From: Alistair Francis <alistair23@gmail.com>
To: Richard Henderson <richard.henderson@linaro.org>
Cc: "qemu-devel@nongnu.org Developers" <qemu-devel@nongnu.org>,
Laurent Vivier <laurent@vivier.eu>
Subject: Re: [PATCH v2 06/41] linux-user: Reorg handling for SIGSEGV
Date: Mon, 20 Sep 2021 09:01:21 +1000 [thread overview]
Message-ID: <CAKmqyKMa9BTVdrVvDUO59zLdK9RbGKUW3d2haNsO00apH3eCsQ@mail.gmail.com> (raw)
In-Reply-To: <20210918184527.408540-7-richard.henderson@linaro.org>
On Sun, Sep 19, 2021 at 4:55 AM Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> Add stub host-signal.h for all linux-user hosts.
> Add new code replacing cpu_signal_handler.
> Full migration will happen one host at a time.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Alistair
> ---
> linux-user/host/aarch64/host-signal.h | 1 +
> linux-user/host/arm/host-signal.h | 1 +
> linux-user/host/i386/host-signal.h | 1 +
> linux-user/host/mips/host-signal.h | 1 +
> linux-user/host/ppc/host-signal.h | 1 +
> linux-user/host/ppc64/host-signal.h | 1 +
> linux-user/host/riscv/host-signal.h | 1 +
> linux-user/host/s390/host-signal.h | 1 +
> linux-user/host/s390x/host-signal.h | 1 +
> linux-user/host/sparc/host-signal.h | 1 +
> linux-user/host/sparc64/host-signal.h | 1 +
> linux-user/host/x32/host-signal.h | 1 +
> linux-user/host/x86_64/host-signal.h | 1 +
> linux-user/signal.c | 109 ++++++++++++++++++++++----
> 14 files changed, 106 insertions(+), 16 deletions(-)
> create mode 100644 linux-user/host/aarch64/host-signal.h
> create mode 100644 linux-user/host/arm/host-signal.h
> create mode 100644 linux-user/host/i386/host-signal.h
> create mode 100644 linux-user/host/mips/host-signal.h
> create mode 100644 linux-user/host/ppc/host-signal.h
> create mode 100644 linux-user/host/ppc64/host-signal.h
> create mode 100644 linux-user/host/riscv/host-signal.h
> create mode 100644 linux-user/host/s390/host-signal.h
> create mode 100644 linux-user/host/s390x/host-signal.h
> create mode 100644 linux-user/host/sparc/host-signal.h
> create mode 100644 linux-user/host/sparc64/host-signal.h
> create mode 100644 linux-user/host/x32/host-signal.h
> create mode 100644 linux-user/host/x86_64/host-signal.h
>
> diff --git a/linux-user/host/aarch64/host-signal.h b/linux-user/host/aarch64/host-signal.h
> new file mode 100644
> index 0000000000..f4b4d65031
> --- /dev/null
> +++ b/linux-user/host/aarch64/host-signal.h
> @@ -0,0 +1 @@
> +#define HOST_SIGNAL_PLACEHOLDER
> diff --git a/linux-user/host/arm/host-signal.h b/linux-user/host/arm/host-signal.h
> new file mode 100644
> index 0000000000..f4b4d65031
> --- /dev/null
> +++ b/linux-user/host/arm/host-signal.h
> @@ -0,0 +1 @@
> +#define HOST_SIGNAL_PLACEHOLDER
> diff --git a/linux-user/host/i386/host-signal.h b/linux-user/host/i386/host-signal.h
> new file mode 100644
> index 0000000000..f4b4d65031
> --- /dev/null
> +++ b/linux-user/host/i386/host-signal.h
> @@ -0,0 +1 @@
> +#define HOST_SIGNAL_PLACEHOLDER
> diff --git a/linux-user/host/mips/host-signal.h b/linux-user/host/mips/host-signal.h
> new file mode 100644
> index 0000000000..f4b4d65031
> --- /dev/null
> +++ b/linux-user/host/mips/host-signal.h
> @@ -0,0 +1 @@
> +#define HOST_SIGNAL_PLACEHOLDER
> diff --git a/linux-user/host/ppc/host-signal.h b/linux-user/host/ppc/host-signal.h
> new file mode 100644
> index 0000000000..f4b4d65031
> --- /dev/null
> +++ b/linux-user/host/ppc/host-signal.h
> @@ -0,0 +1 @@
> +#define HOST_SIGNAL_PLACEHOLDER
> diff --git a/linux-user/host/ppc64/host-signal.h b/linux-user/host/ppc64/host-signal.h
