From 0fdbb7d2c1ecb761b985b176b9bb159d483d9514 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Sun, 12 Sep 2021 19:25:22 -0700 Subject: accel/tcg: Split out adjust_signal_pc Split out a function to adjust the raw signal pc into a value that could be passed to cpu_restore_state. Reviewed-by: Warner Losh Reviewed-by: Philippe Mathieu-Daudé Signed-off-by: Richard Henderson --- v2: Adjust pc in place; return MMUAccessType. --- include/exec/exec-all.h | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'include') diff --git a/include/exec/exec-all.h b/include/exec/exec-all.h index 9d5987ba04..e54f8e5d65 100644 --- a/include/exec/exec-all.h +++ b/include/exec/exec-all.h @@ -663,6 +663,16 @@ static inline tb_page_addr_t get_page_addr_code_hostp(CPUArchState *env, return addr; } +/** + * adjust_signal_pc: + * @pc: raw pc from the host signal ucontext_t. + * @is_write: host memory operation was write, or read-modify-write. + * + * Alter @pc as required for unwinding. Return the type of the + * guest memory access -- host reads may be for guest execution. + */ +MMUAccessType adjust_signal_pc(uintptr_t *pc, bool is_write); + /** * cpu_signal_handler * @signum: host signal number -- cgit v1.2.3-55-g7522 From 5e38ba7dde963414dddc8a83848701b49d0bcb00 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Sun, 12 Sep 2021 19:47:29 -0700 Subject: accel/tcg: Split out handle_sigsegv_accerr_write This is the major portion of handle_cpu_signal which is specific to tcg, handling the page protections for the translations. Most of the rest will migrate to linux-user/ shortly. Reviewed-by: Warner Losh Reviewed-by: Philippe Mathieu-Daudé Signed-off-by: Richard Henderson --- v2: Pass guest address to handle_sigsegv_accerr_write. --- accel/tcg/user-exec.c | 101 ++++++++++++++++++++++++++++-------------------- include/exec/exec-all.h | 12 ++++++ 2 files changed, 72 insertions(+), 41 deletions(-) (limited to 'include') diff --git a/accel/tcg/user-exec.c b/accel/tcg/user-exec.c index 3f3e793b7b..b83f8d12f4 100644 --- a/accel/tcg/user-exec.c +++ b/accel/tcg/user-exec.c @@ -114,6 +114,52 @@ MMUAccessType adjust_signal_pc(uintptr_t *pc, bool is_write) return is_write ? MMU_DATA_STORE : MMU_DATA_LOAD; } +/** + * handle_sigsegv_accerr_write: + * @cpu: the cpu context + * @old_set: the sigset_t from the signal ucontext_t + * @host_pc: the host pc, adjusted for the signal + * @guest_addr: the guest address of the fault + * + * Return true if the write fault has been handled, and should be re-tried. + * + * Note that it is important that we don't call page_unprotect() unless + * this is really a "write to nonwriteable page" fault, because + * page_unprotect() assumes that if it is called for an access to + * a page that's writeable this means we had two threads racing and + * another thread got there first and already made the page writeable; + * so we will retry the access. If we were to call page_unprotect() + * for some other kind of fault that should really be passed to the + * guest, we'd end up in an infinite loop of retrying the faulting access. + */ +bool handle_sigsegv_accerr_write(CPUState *cpu, sigset_t *old_set, + uintptr_t host_pc, abi_ptr guest_addr) +{ + switch (page_unprotect(guest_addr, host_pc)) { + case 0: + /* + * Fault not caused by a page marked unwritable to protect + * cached translations, must be the guest binary's problem. + */ + return false; + case 1: + /* + * Fault caused by protection of cached translation; TBs + * invalidated, so resume execution. + */ + return true; + case 2: + /* + * Fault caused by protection of cached translation, and the + * currently executing TB