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Re: [PATCH v2 05/30] linux-user: Provide new force_sig_fault() function
From: |
Philippe Mathieu-Daudé |
Subject: |
Re: [PATCH v2 05/30] linux-user: Provide new force_sig_fault() function |
Date: |
Tue, 24 Aug 2021 18:36:16 +0200 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 |
On 8/22/21 5:55 AM, Richard Henderson wrote:
> From: Peter Maydell <peter.maydell@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.maydell@linaro.org>
> Message-Id: <20210813131809.28655-6-peter.maydell@linaro.org>
> Signed-off-by: Richard Henderson <richard.henderson@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;
Maybe assign the members directly upon declaration?
(to ease readability...)
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> + 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.
>
- [PATCH v2 00/30] linux-user: Clean up siginfo_t handling, Richard Henderson, 2021/08/21
- [PATCH v2 01/30] linux-user/aarch64: Set siginfo_t addr field for SIGTRAP signals, Richard Henderson, 2021/08/21
- [PATCH v2 04/30] linux-user: Zero out target_siginfo_t in force_sig(), Richard Henderson, 2021/08/21
- [PATCH v2 02/30] linux-user/arm: Set siginfo_t addr field for SIGTRAP signals, Richard Henderson, 2021/08/21
- [PATCH v2 05/30] linux-user: Provide new force_sig_fault() function, Richard Henderson, 2021/08/21
- Re: [PATCH v2 05/30] linux-user: Provide new force_sig_fault() function,
Philippe Mathieu-Daudé <=
- [PATCH v2 06/30] linux-user: Provide new force_sigsegv_for_addr() function, Richard Henderson, 2021/08/21
- [PATCH v2 03/30] linux-user/arm: Use force_sig() to deliver fpa11 emulation SIGFPE, Richard Henderson, 2021/08/21
- [PATCH v2 07/30] linux-user/arm: Use force_sig_fault(), Richard Henderson, 2021/08/21
- [PATCH v2 14/30] linux-user/hppa: Use force_sig_fault, force_sigsegv_for_addr, Richard Henderson, 2021/08/21
- [PATCH v2 24/30] linux-user/openrisc: Use force_sig_fault, force_sigsegv_for_addr, Richard Henderson, 2021/08/21
- [PATCH v2 13/30] linux-user/hexagon: Use force_sigsegv_code, Richard Henderson, 2021/08/21