/* * Copyright (C) 2013 Red Hat, Inc. * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library. If not, see * . * * Author: Michal Privoznik */ #include #ifdef __linux__ # include "internal.h" # include # include # include # include # include # include # include # include # include "viralloc.h" # include "virstring.h" # include "virfile.h" # include "dirname.h" static int (*realaccess)(const char *path, int mode); static int (*reallstat)(const char *path, struct stat *sb); static int (*real__lxstat)(int ver, const char *path, struct stat *sb); static int (*realstat)(const char *path, struct stat *sb); static int (*real__xstat)(int ver, const char *path, struct stat *sb); static char *(*realcanonicalize_file_name)(const char *path); static int (*realopen)(const char *path, int flags, ...); static int (*realclose)(int fd); static DIR * (*realopendir)(const char *name); /* Don't make static, since it causes problems with clang * when passed as an arg to virAsprintf() * vircgroupmock.c:462:22: error: static variable 'fakesysfsdir' is used in an inline function with external linkage [-Werror,-Wstatic-in-inline] */ char *fakesysfsdir; # define PCI_SYSFS_PREFIX "/sys/bus/pci/" # define STDERR(...) \ fprintf(stderr, "%s %zu: ", __FUNCTION__, (size_t) __LINE__); \ fprintf(stderr, __VA_ARGS__); \ fprintf(stderr, "\n"); \ # define ABORT(...) \ do { \ STDERR(__VA_ARGS__); \ abort(); \ } while (0) # define ABORT_OOM() \ ABORT("Out of memory") /* * The plan: * * Mock some file handling functions. Redirect them into a stub tree passed via * LIBVIRT_FAKE_SYSFS_DIR env variable. All files and links within stub tree is * created by us. There are some actions that we must take if some special * files are written to. Here's the list of files we watch: * * /sys/bus/pci/drivers//new_id: * Learn the driver new vendor and device combination. * Data in format "VVVV DDDD". * * /sys/bus/pci/drivers//remove_id * Make the driver forget about vendor and device. * Data in format "VVVV DDDD". * * /sys/bus/pci/drivers//bind * Check if driver supports the device and bind driver to it (create symlink * called 'driver' pointing to the /sys/but/pci/drivers/). * Data in format "DDDD:BB:DD.F" (Domain:Bus:Device.Function). * * /sys/bus/pci/drivers//unbind * Unbind driver from the device. * Data in format "DDDD:BB:DD.F" (Domain:Bus:Device.Function). * * /sys/bus/pci/drivers_probe * Probe for a driver that handles the specified device. * Data in format "DDDD:BB:DD.F" (Domain:Bus:Device.Function). * * As a little hack, we are not mocking write to these files, but close() * instead. The advantage is we don't need any self growing array to hold the * partial writes and construct them back. We can let all the writes finish, * and then just read the file content back. */ /* * * Functions to model kernel behavior * */ enum driverActions { PCI_ACTION_BIND = 1 << 0, PCI_ACTION_UNBIND = 1 << 1, PCI_ACTION_NEW_ID = 1 << 2, PCI_ACTION_REMOVE_ID = 1 << 3, }; struct pciDriver { char *name; int *vendor; /* List of vendor:device IDs the driver can handle */ int *device; size_t len; /* @len is used for both @vendor and @device */ unsigned int fail; /* Bitwise-OR of driverActions that should fail */ }; struct pciDevice { char *id; int vendor; int device; int class; struct pciDriver *driver; /* Driver attached. NULL if attached to no driver */ }; struct fdCallback { int fd; char *path; }; struct pciDevice **pciDevices = NULL; size_t nPciDevices = 0; struct pciDriver **pciDrivers = NULL; size_t nPciDrivers = 0; struct fdCallback *callbacks = NULL; size_t nCallbacks = 0; static void init_env(void); static int pci_device_autobind(struct pciDevice *dev); static void pci_device_new_from_stub(const struct pciDevice *data); static struct pciDevice *pci_device_find_by_id(const char *id); static struct pciDevice *pci_device_find_by_content(const char *path); static void pci_driver_new(const char *name, int fail, ...); static struct pciDriver *pci_driver_find_by_dev(struct pciDevice *dev); static struct pciDriver *pci_driver_find_by_path(const char *path); static int pci_driver_bind(struct pciDriver *driver, struct pciDevice *dev); static int pci_driver_unbind(struct pciDriver *driver, struct pciDevice *dev); static int pci_driver_handle_change(int fd, const char *path); static int pci_driver_handle_bind(const char *path); static int pci_driver_handle_unbind(const char *path); static int pci_driver_handle_new_id(const char *path); static int pci_driver_handle_remove_id(const char *path); /* * Helper functions */ static void make_file(const char *path, const char *name, const char *value, ssize_t len) { int fd = -1; char *filepath = NULL; if (value && len == -1) len = strlen(value); if (virAsprintfQuiet(&filepath, "%s/%s", path, name) < 0) ABORT_OOM(); if ((fd = realopen(filepath, O_CREAT|O_WRONLY, 0666)) < 0) ABORT("Unable to open: %s", filepath); if (value && safewrite(fd, value, len) != len) ABORT("Unable to write: %s", filepath); VIR_FORCE_CLOSE(fd); VIR_FREE(filepath); } static int pci_read_file(const char *path, char *buf, size_t buf_size) { int ret = -1; int fd = -1; char *newpath; if (virAsprintfQuiet(&newpath, "%s/%s", fakesysfsdir, path + strlen(PCI_SYSFS_PREFIX)) < 0) { errno = ENOMEM; goto cleanup; } if ((fd = realopen(newpath, O_RDWR)) < 0) goto cleanup; bzero(buf, buf_size); if (saferead(fd, buf, buf_size - 1) < 0) { STDERR("Unable to read from %s", newpath); goto cleanup; } if (ftruncate(fd, 0) < 0) goto cleanup; ret = 0; cleanup: VIR_FREE(newpath); realclose(fd); return ret; } static int getrealpath(char **newpath, const char *path) { if (!fakesysfsdir) init_env(); if (STRPREFIX(path, PCI_SYSFS_PREFIX)) { if (virAsprintfQuiet(newpath, "%s/%s", fakesysfsdir, path + strlen(PCI_SYSFS_PREFIX)) < 0) { errno = ENOMEM; return -1; } } else { if (VIR_STRDUP_QUIET(*newpath, path) < 0) return -1; } return 0; } static bool find_fd(int fd, size_t *indx) { size_t i; for (i = 0; i < nCallbacks; i++) { if (callbacks[i].fd == fd) { if (indx) *indx = i; return true; } } return false; } static int add_fd(int fd, const char *path) { int ret = -1; size_t i; if (find_fd(fd, &i)) { struct fdCallback cb = callbacks[i]; ABORT("FD %d %s already present in the array as %d %s", fd, path, cb.fd, cb.path); } if (VIR_REALLOC_N_QUIET(callbacks, nCallbacks + 1) < 0 || VIR_STRDUP_QUIET(callbacks[nCallbacks].path, path) < 0) { errno = ENOMEM; goto cleanup; } callbacks[nCallbacks++].fd = fd; ret = 0; cleanup: return