was modified and must be exited immediately. + */ + cpu_exit_tb_from_sighandler(cpu, old_set); + /* NORETURN */ + default: + g_assert_not_reached(); + } +} + /* * 'pc' is the host PC at which the exception was raised. * 'address' is the effective address of the memory exception. @@ -125,8 +171,9 @@ static inline int handle_cpu_signal(uintptr_t pc, siginfo_t *info, { CPUState *cpu = current_cpu; CPUClass *cc; - unsigned long address = (unsigned long)info->si_addr; + unsigned long host_addr = (unsigned long)info->si_addr; MMUAccessType access_type = adjust_signal_pc(&pc, is_write); + abi_ptr guest_addr; /* For synchronous signals we expect to be coming from the vCPU * thread (so current_cpu should be valid) and either from running @@ -143,49 +190,21 @@ static inline int handle_cpu_signal(uintptr_t pc, siginfo_t *info, #if defined(DEBUG_SIGNAL) printf("qemu: SIGSEGV pc=0x%08lx address=%08lx w=%d oldset=0x%08lx\n", - pc, address, is_write, *(unsigned long *)old_set); + pc, host_addr, is_write, *(unsigned long *)old_set); #endif - /* XXX: locking issue */ - /* Note that it is important that we don't call page_unprotect() unless - * this is really a "write to nonwriteable page" fault, because - * page_unprotect() assumes that if it is called for an access to - * a page that's writeable this means we had two threads racing and - * another thread got there first and already made the page writeable; - * so we will retry the access. If we were to call page_unprotect() - * for some other kind of fault that should really be passed to the - * guest, we'd end up in an infinite loop of retrying the faulting - * access. - */ - if (is_write && info->si_signo == SIGSEGV && info->si_code == SEGV_ACCERR && - h2g_valid(address)) { - switch (page_unprotect(h2g(address), pc)) { - case 0: - /* Fault not caused by a page marked unwritable to protect - * cached translations, must be the guest binary's problem. - */ - break; - case 1: - /* Fault caused by protection of cached translation; TBs - * invalidated, so resume execution. Retain helper_retaddr - * for a possible second fault. - */ - return 1; - case 2: - /* Fault caused by protection of cached translation, and the - * currently executing TB was modified and must be exited - * immediately. Clear helper_retaddr for next execution. - */ - cpu_exit_tb_from_sighandler(cpu, old_set); - /* NORETURN */ - - default: - g_assert_not_reached(); - } - } /* Convert forcefully to guest address space, invalid addresses are still valid segv ones */ - address = h2g_nocheck(address); + guest_addr = h2g_nocheck(host_addr); + + /* XXX: locking issue */ + if (is_write && + info->si_signo == SIGSEGV && + info->si_code == SEGV_ACCERR && + h2g_valid(host_addr) && + handle_sigsegv_accerr_write(cpu, old_set, pc, guest_addr)) { + return 1; + } /* * There is no way the target can handle this other than raising @@ -194,7 +213,7 @@ static inline int handle_cpu_signal(uintptr_t pc, siginfo_t *info, sigprocmask(SIG_SETMASK, old_set, NULL); cc = CPU_GET_CLASS(cpu); - cc->tcg_ops->tlb_fill(cpu, address, 0, access_type, + cc->tcg_ops->tlb_fill(cpu, guest_addr, 0, access_type, MMU_USER_IDX, false, pc); g_assert_not_reached(); } diff --git a/include/exec/exec-all.h b/include/exec/exec-all.h index e54f8e5d65..5f94d799aa 100644 --- a/include/exec/exec-all.h +++ b/include/exec/exec-all.h @@ -673,6 +673,18 @@ static inline tb_page_addr_t get_page_addr_code_hostp(CPUArchState *env, */ MMUAccessType adjust_signal_pc(uintptr_t *pc, bool is_write); +/** + * handle_sigsegv_accerr_write: + * @cpu: the cpu context + * @old_set: the sigset_t from the signal ucontext_t + * @host_pc: the