- Linux-kselftest-mirror - lists.linaro.org

by Christian Brauner

This adds the pidfd_open() syscall. It allows a caller to retrieve pollable pidfds for a process which did not get created via CLONE_PIDFD, i.e. for a process that is created via traditional fork()/clone() calls that is only referenced by a PID: int pidfd = pidfd_open(1234, 0); ret = pidfd_send_signal(pidfd, SIGSTOP, NULL, 0); With the introduction of pidfds through CLONE_PIDFD it is possible to created pidfds at process creation time. However, a lot of processes get created with traditional PID-based calls such as fork() or clone() (without CLONE_PIDFD). For these processes a caller can currently not create a pollable pidfd. This is a problem for Android's low memory killer (LMK) and service managers such as systemd. Both are examples of tools that want to make use of pidfds to get reliable notification of process exit for non-parents (pidfd polling) and race-free signal sending (pidfd_send_signal()). They intend to switch to this API for process supervision/management as soon as possible. Having no way to get pollable pidfds from PID-only processes is one of the biggest blockers for them in adopting this api. With pidfd_open() making it possible to retrieve pidfds for PID-based processes we enable them to adopt this api. In line with Arnd's recent changes to consolidate syscall numbers across architectures, I have added the pidfd_open() syscall to all architectures at the same time. Signed-off-by: Christian Brauner <christian(a)brauner.io> Reviewed-by: Oleg Nesterov <oleg(a)redhat.com> Cc: Arnd Bergmann <arnd(a)arndb.de> Cc: "Eric W. Biederman" <ebiederm(a)xmission.com> Cc: Kees Cook <keescook(a)chromium.org> Cc: Joel Fernandes (Google) <joel(a)joelfernandes.org> Cc: Thomas Gleixner <tglx(a)linutronix.de> Cc: Jann Horn <jannh(a)google.com> Cc: David Howells <dhowells(a)redhat.com> Cc: Andy Lutomirsky <luto(a)kernel.org> Cc: Andrew Morton <akpm(a)linux-foundation.org> Cc: Aleksa Sarai <cyphar(a)cyphar.com> Cc: Linus Torvalds <torvalds(a)linux-foundation.org> Cc: Al Viro <viro(a)zeniv.linux.org.uk> Cc: linux-api(a)vger.kernel.org --- v1: - kbuild test robot <lkp(a)intel.com>: - add missing entry for pidfd_open to arch/arm/tools/syscall.tbl - Oleg Nesterov <oleg(a)redhat.com>: - use simpler thread-group leader check v2: - Oleg Nesterov <oleg(a)redhat.com>: - avoid using additional variable - remove unneeded comment - Arnd Bergmann <arnd(a)arndb.de>: - switch from 428 to 434 since the new mount api has taken it - bump syscall numbers in arch/arm64/include/asm/unistd.h - Joel Fernandes (Google) <joel(a)joelfernandes.org>: - switch from ESRCH to EINVAL when the passed-in pid does not refer to a thread-group leader - Christian Brauner <christian(a)brauner.io>: - rebase on v5.2-rc1 - adapt syscall number to account for new mount api syscalls --- arch/alpha/kernel/syscalls/syscall.tbl | 1 + arch/arm/tools/syscall.tbl | 1 + arch/arm64/include/asm/unistd.h | 2 +- arch/arm64/include/asm/unistd32.h | 2 + arch/ia64/kernel/syscalls/syscall.tbl | 1 + arch/m68k/kernel/syscalls/syscall.tbl | 1 + arch/microblaze/kernel/syscalls/syscall.tbl | 1 + arch/mips/kernel/syscalls/syscall_n32.tbl | 1 + arch/parisc/kernel/syscalls/syscall.tbl | 1 + arch/powerpc/kernel/syscalls/syscall.tbl | 1 + arch/s390/kernel/syscalls/syscall.tbl | 1 + arch/sh/kernel/syscalls/syscall.tbl | 1 + arch/sparc/kernel/syscalls/syscall.tbl | 1 + arch/x86/entry/syscalls/syscall_32.tbl | 1 + arch/x86/entry/syscalls/syscall_64.tbl | 1 + arch/xtensa/kernel/syscalls/syscall.tbl | 1 + include/linux/pid.h | 1 + include/linux/syscalls.h | 1 + include/uapi/asm-generic/unistd.h | 4 +- kernel/fork.c | 2 +- kernel/pid.c | 43 +++++++++++++++++++++ 21 files changed, 66 insertions(+), 3 deletions(-) diff --git a/arch/alpha/kernel/syscalls/syscall.tbl b/arch/alpha/kernel/syscalls/syscall.tbl index 9e7704e44f6d..1db9bbcfb84e 100644 --- a/arch/alpha/kernel/syscalls/syscall.tbl +++ b/arch/alpha/kernel/syscalls/syscall.tbl @@ -473,3 +473,4 @@ 541 common fsconfig sys_fsconfig 542 common fsmount sys_fsmount 543 common fspick sys_fspick +544 common pidfd_open sys_pidfd_open diff --git a/arch/arm/tools/syscall.tbl b/arch/arm/tools/syscall.tbl index aaf479a9e92d..81e6e1817c45 100644 --- a/arch/arm/tools/syscall.tbl +++ b/arch/arm/tools/syscall.tbl @@ -447,3 +447,4 @@ 431 common fsconfig sys_fsconfig 432 common fsmount sys_fsmount 433 common fspick sys_fspick +434 common pidfd_open sys_pidfd_open