ret; } static int remove_fd(int fd) { int ret = -1; size_t i; if (find_fd(fd, &i)) { struct fdCallback cb = callbacks[i]; if (pci_driver_handle_change(cb.fd, cb.path) < 0) goto cleanup; VIR_FREE(cb.path); if (VIR_DELETE_ELEMENT(callbacks, i, nCallbacks) < 0) { errno = EINVAL; goto cleanup; } } ret = 0; cleanup: return ret; } /* * PCI Device functions */ static void pci_device_new_from_stub(const struct pciDevice *data) { struct pciDevice *dev; char *devpath; char *configSrc; char tmp[32]; struct stat sb; if (VIR_ALLOC_QUIET(dev) < 0 || virAsprintfQuiet(&configSrc, "%s/virpcitestdata/%s.config", abs_srcdir, data->id) < 0 || virAsprintfQuiet(&devpath, "%s/devices/%s", fakesysfsdir, data->id) < 0) ABORT_OOM(); memcpy(dev, data, sizeof(*dev)); if (virFileMakePath(devpath) < 0) ABORT("Unable to create: %s", devpath); /* If there is a config file for the device within virpcitestdata dir, * symlink it. Otherwise create a dummy config file. */ if ((realstat && realstat(configSrc, &sb) == 0) || (real__xstat && real__xstat(_STAT_VER, configSrc, &sb) == 0)) { /* On success, copy @configSrc into the destination (a copy, * rather than a symlink, is required since we write into the * file, and parallel VPATH builds must not stomp on the * original; besides, 'make distcheck' requires the original * to be read-only */ char *buf; ssize_t len; if ((len = virFileReadAll(configSrc, 4096, &buf)) < 0) ABORT("Unable to read config file '%s'", configSrc); make_file(devpath, "config", buf, len); VIR_FREE(buf); } else { /* If there's no config data in the virpcitestdata dir, create a dummy * config file */ make_file(devpath, "config", "some dummy config", -1); } if (snprintf(tmp, sizeof(tmp), "0x%.4x", dev->vendor) < 0) ABORT("@tmp overflow"); make_file(devpath, "vendor", tmp, -1); if (snprintf(tmp, sizeof(tmp), "0x%.4x", dev->device) < 0) ABORT("@tmp overflow"); make_file(devpath, "device", tmp, -1); if (snprintf(tmp, sizeof(tmp), "0x%.4x", dev->class) < 0) ABORT("@tmp overflow"); make_file(devpath, "class", tmp, -1); if (pci_device_autobind(dev) < 0) ABORT("Unable to bind: %s", data->id); if (VIR_APPEND_ELEMENT_QUIET(pciDevices, nPciDevices, dev) < 0) ABORT_OOM(); VIR_FREE(devpath); VIR_FREE(configSrc); } static struct pciDevice * pci_device_find_by_id(const char *id) { size_t i; for (i = 0; i < nPciDevices; i++) { struct pciDevice *dev = pciDevices[i]; if (STREQ(dev->id, id)) return dev; } return NULL; } static struct pciDevice * pci_device_find_by_content(const char *path) { char tmp[32]; if (pci_read_file(path, tmp, sizeof(tmp)) < 0) return NULL; return pci_device_find_by_id(tmp); } static int pci_device_autobind(struct pciDevice *dev) { struct pciDriver *driver = pci_driver_find_by_dev(dev); if (!driver) { /* No driver found. Nothing to do */ return 0; } return pci_driver_bind(driver, dev); } /* * PCI Driver functions */ static void pci_driver_new(const char *name, int fail, ...) { struct pciDriver *driver; va_list args; int vendor, device; char *driverpath; if (VIR_ALLOC_QUIET(driver) < 0 || VIR_STRDUP_QUIET(driver->name, name) < 0 || virAsprintfQuiet(&driverpath, "%s/drivers/%s", fakesysfsdir, name) < 0) ABORT_OOM(); driver->fail = fail; if (virFileMakePath(driverpath) < 0) ABORT("Unable to