host pc, adjusted for the signal + * @host_addr: the host address of the fault + * + * Return true if the write fault has been handled, and should be re-tried. + */ +bool handle_sigsegv_accerr_write(CPUState *cpu, sigset_t *old_set, + uintptr_t host_pc, abi_ptr guest_addr); + /** * cpu_signal_handler * @signum: host signal number -- cgit v1.2.3-55-g7522 From 04de121aaf0c896812792eb8489ae614c7f6dade Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Fri, 17 Sep 2021 12:00:31 -0700 Subject: linux-user/signal: Drop HOST_SIGNAL_PLACEHOLDER Now that all of the linux-user hosts have been converted to host-signal.h, drop the compatibility code. Reviewed by: Warner Losh Reviewed-by: Philippe Mathieu-Daudé Signed-off-by: Richard Henderson --- include/exec/exec-all.h | 12 ------------ linux-user/signal.c | 14 -------------- 2 files changed, 26 deletions(-) (limited to 'include') diff --git a/include/exec/exec-all.h b/include/exec/exec-all.h index 5f94d799aa..5dd663c153 100644 --- a/include/exec/exec-all.h +++ b/include/exec/exec-all.h @@ -685,18 +685,6 @@ MMUAccessType adjust_signal_pc(uintptr_t *pc, bool is_write); bool handle_sigsegv_accerr_write(CPUState *cpu, sigset_t *old_set, uintptr_t host_pc, abi_ptr guest_addr); -/** - * cpu_signal_handler - * @signum: host signal number - * @pinfo: host siginfo_t - * @puc: host ucontext_t - * - * To be called from the SIGBUS and SIGSEGV signal handler to inform the - * virtual cpu of exceptions. Returns true if the signal was handled by - * the virtual CPU. - */ -int cpu_signal_handler(int signum, void *pinfo, void *puc); - #else static inline void mmap_lock(void) {} static inline void mmap_unlock(void) {} diff --git a/linux-user/signal.c b/linux-user/signal.c index 6900acb122..b816678ba5 100644 --- a/linux-user/signal.c +++ b/linux-user/signal.c @@ -780,17 +780,6 @@ static void host_signal_handler(int host_sig, siginfo_t *info, void *puc) 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_sig == SIGSEGV || host_sig == SIGBUS) - && info->si_code > 0) { - if (cpu_signal_handler(host_sig, info, puc)) { - return; - } - } -#else uintptr_t pc = 0; bool sync_sig = false; @@ -850,7 +839,6 @@ static void host_signal_handler(int host_sig, siginfo_t *info, void *puc) sync_sig = true; } -#endif /* get target signal number */ guest_sig = host_to_target_signal(host_sig); @@ -865,7 +853,6 @@ static void host_signal_handler(int host_sig, siginfo_t *info, void *puc) 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 @@ -875,7 +862,6 @@ static void host_signal_handler(int host_sig, siginfo_t *info, void *puc) cpu->exception_index = EXCP_INTERRUPT; cpu_loop_exit_restore(cpu, pc); } -#endif rewind_if_in_safe_syscall(puc); -- cgit v1.2.3-55-g7522 From 09e94676ade52708cbece8fd4bd255a25b6ee475 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Fri, 17 Sep 2021 17:31:33 -0700 Subject: hw/core: Add TCGCPUOps.record_sigsegv Add a new user-only interface for updating cpu state before raising a signal. This will replace tlb_fill for user-only and should result in less boilerplate for each guest. Reviewed-by: Philippe Mathieu-Daudé Signed-off-by: Richard Henderson --- include/hw/core/tcg-cpu-ops.h | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) (limited to 'include') diff --git a/include/hw/core/tcg-cpu-ops.h b/include/hw/core/tcg-cpu-ops.h index 6cbe17f2e6..41718b695b 100644 --- a/include/hw/core/tcg-cpu-ops.h +++ b/include/hw/core/tcg-cpu-ops.h @@ -111,6 +111,32 @@ struct TCGCPUOps { */ bool (*io_recompile_replay_branch)(CPUState *cpu, const TranslationBlock *tb); +#else + /** + * record_sigsegv: + * @cpu: cpu context + * @addr: faulting guest