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[209.51.188.17]) by mx.google.com with ESMTPS id a17si16343175qtx.206.2021.11.22.00.28.35 for (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Mon, 22 Nov 2021 00:28:35 -0800 (PST) Received-SPF: pass (google.com: domain of qemu-devel-bounces+patch=linaro.org@nongnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; Authentication-Results: mx.google.com; spf=pass (google.com: domain of qemu-devel-bounces+patch=linaro.org@nongnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom="qemu-devel-bounces+patch=linaro.org@nongnu.org" Received: from localhost ([::1]:52572 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mp4gl-0006W7-4n for patch@linaro.org; Mon, 22 Nov 2021 03:28:35 -0500 Received: from eggs.gnu.org ([209.51.188.92]:40806) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mp4br-0001bw-9l for qemu-devel@nongnu.org; Mon, 22 Nov 2021 03:23:37 -0500 Received: from mout.kundenserver.de ([212.227.126.133]:39403) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mp4bn-00038X-4Y for qemu-devel@nongnu.org; Mon, 22 Nov 2021 03:23:31 -0500 Received: from quad ([82.142.2.234]) by mrelayeu.kundenserver.de (mreue011 [212.227.15.167]) with ESMTPSA (Nemesis) id 1MAOa3-1mut5e2LWd-00Bvqw; Mon, 22 Nov 2021 09:23:13 +0100 From: Laurent Vivier To: qemu-devel@nongnu.org Subject: [PULL 4/5] linux-user: Rewrite do_getdents, do_getdents64 Date: Mon, 22 Nov 2021 09:23:09 +0100 Message-Id: <20211122082310.377809-5-laurent@vivier.eu> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20211122082310.377809-1-laurent@vivier.eu> References: <20211122082310.377809-1-laurent@vivier.eu> MIME-Version: 1.0 X-Provags-ID: V03:K1:U3chgT1UfwZszQ+kWmHGEleRdvMdH3UgFwxO2XQyVt3l5ff5pbt 7CPGFva6H8Cd16oohgUdQ2jpRoQBzxJ4tVYNGKxLuJJr2uVPwpe+MMolRWewBETV2bVqz+T ArHd5YXqrtlN5bx2IhFZstuyzKDC6TOKQ1V9KoVcCc1+WOVPx0bYiULnG+dxmkvKrCELSNn e46YOb0L38sIkyx9cGd8Q== X-UI-Out-Filterresults: notjunk:1;V03:K0:DBzNlpGLRxU=:Ev1wNTVoMFnk5XYhUFsnjG HdLcjqIZClJgJXcw/Fu9nVjRSC8wLlXD7axD6zkwoHxaKpsUL1Iti9FncTBe54WbbUM6WG2uY IfOyZLzD6B+rXBKrLQZFpXwBkQCdiY36oE89I2Jc1TyFHohKOfqscKu/sHBMdPth5B8TzVSA1 QOoDPBu+Yg72i8VBV7QdwmKOUwu3mije3MIWpJYlf+UjpzgXwkJGf5raGSWH5X8bNIgpt7/zW B43+0kC9iRhI/tpKuc9BfnIAx7K+ukoguF4ntjympMUB6/Sn+tVkdG4CDATaUmg8bNnwyySPu QtyyyRCGna6RNa7sSVvq/ysOTKj0Z4VBGZlGy2e0iRs/pgrEWSbKpMisoZ6FkQAPDf835ZWL8 8yYVN5kpJLUBfnSDd3cJXhlefpyUgvuCP3SeC1sJ8h1SNcP5cRNo2ghVYiAI8tNsEaB0wGMGT ff5mhnu8BE5dzoD0W/j9GtR3VnwVm1zW8n/AxaNNPVb8VWnV0TgYpGh17oIXTmyMqR1tTPeEV mu8svibYRGFyYSIQYTf3C/a00uqylhNZWimolEfzeeF9YLQ+izJuozDCwPl/UWQCoSpXhbrmR iQeZO+Hb5j2vxZehRNLeug5Isg2Sps+hx6lz7bdb1jXlV6qUy77qdlz+t8N2loF+MZRZBpuIz IPRlHYD/jGVONaQKznHo4zjozmYhWI60dCpizLp1ehan2r8DApQz7lb/XEQDOE1xpSTk= 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_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: 2.1.29 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+patch=linaro.org@nongnu.org Sender: "Qemu-devel" From: Richard Henderson Always allocate host storage; this ensures that the struct is sufficiently aligned for the host. Merge the three host implementations of getdents via a few ifdefs. Utilize the same method for do_getdents64. Resolves: https://gitlab.com/qemu-project/qemu/-/issues/704 Signed-off-by: Richard Henderson Reviewed-by: Philippe Mathieu-Daudé Message-Id: <20211114103539.298686-5-richard.henderson@linaro.org> Signed-off-by: Laurent Vivier --- linux-user/syscall.c | 261 ++++++++++++++++++++----------------------- 1 file changed, 122 insertions(+), 139 deletions(-) diff --git a/linux-user/syscall.c b/linux-user/syscall.c index 499415ad81b8..f1cfcc810486 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -8140,172 +8140,155 @@ static int host_to_target_cpu_mask(const unsigned long *host_mask, } #ifdef TARGET_NR_getdents -static int do_getdents(abi_long arg1, abi_long arg2, abi_long