create: %s", driverpath); va_start(args, fail); while ((vendor = va_arg(args, int)) != -1) { if ((device = va_arg(args, int)) == -1) ABORT("Invalid vendor device pair for driver %s", name); if (VIR_REALLOC_N_QUIET(driver->vendor, driver->len + 1) < 0 || VIR_REALLOC_N_QUIET(driver->device, driver->len + 1) < 0) ABORT_OOM(); driver->vendor[driver->len] = vendor; driver->device[driver->len] = device; driver->len++; } va_end(args); make_file(driverpath, "bind", NULL, -1); make_file(driverpath, "unbind", NULL, -1); make_file(driverpath, "new_id", NULL, -1); make_file(driverpath, "remove_id", NULL, -1); if (VIR_APPEND_ELEMENT_QUIET(pciDrivers, nPciDrivers, driver) < 0) ABORT_OOM(); } static struct pciDriver * pci_driver_find_by_dev(struct pciDevice *dev) { size_t i; for (i = 0; i < nPciDrivers; i++) { struct pciDriver *driver = pciDrivers[i]; size_t j; for (j = 0; j < driver->len; j++) { if (driver->vendor[j] == dev->vendor && driver->device[j] == dev->device) return driver; } } return NULL; } static struct pciDriver * pci_driver_find_by_path(const char *path) { size_t i; for (i = 0; i < nPciDrivers; i++) { struct pciDriver *driver = pciDrivers[i]; if (strstr(path, driver->name)) return driver; } return NULL; } static int pci_driver_bind(struct pciDriver *driver, struct pciDevice *dev) { int ret = -1; char *devpath = NULL, *driverpath = NULL; if (dev->driver || PCI_ACTION_BIND & driver->fail) { /* Device already bound or failing driver requested */ errno = ENODEV; return ret; } /* Make symlink under device tree */ if (virAsprintfQuiet(&devpath, "%s/devices/%s/driver", fakesysfsdir, dev->id) < 0 || virAsprintfQuiet(&driverpath, "%s/drivers/%s", fakesysfsdir, driver->name) < 0) { errno = ENOMEM; goto cleanup; } if (symlink(driverpath, devpath) < 0) goto cleanup; /* Make symlink under driver tree */ VIR_FREE(devpath); VIR_FREE(driverpath); if (virAsprintfQuiet(&devpath, "%s/devices/%s", fakesysfsdir, dev->id) < 0 || virAsprintfQuiet(&driverpath, "%s/drivers/%s/%s", fakesysfsdir, driver->name, dev->id) < 0) { errno = ENOMEM; goto cleanup; } if (symlink(devpath, driverpath) < 0) goto cleanup; dev->driver = driver; ret = 0; cleanup: VIR_FREE(devpath); VIR_FREE(driverpath); return ret; } static int pci_driver_unbind(struct pciDriver *driver, struct pciDevice *dev) { int ret = -1; char *devpath = NULL, *driverpath = NULL; if (dev->driver != driver || PCI_ACTION_UNBIND & driver->fail) { /* Device not bound to the @driver or failing driver used */ errno = ENODEV; return ret; } /* Make symlink under device tree */ if (virAsprintfQuiet(&devpath, "%s/devices/%s/driver", fakesysfsdir, dev->id) < 0 || virAsprintfQuiet(&driverpath, "%s/drivers/%s/%s", fakesysfsdir, driver->name, dev->id) < 0) { errno = ENOMEM; goto cleanup; } if (unlink(devpath) < 0 || unlink(driverpath) < 0) goto cleanup; dev->driver = NULL; ret = 0; cleanup: VIR_FREE(devpath); VIR_FREE(driverpath); return ret; } static int pci_driver_handle_drivers_probe(const char *path) { struct pciDevice *dev; if (!