From patchwork Mon Oct 4 07:44:05 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Laurent Vivier X-Patchwork-Id: 1535974 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) 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 bilbo.ozlabs.org (Postfix) with ESMTPS id 4HNCy114dFz9t25 for ; Mon, 4 Oct 2021 19:07:53 +1100 (AEDT) Received: from localhost ([::1]:49092 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mXJ0o-00073J-TI for incoming@patchwork.ozlabs.org; Mon, 04 Oct 2021 04:07:50 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:44230) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mXIeR-0004Jq-R0 for qemu-devel@nongnu.org; Mon, 04 Oct 2021 03:44:43 -0400 Received: from mout.kundenserver.de ([212.227.126.131]:33885) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mXIeM-0004sk-Vv for qemu-devel@nongnu.org; Mon, 04 Oct 2021 03:44:43 -0400 Received: from quad ([82.142.3.114]) by mrelayeu.kundenserver.de (mreue012 [212.227.15.167]) with ESMTPSA (Nemesis) id 1Mr7iw-1nBGR918Ew-00oHAM; Mon, 04 Oct 2021 09:44:29 +0200 From: Laurent Vivier To: qemu-devel@nongnu.org Subject: [PULL 10/26] linux-user/i386: Implement setup_sigtramp Date: Mon, 4 Oct 2021 09:44:05 +0200 Message-Id: <20211004074421.3141222-11-laurent@vivier.eu> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20211004074421.3141222-1-laurent@vivier.eu> References: <20211004074421.3141222-1-laurent@vivier.eu> MIME-Version: 1.0 X-Provags-ID: V03:K1:3Hn4Y6DOOZamlkovEm0vKdk0tNNiCY9r1+xDPG3nJLDaigqX7Ff QO/v0C8VWCCVNkbIzzAyxWCsm5xCNS5Qgx6a+0orfP24gPMrVV+9m+osgn/TCM3xT8HElBR OtjX+VqbuOK5LcVfo6OQZKUsgGxoj14blTiYFHKTJoZ8CqcjU4A2OOiojuEsyEMBdkGF5iX HtRSCRyT6KX3nNBqS/aqg== X-UI-Out-Filterresults: notjunk:1;V03:K0:KEL9EdmPuG4=:KAo/KQ3jH3oCeu4yqmwnND fxFE6X2insTNGQCwgfpArycwCnCq+KYVMXC5jgmkSIDKTrXIe85bhwE0QeVgWkY9S4oLJV47P F6bemA9KEhB7GcB76mrDvFuufA2PrdbrMIbdwX1kmL6r7jjoO/5V4t1l4mOLQw6Y0pXpAncsv SQp6rmVDKJal3tYEhjP0QBmjsDCtCevvabei/UR9t7TqVJ4ghd7ESCceO80BdyupCa2Dm/gvz 8/oHU4iQgIv6RxFm8wGSr7/3jOG+mE5DmZT7WMGprvefalMOzZv4Wn/Kxc0CkvVoSAV53cj/w k6Qdv6DRlD5d0VHADKYKIITq24KnQZNc4Vbt6yFHVvKgWhZG/VtlDYbzg/ZIveNWwpPWFmYSG N4S2xTzortYwYhPHLcAQq2wHDggQGEM5CIzgs0oVypw5wfpSJbIjFNqcw8DF0r0BNWja7HHr/ h/OS0F/4OwI12vwKtXKKavc+y91BFWBrA79Y6AOAIoBFQgvEDB1V8nJEZqftoGTEYXoUiccP0 I0PL0w9xuzfZS93ZmXR/59ggVWINofaZD1ArsxvQknyijyBKyF5rIxkLJDa9wLIBtR6llzqqe wPfuPWgPqDPqu5vaH+ObVzemojRyBKDQFrzMOu3YUaat9e70yT29xP1N2ulumqfIr+EvLG7Xe SnB9Y5hTuoFVvd4iuSA/TDYKN/iia2cbKlJLlsX/2N1EZBBnetPmq9fG70c3YnAIk1/CDpj30 GeG3wR0yx1bCaEfCMkzTqtaOmGCML7XDJdgxHA== Received-SPF: none client-ip=212.227.126.131; envelope-from=laurent@vivier.eu; helo=mout.kundenserver.de X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_NONE=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: Richard Henderson , =?utf-8?q?Philippe_Mat?= =?utf-8?q?hieu-Daud=C3=A9?= , Laurent Vivier Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" From: Richard Henderson 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 Message-Id: <20210929130553.121567-11-richard.henderson@linaro.org> Signed-off-by: Laurent Vivier --- linux-user/i386/signal.c | 56 +++++++++++++++++++++---------- linux-user/i386/target_signal.h | 2 ++ linux-user/x86_64/target_signal.h | 3 ++ 3 files changed, 43 insertions(+), 18 deletions(-) diff --git a/linux-user/i386/signal.c b/linux-user/i386/signal.c index 3b4b55fc0a24..b38b5f108eaf 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 diff --git a/linux-user/i386/target_signal.h b/linux-user/i386/target_signal.h index 50361af8746e..64d09f2e75bd 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 4ea74f20dd42..4673c5a88691 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 */