Commit 7eddb5dd authored by Laurent Vivier's avatar Laurent Vivier
Browse files

linux-user: fix fork() 



Since commit 5ea2fc84 ("linux-user: Sanity check clone flags"),
trying to run fork() fails with old distro on some architectures.

This is the case with HP-PA and Debian 5 (Lenny).

It fails on:

         if ((flags & CSIGNAL) != TARGET_SIGCHLD) {
             return -TARGET_EINVAL;
         }

because flags is 17, whereas on HP-PA, SIGCHLD is 18.
17 is the SIGCHLD value of my host (x86_64).

It appears that for TARGET_NR_fork and TARGET_NR_vfork, QEMU calls
do_fork() with SIGCHLD instead of TARGET_SIGCHLD.

Signed-off-by: default avatarLaurent Vivier <laurent@vivier.eu>
Reviewed-by: default avatarPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: default avatarPhilippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20170216173707.16209-1-laurent@vivier.eu>
parent 8f2d7c34

linux-user/syscall.c

+3 −2
Original line number Diff line number Diff line
@@ -7680,7 +7680,7 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1, 
        break;

#ifdef TARGET_NR_fork

    case TARGET_NR_fork:

        ret = get_errno(do_fork(cpu_env, SIGCHLD, 0, 0, 0, 0));

        ret = get_errno(do_fork(cpu_env, TARGET_SIGCHLD, 0, 0, 0, 0));

        break;

#endif

#ifdef TARGET_NR_waitpid
@@ -10490,7 +10490,8 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1, 
#endif

#ifdef TARGET_NR_vfork

    case TARGET_NR_vfork:

        ret = get_errno(do_fork(cpu_env, CLONE_VFORK | CLONE_VM | SIGCHLD,

        ret = get_errno(do_fork(cpu_env,

                        CLONE_VFORK | CLONE_VM | TARGET_SIGCHLD,

                        0, 0, 0, 0));

        break;

#endif