From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9169BC433EF for ; Wed, 29 Sep 2021 13:20:29 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 0372F61216 for ; Wed, 29 Sep 2021 13:20:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 0372F61216 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linaro.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from localhost ([::1]:35734 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mVZVc-0003RC-0n for qemu-devel@archiver.kernel.org; Wed, 29 Sep 2021 09:20:28 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:39292) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mVZI0-0006s9-Ik for qemu-devel@nongnu.org; Wed, 29 Sep 2021 09:06:24 -0400 Received: from mail-ot1-x333.google.com ([2607:f8b0:4864:20::333]:46878) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1mVZHy-0006C0-0K for qemu-devel@nongnu.org; Wed, 29 Sep 2021 09:06:23 -0400 Received: by mail-ot1-x333.google.com with SMTP id o59-20020a9d2241000000b0054745f28c69so2708408ota.13 for ; Wed, 29 Sep 2021 06:06:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=/JBwXy3z5lR+XAAxPTtDygRF9ftMDjdSwtnKr4eEXKE=; b=Zn2ExfFG6FFHnTnWDlW/TO4P81U/lrd6S7owvw16ltEgEHafFUATWLp7XDFMDwr0cY fXcf3oasfOVA+PODZ+YrPhA0Q3sPPsNV3EDoqptsMD0lZ7AXP7ySw1YUtEI1qIOHTRXO x5NYx40Igo3GSHrmWD/b8lnZXhl4FgRA2eJXzA+eZcGJcTXjk5yAcEvThrd1a7DyUS6k D/IzOQJxpNaMBQSB96i04g1oeXXSkMicsgu2yaItPYxChoPC6YSUO/2yiQyuc/OcBuqk 29wSRNl4ZWkCxTVHgng3XJ31FLYrf7BspvVgH4pbKVcO/E4LkChKxBl8IO1ESKkaUfSP 4lvA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=/JBwXy3z5lR+XAAxPTtDygRF9ftMDjdSwtnKr4eEXKE=; b=uSTR6ETO66J8YubVHJyhjKA5suECkdYdz8G6QYtV7hGEeoNr9d9DLxsRTXmu62HTm5 t/0ukIWXgjTeSwF32a4MbYGka2SceXGpY6wHRXKWmNE3oyXuwA1tw3F5t6q+nNj7NssO KSlzMYuhenGTx0RdWje1dPxxKiQZGhVUGltI13kS/uiVvkPkhuXNMHl7Ut08K/inqTPN mt3wlvVPUeFVTUYNj/ET4RrQX9+azm8o11Ae4CiCD2xKzptRs3hyQpw51DThd9QDdkwZ rmYutQG2RRtOwrNAqp6TrTgSmE53DKLUwiv8Y8dn9EhS6xdmdpJxQMmxQaz+ZdJy2xFC yXgw== X-Gm-Message-State: AOAM533bP5jc3Y5URipXOOcfBd9Z6krJys0bw6PLQHiupB6bti20QTRd EvoWh3dsqyLMO6E9IX8j8z63eNX8muAXdQ== X-Google-Smtp-Source: ABdhPJwFmMDhkw3dRBtDjBiBeMlnResamYTz0eRG01V0uo4/o+uRnjxtvJVOJb074jDdEe5w9sHLWA== X-Received: by 2002:a9d:7746:: with SMTP id t6mr10167697otl.72.1632920780755; Wed, 29 Sep 2021 06:06:20 -0700 (PDT) Received: from localhost.localdomain ([172.58.171.248]) by smtp.gmail.com with ESMTPSA id w1sm442823ote.41.2021.09.29.06.06.19 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 29 Sep 2021 06:06:20 -0700 (PDT) From: Richard Henderson To: qemu-devel@nongnu.org Subject: [PATCH v5 10/26] linux-user/i386: Implement setup_sigtramp Date: Wed, 29 Sep 2021 09:05:37 -0400 Message-Id: <20210929130553.121567-11-richard.henderson@linaro.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210929130553.121567-1-richard.henderson@linaro.org> References: <20210929130553.121567-1-richard.henderson@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=2607:f8b0:4864:20::333; envelope-from=richard.henderson@linaro.org; helo=mail-ot1-x333.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: alex.bennee@linaro.org, laurent@vivier.eu, =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Create and record the two signal trampolines. Use them when the guest does not use SA_RESTORER. Note that x86_64 does not use this code. Reviewed-by: Philippe Mathieu-Daudé Signed-off-by: Richard Henderson --- linux-user/i386/target_signal.h | 2 ++ linux-user/x86_64/target_signal.h | 3 ++ linux-user/i386/signal.c | 56 +++++++++++++++++++++---------- 3 files changed, 43 insertions(+), 18 deletions(-) diff --git a/linux-user/i386/target_signal.h b/linux-user/i386/target_signal.h index 50361af874..64d09f2e75 