diff --git a/arch/arm64/include/asm/unistd.h b/arch/arm64/include/asm/unistd.h index 70e6882853c0..e8f7d95a1481 100644 --- a/arch/arm64/include/asm/unistd.h +++ b/arch/arm64/include/asm/unistd.h @@ -44,7 +44,7 @@ #define __ARM_NR_compat_set_tls (__ARM_NR_COMPAT_BASE + 5) #define __ARM_NR_COMPAT_END (__ARM_NR_COMPAT_BASE + 0x800) -#define __NR_compat_syscalls 434 +#define __NR_compat_syscalls 435 #endif #define __ARCH_WANT_SYS_CLONE diff --git a/arch/arm64/include/asm/unistd32.h b/arch/arm64/include/asm/unistd32.h index c39e90600bb3..7a3158ccd68e 100644 --- a/arch/arm64/include/asm/unistd32.h +++ b/arch/arm64/include/asm/unistd32.h @@ -886,6 +886,8 @@ __SYSCALL(__NR_fsconfig, sys_fsconfig) __SYSCALL(__NR_fsmount, sys_fsmount) #define __NR_fspick 433 __SYSCALL(__NR_fspick, sys_fspick) +#define __NR_pidfd_open 434 +__SYSCALL(__NR_pidfd_open, sys_pidfd_open) /* * Please add new compat syscalls above this comment and update diff --git a/arch/ia64/kernel/syscalls/syscall.tbl b/arch/ia64/kernel/syscalls/syscall.tbl index e01df3f2f80d..ecc44926737b 100644 --- a/arch/ia64/kernel/syscalls/syscall.tbl +++ b/arch/ia64/kernel/syscalls/syscall.tbl @@ -354,3 +354,4 @@ 431 common fsconfig sys_fsconfig 432 common fsmount sys_fsmount 433 common fspick sys_fspick +434 common pidfd_open sys_pidfd_open diff --git a/arch/m68k/kernel/syscalls/syscall.tbl b/arch/m68k/kernel/syscalls/syscall.tbl index 7e3d0734b2f3..9a3eb2558568 100644 --- a/arch/m68k/kernel/syscalls/syscall.tbl +++ b/arch/m68k/kernel/syscalls/syscall.tbl @@ -433,3 +433,4 @@ 431 common fsconfig sys_fsconfig 432 common fsmount sys_fsmount 433 common fspick sys_fspick +434 common pidfd_open sys_pidfd_open diff --git a/arch/microblaze/kernel/syscalls/syscall.tbl b/arch/microblaze/kernel/syscalls/syscall.tbl index 26339e417695..ad706f83c755 100644 --- a/arch/microblaze/kernel/syscalls/syscall.tbl +++ b/arch/microblaze/kernel/syscalls/syscall.tbl @@ -439,3 +439,4 @@ 431 common fsconfig sys_fsconfig 432 common fsmount sys_fsmount 433 common fspick sys_fspick +434 common pidfd_open sys_pidfd_open diff --git a/arch/mips/kernel/syscalls/syscall_n32.tbl b/arch/mips/kernel/syscalls/syscall_n32.tbl index 0e2dd68ade57..97035e19ad03 100644 --- a/arch/mips/kernel/syscalls/syscall_n32.tbl +++ b/arch/mips/kernel/syscalls/syscall_n32.tbl @@ -372,3 +372,4 @@ 431 n32 fsconfig sys_fsconfig 432 n32 fsmount sys_fsmount 433 n32 fspick sys_fspick +434 n32 pidfd_open sys_pidfd_open diff --git a/arch/parisc/kernel/syscalls/syscall.tbl b/arch/parisc/kernel/syscalls/syscall.tbl index c9e377d59232..5022b9e179c2 100644 --- a/arch/parisc/kernel/syscalls/syscall.tbl +++ b/arch/parisc/kernel/syscalls/syscall.tbl @@ -430,3 +430,4 @@ 431 common fsconfig sys_fsconfig 432 common fsmount sys_fsmount 433 common fspick sys_fspick +434 common pidfd_open sys_pidfd_open diff --git a/arch/powerpc/kernel/syscalls/syscall.tbl b/arch/powerpc/kernel/syscalls/syscall.tbl index 103655d84b4b..f2c3bda2d39f 100644 --- a/arch/powerpc/kernel/syscalls/syscall.tbl +++ b/arch/powerpc/kernel/syscalls/syscall.tbl @@ -515,3 +515,4 @@ 431 common fsconfig sys_fsconfig 432 common fsmount sys_fsmount 433 common fspick sys_fspick +434 common pidfd_open sys_pidfd_open diff --git a/arch/s390/kernel/syscalls/syscall.tbl b/arch/s390/kernel/syscalls/syscall.tbl index e822b2964a83..6ebacfeaf853 100644 --- a/arch/s390/kernel/syscalls/syscall.tbl +++ b/arch/s390/kernel/syscalls/syscall.tbl @@ -436,3 +436,4 @@ 431 common fsconfig sys_fsconfig sys_fsconfig 432 common fsmount sys_fsmount sys_fsmount 433 common fspick sys_fspick sys_fspick +434 common pidfd_open sys_pidfd_open sys_pidfd_open diff --git a/arch/sh/kernel/syscalls/syscall.tbl b/arch/sh/kernel/syscalls/syscall.tbl index 016a727d4357..834c9c7d79fa 100644 --- a/arch/sh/kernel/syscalls/syscall.tbl +++ b/arch/sh/kernel/syscalls/syscall.tbl @@ -436,3 +436,4 @@ 431 common fsconfig sys_fsconfig 432 common fsmount sys_fsmount 433 common fspick sys_fspick +434 common pidfd_open sys_pidfd_open diff --git a/arch/sparc/kernel/syscalls/syscall.tbl b/arch/sparc/kernel/syscalls/syscall.tbl index e047480b1605..c58e71f21129 100644 --- a/arch/sparc/kernel/syscalls/syscall.tbl +++ b/arch/sparc/kernel/syscalls/syscall.tbl @@ -479,3 +479,4 @@ 431 common fsconfig sys_fsconfig 432 common fsmount sys_fsmount 433 common fspick sys_fspick +434 common pidfd_open sys_pidfd_open diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl index ad968b7bac72..43e4429a5272 100644 --- a/arch/x86/entry/syscalls/syscall_32.tbl +++ b/arch/x86/entry/syscalls/syscall_32.tbl @@ -438,3 +438,4 @@ 431 i386 fsconfig sys_fsconfig __ia32_sys_fsconfig 432 i386 fsmount sys_fsmount __ia32_sys_fsmount 433 i386 fspick sys_fspick __ia32_sys_fspick +434 i386 pidfd_open sys_pidfd_open __ia32_sys_pidfd_open diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl index b4e6f9e6204a..1bee0a77fdd3 100644 --- a/arch/x86/entry/syscalls/syscall_64.tbl +++ b/arch/x86/entry/syscalls/syscall_64.tbl @@ -355,6 +355,7 @@ 431 common fsconfig __x64_sys_fsconfig 432 common fsmount __x64_sys_fsmount 433 common fspick __x64_sys_fspick +434 common pidfd_open __x64_sys_pidfd_open # # x32-specific system call numbers start at 512 to avoid cache impact diff --git a/arch/xtensa/kernel/syscalls/syscall.tbl b/arch/xtensa/kernel/syscalls/syscall.tbl index 5fa0ee1c8e00..782b81945ccc 100644 --- a/arch/xtensa/kernel/syscalls/syscall.tbl +++ b/arch/xtensa/kernel/syscalls/syscall.tbl @@ -404,3 +404,4 @@ 431 common fsconfig sys_fsconfig 432 common fsmount sys_fsmount 433 common fspick sys_fspick +434 common pidfd_open sys_pidfd_open diff --git a/include/linux/pid.h b/include/linux/pid.h index 3c8ef5a199ca..c938a92eab99 100644 --- a/include/linux/pid.h +++ b/include/linux/pid.h @@ -67,6 +67,7 @@ struct pid extern struct pid init_struct_pid; extern const struct file_operations pidfd_fops; +extern int pidfd_create(struct pid *pid); static inline struct pid *get_pid(struct pid *pid) { diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index e2870fe1be5b..989055e0b501 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -929,6 +929,7 @@ asmlinkage long sys_clock_adjtime32(clockid_t which_clock, struct old_timex32 __user *tx); asmlinkage long sys_syncfs(int fd); asmlinkage long sys_setns(int fd, int nstype); +asmlinkage long sys_pidfd_open(pid_t pid, unsigned int flags); asmlinkage long sys_sendmmsg(int fd, struct mmsghdr __user *msg, unsigned int vlen, unsigned flags); asmlinkage long sys_process_vm_readv(pid_t pid, diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h index a87904daf103..e5684a4512c0 100644 --- a/include/uapi/asm-generic/unistd.h +++ b/include/uapi/asm-generic/unistd.h @@ -844,9 +844,11 @@ __SYSCALL(__NR_fsconfig, sys_fsconfig) __SYSCALL(__NR_fsmount, sys_fsmount) #define __NR_fspick 433 __SYSCALL(__NR_fspick, sys_fspick) +#define __NR_pidfd_open 434 +__SYSCALL(__NR_pidfd_open, sys_pidfd_open) #undef __NR_syscalls -#define __NR_syscalls 434 +#define __NR_syscalls 435 /* * 32 bit systems traditionally used different diff --git a/kernel/fork.c b/kernel/fork.c index b4cba953040a..c3df226f47a1 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1724,7 +1724,7 @@ const struct file_operations pidfd_fops = { * Return: On success, a cloexec pidfd is returned. * On error, a negative errno number will be returned. */ -static int pidfd_create(struct pid *pid) +int pidfd_create(struct pid *pid) { int fd; diff --git a/kernel/pid.c b/kernel/pid.c index 89548d35eefb..8fc9d94f6ac1 100644 --- a/kernel/pid.c +++ b/kernel/pid.c @@ -37,6 +37,7 @@ #include <linux/syscalls.h> #include <linux/proc_ns.h> #include <linux/proc_fs.h> +#include <linux/sched/signal.h> #include <linux/sched/task.h> #include <linux/idr.h> @@ -450,6 +451,48 @@ struct pid *find_ge_pid(int nr, struct pid_namespace *ns) return idr_get_next(&ns->idr, &nr); } +/** + * pidfd_open() - Open new pid file descriptor. + * + * @pid: pid for which to retrieve a pidfd + * @flags: flags to pass + * + * This creates a new pid file descriptor with the O_CLOEXEC flag set for + * the process identified by @pid. Currently, the process identified by + * @pid must be a thread-group leader. This restriction currently exists + * for all aspects of pidfds including pidfd creation (CLONE_PIDFD cannot + * be used with CLONE_THREAD) and pidfd polling (only supports thread group + * leaders). + * + * Return: On success, a cloexec pidfd is returned. + * On error, a negative errno number will be returned. + */ +SYSCALL_DEFINE2(pidfd_open, pid_t, pid, unsigned int, flags) +{ + int fd, ret; + struct pid *p; + + if (flags) + return -EINVAL; + + if (pid <= 0) + return -EINVAL; + + p = find_get_pid(pid); + if (!p) + return -ESRCH; + + ret = 0; + rcu_read_lock(); + if (!pid_task(p, PIDTYPE_TGID)) + ret = -EINVAL; + rcu_read_unlock(); + + fd = ret ?: pidfd_create(p); + put_pid(p); + return fd; +} + void __init pid_idr_init(void) { /* Verify no one has done anything silly: */ -- 2.21.0

