLAGS += $(KHDR_INCLUDES) + +TEST_GEN_PROGS := kcmp_test + +EXTRA_CLEAN := $(OUTPUT)/kcmp-test-file + +include ../lib.mk + diff --git a/tools/testing/selftests/kcmp/kcmp_test.c b/tools/testing/selftests/kcmp/kcmp_test.c new file mode 100644 index 000000000..79aa438b7 --- /dev/null +++ b/tools/testing/selftests/kcmp/kcmp_test.c @@ -0,0 +1,168 @@ +// SPDX-License-Identifier: GPL-2.0 +#define _GNU_SOURCE + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include + +#include "kselftest.h" + +static long sys_kcmp(int pid1, int pid2, int type, unsigned long fd1, unsigned long fd2) +{ + return syscall(__NR_kcmp, pid1, pid2, type, fd1, fd2); +} + +static const unsigned int duped_num = 64; + +int main(int argc, char **argv) +{ + const char kpath[] = "kcmp-test-file"; + struct kcmp_epoll_slot epoll_slot; + struct epoll_event ev; + int pid1, pid2; + int pipefd[2]; + int fd1, fd2; + int epollfd; + int status; + int fddup; + + fd1 = open(kpath, O_RDWR | O_CREAT | O_TRUNC, 0644); + pid1 = getpid(); + + if (fd1 < 0) { + perror("Can't create file"); + ksft_exit_fail(); + } + + if (pipe(pipefd)) { + perror("Can't create pipe"); + ksft_exit_fail(); + } + + epollfd = epoll_create1(0); + if (epollfd < 0) { + perror("epoll_create1 failed"); + ksft_exit_fail(); + } + + memset(&ev, 0xff, sizeof(ev)); + ev.events = EPOLLIN | EPOLLOUT; + + if (epoll_ctl(epollfd, EPOLL_CTL_ADD, pipefd[0], &ev)) { + perror("epoll_ctl failed"); + ksft_exit_fail(); + } + + fddup = dup2(pipefd[1], duped_num); + if (fddup < 0) { + perror("dup2 failed"); + ksft_exit_fail(); + } + + if (epoll_ctl(epollfd, EPOLL_CTL_ADD, fddup, &ev)) { + perror("epoll_ctl failed"); + ksft_exit_fail(); + } + close(fddup); + + pid2 = fork(); + if (pid2 < 0) { + perror("fork failed"); + ksft_exit_fail(); + } + + if (!pid2) { + int pid2 = getpid(); + int ret; + + ksft_print_header(); + ksft_set_plan(3); + + fd2 = open(kpath, O_RDWR); + if (fd2 < 0) { + perror("Can't open file"); + ksft_exit_fail(); + } + + /* An example of output and arguments */ + printf("pid1: %6d pid2: %6d FD: %2ld FILES: %2ld VM: %2ld " + "FS: %2ld SIGHAND: %2ld IO: %2ld SYSVSEM: %2ld " + "INV: %2ld\n", + pid1, pid2, + sys_kcmp(pid1, pid2, KCMP_FILE, fd1, fd2), + sys_kcmp(pid1, pid2, KCMP_FILES, 0, 0), + sys_kcmp(pid1, pid2, KCMP_VM, 0, 0), + sys_kcmp(pid1, pid2, KCMP_FS, 0, 0), + sys_kcmp(pid1, pid2, KCMP_SIGHAND, 0, 0), + sys_kcmp(pid1, pid2, KCMP_IO, 0, 0), + sys_kcmp(pid1, pid2, KCMP_SYSVSEM, 0, 0), + + /* This one should fail */ + sys_kcmp(pid1, pid2, KCMP_TYPES + 1, 0, 0)); + + /* This one should return same fd */ + ret = sys_kcmp(pid1, pid2, KCMP_FILE, fd1, fd1); + if (ret) { + printf("FAIL: 0 expected but %d returned (%s)\n", + ret, strerror(errno)); + ksft_inc_fail_cnt(); + ret = -1; + } else { + printf("PASS: 0 returned as expected\n"); + ksft_inc_pass_cnt(); + } + + /* Compare with self */ + ret = sys_kcmp(pid1, pid1, KCMP_VM, 0, 0); + if (ret) { + printf("FAIL: 0 expected but %d returned (%s)\n", + ret, strerror(errno)); + ksft_inc_fail_cnt(); + ret = -1; + } else { + printf("PASS: 0 returned as expected\n"); + ksft_inc_pass_cnt(); + } + + /* Compare epoll target */ + epoll_slot = (struct kcmp_epoll_slot) { + .efd = epollfd, + .tfd = duped_num, + .toff = 0, + }; + ret = sys_kcmp(pid1, pid1, KCMP_EPOLL_TFD, pipefd[1], + (unsigned long)(void *)&epoll_slot); + if (ret) { + printf("FAIL: 0 expected but %d returned (%s)\n", + ret, strerror(errno)); + ksft_inc_fail_cnt(); + ret = -1; + } else { + printf("PASS: 0 returned as expected\n"); + ksft_inc_pass_cnt(); + } + + + if (ret) + ksft_exit_fail(); + else + ksft_exit_pass(); + } + + waitpid(pid2, &status, P_ALL); + + return 0; +} -- cgit v1.3.1