100644 --- a/linux-user/i386/target_signal.h +++ b/linux-user/i386/target_signal.h @@ -22,4 +22,6 @@ typedef struct target_sigaltstack { #include "../generic/signal.h" #define TARGET_ARCH_HAS_SETUP_FRAME +#define TARGET_ARCH_HAS_SIGTRAMP_PAGE 1 + #endif /* I386_TARGET_SIGNAL_H */ diff --git a/linux-user/x86_64/target_signal.h b/linux-user/x86_64/target_signal.h index 4ea74f20dd..4673c5a886 100644 --- a/linux-user/x86_64/target_signal.h +++ b/linux-user/x86_64/target_signal.h @@ -21,4 +21,7 @@ typedef struct target_sigaltstack { #include "../generic/signal.h" +/* For x86_64, use of SA_RESTORER is mandatory. */ +#define TARGET_ARCH_HAS_SIGTRAMP_PAGE 0 + #endif /* X86_64_TARGET_SIGNAL_H */ diff --git a/linux-user/i386/signal.c b/linux-user/i386/signal.c index 3b4b55fc0a..b38b5f108e 100644 --- a/linux-user/i386/signal.c +++ b/linux-user/i386/signal.c @@ -310,6 +310,22 @@ get_sigframe(struct target_sigaction *ka, CPUX86State *env, size_t frame_size) } #ifndef TARGET_X86_64 +static void install_sigtramp(void *tramp) +{ + /* This is popl %eax ; movl $syscall,%eax ; int $0x80 */ + __put_user(0xb858, (uint16_t *)(tramp + 0)); + __put_user(TARGET_NR_sigreturn, (int32_t *)(tramp + 2)); + __put_user(0x80cd, (uint16_t *)(tramp + 6)); +} + +static void install_rt_sigtramp(void *tramp) +{ + /* This is movl $syscall,%eax ; int $0x80 */ + __put_user(0xb8, (uint8_t *)(tramp + 0)); + __put_user(TARGET_NR_rt_sigreturn, (int32_t *)(tramp + 1)); + __put_user(0x80cd, (uint16_t *)(tramp + 5)); +} + /* compare linux/arch/i386/kernel/signal.c:setup_frame() */ void setup_frame(int sig, struct target_sigaction *ka, target_sigset_t *set, CPUX86State *env) @@ -338,16 +354,9 @@ void setup_frame(int sig, struct target_sigaction *ka, if (ka->sa_flags & TARGET_SA_RESTORER) { __put_user(ka->sa_restorer, &frame->pretcode); } else { - uint16_t val16; - abi_ulong retcode_addr; - retcode_addr = frame_addr + offsetof(struct sigframe, retcode); - __put_user(retcode_addr, &frame->pretcode); - /* This is popl %eax ; movl $,%eax ; int $0x80 */ - val16 = 0xb858; - __put_user(val16, (uint16_t *)(frame->retcode+0)); - __put_user(TARGET_NR_sigreturn, (int *)(frame->retcode+2)); - val16 = 0x80cd; - __put_user(val16, (uint16_t *)(frame->retcode+6)); + /* This is no longer used, but is retained for ABI compatibility. */ + install_sigtramp(frame->retcode); + __put_user(default_sigreturn, &frame->pretcode); } /* Set up registers for signal handler */ @@ -416,14 +425,9 @@ void setup_rt_frame(int sig, struct target_sigaction *ka, if (ka->sa_flags & TARGET_SA_RESTORER) { __put_user(ka->sa_restorer, &frame->pretcode); } else { - uint16_t val16; - addr = frame_addr + offsetof(struct rt_sigframe, retcode); - __put_user(addr, &frame->pretcode); - /* This is movl $,%eax ; int $0x80 */ - __put_user(0xb8, (char *)(frame->retcode+0)); - __put_user(TARGET_NR_rt_sigreturn, (int *)(frame->retcode+1)); - val16 = 0x80cd; - __put_user(val16, (uint16_t *)(frame->retcode+5)); + /* This is no longer used, but is retained for ABI compatibility. */ + install_rt_sigtramp(frame->retcode); + __put_user(default_rt_sigreturn, &frame->pretcode); } #else /* XXX: Would be slightly better to return -EFAULT here if test fails @@ -592,3 +596,19 @@ badframe: force_sig(TARGET_SIGSEGV); return -TARGET_QEMU_ESIGRETURN; } + +#ifndef TARGET_X86_64 +void setup_sigtramp(abi_ulong sigtramp_page) +{ + uint16_t *tramp = lock_user(VERIFY_WRITE, sigtramp_page, 2 * 8, 0); + assert(tramp != NULL); + + default_sigreturn = sigtramp_page; + install_sigtramp(tramp); + + default_rt_sigreturn = sigtramp_page + 8; + install_rt_sigtramp(tramp + 8); + + unlock_user(tramp, sigtramp_page, 2 * 8); +} +#endif -- 2.25.1