From: Richard Henderson <richard.henderson@linaro.org>
To: qemu-devel@nongnu.org
Cc: "Alistair Francis" <alistair.francis@wdc.com>,
"Philippe Mathieu-Daudé" <f4bug@amsat.org>,
"Warner Losh" <imp@bsdimp.com>
Subject: [PATCH v7 06/60] linux-user: Reorg handling for SIGSEGV
Date: Mon, 1 Nov 2021 13:26:35 -0400 [thread overview]
Message-ID: <20211101172729.23149-7-richard.henderson@linaro.org> (raw)
In-Reply-To: <20211101172729.23149-1-richard.henderson@linaro.org>
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.
Reviewed-by: Warner Losh <imp@bsdimp.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
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 14d8fdfde1..6900acb122 100644
--- a/linux-user/signal.c
+++ b/linux-user/signal.c
@@ -19,6 +19,7 @@
#include "qemu/osdep.h"
#include "qemu/bitops.h"
#include "exec/gdbstub.h"
+#include "hw/core/tcg-cpu-ops.h"
#include <sys/ucontext.h>
#include <sys/resource.h>
@@ -29,6 +30,7 @@
#include "loader.h"
#include "trace.h"
#include "signal-common.h"
+#include "host-signal.h"
static struct target_sigaction sigact_table[TARGET_NSIG];
@@ -769,41 +771,116 @@ 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:[~2021-11-01 17:35 UTC|newest]
Thread overview: 62+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-01 17:26 [PATCH v7 00/60] user-only: Cleanup SIGSEGV and SIGBUS handling Richard Henderson
2021-11-01 17:26 ` [PATCH v7 01/60] accel/tcg: Split out adjust_signal_pc Richard Henderson
2021-11-01 17:26 ` [PATCH v7 02/60] accel/tcg: Move clear_helper_retaddr to cpu loop Richard Henderson
2021-11-01 17:26 ` [PATCH v7 03/60] accel/tcg: Split out handle_sigsegv_accerr_write Richard Henderson
2021-11-01 17:26 ` [PATCH v7 04/60] accel/tcg: Fold cpu_exit_tb_from_sighandler into caller Richard Henderson
2021-11-01 17:26 ` [PATCH v7 05/60] configure: Merge riscv32 and riscv64 host architectures Richard Henderson
2021-11-01 17:26 ` Richard Henderson [this message]
2021-11-01 17:26 ` [PATCH v7 07/60] linux-user/host/x86: Populate host_signal.h Richard Henderson
2021-11-01 17:26 ` [PATCH v7 08/60] linux-user/host/ppc: " Richard Henderson
2021-11-01 17:26 ` [PATCH v7 09/60] linux-user/host/alpha: " Richard Henderson
2021-11-01 17:26 ` [PATCH v7 10/60] linux-user/host/sparc: " Richard Henderson
2021-11-01 17:26 ` [PATCH v7 11/60] linux-user/host/arm: " Richard Henderson
2021-11-01 17:26 ` [PATCH v7 12/60] linux-user/host/aarch64: " Richard Henderson
2021-11-01 17:26 ` [PATCH v7 13/60] linux-user/host/s390: " Richard Henderson
2021-11-02 6:52 ` Thomas Huth
2021-11-01 17:26 ` [PATCH v7 14/60] linux-user/host/mips: " Richard Henderson
2021-11-01 17:26 ` [PATCH v7 15/60] linux-user/host/riscv: " Richard Henderson
2021-11-01 17:26 ` [PATCH v7 16/60] target/arm: Fixup comment re handle_cpu_signal Richard Henderson
2021-11-01 17:26 ` [PATCH v7 17/60] linux-user/host/riscv: Improve host_signal_write Richard Henderson
2021-11-01 17:26 ` [PATCH v7 18/60] linux-user/signal: Drop HOST_SIGNAL_PLACEHOLDER Richard Henderson
2021-11-01 17:26 ` [PATCH v7 19/60] hw/core: Add TCGCPUOps.record_sigsegv Richard Henderson
2021-11-01 17:26 ` [PATCH v7 20/60] linux-user: Add cpu_loop_exit_sigsegv Richard Henderson
2021-11-01 17:26 ` [PATCH v7 21/60] target/alpha: Implement alpha_cpu_record_sigsegv Richard Henderson
2021-11-01 17:26 ` [PATCH v7 22/60] target/arm: Use cpu_loop_exit_sigsegv for mte tag lookup Richard Henderson
2021-11-01 17:26 ` [PATCH v7 23/60] target/arm: Implement arm_cpu_record_sigsegv Richard Henderson
2021-11-01 17:26 ` [PATCH v7 24/60] target/cris: Make cris_cpu_tlb_fill sysemu only Richard Henderson
2021-11-01 17:26 ` [PATCH v7 25/60] target/hexagon: Remove hexagon_cpu_tlb_fill Richard Henderson
