From 1af354120dc4d9187ee1162b95ac84aafd7c4df0 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Fri, 13 Aug 2021 14:18:04 +0100 Subject: linux-user/arm: Set siginfo_t addr field for SIGTRAP signals When generating a TRAP_BRKPT SIGTRAP, set the siginfo_t addr field to the PC where the breakpoint/singlestep trap occurred; this is what the kernel does for this signal for this architecture. Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-Id: <20210813131809.28655-3-peter.maydell@linaro.org> Signed-off-by: Laurent Vivier --- linux-user/arm/cpu_loop.c | 1 + 1 file changed, 1 insertion(+) (limited to 'linux-user/arm/cpu_loop.c') diff --git a/linux-user/arm/cpu_loop.c b/linux-user/arm/cpu_loop.c index 07032b3006..0900d18105 100644 --- a/linux-user/arm/cpu_loop.c +++ b/linux-user/arm/cpu_loop.c @@ -455,6 +455,7 @@ void cpu_loop(CPUARMState *env) info.si_signo = TARGET_SIGTRAP; info.si_errno = 0; info.si_code = TARGET_TRAP_BRKPT; + info._sifields._sigfault._addr = env->regs[15]; queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info); break; case EXCP_KERNEL_TRAP: -- cgit v1.2.3 From babe6d5c88b587d30f72f31a81ce87610b68e952 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Fri, 13 Aug 2021 14:18:05 +0100 Subject: linux-user/arm: Use force_sig() to deliver fpa11 emulation SIGFPE In the Arm target code, when the fpa11 emulation code tells us we need to send the guest a SIGFPE, we do this with queue_signal(), but we are using the wrong si_type, and we aren't setting the _sifields union members corresponding to either the si_type we are using or the si_type we should be using. As the existing comment notes, the kernel code for this calls the old send_sig() function to deliver the signal. This eventually results in the kernel's signal handling code fabricating a siginfo_t with a SI_KERNEL code and a zero pid and uid. For QEMU this means we need to use QEMU_SI_KILL. We already have a function for that: force_sig() sets up the whole target_siginfo_t the way we need it. Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-Id: <20210813131809.28655-4-peter.maydell@linaro.org> Signed-off-by: Laurent Vivier --- linux-user/arm/cpu_loop.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) (limited to 'linux-user/arm/cpu_loop.c') diff --git a/linux-user/arm/cpu_loop.c b/linux-user/arm/cpu_loop.c index 0900d18105..fb78a1aab3 100644 --- a/linux-user/arm/cpu_loop.c +++ b/linux-user/arm/cpu_loop.c @@ -268,16 +268,13 @@ static bool emulate_arm_fpa11(CPUARMState *env, uint32_t opcode) ts->fpa.fpsr |= raise & ~enabled; if (raise & enabled) { - target_siginfo_t info = { }; - /* * The kernel's nwfpe emulator does not pass a real si_code. - * It merely uses send_sig(SIGFPE, current, 1). + * It merely uses send_sig(SIGFPE, current, 1), which results in + * __send_signal() filling out SI_KERNEL with pid and uid 0 (under + * the "SEND_SIG_PRIV" case). That's what our force_sig() does. */ - info.si_signo = TARGET_SIGFPE; - info.si_code = TARGET_SI_KERNEL; - - queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info); + force_sig(TARGET_SIGFPE); } else { env->regs[15] += 4; } -- cgit v1.2.3 From 4c90f0ba9d949073935b320aefd133b4d369f70a Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Fri, 13 Aug 2021 14:18:08 +0100 Subject: linux-user/arm: Use force_sig_fault() Use the new force_sig_fault() function instead of setting up a target_siginfo_t and calling queue_signal(). Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-Id: <20210813131809.28655-7-peter.maydell@linaro.org> Signed-off-by: Laurent Vivier --- linux-user/arm/cpu_loop.c | 53 ++++++++++++++--------------------------------- 1 file changed, 15 insertions(+), 38 deletions(-) (limited to 'linux-user/arm/cpu_loop.c') diff --git a/linux-user/arm/cpu_loop.c b/linux-user/arm/cpu_loop.c index fb78a1aab3..ae09adcb95 100644 --- a/linux-user/arm/cpu_loop.c +++ b/linux-user/arm/cpu_loop.c @@ -94,7 +94,6 @@ static void arm_kernel_cmpxchg64_helper(CPUARMState *env) { uint64_t oldval, newval, val; uint32_t addr, cpsr; - target_siginfo_t info; /* Based on the 32 bit code in do_kernel_trap */ @@ -143,12 +142,9 @@ segv: end_exclusive(); /* We get the PC of the entry address - which is as good as anything, on a real kernel what you get depends on which mode it uses. */ - info.si_signo = TARGET_SIGSEGV; - info.si_errno = 0; /* XXX: check env->error_code */ - info.si_code = TARGET_SEGV_MAPERR; - info._sifields._sigfault._addr = env->exception.vaddress; - queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info); + force_sig_fault(TARGET_SIGSEGV, TARGET_SEGV_MAPERR, + env->exception.vaddress); } /* Handle a jump to the kernel code page. */ @@ -286,8 +282,6 @@ void cpu_loop(CPUARMState *env) CPUState *cs = env_cpu(env); int trapnr; unsigned int n, insn; - target_siginfo_t info; - uint32_t addr; abi_ulong ret; for(;;) { @@ -322,11 +316,8 @@ void cpu_loop(CPUARMState *env) break; } - info.si_signo = TARGET_SIGILL; - info.si_errno = 0; - info.si_code = TARGET_ILL_ILLOPN; - info._sifields._sigfault._addr = env->regs[15]; - queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info); + force_sig_fault(TARGET_SIGILL, TARGET_ILL_ILLOPN, + env->regs[15]); } break; case EXCP_SWI: @@ -394,18 +385,14 @@ void cpu_loop(CPUARMState *env) * Otherwise SIGILL. This includes any SWI with * immediate not originally 0x9fxxxx, because * of the earlier XOR. + * Like the real kernel, we report the addr of the + * SWI in the siginfo si_addr but leave the PC + * pointing at the insn after the SWI. */ - info.si_signo = TARGET_SIGILL; - info.si_errno = 0; - info.si_code = TARGET_ILL_ILLTRP; - info._sifields._sigfault._addr = env->regs[15]; - if (env->thumb) { - info._sifields._sigfault._addr -= 2; - } else { - info._sifields._sigfault._addr -= 4; - } - queue_signal(env, info.si_signo, - QEMU_SI_FAULT, &info); + abi_ulong faultaddr = env->regs[15]; + faultaddr -= env->thumb ? 2 : 4; + force_sig_fault(TARGET_SIGILL, TARGET_ILL_ILLTRP, + faultaddr); } break; } @@ -436,24 +423,14 @@ void cpu_loop(CPUARMState *env) break; case EXCP_PREFETCH_ABORT: case EXCP_DATA_ABORT: - addr = env->exception.vaddress; - { - info.si_signo = TARGET_SIGSEGV; - info.si_errno = 0; - /* XXX: check env->error_code */ - info.si_code = TARGET_SEGV_MAPERR; - info._sifields._sigfault._addr = addr; - queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info); - } + /* XXX: check env->error_code */ + force_sig_fault(TARGET_SIGSEGV, TARGET_SEGV_MAPERR, + env->exception.vaddress); break; case EXCP_DEBUG: case EXCP_BKPT: excp_debug: - info.si_signo = TARGET_SIGTRAP; - info.si_errno = 0; - info.si_code = TARGET_TRAP_BRKPT; - info._sifields._sigfault._addr = env->regs[15]; - queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info); + force_sig_fault(TARGET_SIGTRAP, TARGET_TRAP_BRKPT, env->regs[15]); break; case EXCP_KERNEL_TRAP: if (do_kernel_trap(env)) -- cgit v1.2.3