address + * @access_type: access was read/write/execute + * @maperr: true for invalid page, false for permission fault + * @ra: host pc for unwinding + * + * We are about to raise SIGSEGV with si_code set for @maperr, + * and si_addr set for @addr. Record anything further needed + * for the signal ucontext_t. + * + * If the emulated kernel does not provide anything to the signal + * handler with anything besides the user context registers, and + * the siginfo_t, then this hook need do nothing and may be omitted. + * Otherwise, record the data and return; the caller will raise + * the signal, unwind the cpu state, and return to the main loop. + * + * If it is simpler to re-use the sysemu tlb_fill code, @ra is provided + * so that a "normal" cpu exception can be raised. In this case, + * the signal must be raised by the architecture cpu_loop. + */ + void (*record_sigsegv)(CPUState *cpu, vaddr addr, + MMUAccessType access_type, + bool maperr, uintptr_t ra); #endif /* CONFIG_SOFTMMU */ #endif /* NEED_CPU_H */ -- cgit v1.2.3-55-g7522 From 72d2bbf9ff3e1edf5d57b53149eeaa36f19fb891 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Fri, 17 Sep 2021 17:32:56 -0700 Subject: linux-user: Add cpu_loop_exit_sigsegv This is a new interface to be provided by the os emulator for raising SIGSEGV on fault. Use the new record_sigsegv target hook. Reviewed by: Warner Losh Reviewed-by: Philippe Mathieu-Daudé Signed-off-by: Richard Henderson --- accel/tcg/user-exec.c | 33 ++++++++++++++++++--------------- include/exec/exec-all.h | 15 +++++++++++++++ linux-user/signal.c | 30 ++++++++++++++++++++++-------- 3 files changed, 55 insertions(+), 23 deletions(-) (limited to 'include') diff --git a/accel/tcg/user-exec.c b/accel/tcg/user-exec.c index a0cba61e83..c4f69908e9 100644 --- a/accel/tcg/user-exec.c +++ b/accel/tcg/user-exec.c @@ -141,35 +141,38 @@ static int probe_access_internal(CPUArchState *env, target_ulong addr, int fault_size, MMUAccessType access_type, bool nonfault, uintptr_t ra) { - int flags; + int acc_flag; + bool maperr; switch (access_type) { case MMU_DATA_STORE: - flags = PAGE_WRITE; + acc_flag = PAGE_WRITE_ORG; break; case MMU_DATA_LOAD: - flags = PAGE_READ; + acc_flag = PAGE_READ; break; case MMU_INST_FETCH: - flags = PAGE_EXEC; + acc_flag = PAGE_EXEC; break; default: g_assert_not_reached(); } - if (!guest_addr_valid_untagged(addr) || - page_check_range(addr, 1, flags) < 0) { - if (nonfault) { - return TLB_INVALID_MASK; - } else { - CPUState *cpu = env_cpu(env); - CPUClass *cc = CPU_GET_CLASS(cpu); - cc->tcg_ops->tlb_fill(cpu, addr, fault_size, access_type, - MMU_USER_IDX, false, ra); - g_assert_not_reached(); + if (guest_addr_valid_untagged(addr)) { + int page_flags = page_get_flags(addr); + if (page_flags & acc_flag) { + return 0; /* success */ } + maperr = !(page_flags & PAGE_VALID); + } else { + maperr = true; + } + + if (nonfault) { + return TLB_INVALID_MASK; } - return 0; + + cpu_loop_exit_sigsegv(env_cpu(env), addr, access_type, maperr, ra); } int probe_access_flags(CPUArchState *env, target_ulong addr, diff --git a/include/exec/exec-all.h b/include/exec/exec-all.h index 5dd663c153..f74578500c 100644 --- a/include/exec/exec-all.h +++ b/include/exec/exec-all.h @@ -685,6 +685,21 @@ MMUAccessType adjust_signal_pc(uintptr_t *pc, bool is_write); bool handle_sigsegv_accerr_write(CPUState *cpu, sigset_t *old_set, uintptr_t host_pc, abi_ptr guest_addr); +/** + * cpu_loop_exit_sigsegv: + * @cpu: the cpu context + * @addr: the guest address of the fault + * @access_type: access was read/write/execute + * @maperr: true for invalid page, false for permission fault + * @ra: host