> new file mode 100644
> index 0000000000..f4b4d65031
> --- /dev/null
> +++ b/linux-user/host/ppc64/host-signal.h
> @@ -0,0 +1 @@
> +#define HOST_SIGNAL_PLACEHOLDER
> diff --git a/linux-user/host/riscv/host-signal.h b/linux-user/host/riscv/host-signal.h
> new file mode 100644
> index 0000000000..f4b4d65031
> --- /dev/null
> +++ b/linux-user/host/riscv/host-signal.h
> @@ -0,0 +1 @@
> +#define HOST_SIGNAL_PLACEHOLDER
> diff --git a/linux-user/host/s390/host-signal.h b/linux-user/host/s390/host-signal.h
> new file mode 100644
> index 0000000000..f4b4d65031
> --- /dev/null
> +++ b/linux-user/host/s390/host-signal.h
> @@ -0,0 +1 @@
> +#define HOST_SIGNAL_PLACEHOLDER
> diff --git a/linux-user/host/s390x/host-signal.h b/linux-user/host/s390x/host-signal.h
> new file mode 100644
> index 0000000000..f4b4d65031
> --- /dev/null
> +++ b/linux-user/host/s390x/host-signal.h
> @@ -0,0 +1 @@
> +#define HOST_SIGNAL_PLACEHOLDER
> diff --git a/linux-user/host/sparc/host-signal.h b/linux-user/host/sparc/host-signal.h
> new file mode 100644
> index 0000000000..f4b4d65031
> --- /dev/null
> +++ b/linux-user/host/sparc/host-signal.h
> @@ -0,0 +1 @@
> +#define HOST_SIGNAL_PLACEHOLDER
> diff --git a/linux-user/host/sparc64/host-signal.h b/linux-user/host/sparc64/host-signal.h
> new file mode 100644
> index 0000000000..f4b4d65031
> --- /dev/null
> +++ b/linux-user/host/sparc64/host-signal.h
> @@ -0,0 +1 @@
> +#define HOST_SIGNAL_PLACEHOLDER
> diff --git a/linux-user/host/x32/host-signal.h b/linux-user/host/x32/host-signal.h
> new file mode 100644
> index 0000000000..f4b4d65031
> --- /dev/null
> +++ b/linux-user/host/x32/host-signal.h
> @@ -0,0 +1 @@
> +#define HOST_SIGNAL_PLACEHOLDER
> diff --git a/linux-user/host/x86_64/host-signal.h b/linux-user/host/x86_64/host-signal.h
> new file mode 100644
> index 0000000000..f4b4d65031
> --- /dev/null
> +++ b/linux-user/host/x86_64/host-signal.h
> @@ -0,0 +1 @@
> +#define HOST_SIGNAL_PLACEHOLDER
> diff --git a/linux-user/signal.c b/linux-user/signal.c
> index 5ea8e4584a..6f953f10d4 100644
> --- a/linux-user/signal.c
> +++ b/linux-user/signal.c
> @@ -18,12 +18,15 @@
> */
> #include "qemu/osdep.h"
> #include "qemu/bitops.h"
> +#include "hw/core/tcg-cpu-ops.h"
> +
> #include <sys/ucontext.h>
> #include <sys/resource.h>
>
> #include "qemu.h"
> #include "trace.h"
> #include "signal-common.h"
> +#include "host-signal.h"
>
> static struct target_sigaction sigact_table[TARGET_NSIG];
>
> @@ -761,41 +764,115 @@ static inline void rewind_if_in_safe_syscall(void *puc)
> }
> #endif
>
> -static void host_signal_handler(int host_signum, siginfo_t *info,
> - void *puc)
> +static void host_signal_handler(int host_sig, siginfo_t *info, void *puc)
> {
> CPUArchState *env = thread_cpu->env_ptr;
> CPUState *cpu = env_cpu(env);
> TaskState *ts = cpu->opaque;
> -
> - int sig;
> target_siginfo_t tinfo;
> ucontext_t *uc = puc;
> struct emulated_sigtable *k;
> + int guest_sig;
>
> +#ifdef HOST_SIGNAL_PLACEHOLDER
> /* the CPU emulator uses some host signals to detect exceptions,
> we forward to it some signals */
> - if ((host_signum == SIGSEGV || host_signum == SIGBUS)
> + if ((host_sig == SIGSEGV || host_sig == SIGBUS)
> && info->si_code > 0) {
> - if (cpu_signal_handler(host_signum, info, puc))
> + if (cpu_signal_handler(host_sig, info, puc))
> return;
> }
> +#else
> + uintptr_t pc = 0;
> + bool sync_sig = false;
> +
> + /*
> + * Non-spoofed SIGSEGV and SIGBUS are synchronous, and need special
> + * handling wrt signal blocking and unwinding.
