From nobody Wed Feb 11 03:44:01 2026 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1633334980717961.2620930294812; Mon, 4 Oct 2021 01:09:40 -0700 (PDT) Received: from localhost ([::1]:53154 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mXJ2Z-0001Xi-FV for importer@patchew.org; Mon, 04 Oct 2021 04:09:39 -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 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable 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: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; 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=20Mathieu-Daud=C3=A9?= , Laurent Vivier Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZM-MESSAGEID: 1633334982545100001 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-Daud=C3=A9 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) } =20 #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 =3D frame_addr + offsetof(struct sigframe, retcode); - __put_user(retcode_addr, &frame->pretcode); - /* This is popl %eax ; movl $,%eax ; int $0x80 */ - val16 =3D 0xb858; - __put_user(val16, (uint16_t *)(frame->retcode+0)); - __put_user(TARGET_NR_sigreturn, (int *)(frame->retcode+2)); - val16 =3D 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); } =20 /* 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 =3D 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 =3D 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 =3D lock_user(VERIFY_WRITE, sigtramp_page, 2 * 8, 0); + assert(tramp !=3D NULL); + + default_sigreturn =3D sigtramp_page; + install_sigtramp(tramp); + + default_rt_sigreturn =3D 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_signa= l.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" =20 #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_s= ignal.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 { =20 #include "../generic/signal.h" =20 +/* For x86_64, use of SA_RESTORER is mandatory. */ +#define TARGET_ARCH_HAS_SIGTRAMP_PAGE 0 + #endif /* X86_64_TARGET_SIGNAL_H */ --=20 2.31.1