pc for unwinding + * + * Use the TCGCPUOps hook to record cpu state, do guest operating system + * specific things to raise SIGSEGV, and jump to the main cpu loop. + */ +void QEMU_NORETURN cpu_loop_exit_sigsegv(CPUState *cpu, target_ulong addr, + MMUAccessType access_type, + bool maperr, uintptr_t ra); + #else static inline void mmap_lock(void) {} static inline void mmap_unlock(void) {} diff --git a/linux-user/signal.c b/linux-user/signal.c index b816678ba5..135983747d 100644 --- a/linux-user/signal.c +++ b/linux-user/signal.c @@ -688,9 +688,27 @@ void force_sigsegv(int oldsig) } force_sig(TARGET_SIGSEGV); } - #endif +void cpu_loop_exit_sigsegv(CPUState *cpu, target_ulong addr, + MMUAccessType access_type, bool maperr, uintptr_t ra) +{ + const struct TCGCPUOps *tcg_ops = CPU_GET_CLASS(cpu)->tcg_ops; + + if (tcg_ops->record_sigsegv) { + tcg_ops->record_sigsegv(cpu, addr, access_type, maperr, ra); + } else if (tcg_ops->tlb_fill) { + tcg_ops->tlb_fill(cpu, addr, 0, access_type, MMU_USER_IDX, false, ra); + g_assert_not_reached(); + } + + force_sig_fault(TARGET_SIGSEGV, + maperr ? TARGET_SEGV_MAPERR : TARGET_SEGV_ACCERR, + addr); + cpu->exception_index = EXCP_INTERRUPT; + cpu_loop_exit_restore(cpu, ra); +} + /* abort execution with signal */ static void QEMU_NORETURN dump_core_and_abort(int target_sig) { @@ -806,7 +824,7 @@ static void host_signal_handler(int host_sig, siginfo_t *info, void *puc) access_type = adjust_signal_pc(&pc, is_write); if (host_sig == SIGSEGV) { - const struct TCGCPUOps *tcg_ops; + bool maperr = true; if (info->si_code == SEGV_ACCERR && h2g_valid(host_addr)) { /* If this was a write to a TB protected page, restart. */ @@ -821,18 +839,14 @@ static void host_signal_handler(int host_sig, siginfo_t *info, void *puc) * which means that we may get ACCERR when we want MAPERR. */ if (page_get_flags(guest_addr) & PAGE_VALID) { - /* maperr = false; */ + 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(); + cpu_loop_exit_sigsegv(cpu, guest_addr, access_type, maperr, pc); } else { sigprocmask(SIG_SETMASK, &uc->uc_sigmask, NULL); } -- cgit v1.2.3-55-g7522 From eeca7dc566076d6130d986e17508372bc7916281 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Wed, 15 Sep 2021 08:13:38 -0700 Subject: accel/tcg: Restrict TCGCPUOps::tlb_fill() to sysemu We have replaced tlb_fill with record_sigsegv for user mode. Move the declaration to restrict it to system emulation. Reviewed-by: Philippe Mathieu-Daudé Signed-off-by: Richard Henderson --- include/hw/core/tcg-cpu-ops.h | 22 ++++++++++------------ linux-user/signal.c | 3 --- 2 files changed, 10 insertions(+), 15 deletions(-) (limited to 'include') diff --git a/include/hw/core/tcg-cpu-ops.h b/include/hw/core/tcg-cpu-ops.h index 41718b695b..8eadd404c8 100644 --- a/include/hw/core/tcg-cpu-ops.h +++ b/include/hw/core/tcg-cpu-ops.h @@ -35,18 +35,6 @@ struct TCGCPUOps { void (*cpu_exec_enter)(CPUState *cpu); /** @cpu_exec_exit: Callback for cpu_exec cleanup */ void (*cpu_exec_exit)(CPUState *cpu); - /** - * @tlb_fill: Handle a softmmu tlb miss or user-only address fault - * - * For system mode, if the access is valid, call tlb_set_page - * and return true; if the access is invalid, and probe is - * true, return false; otherwise raise an exception and do - * not return. For user-only mode, always raise an exception - * and do not return. - */ - bool (*tlb_fill)(CPUState *cpu, vaddr address, int size, - MMUAccessType access_type, int mmu_idx, - bool probe, uintptr_t retaddr); /** @debug_excp_handler: Callback for handling debug exceptions */ void (*debug_excp_handler)(CPUState *cpu); @@ -68,6 +56,16 @@ struct TCGCPUOps { #ifdef