> + */
> + if ((host_sig == SIGSEGV || host_sig == SIGBUS) && info->si_code > 0) {
> + MMUAccessType access_type;
> + uintptr_t host_addr;
> + abi_ptr guest_addr;
> + bool is_write;
> +
> + host_addr = (uintptr_t)info->si_addr;
> +
> + /*
> + * Convert forcefully to guest address space: addresses outside
> + * reserved_va are still valid to report via SEGV_MAPERR.
> + */
> + guest_addr = h2g_nocheck(host_addr);
> +
> + pc = host_signal_pc(uc);
> + is_write = host_signal_write(info, uc);
> + access_type = adjust_signal_pc(&pc, is_write);
> +
> + if (host_sig == SIGSEGV) {
> + const struct TCGCPUOps *tcg_ops;
> +
> + if (info->si_code == SEGV_ACCERR && h2g_valid(host_addr)) {
> + /* If this was a write to a TB protected page, restart. */
> + if (is_write &&
> + handle_sigsegv_accerr_write(cpu, &uc->uc_sigmask,
> + pc, guest_addr)) {
> + return;
> + }
> +
> + /*
> + * With reserved_va, the whole address space is PROT_NONE,
> + * which means that we may get ACCERR when we want MAPERR.
> + */
> + if (page_get_flags(guest_addr) & PAGE_VALID) {
> + /* maperr = false; */
> + } else {
> + info->si_code = SEGV_MAPERR;
> + }
> + }
> +
> + sigprocmask(SIG_SETMASK, &uc->uc_sigmask, NULL);
> +
> + tcg_ops = CPU_GET_CLASS(cpu)->tcg_ops;
> + tcg_ops->tlb_fill(cpu, guest_addr, 0, access_type,
> + MMU_USER_IDX, false, pc);
> + g_assert_not_reached();
> + } else {
> + sigprocmask(SIG_SETMASK, &uc->uc_sigmask, NULL);
> + }
> +
> + sync_sig = true;
> + }
> +#endif
>
> /* get target signal number */
> - sig = host_to_target_signal(host_signum);
> - if (sig < 1 || sig > TARGET_NSIG)
> + guest_sig = host_to_target_signal(host_sig);
> + if (guest_sig < 1 || guest_sig > TARGET_NSIG) {
> return;
> - trace_user_host_signal(env, host_signum, sig);
> + }
> + trace_user_host_signal(env, host_sig, guest_sig);
> +
> + host_to_target_siginfo_noswap(&tinfo, info);
> + k = &ts->sigtab[guest_sig - 1];
> + k->info = tinfo;
> + k->pending = guest_sig;
> + ts->signal_pending = 1;
> +
> +#ifndef HOST_SIGNAL_PLACEHOLDER
> + /*
> + * For synchronous signals, unwind the cpu state to the faulting
> + * insn and then exit back to the main loop so that the signal
> + * is delivered immediately.