arg3) +static int do_getdents(abi_long dirfd, abi_long arg2, abi_long count) { - int ret; + g_autofree void *hdirp = NULL; + void *tdirp; + int hlen, hoff, toff; + int hreclen, treclen; + off64_t prev_diroff = 0; + + hdirp = g_try_malloc(count); + if (!hdirp) { + return -TARGET_ENOMEM; + } #ifdef EMULATE_GETDENTS_WITH_GETDENTS -# if TARGET_ABI_BITS == 32 && HOST_LONG_BITS == 64 - struct target_dirent *target_dirp; - struct linux_dirent *dirp; - abi_long count = arg3; + hlen = sys_getdents(dirfd, hdirp, count); +#else + hlen = sys_getdents64(dirfd, hdirp, count); +#endif - dirp = g_try_malloc(count); - if (!dirp) { - return -TARGET_ENOMEM; + hlen = get_errno(hlen); + if (is_error(hlen)) { + return hlen; } - ret = get_errno(sys_getdents(arg1, dirp, count)); - if (!is_error(ret)) { - struct linux_dirent *de; - struct target_dirent *tde; - int len = ret; - int reclen, treclen; - int count1, tnamelen; - - count1 = 0; - de = dirp; - target_dirp = lock_user(VERIFY_WRITE, arg2, count, 0); - if (!target_dirp) { - return -TARGET_EFAULT; - } - tde = target_dirp; - while (len > 0) { - reclen = de->d_reclen; - tnamelen = reclen - offsetof(struct linux_dirent, d_name); - assert(tnamelen >= 0); - treclen = tnamelen + offsetof(struct target_dirent, d_name); - assert(count1 + treclen <= count); - tde->d_reclen = tswap16(treclen); - tde->d_ino = tswapal(de->d_ino); - tde->d_off = tswapal(de->d_off); - memcpy(tde->d_name, de->d_name, tnamelen); - de = (struct linux_dirent *)((char *)de + reclen); - len -= reclen; - tde = (struct target_dirent *)((char *)tde + treclen); - count1 += treclen; - } - ret = count1; - unlock_user(target_dirp, arg2, ret); - } - g_free(dirp); -# else - struct linux_dirent *dirp; - abi_long count = arg3; - - dirp = lock_user(VERIFY_WRITE, arg2, count, 0); - if (!dirp) { + tdirp = lock_user(VERIFY_WRITE, arg2, count, 0); + if (!tdirp) { return -TARGET_EFAULT; } - ret = get_errno(sys_getdents(arg1, dirp, count)); - if (!is_error(ret)) { - struct linux_dirent *de; - int len = ret; - int reclen; - de = dirp; - while (len > 0) { - reclen = de->d_reclen; - if (reclen > len) { - break; - } - de->d_reclen = tswap16(reclen); - tswapls(&de->d_ino); - tswapls(&de->d_off); - de = (struct linux_dirent *)((char *)de + reclen); - len -= reclen; - } - } - unlock_user(dirp, arg2, ret); -# endif + + for (hoff = toff = 0; hoff < hlen; hoff += hreclen, toff += treclen) { +#ifdef EMULATE_GETDENTS_WITH_GETDENTS + struct linux_dirent *hde = hdirp + hoff; #else - /* Implement getdents in terms of getdents64 */ - struct linux_dirent64 *dirp; - abi_long count = arg3; + struct linux_dirent64 *hde = hdirp + hoff; +#endif + struct target_dirent *tde = tdirp + toff; + int namelen; + uint8_t type; - dirp = lock_user(VERIFY_WRITE, arg2, count, 0); - if (!dirp) { - return -TARGET_EFAULT; - } - ret = get_errno(sys_getdents64(arg1, dirp, count)); - if (!is_error(ret)) { - /* - * Convert the dirent64 structs to target dirent. We do this - * in-place, since we can guarantee that a target_dirent is no - * larger than a dirent64; however this means we have to be - * careful to read everything before writing in the new format. - */ - struct linux_dirent64 *de; - struct target_dirent *tde; - int len = ret; - int tlen = 0; + namelen = strlen(hde->d_name); + hreclen = hde->d_reclen; + treclen = offsetof(struct target_dirent, d_name) + namelen + 2; + treclen = QEMU_ALIGN_UP(treclen, __alignof(struct target_dirent)); - de = dirp; - tde = (struct target_dirent *)dirp; - while (len > 0) { - int namelen, treclen; - int reclen = de->d_reclen; - uint64_t ino = de->d_ino; - int64_t off = de->d_off; - uint8_t type = de->d_type; - - namelen = strlen(de->d_name); - treclen = offsetof(struct target_dirent, d_name) + namelen + 2; - treclen = QEMU_ALIGN_UP(treclen, sizeof(abi_long)); - - memmove(tde->d_name, de->d_name, namelen + 1); - tde->d_ino = tswapal(ino); - tde->d_off = tswapal(off); - tde->d_reclen = tswap16(treclen); + if (toff + treclen > count) { /* - * The target_dirent type is in what was formerly a padding - * byte at the end of the structure: + * If the host struct is smaller than the target struct, or + * requires less alignment and thus packs into less space, + * then the host can return more entries than we can pass + * on to the guest. */ - *(((char *)tde) + treclen - 1) = type; - - de = (struct linux_dirent64 *)((char *)de + reclen); - tde = (struct target_dirent *)((char *)tde + treclen); - len -= reclen; - tlen += treclen; + if (toff == 0) { + toff = -TARGET_EINVAL; /* result buffer is too small */ + break; + } + /* + * Return what we have, resetting the file pointer to the + * location of the first record not returned. + */ + lseek64(dirfd, prev_diroff, SEEK_SET); + break; } - ret = tlen; - } - unlock_user(dirp, arg2, ret); + + prev_diroff = hde->d_off; + tde->d_ino = tswapal(hde->d_ino); + tde->d_off = tswapal(hde->d_off); + tde->d_reclen = tswap16(treclen); + memcpy(tde->d_name, hde->d_name, namelen + 1); + + /* + * The getdents type is in what was formerly a padding byte at the + * end of the structure. + */ +#ifdef EMULATE_GETDENTS_WITH_GETDENTS + type = *((uint8_t *)hde + hreclen - 1); +#else + type = hde->d_type; #endif - return ret; + *((uint8_t *)tde + treclen - 1) = type; + } + + unlock_user(tdirp, arg2, toff); + return toff; } #endif /* TARGET_NR_getdents */ #if defined(TARGET_NR_getdents64) && defined(__NR_getdents64) -static int do_getdents64(abi_long arg1, abi_long arg2, abi_long arg3) +static int do_getdents64(abi_long dirfd, abi_long arg2, abi_long count) { - struct linux_dirent64 *dirp; - abi_long count = arg3; - int ret; + g_autofree void *hdirp = NULL; + void *tdirp; + int hlen, hoff, toff; + int hreclen, treclen; + off64_t prev_diroff = 0; + + hdirp = g_try_malloc(count); + if (!hdirp) { + return -TARGET_ENOMEM; + } - dirp = lock_user(VERIFY_WRITE, arg2, count, 0); - if (!dirp) { + hlen = get_errno(sys_getdents64(dirfd, hdirp, count)); + if (is_error(hlen)) { + return hlen; + } + + tdirp = lock_user(VERIFY_WRITE, arg2, count, 0); + if (!tdirp) { return -TARGET_EFAULT; } - ret = get_errno(sys_getdents64(arg1, dirp, count)); - if (!is_error(ret)) { - struct linux_dirent64 *de; - int len = ret; - int reclen; - de = dirp; - while (len > 0) { - reclen = de->d_reclen; - if (reclen > len) { + + for (hoff = toff = 0; hoff < hlen; hoff += hreclen, toff += treclen) { + struct linux_dirent64 *hde = hdirp + hoff; + struct target_dirent64 *tde = tdirp + toff; + int namelen; + + namelen = strlen(hde->d_name) + 1; + hreclen = hde->d_reclen; + treclen = offsetof(struct target_dirent64, d_name) + namelen; + treclen = QEMU_ALIGN_UP(treclen, __alignof(struct target_dirent64)); + + if (toff + treclen > count) { + /* + * If the host struct is smaller than the target struct, or + * requires less alignment and thus packs into less space, + * then the host can return more entries than we can pass + * on to the guest. + */ + if (toff == 0) { + toff = -TARGET_EINVAL; /* result buffer is too small */ break; } - de->d_reclen = tswap16(reclen); - tswap64s((uint64_t *)&de->d_ino); - tswap64s((uint64_t *)&de->d_off); - de = (struct linux_dirent64 *)((char *)de + reclen); - len -= reclen; + /* + * Return what we have, resetting the file pointer to the + * location of the first record not returned. + */ + lseek64(dirfd, prev_diroff, SEEK_SET); + break; } + + prev_diroff = hde->d_off; + tde->d_ino = tswap64(hde->d_ino); + tde->d_off = tswap64(hde->d_off); + tde->d_reclen = tswap16(treclen); + tde->d_type = hde->d_type; + memcpy(tde->d_name, hde->d_name, namelen); } - unlock_user(dirp, arg2, ret); - return ret; + + unlock_user(tdirp, arg2, toff); + return toff; } #endif /* TARGET_NR_getdents64 */