From: Peter Maydell <peter.mayd...@linaro.org>
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 <peter.mayd...@linaro.org>
Message-Id: <20210813131809.28655-6-peter.mayd...@linaro.org>
Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
---
linux-user/signal-common.h | 1 +
linux-user/signal.c | 17 +++++++++++++++++
2 files changed, 18 insertions(+)
diff --git a/linux-user/signal-common.h b/linux-user/signal-common.h
index ea86328b28..536c7ac2c2 100644
--- a/linux-user/signal-common.h
+++ b/linux-user/signal-common.h
@@ -40,6 +40,7 @@ void tswap_siginfo(target_siginfo_t *tinfo,
void set_sigmask(const sigset_t *set);
void force_sig(int sig);
void force_sigsegv(int oldsig);
+void force_sig_fault(int sig, int code, abi_ulong addr);
#if defined(TARGET_ARCH_HAS_SETUP_FRAME)
void setup_frame(int sig, struct target_sigaction *ka,
target_sigset_t *set, CPUArchState *env);
diff --git a/linux-user/signal.c b/linux-user/signal.c
index fd3c6a3e60..5ea8e4584a 100644
--- a/linux-user/signal.c
+++ b/linux-user/signal.c
@@ -646,6 +646,23 @@ 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.
--
2.25.1
