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([203.56.128.103]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-7106ed16cb3sm4576038b3a.179.2024.08.04.17.31.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 04 Aug 2024 17:31:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1722817912; x=1723422712; darn=nongnu.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=9loKzQW0fz51/k/WMOHKeqW5+iqLnIhl+VnJpSdO5ZI=; b=z8JohOe5JP8EdqkOEMIzg7roJLJ9w0DnhGtYH8RzmrDAWxQvQ4k1XqMLV4P200wwa+ S6DyzEpIMYkiJHO4q9+EAUbdyo7bHnQZx2dlYZHArmmGI20cvOy5TJOdeAz7A0j71XAy JRsxlT6YiXG4iyw6wC8dUKoBbecSUdR2LplJ43k6Ov96TGhi2dBSvA7liIt0DECxi6HC aVLGAJG2HS9HCz8q59h/76IO6DPGFqiqtTNAyX+Fp+iQhZCetuDygh7x1NaKpn3TDmt/ dBFLDyd2cwpYnkf59vP4f0/5M+lYHL614CaagUD0z3SJukXW6X99nnjvYs+cJbk06NnQ WCFg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1722817912; x=1723422712; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=9loKzQW0fz51/k/WMOHKeqW5+iqLnIhl+VnJpSdO5ZI=; b=nXUNWaoQNbu1N8j3dOBOoZ+uOBXvSQemn1M3bgNXWD6ovOqlSVyw1mDHxfL3tOcag9 c9/0SpcgtgQQvCBab7TUMRLxU3PIq27gjOyfeSgRcQN1sppipaFZjjKNvyaajdBlXC83 0XURflMuq/6b4iIHz7inxub4m2qrQMpkWmoA75jOMTKNGmpcbLDf9aC00fpiulCcDOyh PYu1Yi2VJPpLjSf0kr+uQf3fv4R2x6uggyB7TZhPge7GPE5Vw5grlhlD3LDycM/HKCc3 8RhxLrozBwnhTbNAdaEFS99rroH4aqxkt/RO1nNTtaWLVY17sc9Q5rzfBjqiiuBbY+Pu Ad3w== X-Gm-Message-State: AOJu0Yyehg4RrOKq5QcReITwmAuj/ymPgY2LvAKu5PW0RDQ9qh+BX8x/ l2coECoFi3G9xWp0nNgrbpQHnhvnlN+rUbRVACy+wSSCEiG6tED7cJBnQP80ls9HT7V7G6jask6 gnIRLSA== X-Google-Smtp-Source: AGHT+IEvdMNgPGsehcKqxCVF7owcv9eNvXWwTqHmDDWT5K9tnLJhGkLLkBmAhXEYjFBIwLm4jyAdXw== X-Received: by 2002:a05:6a00:22d6:b0:710:591e:b52f with SMTP id d2e1a72fcca58-7106cf933f9mr13521120b3a.5.1722817911689; Sun, 04 Aug 2024 17:31:51 -0700 (PDT) From: Richard Henderson To: qemu-devel@nongnu.org Cc: =?UTF-8?q?Cl=C3=A9ment=20L=C3=A9ger?= Subject: [PULL 5/6] qemu/osdep: Add excluded fd parameter to qemu_close_all_open_fd() Date: Mon, 5 Aug 2024 10:31:28 +1000 Message-ID: <20240805003130.1421051-7-richard.henderson@linaro.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240805003130.1421051-1-richard.henderson@linaro.org> References: <20240805003130.1421051-1-richard.henderson@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable 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: pass client-ip=2607:f8b0:4864:20::431; envelope-from=richard.henderson@linaro.org; helo=mail-pf1-x431.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: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZohoMail-DKIM: pass (identity @linaro.org) X-ZM-MESSAGEID: 1722817984500116600 From: Cl=C3=A9ment L=C3=A9ger In order for this function to be usable by tap.c code, add a list of file descriptors that should not be closed. Signed-off-by: Cl=C3=A9ment L=C3=A9ger Message-ID: <20240802145423.3232974-5-cleger@rivosinc.com> [rth: Use max_fd in qemu_close_all_open_fd_close_range] Signed-off-by: Richard Henderson --- include/qemu/osdep.h | 8 +++- system/async-teardown.c | 2 +- util/oslib-posix.c | 98 ++++++++++++++++++++++++++++++++++------- 3 files changed, 89 insertions(+), 19 deletions(-) diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h index de77c5c254..4cc4c32b14 100644 --- a/include/qemu/osdep.h +++ b/include/qemu/osdep.h @@ -760,9 +760,13 @@ int qemu_fdatasync(int fd); /** * qemu_close_all_open_fd: * - * Close all open file descriptors + * Close all open file descriptors except the ones supplied in the @skip a= rray + * + * @skip: ordered array of distinct file descriptors that should not be cl= osed + * if any, or NULL. + * @nskip: number of entries in the @skip array or 0 if @skip is NULL. */ -void qemu_close_all_open_fd(void); +void qemu_close_all_open_fd(const int *skip, unsigned int nskip); =20 /** * Sync changes made to the memory mapped file back to the backing diff --git a/system/async-teardown.c