(dev = pci_device_find_by_content(path))) { errno = ENODEV; return -1; } if (dev->driver) return 0; return pci_device_autobind(dev); } static int pci_driver_handle_change(int fd ATTRIBUTE_UNUSED, const char *path) { int ret; const char *file = last_component(path); if (STREQ(file, "bind")) ret = pci_driver_handle_bind(path); else if (STREQ(file, "unbind")) ret = pci_driver_handle_unbind(path); else if (STREQ(file, "new_id")) ret = pci_driver_handle_new_id(path); else if (STREQ(file, "remove_id")) ret = pci_driver_handle_remove_id(path); else if (STREQ(file, "drivers_probe")) ret = pci_driver_handle_drivers_probe(path); else ABORT("Not handled write to: %s", path); return ret; } static int pci_driver_handle_bind(const char *path) { int ret = -1; struct pciDevice *dev = pci_device_find_by_content(path); struct pciDriver *driver = pci_driver_find_by_path(path); if (!driver || !dev) { /* This should never happen (TM) */ errno = ENODEV; goto cleanup; } ret = pci_driver_bind(driver, dev); cleanup: return ret; } static int pci_driver_handle_unbind(const char *path) { int ret = -1; struct pciDevice *dev = pci_device_find_by_content(path); if (!dev || !dev->driver) { /* This should never happen (TM) */ errno = ENODEV; goto cleanup; } ret = pci_driver_unbind(dev->driver, dev); cleanup: return ret; } static int pci_driver_handle_new_id(const char *path) { int ret = -1; struct pciDriver *driver = pci_driver_find_by_path(path); size_t i; int vendor, device; char buf[32]; if (!driver || PCI_ACTION_NEW_ID & driver->fail) { errno = ENODEV; goto cleanup; } if (pci_read_file(path, buf, sizeof(buf)) < 0) goto cleanup; if (sscanf(buf, "%x %x", &vendor, &device) < 2) { errno = EINVAL; goto cleanup; } for (i = 0; i < driver->len; i++) { if (driver->vendor[i] == vendor && driver->device[i] == device) break; } if (i == driver->len) { if (VIR_REALLOC_N_QUIET(driver->vendor, driver->len + 1) < 0 || VIR_REALLOC_N_QUIET(driver->device, driver->len + 1) < 0) { errno = ENOMEM; goto cleanup; } driver->vendor[driver->len] = vendor; driver->device[driver->len] = device; driver->len++; } for (i = 0; i < nPciDevices; i++) { struct pciDevice *dev = pciDevices[i]; if (!dev->driver && dev->vendor == vendor && dev->device == device && pci_driver_bind(driver, dev) < 0) goto cleanup; } ret = 0; cleanup: return ret; } static int pci_driver_handle_remove_id(const char *path) { int ret = -1; struct pciDriver *driver = pci_driver_find_by_path(path); size_t i; int vendor, device; char buf[32]; if (!driver || PCI_ACTION_REMOVE_ID & driver->fail) { errno = ENODEV; goto cleanup; } if (pci_read_file(path, buf, sizeof(buf)) < 0) goto cleanup; if (sscanf(buf, "%x %x", &vendor, &device) < 2) { errno = EINVAL; goto cleanup; } for (i = 0; i < driver->len; i++) { if (driver->vendor[i] == vendor && driver->device[i] == device) continue; } if (i != driver->len) { if (VIR_DELETE_ELEMENT(driver->vendor, i, driver->len) < 0) goto cleanup; driver->len++; if (VIR_DELETE_ELEMENT(driver->device, i, driver->len) < 0) goto cleanup; } ret = 0; cleanup: return ret; } /* * Functions to load the symbols and init the environment */ static void init_syms(void) { if (realaccess) return; # define LOAD_SYM(name) \ do { \ if (!(real ## name = dlsym(RTLD_NEXT, #name))) \ ABORT("Cannot find real '%s' symbol\n", #name); \ } while (0) # define LOAD_SYM_ALT(name1, name2) \ do { \ if (!(real ## name1 = dlsym(RTLD_NEXT, #name1)) && \ !