2021-11-01 17:26 ` [PATCH v7 26/60] target/hppa: Make hppa_cpu_tlb_fill sysemu only Richard Henderson
2021-11-01 17:26 ` [PATCH v7 27/60] target/i386: Implement x86_cpu_record_sigsegv Richard Henderson
2021-11-01 17:26 ` [PATCH v7 28/60] target/m68k: Make m68k_cpu_tlb_fill sysemu only Richard Henderson
2021-11-01 17:26 ` [PATCH v7 29/60] target/microblaze: Make mb_cpu_tlb_fill " Richard Henderson
2021-11-01 17:26 ` [PATCH v7 30/60] target/mips: Make mips_cpu_tlb_fill " Richard Henderson
2021-11-01 17:27 ` [PATCH v7 31/60] target/nios2: Implement nios2_cpu_record_sigsegv Richard Henderson
2021-11-01 17:27 ` [PATCH v7 32/60] linux-user/openrisc: Abort for EXCP_RANGE, EXCP_FPE Richard Henderson
2021-11-01 17:27 ` [PATCH v7 33/60] target/openrisc: Make openrisc_cpu_tlb_fill sysemu only Richard Henderson
2021-11-01 17:27 ` [PATCH v7 34/60] target/ppc: Implement ppc_cpu_record_sigsegv Richard Henderson
2021-11-01 17:27 ` [PATCH v7 35/60] target/riscv: Make riscv_cpu_tlb_fill sysemu only Richard Henderson
2021-11-01 17:27 ` [PATCH v7 36/60] target/s390x: Use probe_access_flags in s390_probe_access Richard Henderson
2021-11-01 17:27 ` [PATCH v7 37/60] target/s390x: Implement s390_cpu_record_sigsegv Richard Henderson
2021-11-01 17:27 ` [PATCH v7 38/60] target/sh4: Make sh4_cpu_tlb_fill sysemu only Richard Henderson
2021-11-01 17:27 ` [PATCH v7 39/60] target/sparc: Make sparc_cpu_tlb_fill " Richard Henderson
2021-11-01 17:27 ` [PATCH v7 40/60] target/xtensa: Make xtensa_cpu_tlb_fill " Richard Henderson
2021-11-01 17:27 ` [PATCH v7 41/60] accel/tcg: Restrict TCGCPUOps::tlb_fill() to sysemu Richard Henderson
2021-11-01 17:27 ` [PATCH v7 42/60] hw/core: Add TCGCPUOps.record_sigbus Richard Henderson
2021-11-01 17:27 ` [PATCH v7 43/60] linux-user: Add cpu_loop_exit_sigbus Richard Henderson
2021-11-01 17:27 ` [PATCH v7 44/60] target/alpha: Implement alpha_cpu_record_sigbus Richard Henderson
2021-11-01 17:27 ` [PATCH v7 45/60] target/arm: Implement arm_cpu_record_sigbus Richard Henderson
2021-11-01 17:27 ` [PATCH v7 46/60] linux-user/hppa: Remove EXCP_UNALIGN handling Richard Henderson
2021-11-01 17:27 ` [PATCH v7 47/60] target/microblaze: Do not set MO_ALIGN for user-only Richard Henderson
2021-11-01 17:27 ` [PATCH v7 48/60] target/ppc: Move SPR_DSISR setting to powerpc_excp Richard Henderson
2021-11-01 17:27 ` [PATCH v7 49/60] target/ppc: Set fault address in ppc_cpu_do_unaligned_access Richard Henderson
2021-11-01 17:27 ` [PATCH v7 50/60] target/ppc: Restrict ppc_cpu_do_unaligned_access to sysemu Richard Henderson
2021-11-01 17:27 ` [PATCH v7 51/60] linux-user/ppc: Remove POWERPC_EXCP_ALIGN handling Richard Henderson
2021-11-01 17:27 ` [PATCH v7 52/60] target/s390x: Implement s390x_cpu_record_sigbus Richard Henderson
2021-11-01 17:27 ` [PATCH v7 53/60] target/sh4: Set fault address in superh_cpu_do_unaligned_access Richard Henderson
2021-11-01 17:27 ` [PATCH v7 54/60] target/sparc: Remove DEBUG_UNALIGNED Richard Henderson
2021-11-01 17:27 ` [PATCH v7 55/60] target/sparc: Split out build_sfsr Richard Henderson
2021-11-01 17:27 ` [PATCH v7 56/60] target/sparc: Set fault address in sparc_cpu_do_unaligned_access Richard Henderson
2021-11-01 17:27 ` [PATCH v7 57/60] accel/tcg: Report unaligned atomics for user-only Richard Henderson
2021-11-01 17:27 ` [PATCH v7 58/60] accel/tcg: Report unaligned load/store " Richard Henderson
2021-11-01 17:27 ` [PATCH v7 59/60] tcg: Add helper_unaligned_{ld, st} for user-only sigbus Richard Henderson
2021-11-01 17:27 ` [PATCH v7 60/60] linux-user: Handle BUS_ADRALN in host_signal_handler Richard Henderson
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