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fix(waitid): Proper marshalling for siginfo_t
Linux and BSD siginfo_t has different layouts, making processes calling waitid confused about the output.
+106
-10
+19
-4
src/kernel/emulation/linux/process/waitid.c
+19
-4
src/kernel/emulation/linux/process/waitid.c
···
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#include <linux-syscalls/linux.h>
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#include <stddef.h>
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long sys_waitid(int idtype, int id, struct simple_siginfo* si, int options)
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static void siginfo_linux_to_bsd(const linux_siginfo_t* linux_si, siginfo_t* si);
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long sys_waitid(int idtype, int id, siginfo_t* si, int options)
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{
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int ret, linux_options;
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linux_options = waitopts_bsd_to_linux(options);
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ret = LINUX_SYSCALL(__NR_waitid, idtype, id, si, linux_options);
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linux_siginfo_t linux_si;
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ret = LINUX_SYSCALL(__NR_waitid, idtype, id, &linux_si, linux_options);
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if (ret < 0)
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return errno_linux_to_bsd(ret);
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if (si != NULL)
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{
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si->si_signo = signum_linux_to_bsd(si->si_signo);
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si->si_errno = errno_linux_to_bsd(si->si_errno);
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siginfo_linux_to_bsd(&linux_si, si);
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}
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return ret;
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}
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static void siginfo_linux_to_bsd(const linux_siginfo_t* linux_si, siginfo_t* si)
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{
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si->si_signo = signum_linux_to_bsd(linux_si->si_signo);
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si->si_errno = errno_linux_to_bsd(linux_si->si_errno);
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si->si_code = linux_si->si_code;
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si->si_pid = linux_si->linux_si_pid;
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si->si_uid = linux_si->linux_si_uid;
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si->si_status = linux_si->linux_si_status;
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si->si_addr = linux_si->linux_si_addr;
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si->si_value = linux_si->linux_si_value;
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si->si_band = linux_si->linux_si_band;
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}
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+87
-6
src/kernel/emulation/linux/process/waitid.h
+87
-6
src/kernel/emulation/linux/process/waitid.h
···
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#ifndef LINUX_WAITID_H
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#define LINUX_WAITID_H
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struct simple_siginfo
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#include <sys/signal.h>
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#define LINUX_SI_MAX_SIZE 128
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#if __WORDSIZE == 64
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# define LINUX_SI_PAD_SIZE ((LINUX_SI_MAX_SIZE / sizeof (int)) - 4)
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#else
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# define LINUX_SI_PAD_SIZE ((LINUX_SI_MAX_SIZE / sizeof (int)) - 3)
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#endif
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// TODO: see when this is defind in Linux
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#ifndef LINUX_SI_ERRNO_THEN_CODE
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# define LINUX_SI_ERRNO_THEN_CODE 1
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#endif
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// This struct is heavily simplified.
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typedef struct
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{
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int si_signo;
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int si_errno;
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int si_code;
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};
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int si_signo; /* Signal number. */
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#if LINUX_SI_ERRNO_THEN_CODE
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int si_errno; /* If non-zero, an errno value associated with
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this signal, as defined in <errno.h>. */
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int si_code; /* Signal code. */
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#else
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int si_code;
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int si_errno;
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#endif
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#if __WORDSIZE == 64
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int __pad0; /* Explicit padding. */
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#endif
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union
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{
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int _pad[LINUX_SI_PAD_SIZE];
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/* kill(). */
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struct
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{
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pid_t si_pid; /* Sending process ID. */
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uid_t si_uid; /* Real user ID of sending process. */
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} _kill;
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/* POSIX.1b timers. */
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struct
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{
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int si_tid; /* Timer ID. */
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int si_overrun; /* Overrun count. */
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union sigval si_sigval; /* Signal value. */
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} _timer;
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/* POSIX.1b signals. */
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struct
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{
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pid_t si_pid; /* Sending process ID. */
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uid_t si_uid; /* Real user ID of sending process. */
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union sigval si_sigval; /* Signal value. */
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} _rt;
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/* SIGCHLD. */
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struct
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{
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pid_t si_pid; /* Which child. */
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uid_t si_uid; /* Real user ID of sending process. */
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int si_status; /* Exit value or signal. */
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} _sigchld;
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/* SIGILL, SIGFPE, SIGSEGV, SIGBUS. */
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struct
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{
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void *si_addr; /* Faulting insn/memory ref. */
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} _sigfault;
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/* SIGPOLL. */
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struct
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{
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long si_band; /* Band event for SIGPOLL. */
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int si_fd;
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} _sigpoll;
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/* SIGSYS. */
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struct
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{
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void *_call_addr; /* Calling user insn. */
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int _syscall; /* Triggering system call number. */
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unsigned int _arch; /* AUDIT_ARCH_* of syscall. */
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} _sigsys;
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} _sifields;
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} linux_siginfo_t;
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long sys_waitid(int idtype, int id, struct simple_siginfo* si, int options);
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// We keep only the fields defined in the BSD version.
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#define linux_si_pid _sifields._kill.si_pid
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#define linux_si_uid _sifields._kill.si_uid
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#define linux_si_status _sifields._sigchld.si_status
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#define linux_si_value _sifields._rt.si_sigval
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#define linux_si_addr _sifields._sigfault.si_addr
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#define linux_si_band _sifields._sigpoll.si_band
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long sys_waitid(int idtype, int id, siginfo_t* si, int options);
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#endif
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