From nobody Mon Feb 9 23:03:01 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 1641466829415162.27050865674744; Thu, 6 Jan 2022 03:00:29 -0800 (PST) Received: from localhost ([::1]:40794 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1n5QVQ-00084R-B1 for importer@patchew.org; Thu, 06 Jan 2022 06:00:28 -0500 Received: from eggs.gnu.org ([209.51.188.92]:60980) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1n5QDZ-0007nh-H4 for qemu-devel@nongnu.org; Thu, 06 Jan 2022 05:42:01 -0500 Received: from mout.kundenserver.de ([212.227.126.133]:59149) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1n5QDR-0004k0-Sj for qemu-devel@nongnu.org; Thu, 06 Jan 2022 05:42:00 -0500 Received: from quad ([82.142.12.178]) by mrelayeu.kundenserver.de (mreue012 [212.227.15.167]) with ESMTPSA (Nemesis) id 1MEUaQ-1nBWsf3hRS-00Fz6D; Thu, 06 Jan 2022 11:41:52 +0100 From: Laurent Vivier To: qemu-devel@nongnu.org Subject: [PULL 20/27] linux-user/nios2: Map a real kuser page Date: Thu, 6 Jan 2022 11:41:30 +0100 Message-Id: <20220106104137.732883-21-laurent@vivier.eu> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20220106104137.732883-1-laurent@vivier.eu> References: <20220106104137.732883-1-laurent@vivier.eu> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Provags-ID: V03:K1:V5mQcKaknO/dQ4BbmLpggz5nfGAs+HZS3fVhdM6wIjkh2Ad7UL0 1L1fNRnQucUCeLWne5MuHKdr6GsX60NyWZZKIvVnQ/ACchBbsPnN+jYfNVPunCEJjZfHcYN J2GSHVFq8EBEadz3TQlUpSAMZn00+GTGL2QomnCWmlUCjgsAeCzpUgfShIviQ0VX0634egF /6oFDU6ISk7lpSM5BQCUw== X-UI-Out-Filterresults: notjunk:1;V03:K0:vhlb68p/hRI=:Ur7CfeKUJdJCW9RQU1SpOo YTfRgyBsVJTF00lFf3BGWXrJsslqTqCOBJGQl73qji9fNfnyMn2SQmO08JF+hvMs9FcHZDhM/ ++kJhAMik7gpIdEvcdSiy7oKmnu8UdpmHrEqQX2nY9nZxS4gJTh0bvfkg9O3346mRXXL9oopt NU3gvUQ0jKnq63ncfj8p6lAjBrFW6m1S6KkzkxhvaHEGrSY5pNEpMvT+7h53GJ93ra0kuz5He Mihw9MHPi0zFCgz4OjKx3srq1u7acVEwLqcNENBVj/6R2oPoF5nL9drdbOAGhRPEBI72dbqyF QDzE3WPjcqbZ/Or07X/KYbNjqsBrMb4b15KXEq0y2R+mixeX5KZDDvx5y814EIG3JKpK6qoJc yGDh4WP4EJPTDD/kjpm8+fDElEUWul5z87Q6R+Rq8U+MtZy0ZMWUMhq6gq7Jw9n/h4oKHngkJ YO5QmKIAidl48HchrEsA+5qMgiSaw4jJC9N2k0QTxu7PTVFVbH6C56UEG1uGafrOVTDjrmLe3 fclk4Sk8aykKoYGMarSQ65WVFwFyvb9EPjeg/WtAqrgmPUPnbaqcD+oas3NZqYZxEojFqOXXK jMJInVuuRAVp81fvMGZzDhbej+qKUoSH+bwRnMzmewqh4X6tZlqxX7fXnl2RNEBNvToy5hxKM mZF8zd0GmHugjeptuv1SPlBbTPXDu4VPGPaFD9COGiQUB1ew2pn0IeDKjju8pvSl5ZWk= 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=212.227.126.133; 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_H4=0.001, RCVD_IN_MSPIKE_WL=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: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Richard Henderson , Laurent Vivier Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZM-MESSAGEID: 1641466831232100001 Content-Type: text/plain; charset="utf-8" From: Richard Henderson The first word of page1 is data, so the whole thing can't be implemented with emulation of addresses. Use init_guest_commpage for the allocation. Hijack trap number 16 to implement cmpxchg. Signed-off-by: Richard Henderson Reviewed-by: Laurent Vivier Message-Id: <20211221025012.1057923-5-richard.henderson@linaro.org> Signed-off-by: Laurent Vivier --- linux-user/elfload.c | 50 ++++++++++++++++++++++++++++++++++++- linux-user/nios2/cpu_loop.c | 50 ++++++++++++++++++++----------------- target/nios2/translate.c | 9 ------- 3 files changed, 76 insertions(+), 33 deletions(-) diff --git a/linux-user/elfload.c b/linux-user/elfload.c index d34cd4fe43fb..329b2375ef15 100644 --- a/linux-user/elfload.c +++ b/linux-user/elfload.c @@ -1099,6 +1099,47 @@ static void init_thread(struct target_pt_regs *regs,= struct image_info *infop) regs->estatus =3D 0x3; } =20 +#define LO_COMMPAGE TARGET_PAGE_SIZE + +static bool init_guest_commpage(void) +{ + static const uint8_t kuser_page[4 + 2 * 64] =3D { + /* __kuser_helper_version */ + [0x00] =3D 0x02, 0x00, 0x00, 0x00, + + /* __kuser_cmpxchg */ + [0x04] =3D 0x3a, 0x6c, 0x3b, 0x00, /* trap 16 */ + 0x3a, 0x28, 0x00, 0xf8, /* ret */ + + /* __kuser_sigtramp */ + [0x44] =3D 0xc4, 0x22, 0x80, 0x00, /* movi r2, __NR_rt_sigreturn = */ + 0x3a, 0x68, 0x3b, 0x00, /* trap 0 */ + }; + + void *want =3D g2h_untagged(LO_COMMPAGE & -qemu_host_page_size); + void *addr =3D mmap(want, qemu_host_page_size, PROT_READ | PROT_WRITE, + MAP_ANONYMOUS | MAP_PRIVATE | MAP_FIXED, -1, 0); + + if (addr =3D=3D MAP_FAILED) { + perror("Allocating guest commpage"); + exit(EXIT_FAILURE); + } + if (addr !