5 years, 11 months

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Inquiry 20/May/2019

by Daniel Murray

Hi,friend, This is Daniel Murray and i am from Sinara Group Co.Ltd in Russia. We are glad to know about your company from the web and we are interested in your products. Could you kindly send us your Latest catalog and price list for our trial order. Best Regards, Daniel Murray Purchasing Manager

5 years, 11 months

1
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[PATCH] KVM: selftests: Remove duplicated TEST_ASSERT in hyperv_cpuid.c

by Thomas Huth

The check for entry->index == 0 is done twice. One time should be sufficient. Suggested-by: Vitaly Kuznetsov <vkuznets(a)redhat.com> Signed-off-by: Thomas Huth <thuth(a)redhat.com> --- Vitaly already noticed this in his review to the "Fix a condition in test_hv_cpuid()" patch a couple of days ago, but so far I haven't seen any patch yet on the list that fixes this ... if I missed it instead, please simply ignore this patch. tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c b/tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c index 9a21e912097c..8bdf1e7da6cc 100644 --- a/tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c +++ b/tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c @@ -52,9 +52,6 @@ static void test_hv_cpuid(struct kvm_cpuid2 *hv_cpuid_entries, TEST_ASSERT(entry->index == 0, ".index field should be zero"); - TEST_ASSERT(entry->index == 0, - ".index field should be zero"); - TEST_ASSERT(entry->flags == 0, ".flags field should be zero"); -- 2.21.0

5 years, 11 months

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[PATCH] KVM: selftests: Fix a condition in test_hv_cpuid()

by Dan Carpenter

The code is trying to check that all the padding is zeroed out and it does this: entry->padding[0] == entry->padding[1] == entry->padding[2] == 0 Assume everything is zeroed correctly, then the first comparison is true, the next comparison is false and false is equal to zero so the overall condition is true. This bug doesn't affect run time very badly, but the code should instead just check that all three paddings are zero individually. Also the error message was copy and pasted from an earlier error and it wasn't correct. Fixes: 7edcb7343327 ("KVM: selftests: Add hyperv_cpuid test") Signed-off-by: Dan Carpenter <dan.carpenter(a)oracle.com> --- tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c b/tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c index 9a21e912097c..63b9fc3fdfbe 100644 --- a/tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c +++ b/tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c @@ -58,9 +58,8 @@ static void test_hv_cpuid(struct kvm_cpuid2 *hv_cpuid_entries, TEST_ASSERT(entry->flags == 0, ".flags field should be zero"); - TEST_ASSERT(entry->padding[0] == entry->padding[1] - == entry->padding[2] == 0, - ".index field should be zero"); + TEST_ASSERT(!entry->padding[0] && !entry->padding[1] && + !entry->padding[2], "padding should be zero"); /* * If needed for debug: -- 2.20.1

5 years, 11 months

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Re: [PATCH 1/3] kselftest/cgroup: fix unexcepted testing failure on test_memcontrol

by Alex Shi

> Hi Alex! > > Sorry for the late reply, somehow I missed your e-mails. > > The patchset looks good to me, except a typo in subjects/commit logs: > you probably meant "unexpected failures". > > Please, fix and feel free to use: > Reviewed-by: Roman Gushchin <guro(a)fb.com> > for the series. > Thanks Roman! BTW, do you know other test cases for cgroup2 function or performance? Thanks Alex

5 years, 11 months

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[PATCH v2 3/3] kselftest/cgroup: fix incorrect test_core skip

by Alex Shi

The test_core will skip the test_cgcore_no_internal_process_constraint_on_threads test case if the 'cpu' controller missing in root's subtree_control. In fact we need to set the 'cpu' in subtree_control, to make the testing meaningful. ./test_core ... ok 4 # skip test_cgcore_no_internal_process_constraint_on_threads ... Signed-off-by: Alex Shi <alex.shi(a)linux.alibaba.com> Cc: Shuah Khan <shuah(a)kernel.org> Cc: Tejun Heo <tj(a)kernel.org> Cc: Roman Gushchin <guro(a)fb.com> Cc: Claudio Zumbo <claudioz(a)fb.com> Cc: Claudio <claudiozumbo(a)gmail.com> Cc: linux-kselftest(a)vger.kernel.org Cc: linux-kernel(a)vger.kernel.org Reviewed-by: Roman Gushchin <guro(a)fb.com> --- tools/testing/selftests/cgroup/test_core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/selftests/cgroup/test_core.c b/tools/testing/selftests/cgroup/test_core.c index b1a570d7c557..2ffc3e07d98d 100644 --- a/tools/testing/selftests/cgroup/test_core.c +++ b/tools/testing/selftests/cgroup/test_core.c @@ -198,7 +198,7 @@ static int test_cgcore_no_internal_process_constraint_on_threads(const char *roo char *parent = NULL, *child = NULL; if (cg_read_strstr(root, "cgroup.controllers", "cpu") || - cg_read_strstr(root, "cgroup.subtree_control", "cpu")) { + cg_write(root, "cgroup.subtree_control", "+cpu")) { ret = KSFT_SKIP; goto cleanup; } -- 2.19.1.856.g8858448bb