CONFIG_SOFTMMU /** @cpu_exec_interrupt: Callback for processing interrupts in cpu_exec */ bool (*cpu_exec_interrupt)(CPUState *cpu, int interrupt_request); + /** + * @tlb_fill: Handle a softmmu tlb miss + * + * If the access is valid, call tlb_set_page and return true; + * if the access is invalid and probe is true, return false; + * otherwise raise an exception and do not return. + */ + bool (*tlb_fill)(CPUState *cpu, vaddr address, int size, + MMUAccessType access_type, int mmu_idx, + bool probe, uintptr_t retaddr); /** * @do_transaction_failed: Callback for handling failed memory transactions * (ie bus faults or external aborts; not MMU faults) diff --git a/linux-user/signal.c b/linux-user/signal.c index 135983747d..9d60abc038 100644 --- a/linux-user/signal.c +++ b/linux-user/signal.c @@ -697,9 +697,6 @@ void cpu_loop_exit_sigsegv(CPUState *cpu, target_ulong addr, if (tcg_ops->record_sigsegv) { tcg_ops->record_sigsegv(cpu, addr, access_type, maperr, ra); - } else if (tcg_ops->tlb_fill) { - tcg_ops->tlb_fill(cpu, addr, 0, access_type, MMU_USER_IDX, false, ra); - g_assert_not_reached(); } force_sig_fault(TARGET_SIGSEGV, -- cgit v1.2.3-55-g7522 From 644a9fece426d52cf8fb51e24e003dd4c590c5cc Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Mon, 4 Oct 2021 10:05:20 -0700 Subject: hw/core: Add TCGCPUOps.record_sigbus Add a new user-only interface for updating cpu state before raising a signal. This will take the place of do_unaligned_access for user-only and should result in less boilerplate for each guest. Reviewed-by: Warner Losh Signed-off-by: Richard Henderson --- include/hw/core/tcg-cpu-ops.h | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) (limited to 'include') diff --git a/include/hw/core/tcg-cpu-ops.h b/include/hw/core/tcg-cpu-ops.h index 8eadd404c8..e13898553a 100644 --- a/include/hw/core/tcg-cpu-ops.h +++ b/include/hw/core/tcg-cpu-ops.h @@ -135,6 +135,29 @@ struct TCGCPUOps { void (*record_sigsegv)(CPUState *cpu, vaddr addr, MMUAccessType access_type, bool maperr, uintptr_t ra); + /** + * record_sigbus: + * @cpu: cpu context + * @addr: misaligned guest address + * @access_type: access was read/write/execute + * @ra: host pc for unwinding + * + * We are about to raise SIGBUS with si_code BUS_ADRALN, + * and si_addr set for @addr. Record anything further needed + * for the signal ucontext_t. + * + * If the emulated kernel does not provide the signal handler with + * anything besides the user context registers, and the siginfo_t, + * then this hook need do nothing and may be omitted. + * Otherwise, record the data and return; the caller will raise + * the signal, unwind the cpu state, and return to the main loop. + * + * If it is simpler to re-use the sysemu do_unaligned_access code, + * @ra is provided so that a "normal" cpu exception can be raised. + * In this case, the signal must be raised by the architecture cpu_loop. + */ + void (*record_sigbus)(CPUState *cpu, vaddr addr, + MMUAccessType access_type, uintptr_t ra); #endif /* CONFIG_SOFTMMU */ #endif /* NEED_CPU_H */ -- cgit v1.2.3-55-g7522 From 12ed56407e60371d45ffa3b7f2fd00c4d7efa580 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Mon, 4 Oct 2021 10:06:10 -0700 Subject: linux-user: Add cpu_loop_exit_sigbus This is a new interface to be provided by the os emulator for raising SIGBUS on fault. Use the new record_sigbus target hook. Reviewed-by: Warner Losh Reviewed-by: Philippe Mathieu-Daudé Signed-off-by: Richard Henderson --- include/exec/exec-all.h | 14 ++++++++++++++ linux-user/signal.c | 14 ++++++++++++++ 2 files changed, 28 insertions(+) (limited to 'include') diff --git a/include/exec/exec-all.h