=3D want) { + return false; + } + + memcpy(addr, kuser_page, sizeof(kuser_page)); + + if (mprotect(addr, qemu_host_page_size, PROT_READ)) { + perror("Protecting guest commpage"); + exit(EXIT_FAILURE); + } + + page_set_flags(LO_COMMPAGE, LO_COMMPAGE + TARGET_PAGE_SIZE, + PAGE_READ | PAGE_EXEC | PAGE_VALID); + return true; +} + #define ELF_EXEC_PAGESIZE 4096 =20 #define USE_ELF_CORE_DUMP @@ -2160,8 +2201,13 @@ static abi_ulong create_elf_tables(abi_ulong p, int = argc, int envc, return sp; } =20 -#ifndef HI_COMMPAGE +#if defined(HI_COMMPAGE) +#define LO_COMMPAGE 0 +#elif defined(LO_COMMPAGE) +#define HI_COMMPAGE 0 +#else #define HI_COMMPAGE 0 +#define LO_COMMPAGE 0 #define init_guest_commpage() true #endif =20 @@ -2374,6 +2420,8 @@ static void pgb_static(const char *image_name, abi_ul= ong orig_loaddr, } else { offset =3D -(HI_COMMPAGE & -align); } + } else if (LO_COMMPAGE) { + loaddr =3D MIN(loaddr, LO_COMMPAGE & -align); } =20 addr =3D pgb_find_hole(loaddr, hiaddr - loaddr, align, offset); diff --git a/linux-user/nios2/cpu_loop.c b/linux-user/nios2/cpu_loop.c index 5c3d01d22dd7..de0fc63e2196 100644 --- a/linux-user/nios2/cpu_loop.c +++ b/linux-user/nios2/cpu_loop.c @@ -76,6 +76,32 @@ void cpu_loop(CPUNios2State *env) force_sig_fault(TARGET_SIGILL, TARGET_ILL_ILLTRP, env->regs[R_PC]); break; + + case 16: /* QEMU specific, for __kuser_cmpxchg */ + { + abi_ptr g =3D env->regs[4]; + uint32_t *h, n, o; + + if (g & 0x3) { + force_sig_fault(TARGET_SIGBUS, TARGET_BUS_ADRALN, = g); + break; + } + ret =3D page_get_flags(g); + if (!(ret & PAGE_VALID)) { + force_sig_fault(TARGET_SIGSEGV, TARGET_SEGV_MAPERR= , g); + break; + } + if (!(ret & PAGE_READ) || !(ret & PAGE_WRITE)) { + force_sig_fault(TARGET_SIGSEGV, TARGET_SEGV_ACCERR= , g); + break; + } + h =3D g2h(cs, g); + o =3D env->regs[5]; + n =3D env->regs[6]; + env->regs[2] =3D qatomic_cmpxchg(h, o, n) - o; + env->regs[R_PC] +=3D 4; + } + break; } break; =20 @@ -86,29 +112,7 @@ void cpu_loop(CPUNios2State *env) queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info); break; case 0xaa: - switch (env->regs[R_PC]) { - /*case 0x1000:*/ /* TODO:__kuser_helper_version */ - case 0x1004: /* __kuser_cmpxchg */ - start_exclusive(); - if (env->regs[4] & 0x3) { - goto kuser_fail; - } - ret =3D get_user_u32(env->regs[2], env->regs[4]); - if (ret) { - end_exclusive(); - goto kuser_fail; - } - env->regs[2] -=3D env->regs[5]; - if (env->regs[2] =3D=3D 0) { - put_user_u32(env->regs[6], env->regs[4]); - } - end_exclusive(); - env->regs[R_PC] =3D env->regs[R_RA]; - break; - /*case 0x1040:*/ /* TODO:__kuser_sigtramp */ - default: - ; -kuser_fail: + { info.si_signo =3D TARGET_SIGSEGV; info.si_errno =3D 0; /* TODO: check env->error_code */ diff --git a/target/nios2/translate.c b/target/nios2/translate.c index a75987751926..f9abc2fdd200 100644 --- a/target/nios2/translate.c +++ b/target/nios2/translate.c @@ -795,15 +795,6 @@ static void nios2_tr_translate_insn(DisasContextBase *= dcbase, CPUState *cs) dc->base.pc_next =3D pc + 4; =20 /* Decode an instruction */ - -#if defined(CONFIG_USER_ONLY) - /* FIXME: Is this needed ? */ - if (pc >=3D 0x1000 && pc < 0x2000) { - t_gen_helper_raise_exception(dc, 0xaa); - return; - } -#endif - code =3D cpu_ldl_code(env, pc); op =3D get_opcode(code); =20 --=20 2.33.1