From 819121b9b08a41ccfcde2e18eb782f8f6b2912f1 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Fri, 13 Aug 2021 14:18:06 +0100 Subject: linux-user: Zero out target_siginfo_t in force_sig() The target_siginfo_t we populate in force_sig() will eventually get copied onto the target's stack. Zero it out so that any extra padding in the sifields union is consistently zero when the guest sees it. Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-Id: <20210813131809.28655-5-peter.maydell@linaro.org> Signed-off-by: Laurent Vivier --- linux-user/signal.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'linux-user/signal.c') diff --git a/linux-user/signal.c b/linux-user/signal.c index f8346f5ec5..910b9dc6f7 100644 --- a/linux-user/signal.c +++ b/linux-user/signal.c @@ -641,7 +641,7 @@ void force_sig(int sig) { CPUState *cpu = thread_cpu; CPUArchState *env = cpu->env_ptr; - target_siginfo_t info; + target_siginfo_t info = {}; info.si_signo = sig; info.si_errno = 0; -- cgit v1.2.3 From af7969605eed067320fe9eca80f1aa35b67ec46d Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Fri, 13 Aug 2021 14:18:07 +0100 Subject: linux-user: Provide new force_sig_fault() function In many places in the linux-user code we need to queue a signal for the guest using the QEMU_SI_FAULT si_type. This requires that the caller sets up and passes us a target_siginfo, including setting the appropriate part of the _sifields union for the si_type. In a number of places the code forgets to set the _sifields union field. Provide a new force_sig_fault() function, which does the same thing as the Linux kernel function of that name -- it takes the signal number, the si_code value and the address to use in _sifields._sigfault, and assembles the target_siginfo itself. This makes the callsites simpler and means it's harder to forget to pass in an address value. We follow force_sig() and the kernel's force_sig_fault() in not requiring the caller to pass in the CPU pointer but always acting on the CPU of the current thread. Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-Id: <20210813131809.28655-6-peter.maydell@linaro.org> Signed-off-by: Laurent Vivier --- linux-user/signal.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) (limited to 'linux-user/signal.c') diff --git a/linux-user/signal.c b/linux-user/signal.c index 910b9dc6f7..2038216455 100644 --- a/linux-user/signal.c +++ b/linux-user/signal.c @@ -651,6 +651,23 @@ void force_sig(int sig) queue_signal(env, info.si_signo, QEMU_SI_KILL, &info); } +/* + * Force a synchronously taken QEMU_SI_FAULT signal. For QEMU the + * 'force' part is handled in process_pending_signals(). + */ +void force_sig_fault(int sig, int code, abi_ulong addr) +{ + CPUState *cpu = thread_cpu; + CPUArchState *env = cpu->env_ptr; + target_siginfo_t info = {}; + + info.si_signo = sig; + info.si_errno = 0; + info.si_code = code; + info._sifields._sigfault._addr = addr; + queue_signal(env, sig, QEMU_SI_FAULT, &info); +} + /* Force a SIGSEGV if we couldn't write to memory trying to set * up the signal frame. oldsig is the signal we were trying to handle * at the point of failure. -- cgit v1.2.3