> + */
> + if (sync_sig) {
> + cpu->exception_index = EXCP_INTERRUPT;
> + cpu_loop_exit_restore(cpu, pc);
> + }
> +#endif
>
> rewind_if_in_safe_syscall(puc);
>
> - host_to_target_siginfo_noswap(&tinfo, info);
> - k = &ts->sigtab[sig - 1];
> - k->info = tinfo;
> - k->pending = sig;
> - ts->signal_pending = 1;
> -
> - /* Block host signals until target signal handler entered. We
> + /*
> + * Block host signals until target signal handler entered. We
> * can't block SIGSEGV or SIGBUS while we're executing guest
> * code in case the guest code provokes one in the window between
> * now and it getting out to the main loop. Signals will be
> --
> 2.25.1
>
>
next prev parent reply other threads:[~2021-09-19 23:03 UTC|newest]
Thread overview: 71+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-18 18:44 [PATCH v2 00/41] linux-user: Streamline handling of SIGSEGV Richard Henderson
2021-09-18 18:44 ` [PATCH v2 01/41] accel/tcg: Split out adjust_signal_pc Richard Henderson
2021-09-18 18:44 ` [PATCH v2 02/41] accel/tcg: Move clear_helper_retaddr to cpu loop Richard Henderson
2021-09-19 19:35 ` Warner Losh
2021-09-18 18:44 ` [PATCH v2 03/41] accel/tcg: Split out handle_sigsegv_accerr_write Richard Henderson
2021-09-18 18:44 ` [PATCH v2 04/41] accel/tcg: Fold cpu_exit_tb_from_sighandler into caller Richard Henderson
2021-09-18 18:44 ` [PATCH v2 05/41] configure: Merge riscv32 and riscv64 host architectures Richard Henderson
2021-09-19 17:56 ` Philippe Mathieu-Daudé
2021-09-19 22:57 ` Alistair Francis
2021-09-18 18:44 ` [PATCH v2 06/41] linux-user: Reorg handling for SIGSEGV Richard Henderson
2021-09-19 18:02 ` Philippe Mathieu-Daudé
2021-09-19 19:01 ` Warner Losh
2021-09-19 23:01 ` Alistair Francis [this message]
2021-09-18 18:44 ` [PATCH v2 07/41] linux-user/host/x86: Populate host_signal.h Richard Henderson
2021-09-18 18:44 ` [PATCH v2 08/41] linux-user/host/ppc: " Richard Henderson
2021-09-19 19:34 ` Warner Losh
2021-09-18 18:44 ` [PATCH v2 09/41] linux-user/host/alpha: " Richard Henderson
2021-09-19 18:03 ` Philippe Mathieu-Daudé
2021-09-19 18:07 ` Richard Henderson
2021-09-19 18:11 ` Philippe Mathieu-Daudé
2021-09-19 18:13 ` Philippe Mathieu-Daudé
2021-09-18 18:44 ` [PATCH v2 10/41] linux-user/host/sparc: " Richard Henderson
2021-09-18 18:44 ` [PATCH v2 11/41] linux-user/host/arm: " Richard Henderson
2021-09-18 18:44 ` [PATCH v2 12/41] linux-user/host/aarch64: " Richard Henderson
2021-09-18 18:44 ` [PATCH v2 13/41] linux-user/host/s390: " Richard Henderson
2021-09-19 18:07 ` Philippe Mathieu-Daudé
2021-09-18 18:45 ` [PATCH v2 14/41] linux-user/host/mips: " Richard Henderson
2021-09-19 18:08 ` Philippe Mathieu-Daudé
2021-09-18 18:45 ` [PATCH v2 15/41] linux-user/host/riscv: " Richard Henderson
2021-09-18 18:45 ` [PATCH v2 16/41] target/arm: Fixup comment re handle_cpu_signal Richard Henderson
2021-09-18 18:45 ` [PATCH v2 17/41] linux-user/host/riscv: Improve host_signal_write Richard Henderson
2021-09-18 18:45 ` [PATCH v2 18/41] linux-user/signal: Drop HOST_SIGNAL_PLACEHOLDER Richard Henderson