b/system/async-teardown.c index edf49e1007..9148ee8d04 100644 --- a/system/async-teardown.c +++ b/system/async-teardown.c @@ -52,7 +52,7 @@ static int async_teardown_fn(void *arg) * Close all file descriptors that might have been inherited from the * main qemu process when doing clone, needed to make libvirt happy. */ - qemu_close_all_open_fd(); + qemu_close_all_open_fd(NULL, 0); =20 /* Set up a handler for SIGHUP and unblock SIGHUP. */ sigaction(SIGHUP, &sa, NULL); diff --git a/util/oslib-posix.c b/util/oslib-posix.c index 9b79fc7cff..11b35e48fb 100644 --- a/util/oslib-posix.c +++ b/util/oslib-posix.c @@ -808,11 +808,12 @@ int qemu_msync(void *addr, size_t length, int fd) return msync(addr, length, MS_SYNC); } =20 -static bool qemu_close_all_open_fd_proc(void) +static bool qemu_close_all_open_fd_proc(const int *skip, unsigned int nski= p) { struct dirent *de; int fd, dfd; DIR *dir; + unsigned int skip_start =3D 0, skip_end =3D nskip; =20 dir =3D opendir("/proc/self/fd"); if (!dir) { @@ -823,8 +824,33 @@ static bool qemu_close_all_open_fd_proc(void) dfd =3D dirfd(dir); =20 for (de =3D readdir(dir); de; de =3D readdir(dir)) { + bool close_fd =3D true; + + if (de->d_name[0] =3D=3D '.') { + continue; + } fd =3D atoi(de->d_name); - if (fd !=3D dfd) { + if (fd =3D=3D dfd) { + continue; + } + + for (unsigned int i =3D skip_start; i < skip_end; i++) { + if (fd < skip[i]) { + /* We are below the next skipped fd, break */ + break; + } else if (fd =3D=3D skip[i]) { + close_fd =3D false; + /* Restrict the range as we found fds matching start/end */ + if (i =3D=3D skip_start) { + skip_start++; + } else if (i =3D=3D skip_end) { + skip_end--; + } + break; + } + } + + if (close_fd) { close(fd); } } @@ -833,24 +859,60 @@ static bool qemu_close_all_open_fd_proc(void) return true; } =20 -static bool qemu_close_all_open_fd_close_range(void) +static bool qemu_close_all_open_fd_close_range(const int *skip, + unsigned int nskip, + int open_max) { #ifdef CONFIG_CLOSE_RANGE - int r =3D close_range(0, ~0U, 0); - if (!r) { - /* Success, no need to try other ways. */ - return true; - } -#endif + int max_fd =3D open_max - 1; + int first =3D 0, last; + unsigned int cur_skip =3D 0; + int ret; + + do { + /* Find the start boundary of the range to close */ + while (cur_skip < nskip && first =3D=3D skip[cur_skip]) { + cur_skip++; + first++; + } + + /* Find the upper boundary of the range to close */ + last =3D max_fd; + if (cur_skip < nskip) { + last =3D skip[cur_skip] - 1; + last =3D MIN(last, max_fd); + } + + /* With the adjustments to the range, we might be done. */ + if (first > last) { + break; + } + + ret =3D close_range(first, last, 0); + if (ret < 0) { + return false; + } + + first =3D last + 1; + } while (last < max_fd); + + return true; +#else return false; +#endif } =20 -static void qemu_close_all_open_fd_fallback(void) +static void qemu_close_all_open_fd_fallback(const int *skip, unsigned int = nskip, + int open_max) { - int open_max =3D sysconf(_SC_OPEN_MAX), i; + unsigned int cur_skip =3D 0; =20 /* Fallback */ - for (i =3D 0; i < open_max; i++) { + for (int i =3D 0; i < open_max; i++) { + if (cur_skip < nskip && i =3D=3D skip[cur_skip]) { + cur_skip++; + continue; + } close(i); } } @@ -858,10 +920,14 @@ static void qemu_close_all_open_fd_fallback(void) /* * Close all open file descriptors. */ -void qemu_close_all_open_fd(void) +void qemu_close_all_open_fd(const int *skip, unsigned int nskip) { - if (!qemu_close_all_open_fd_close_range() && - !qemu_close_all_open_fd_proc()) { - qemu_close_all_open_fd_fallback(); + int open_max =3D sysconf(_SC_OPEN_MAX); + + assert(skip !=3D NULL || nskip =3D=3D 0); + + if (!qemu_close_all_open_fd_close_range(skip, nskip, open_max) && + !qemu_close_all_open_fd_proc(skip, nskip)) { + qemu_close_all_open_fd_fallback(skip, nskip, open_max); } } --=20 2.43.0