5 years, 11 months

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[PATCH v2 2/3] kselftest/cgroup: fix unexpected testing failure on test_core

by Alex Shi

The cgroup testing relys on the root cgroup's subtree_control setting, If the 'memory' controller isn't set, some test cases will be failed as following: $sudo ./test_core not ok 1 test_cgcore_internal_process_constraint ok 2 test_cgcore_top_down_constraint_enable not ok 3 test_cgcore_top_down_constraint_disable ... To correct this unexpected failure, this patch write the 'memory' to subtree_control of root to get a right result. Signed-off-by: Alex Shi <alex.shi(a)linux.alibaba.com> Cc: Shuah Khan <shuah(a)kernel.org> Cc: Tejun Heo <tj(a)kernel.org> Cc: Roman Gushchin <guro(a)fb.com> Cc: Claudio Zumbo <claudioz(a)fb.com> Cc: Claudio <claudiozumbo(a)gmail.com> Cc: linux-kselftest(a)vger.kernel.org Cc: linux-kernel(a)vger.kernel.org Reviewed-by: Roman Gushchin <guro(a)fb.com> --- tools/testing/selftests/cgroup/test_core.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/tools/testing/selftests/cgroup/test_core.c b/tools/testing/selftests/cgroup/test_core.c index be59f9c34ea2..b1a570d7c557 100644 --- a/tools/testing/selftests/cgroup/test_core.c +++ b/tools/testing/selftests/cgroup/test_core.c @@ -376,6 +376,11 @@ int main(int argc, char *argv[]) if (cg_find_unified_root(root, sizeof(root))) ksft_exit_skip("cgroup v2 isn't mounted\n"); + + if (cg_read_strstr(root, "cgroup.subtree_control", "memory")) + if (cg_write(root, "cgroup.subtree_control", "+memory")) + ksft_exit_skip("Failed to set root memory controller\n"); + for (i = 0; i < ARRAY_SIZE(tests); i++) { switch (tests[i].fn(root)) { case KSFT_PASS: -- 2.19.1.856.g8858448bb

5 years, 11 months

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Re: [PATCH 1/3] kselftest/cgroup: fix unexcepted testing failure on test_memcontrol

by Alex Shi

> Hi Alex! > > Sorry for the late reply, somehow I missed your e-mails. > > The patchset looks good to me, except a typo in subjects/commit logs: > you probably meant "unexpected failures". > > Please, fix and feel free to use: > Reviewed-by: Roman Gushchin <guro(a)fb.com> > for the series. Hi Roman, Thanks for the typo correct and review. I will resend them with your suggestion. BTW, How do you test cgroup2 except kselftest? Any other function/performance testing case? Thanks a lot! Alex

5 years, 11 months

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[PATCH v1 1/2] pid: add pidfd_open()