2021-09-19 18:18 ` Philippe Mathieu-Daudé
2021-09-19 18:59 ` Warner Losh
2021-09-18 18:45 ` [PATCH v2 19/41] hw/core: Add TCGCPUOps.record_sigsegv Richard Henderson
2021-09-19 18:22 ` Philippe Mathieu-Daudé
2021-09-19 18:24 ` Philippe Mathieu-Daudé
2021-09-19 18:32 ` Richard Henderson
2021-09-18 18:45 ` [PATCH v2 20/41] linux-user: Add raise_sigsegv Richard Henderson
2021-09-19 18:26 ` Philippe Mathieu-Daudé
2021-09-19 18:35 ` Richard Henderson
2021-09-19 18:43 ` Philippe Mathieu-Daudé
2021-09-19 18:53 ` Warner Losh
2021-09-18 18:45 ` [PATCH v2 21/41] target/alpha: Make alpha_cpu_tlb_fill sysemu only Richard Henderson
2021-09-18 18:45 ` [PATCH v2 22/41] target/arm: Use raise_sigsegv for mte tag lookup Richard Henderson
2021-09-18 18:45 ` [PATCH v2 23/41] target/arm: Implement arm_cpu_record_sigsegv Richard Henderson
2021-09-18 18:45 ` [PATCH v2 24/41] target/cris: Make cris_cpu_tlb_fill sysemu only Richard Henderson
2021-09-19 18:28 ` Philippe Mathieu-Daudé
2021-09-18 18:45 ` [PATCH v2 25/41] target/hexagon: Remove hexagon_cpu_tlb_fill Richard Henderson
2021-09-18 18:45 ` [PATCH v2 26/41] target/hppa: Make hppa_cpu_tlb_fill sysemu only Richard Henderson
2021-09-18 18:45 ` [PATCH v2 27/41] target/i386: Implement x86_cpu_record_sigsegv Richard Henderson
2021-09-19 18:32 ` Philippe Mathieu-Daudé
2021-09-19 18:59 ` Warner Losh
2021-09-18 18:45 ` [PATCH v2 28/41] target/m68k: Make m68k_cpu_tlb_fill sysemu only Richard Henderson
2021-09-18 18:45 ` [PATCH v2 29/41] target/microblaze: Make mb_cpu_tlb_fill " Richard Henderson
2021-09-18 18:45 ` [PATCH v2 30/41] target/mips: Make mips_cpu_tlb_fill " Richard Henderson
2021-09-18 18:45 ` [PATCH v2 31/41] target/nios2: Make nios2_cpu_tlb_fill " Richard Henderson
2021-09-18 18:45 ` [PATCH v2 32/41] linux-user/openrisc: Adjust signal for EXCP_RANGE, EXCP_FPE Richard Henderson
2021-09-18 18:45 ` [PATCH v2 33/41] target/openrisc: Make openrisc_cpu_tlb_fill sysemu only Richard Henderson
2021-09-18 18:45 ` [PATCH v2 34/41] target/ppc: Implement ppc_cpu_record_sigsegv Richard Henderson
2021-09-19 18:37 ` Philippe Mathieu-Daudé
2021-09-18 18:45 ` [PATCH v2 35/41] target/riscv: Make riscv_cpu_tlb_fill sysemu only Richard Henderson
2021-09-18 18:45 ` [PATCH v2 36/41] target/s390x: Use probe_access_flags in s390_probe_access Richard Henderson
2021-09-18 18:45 ` [PATCH v2 37/41] target/s390x: Implement s390_cpu_record_sigsegv Richard Henderson
2021-09-19 18:39 ` Philippe Mathieu-Daudé
2021-09-18 18:45 ` [PATCH v2 38/41] target/sh4: Make sh4_cpu_tlb_fill sysemu only Richard Henderson
2021-09-18 18:45 ` [PATCH v2 39/41] target/sparc: Make sparc_cpu_tlb_fill " Richard Henderson
2021-09-18 18:45 ` [PATCH v2 40/41] target/xtensa: Make xtensa_cpu_tlb_fill " Richard Henderson
2021-09-18 18:45 ` [PATCH v2 41/41] accel/tcg: Restrict TCGCPUOps::tlb_fill() to sysemu Richard Henderson
2021-09-19 18:40 ` Philippe Mathieu-Daudé
2021-09-19 10:38 ` [PATCH v2 00/41] linux-user: Streamline handling of SIGSEGV Philippe Mathieu-Daudé
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