diff options
| author | Helge Deller <deller@gmx.de> | 2022-11-29 12:08:20 +0100 |
|---|---|---|
| committer | Laurent Vivier <laurent@vivier.eu> | 2023-03-10 20:45:47 +0100 |
| commit | 895ce8bb534e66ca418dea62ae67a92dccafb2e1 (patch) | |
| tree | 6d9292795056aa8d2650f34ad0837dfa64046fba /linux-user | |
| parent | fe080593dd4f2c2763f7c27a3ba6e69b64fe3b0c (diff) | |
linux-user: Emulate CLONE_PIDFD flag in clone()
Add emulation for the CLONE_PIDFD flag of the clone() syscall.
This flag was added in Linux kernel 5.2.
Successfully tested on a x86-64 Linux host with hppa-linux target.
Can be verified by running the testsuite of the qcoro debian package,
which breaks hard and kills the currently logged-in user without this
patch.
Signed-off-by: Helge Deller <deller@gmx.de>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <Y4XoJCpvUA1JD7Sj@p100>
[lv: define CLONE_PIDFD if it is not]
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Diffstat (limited to 'linux-user')
| -rw-r--r-- | linux-user/strace.c | 5 | ||||
| -rw-r--r-- | linux-user/syscall.c | 31 |
2 files changed, 35 insertions, 1 deletions
diff --git a/linux-user/strace.c b/linux-user/strace.c index e08bd53afb..aad2b62ca4 100644 --- a/linux-user/strace.c +++ b/linux-user/strace.c @@ -1111,11 +1111,16 @@ UNUSED static const struct flags mmap_flags[] = { FLAG_END, }; +#ifndef CLONE_PIDFD +# define CLONE_PIDFD 0x00001000 +#endif + UNUSED static const struct flags clone_flags[] = { FLAG_GENERIC(CLONE_VM), FLAG_GENERIC(CLONE_FS), FLAG_GENERIC(CLONE_FILES), FLAG_GENERIC(CLONE_SIGHAND), + FLAG_GENERIC(CLONE_PIDFD), FLAG_GENERIC(CLONE_PTRACE), FLAG_GENERIC(CLONE_VFORK), FLAG_GENERIC(CLONE_PARENT), diff --git a/linux-user/syscall.c b/linux-user/syscall.c index dad2c33120..24cea6fb6a 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -169,9 +169,13 @@ #define CLONE_IGNORED_FLAGS \ (CLONE_DETACHED | CLONE_IO) +#ifndef CLONE_PIDFD +# define CLONE_PIDFD 0x00001000 +#endif + /* Flags for fork which we can implement within QEMU itself */ #define CLONE_OPTIONAL_FORK_FLAGS \ - (CLONE_SETTLS | CLONE_PARENT_SETTID | \ + (CLONE_SETTLS | CLONE_PARENT_SETTID | CLONE_PIDFD | \ CLONE_CHILD_CLEARTID | CLONE_CHILD_SETTID) /* Flags for thread creation which we can implement within QEMU itself */ @@ -6730,6 +6734,17 @@ static int do_fork(CPUArchState *env, unsigned int flags, abi_ulong newsp, return -TARGET_EINVAL; } +#if !defined(__NR_pidfd_open) || !defined(TARGET_NR_pidfd_open) + if (flags & CLONE_PIDFD) { + return -TARGET_EINVAL; + } +#endif + + /* Can not allow CLONE_PIDFD with CLONE_PARENT_SETTID */ + if ((flags & CLONE_PIDFD) && (flags & CLONE_PARENT_SETTID)) { + return -TARGET_EINVAL; + } + if (block_signals()) { return -QEMU_ERESTARTSYS; } @@ -6757,6 +6772,20 @@ static int do_fork(CPUArchState *env, unsigned int flags, abi_ulong newsp, ts->child_tidptr = child_tidptr; } else { cpu_clone_regs_parent(env, flags); + if (flags & CLONE_PIDFD) { + int pid_fd = 0; +#if defined(__NR_pidfd_open) && defined(TARGET_NR_pidfd_open) + int pid_child = ret; + pid_fd = pidfd_open(pid_child, 0); + if (pid_fd >= 0) { + fcntl(pid_fd, F_SETFD, fcntl(pid_fd, F_GETFL) + | FD_CLOEXEC); + } else { + pid_fd = 0; + } +#endif + put_user_u32(pid_fd, parent_tidptr); + } fork_end(0); } g_assert(!cpu_in_exclusive_context(cpu)); |