by Christian Brauner

This adds the pidfd_open() syscall. It allows a caller to retrieve pollable pidfds for a process which did not get created via CLONE_PIDFD, i.e. for a process that is created via traditional fork()/clone() calls that is only referenced by a PID: int pidfd = pidfd_open(1234, 0); ret = pidfd_send_signal(pidfd, SIGSTOP, NULL, 0); With the introduction of pidfds through CLONE_PIDFD it is possible to created pidfds at process creation time. However, a lot of processes get created with traditional PID-based calls such as fork() or clone() (without CLONE_PIDFD). For these processes a caller can currently not create a pollable pidfd. This is a huge problem for Android's low memory killer (LMK) and service managers such as systemd. Both are examples of tools that want to make use of pidfds to get reliable notification of process exit for non-parents (pidfd polling) and race-free signal sending (pidfd_send_signal()). They intend to switch to this API for process supervision/management as soon as possible. Having no way to get pollable pidfds from PID-only processes is one of the biggest blockers for them in adopting this api. With pidfd_open() making it possible to retrieve pidfd for PID-based processes we enable them to adopt this api. In line with Arnd's recent changes to consolidate syscall numbers across architectures, I have added the pidfd_open() syscall to all architectures at the same time. Signed-off-by: Christian Brauner <christian(a)brauner.io> Acked-by: Geert Uytterhoeven <geert(a)linux-m68k.org> Cc: Arnd Bergmann <arnd(a)arndb.de> Cc: "Eric W. Biederman" <ebiederm(a)xmission.com> Cc: Kees Cook <keescook(a)chromium.org> Cc: Thomas Gleixner <tglx(a)linutronix.de> Cc: Jann Horn <jannh(a)google.com> Cc: David Howells <dhowells(a)redhat.com> Cc: Andy Lutomirsky <luto(a)kernel.org> Cc: Andrew Morton <akpm(a)linux-foundation.org> Cc: Oleg Nesterov <oleg(a)redhat.com> Cc: Aleksa Sarai <cyphar(a)cyphar.com> Cc: Linus Torvalds <torvalds(a)linux-foundation.org> Cc: Al Viro <viro(a)zeniv.linux.org.uk> Cc: linux-api(a)vger.kernel.org --- v1: - kbuild test robot <lkp(a)intel.com>: - add missing entry for pidfd_open to arch/arm/tools/syscall.tbl - Oleg Nesterov <oleg(a)redhat.com>: - use simpler thread-group leader check --- arch/alpha/kernel/syscalls/syscall.tbl | 1 + arch/arm/tools/syscall.tbl | 1 + arch/arm64/include/asm/unistd32.h | 2 + arch/ia64/kernel/syscalls/syscall.tbl | 1 + arch/m68k/kernel/syscalls/syscall.tbl | 1 + arch/microblaze/kernel/syscalls/syscall.tbl | 1 + arch/mips/kernel/syscalls/syscall_n32.tbl | 1 + arch/parisc/kernel/syscalls/syscall.tbl | 1 + arch/powerpc/kernel/syscalls/syscall.tbl | 1 + arch/s390/kernel/syscalls/syscall.tbl | 1 + arch/sh/kernel/syscalls/syscall.tbl | 1 + arch/sparc/kernel/syscalls/syscall.tbl | 1 + arch/x86/entry/syscalls/syscall_32.tbl | 1 + arch/x86/entry/syscalls/syscall_64.tbl | 1 + arch/xtensa/kernel/syscalls/syscall.tbl | 1 + include/linux/pid.h | 1 + include/linux/syscalls.h | 1 + include/uapi/asm-generic/unistd.h | 4 +- kernel/fork.c | 2 +- kernel/pid.c | 50 +++++++++++++++++++++ 20 files changed, 72 insertions(+), 2 deletions(-) diff --git a/arch/alpha/kernel/syscalls/syscall.tbl b/arch/alpha/kernel/syscalls/syscall.tbl index 165f268beafc..ddc3c93ad7a7 100644 --- a/arch/alpha/kernel/syscalls/syscall.tbl +++ b/arch/alpha/kernel/syscalls/syscall.tbl @@ -467,3 +467,4 @@ 535 common io_uring_setup sys_io_uring_setup 536 common io_uring_enter sys_io_uring_enter 537 common io_uring_register sys_io_uring_register +538 common pidfd_open sys_pidfd_open diff --git a/arch/arm/tools/syscall.tbl b/arch/arm/tools/syscall.tbl index 0393917eaa57..fc41fb34a636 100644 --- a/arch/arm/tools/syscall.tbl +++ b/arch/arm/tools/syscall.tbl @@ -441,3 +441,4 @@ 425 common io_uring_setup sys_io_uring_setup 426 common io_uring_enter sys_io_uring_enter 427 common io_uring_register sys_io_uring_register +428 common pidfd_open sys_pidfd_open diff --git a/arch/arm64/include/asm/unistd32.h b/arch/arm64/include/asm/unistd32.h index 23f1a44acada..350e2049b4a9 100644 --- a/arch/arm64/include/asm/unistd32.h +++ b/arch/arm64/include/asm/unistd32.h @@ -874,6 +874,8 @@ __SYSCALL(__NR_io_uring_setup, sys_io_uring_setup) __SYSCALL(__NR_io_uring_enter, sys_io_uring_enter) #define __NR_io_uring_register 427 __SYSCALL(__NR_io_uring_register, sys_io_uring_register) +#define __NR_pidfd_open 428 +__SYSCALL(__NR_pidfd_open, sys_pidfd_open) /* * Please add new compat syscalls above this comment and update diff --git a/arch/ia64/kernel/syscalls/syscall.tbl b/arch/ia64/kernel/syscalls/syscall.tbl index 56e3d0b685e1..7115f6dd347a 100644 --- a/arch/ia64/kernel/syscalls/syscall.tbl +++ b/arch/ia64/kernel/syscalls/syscall.tbl @@ -348,3 +348,4 @@ 425 common io_uring_setup sys_io_uring_setup 426 common io_uring_enter sys_io_uring_enter 427 common io_uring_register sys_io_uring_register +428 common pidfd_open sys_pidfd_open diff --git a/arch/m68k/kernel/syscalls/syscall.tbl b/arch/m68k/kernel/syscalls/syscall.tbl index df4ec3ec71d1..44bf12b16ffe 100644 --- a/arch/m68k/kernel/syscalls/syscall.tbl +++ b/arch/m68k/kernel/syscalls/syscall.tbl @@ -427,3 +427,4 @@ 425 common io_uring_setup sys_io_uring_setup 426 common io_uring_enter sys_io_uring_enter 427 common io_uring_register sys_io_uring_register +428 common pidfd_open sys_pidfd_open diff --git a/arch/microblaze/kernel/syscalls/syscall.tbl b/arch/microblaze/kernel/syscalls/syscall.tbl index 4964947732af..0d32e5152dc0 100644 --- a/arch/microblaze/kernel/syscalls/syscall.tbl +++ b/arch/microblaze/kernel/syscalls/syscall.tbl @@ -433,3 +433,4 @@ 425 common io_uring_setup sys_io_uring_setup 426 common io_uring_enter sys_io_uring_enter 427 common io_uring_register sys_io_uring_register +428 common pidfd_open sys_pidfd_open diff --git a/arch/mips/kernel/syscalls/syscall_n32.tbl b/arch/mips/kernel/syscalls/syscall_n32.tbl index 9392dfe33f97..726e107b3c9f 100644 --- a/arch/mips/kernel/syscalls/syscall_n32.tbl +++ b/arch/mips/kernel/syscalls/syscall_n32.tbl @@ -366,3 +366,4 @@ 425 n32 io_uring_setup sys_io_uring_setup 426 n32 io_uring_enter sys_io_uring_enter 427 n32 io_uring_register sys_io_uring_register +428 n32 pidfd_open sys_pidfd_open diff --git a/arch/parisc/kernel/syscalls/syscall.tbl b/arch/parisc/kernel/syscalls/syscall.tbl index fe8ca623add8..83b46b568d51 100644 --- a/arch/parisc/kernel/syscalls/syscall.tbl +++ b/arch/parisc/kernel/syscalls/syscall.tbl @@ -424,3 +424,4 @@ 425 common io_uring_setup sys_io_uring_setup 426 common io_uring_enter sys_io_uring_enter 427 common io_uring_register sys_io_uring_register +428 common pidfd_open sys_pidfd_open diff --git a/arch/powerpc/kernel/syscalls/syscall.tbl b/arch/powerpc/kernel/syscalls/syscall.tbl