b/include/exec/exec-all.h index f74578500c..6bb2a0f7ec 100644 --- a/include/exec/exec-all.h +++ b/include/exec/exec-all.h @@ -700,6 +700,20 @@ void QEMU_NORETURN cpu_loop_exit_sigsegv(CPUState *cpu, target_ulong addr, MMUAccessType access_type, bool maperr, uintptr_t ra); +/** + * cpu_loop_exit_sigbus: + * @cpu: the cpu context + * @addr: the guest address of the alignment fault + * @access_type: access was read/write/execute + * @ra: host pc for unwinding + * + * Use the TCGCPUOps hook to record cpu state, do guest operating system + * specific things to raise SIGBUS, and jump to the main cpu loop. + */ +void QEMU_NORETURN cpu_loop_exit_sigbus(CPUState *cpu, target_ulong addr, + MMUAccessType access_type, + uintptr_t ra); + #else static inline void mmap_lock(void) {} static inline void mmap_unlock(void) {} diff --git a/linux-user/signal.c b/linux-user/signal.c index 9d60abc038..df2c8678d0 100644 --- a/linux-user/signal.c +++ b/linux-user/signal.c @@ -706,6 +706,20 @@ void cpu_loop_exit_sigsegv(CPUState *cpu, target_ulong addr, cpu_loop_exit_restore(cpu, ra); } +void cpu_loop_exit_sigbus(CPUState *cpu, target_ulong addr, + MMUAccessType access_type, uintptr_t ra) +{ + const struct TCGCPUOps *tcg_ops = CPU_GET_CLASS(cpu)->tcg_ops; + + if (tcg_ops->record_sigbus) { + tcg_ops->record_sigbus(cpu, addr, access_type, ra); + } + + force_sig_fault(TARGET_SIGBUS, TARGET_BUS_ADRALN, addr); + cpu->exception_index = EXCP_INTERRUPT; + cpu_loop_exit_restore(cpu, ra); +} + /* abort execution with signal */ static void QEMU_NORETURN dump_core_and_abort(int target_sig) { -- cgit v1.2.3-55-g7522 From 37e891e38fe1e81fc468d8a000912f8e7ee61336 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Tue, 27 Jul 2021 19:41:04 -1000 Subject: tcg: Add helper_unaligned_{ld,st} for user-only sigbus To be called from tcg generated code on hosts that support unaligned accesses natively, in response to an access that is supposed to be aligned. Reviewed-by: Warner Losh Reviewed-by: Peter Maydell Reviewed-by: Philippe Mathieu-Daudé Signed-off-by: Richard Henderson --- accel/tcg/user-exec.c | 11 +++++++++++ include/tcg/tcg-ldst.h | 5 +++++ 2 files changed, 16 insertions(+) (limited to 'include') diff --git a/accel/tcg/user-exec.c b/accel/tcg/user-exec.c index aaf47d89d2..1528a21fad 100644 --- a/accel/tcg/user-exec.c +++ b/accel/tcg/user-exec.c @@ -27,6 +27,7 @@ #include "exec/helper-proto.h" #include "qemu/atomic128.h" #include "trace/trace-root.h" +#include "tcg/tcg-ldst.h" #include "internal.h" __thread uintptr_t helper_retaddr; @@ -215,6 +216,16 @@ static void validate_memop(MemOpIdx oi, MemOp expected) #endif } +void helper_unaligned_ld(CPUArchState *env, target_ulong addr) +{ + cpu_loop_exit_sigbus(env_cpu(env), addr, MMU_DATA_LOAD, GETPC()); +} + +void helper_unaligned_st(CPUArchState *env, target_ulong addr) +{ + cpu_loop_exit_sigbus(env_cpu(env), addr, MMU_DATA_STORE, GETPC()); +} + static void *cpu_mmu_lookup(CPUArchState *env, target_ulong addr, MemOpIdx oi, uintptr_t ra, MMUAccessType type) { diff --git a/include/tcg/tcg-ldst.h b/include/tcg/tcg-ldst.h index 8c86365611..bf40942de4 100644 --- a/include/tcg/tcg-ldst.h +++ b/include/tcg/tcg-ldst.h @@ -70,5 +70,10 @@ void helper_be_stl_mmu(CPUArchState *env, target_ulong addr, uint32_t val, void helper_be_stq_mmu(CPUArchState *env, target_ulong addr, uint64_t val, MemOpIdx oi, uintptr_t retaddr); +#else + +void QEMU_NORETURN helper_unaligned_ld(CPUArchState *env, target_ulong addr); +void QEMU_NORETURN helper_unaligned_st(CPUArchState *env, target_ulong addr); + #endif /* CONFIG_SOFTMMU */ #endif /* TCG_LDST_H */ -- cgit v1.2.3-55-g7522