From c065976f2bca9b87bc699c5fdeb4d3ff1299b8c4 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Sat, 9 Aug 2014 15:42:32 +0100 Subject: [PATCH] linux-user: Fix conversion of sigevent argument to timer_create There were a number of bugs in the conversion of the sigevent argument to timer_create from target to host format: * signal number not converted from target to host * thread ID not copied across * sigev_value not copied across * we never unlocked the struct when we were done Between them, these problems meant that SIGEV_THREAD_ID timers (and the glibc-implemented SIGEV_THREAD timers which depend on them) didn't work. Fix these problems and clean up the code a little by pulling the struct conversion out into its own function, in line with how we convert various other structs. This allows the test program in bug LP:1042388 to run. Signed-off-by: Peter Maydell Signed-off-by: Riku Voipio --- linux-user/syscall.c | 38 ++++++++++++++++++++++++++++++-------- 1 file changed, 30 insertions(+), 8 deletions(-) diff --git a/linux-user/syscall.c b/linux-user/syscall.c index dd776735b5..fccf9f0a26 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -4912,6 +4912,32 @@ static inline abi_long host_to_target_itimerspec(abi_ulong target_addr, return 0; } +static inline abi_long target_to_host_sigevent(struct sigevent *host_sevp, + abi_ulong target_addr) +{ + struct target_sigevent *target_sevp; + + if (!lock_user_struct(VERIFY_READ, target_sevp, target_addr, 1)) { + return -TARGET_EFAULT; + } + + /* This union is awkward on 64 bit systems because it has a 32 bit + * integer and a pointer in it; we follow the conversion approach + * used for handling sigval types in signal.c so the guest should get + * the correct value back even if we did a 64 bit byteswap and it's + * using the 32 bit integer. + */ + host_sevp->sigev_value.sival_ptr = + (void *)(uintptr_t)tswapal(target_sevp->sigev_value.sival_ptr); + host_sevp->sigev_signo = + target_to_host_signal(tswap32(target_sevp->sigev_signo)); + host_sevp->sigev_notify = tswap32(target_sevp->sigev_notify); + host_sevp->_sigev_un._tid = tswap32(target_sevp->_sigev_un._tid); + + unlock_user_struct(target_sevp, target_addr, 1); + return 0; +} + #if defined(TARGET_NR_stat64) || defined(TARGET_NR_newfstatat) static inline abi_long host_to_target_stat64(void *cpu_env, abi_ulong target_addr, @@ -9403,7 +9429,6 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1, /* args: clockid_t clockid, struct sigevent *sevp, timer_t *timerid */ struct sigevent host_sevp = { {0}, }, *phost_sevp = NULL; - struct target_sigevent *ptarget_sevp; struct target_timer_t *ptarget_timer; int clkid = arg1; @@ -9415,14 +9440,11 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1, timer_t *phtimer = g_posix_timers + timer_index; if (arg2) { - if (!lock_user_struct(VERIFY_READ, ptarget_sevp, arg2, 1)) { - goto efault; - } - - host_sevp.sigev_signo = tswap32(ptarget_sevp->sigev_signo); - host_sevp.sigev_notify = tswap32(ptarget_sevp->sigev_notify); - phost_sevp = &host_sevp; + ret = target_to_host_sigevent(phost_sevp, arg2); + if (ret != 0) { + break; + } } ret = get_errno(timer_create(clkid, phost_sevp, phtimer));