index 00f5a63c8d9a..5294d04d7fa5 100644 --- a/arch/powerpc/kernel/syscalls/syscall.tbl +++ b/arch/powerpc/kernel/syscalls/syscall.tbl @@ -509,3 +509,4 @@ 425 common io_uring_setup sys_io_uring_setup 426 common io_uring_enter sys_io_uring_enter 427 common io_uring_register sys_io_uring_register +428 common pidfd_open sys_pidfd_open diff --git a/arch/s390/kernel/syscalls/syscall.tbl b/arch/s390/kernel/syscalls/syscall.tbl index 061418f787c3..dcdb838adf49 100644 --- a/arch/s390/kernel/syscalls/syscall.tbl +++ b/arch/s390/kernel/syscalls/syscall.tbl @@ -430,3 +430,4 @@ 425 common io_uring_setup sys_io_uring_setup sys_io_uring_setup 426 common io_uring_enter sys_io_uring_enter sys_io_uring_enter 427 common io_uring_register sys_io_uring_register sys_io_uring_register +428 common pidfd_open sys_pidfd_open sys_pidfd_open diff --git a/arch/sh/kernel/syscalls/syscall.tbl b/arch/sh/kernel/syscalls/syscall.tbl index 480b057556ee..8e66edfbc521 100644 --- a/arch/sh/kernel/syscalls/syscall.tbl +++ b/arch/sh/kernel/syscalls/syscall.tbl @@ -430,3 +430,4 @@ 425 common io_uring_setup sys_io_uring_setup 426 common io_uring_enter sys_io_uring_enter 427 common io_uring_register sys_io_uring_register +428 common pidfd_open sys_pidfd_open diff --git a/arch/sparc/kernel/syscalls/syscall.tbl b/arch/sparc/kernel/syscalls/syscall.tbl index a1dd24307b00..d6f3bc686939 100644 --- a/arch/sparc/kernel/syscalls/syscall.tbl +++ b/arch/sparc/kernel/syscalls/syscall.tbl @@ -473,3 +473,4 @@ 425 common io_uring_setup sys_io_uring_setup 426 common io_uring_enter sys_io_uring_enter 427 common io_uring_register sys_io_uring_register +428 common pidfd_open sys_pidfd_open diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl index 4cd5f982b1e5..1af6b469160a 100644 --- a/arch/x86/entry/syscalls/syscall_32.tbl +++ b/arch/x86/entry/syscalls/syscall_32.tbl @@ -438,3 +438,4 @@ 425 i386 io_uring_setup sys_io_uring_setup __ia32_sys_io_uring_setup 426 i386 io_uring_enter sys_io_uring_enter __ia32_sys_io_uring_enter 427 i386 io_uring_register sys_io_uring_register __ia32_sys_io_uring_register +428 i386 pidfd_open sys_pidfd_open __ia32_sys_pidfd_open diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl index 64ca0d06259a..c18e6ebe3387 100644 --- a/arch/x86/entry/syscalls/syscall_64.tbl +++ b/arch/x86/entry/syscalls/syscall_64.tbl @@ -355,6 +355,7 @@ 425 common io_uring_setup __x64_sys_io_uring_setup 426 common io_uring_enter __x64_sys_io_uring_enter 427 common io_uring_register __x64_sys_io_uring_register +428 common pidfd_open __x64_sys_pidfd_open # # x32-specific system call numbers start at 512 to avoid cache impact diff --git a/arch/xtensa/kernel/syscalls/syscall.tbl b/arch/xtensa/kernel/syscalls/syscall.tbl index 30084eaf8422..21ee795f3003 100644 --- a/arch/xtensa/kernel/syscalls/syscall.tbl +++ b/arch/xtensa/kernel/syscalls/syscall.tbl @@ -398,3 +398,4 @@ 425 common io_uring_setup sys_io_uring_setup 426 common io_uring_enter sys_io_uring_enter 427 common io_uring_register sys_io_uring_register +428 common pidfd_open sys_pidfd_open diff --git a/include/linux/pid.h b/include/linux/pid.h index 3c8ef5a199ca..c938a92eab99 100644 --- a/include/linux/pid.h +++ b/include/linux/pid.h @@ -67,6 +67,7 @@ struct pid extern struct pid init_struct_pid; extern const struct file_operations pidfd_fops; +extern int pidfd_create(struct pid *pid); static inline struct pid *get_pid(struct pid *pid) { diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index e2870fe1be5b..989055e0b501 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -929,6 +929,7 @@ asmlinkage long sys_clock_adjtime32(clockid_t which_clock, struct old_timex32 __user *tx); asmlinkage long sys_syncfs(int fd); asmlinkage long sys_setns(int fd, int nstype); +asmlinkage long sys_pidfd_open(pid_t pid, unsigned int flags); asmlinkage long sys_sendmmsg(int fd, struct mmsghdr __user *msg, unsigned int vlen, unsigned flags); asmlinkage long sys_process_vm_readv(pid_t pid, diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h index dee7292e1df6..94a257a93d20 100644 --- a/include/uapi/asm-generic/unistd.h +++ b/include/uapi/asm-generic/unistd.h @@ -832,9 +832,11 @@ __SYSCALL(__NR_io_uring_setup, sys_io_uring_setup) __SYSCALL(__NR_io_uring_enter, sys_io_uring_enter) #define __NR_io_uring_register 427 __SYSCALL(__NR_io_uring_register, sys_io_uring_register) +#define __NR_pidfd_open 428 +__SYSCALL(__NR_pidfd_open, sys_pidfd_open) #undef __NR_syscalls -#define __NR_syscalls 428 +#define __NR_syscalls 429 /* * 32 bit systems traditionally used different diff --git a/kernel/fork.c b/kernel/fork.c index 737db1828437..980cc1d2b8d4 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1714,7 +1714,7 @@ const struct file_operations pidfd_fops = { * Return: On success, a cloexec pidfd is returned. * On error, a negative errno number will be returned. */ -static int pidfd_create(struct pid *pid) +int pidfd_create(struct pid *pid) { int fd; diff --git a/kernel/pid.c b/kernel/pid.c index 20881598bdfa..4afca3d6dcb8 100644 --- a/kernel/pid.c +++ b/kernel/pid.c @@ -38,6 +38,7 @@ #include <linux/syscalls.h> #include <linux/proc_ns.h> #include <linux/proc_fs.h> +#include <linux/sched/signal.h> #include <linux/sched/task.h> #include <linux/idr.h> @@ -451,6 +452,55 @@ struct pid *find_ge_pid(int nr, struct pid_namespace *ns) return idr_get_next(&ns->idr, &nr); } +/** + * pidfd_open() - Open new pid file descriptor. + * + * @pid: pid for which to retrieve a pidfd + * @flags: flags to pass + * + * This creates a new pid file descriptor with the O_CLOEXEC flag set for + * the process identified by @pid. Currently, the process identified by + * @pid must be a thread-group leader. This restriction currently exists + * for all aspects of pidfds including pidfd creation (CLONE_PIDFD cannot + * be used with CLONE_THREAD) and pidfd polling (only supports thread group + * leaders). + * + * Return: On success, a cloexec pidfd is returned. + * On error, a negative errno number will be returned. + */ +SYSCALL_DEFINE2(pidfd_open, pid_t, pid, unsigned int, flags) +{ + int fd, ret; + struct pid *p; + struct task_struct *tsk; + + if (flags) + return -EINVAL; + + if (pid <= 0) + return -EINVAL; + + p = find_get_pid(pid); + if (!p) + return -ESRCH; + + ret = 0; + rcu_read_lock(); + /* + * If this returns non-NULL the pid was used as a thread-group + * leader. Note, we race with exec here: If it changes the + * thread-group leader we might return the old leader. + */ + tsk = pid_task(p, PIDTYPE_TGID); + if (!tsk) + ret = -ESRCH; + rcu_read_unlock(); + + fd = ret ?: pidfd_create(p); + put_pid(p); + return fd; +} + void __init pid_idr_init(void) { /* Verify no one has done anything silly: */ -- 2.21.0

5 years, 11 months

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[PATCH bpf-next 0/2] Move bpf_printk to bpf_helpers.h

by Michal Rostecki

This series of patches move the commonly used bpf_printk macro to bpf_helpers.h which is already included in all BPF programs which defined that macro on their own. Michal Rostecki (2): selftests: bpf: Move bpf_printk to bpf_helpers.h samples: bpf: Do not define bpf_printk macro samples/bpf/hbm_kern.h | 12 +++--------- samples/bpf/hbm_out_kern.c | 2 ++ samples/bpf/tcp_basertt_kern.c | 7 ------- samples/bpf/tcp_bufs_kern.c | 7 ------- samples/bpf/tcp_clamp_kern.c | 7 ------- samples/bpf/tcp_cong_kern.c | 7 ------- samples/bpf/tcp_iw_kern.c | 7 ------- samples/bpf/tcp_rwnd_kern.c | 7 ------- samples/bpf/tcp_synrto_kern.c | 7 ------- samples/bpf/tcp_tos_reflect_kern.c | 7 ------- samples/bpf/xdp_sample_pkts_kern.c | 7 ------- tools/testing/selftests/bpf/bpf_helpers.h | 8 ++++++++ .../testing/selftests/bpf/progs/sockmap_parse_prog.c | 7 ------- .../selftests/bpf/progs/sockmap_tcp_msg_prog.c | 7 ------- .../selftests/bpf/progs/sockmap_verdict_prog.c | 7 ------- .../testing/selftests/bpf/progs/test_lwt_seg6local.c | 7 ------- .../testing/selftests/bpf/progs/test_xdp_noinline.c | 7 ------- tools/testing/selftests/bpf/test_sockmap_kern.h | 7 ------- 18 files changed, 13 insertions(+), 114 deletions(-) -- 2.21.0

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