(real ## name2 = dlsym(RTLD_NEXT, #name2))) \ ABORT("Cannot find real '%s' or '%s' symbol\n", \ #name1, #name2); \ } while (0) LOAD_SYM(access); LOAD_SYM_ALT(lstat, __lxstat); LOAD_SYM_ALT(stat, __xstat); LOAD_SYM(canonicalize_file_name); LOAD_SYM(open); LOAD_SYM(close); LOAD_SYM(opendir); } static void init_env(void) { if (fakesysfsdir) return; if (!(fakesysfsdir = getenv("LIBVIRT_FAKE_SYSFS_DIR"))) ABORT("Missing LIBVIRT_FAKE_SYSFS_DIR env variable\n"); make_file(fakesysfsdir, "drivers_probe", NULL, -1); # define MAKE_PCI_DRIVER(name, ...) \ pci_driver_new(name, 0, __VA_ARGS__, -1, -1) MAKE_PCI_DRIVER("iwlwifi", 0x8086, 0x0044); MAKE_PCI_DRIVER("i915", 0x8086, 0x0046, 0x8086, 0x0047); MAKE_PCI_DRIVER("pci-stub", -1, -1); pci_driver_new("vfio-pci", PCI_ACTION_BIND, -1, -1); # define MAKE_PCI_DEVICE(Id, Vendor, Device, ...) \ do { \ struct pciDevice dev = {.id = (char *)Id, .vendor = Vendor, \ .device = Device, __VA_ARGS__}; \ pci_device_new_from_stub(&dev); \ } while (0) MAKE_PCI_DEVICE("0000:00:00.0", 0x8086, 0x0044); MAKE_PCI_DEVICE("0000:00:01.0", 0x8086, 0x0044); MAKE_PCI_DEVICE("0000:00:02.0", 0x8086, 0x0046); MAKE_PCI_DEVICE("0000:00:03.0", 0x8086, 0x0048); MAKE_PCI_DEVICE("0001:00:00.0", 0x1014, 0x03b9, .class = 0x060400); MAKE_PCI_DEVICE("0001:01:00.0", 0x8086, 0x105e); MAKE_PCI_DEVICE("0001:01:00.1", 0x8086, 0x105e); MAKE_PCI_DEVICE("0005:80:00.0", 0x10b5, 0x8112, .class = 0x060400); MAKE_PCI_DEVICE("0005:90:01.0", 0x1033, 0x0035); MAKE_PCI_DEVICE("0005:90:01.1", 0x1033, 0x0035); MAKE_PCI_DEVICE("0005:90:01.2", 0x1033, 0x00e0); MAKE_PCI_DEVICE("0000:0a:01.0", 0x8086, 0x0047); MAKE_PCI_DEVICE("0000:0a:02.0", 0x8286, 0x0048); MAKE_PCI_DEVICE("0000:0a:03.0", 0x8386, 0x0048); } /* * * Mocked functions * */ int access(const char *path, int mode) { int ret; init_syms(); if (STRPREFIX(path, PCI_SYSFS_PREFIX)) { char *newpath; if (getrealpath(&newpath, path) < 0) return -1; ret = realaccess(newpath, mode); VIR_FREE(newpath); } else { ret = realaccess(path, mode); } return ret; } int __lxstat(int ver, const char *path, struct stat *sb) { int ret; init_syms(); if (STRPREFIX(path, PCI_SYSFS_PREFIX)) { char *newpath; if (getrealpath(&newpath, path) < 0) return -1; ret = real__lxstat(ver, newpath, sb); VIR_FREE(newpath); } else { ret = real__lxstat(ver, path, sb); } return ret; } int lstat(const char *path, struct stat *sb) { int ret; init_syms(); if (STRPREFIX(path, PCI_SYSFS_PREFIX)) { char *newpath; if (getrealpath(&newpath, path) < 0) return -1; ret = reallstat(newpath, sb); VIR_FREE(newpath); } else { ret = reallstat(path, sb); } return ret; } int __xstat(int ver, const char *path, struct stat *sb) { int ret; init_syms(); if (STRPREFIX(path, PCI_SYSFS_PREFIX)) { char *newpath; if (getrealpath(&newpath, path) < 0) return -1; ret = real__xstat(ver, newpath, sb); VIR_FREE(newpath); } else { ret = real__xstat(ver, path, sb); } return ret; } int stat(const char *path, struct stat *sb) { int ret; init_syms(); if (STRPREFIX(path, PCI_SYSFS_PREFIX)) { char *newpath; if (getrealpath(&newpath, path) < 0) return -1; ret = realstat(newpath, sb); VIR_FREE(newpath); } else { ret = realstat(path, sb); } return ret; } char * canonicalize_file_name(const char *path) { char *ret; init_syms(); if (STRPREFIX(path, PCI_SYSFS_PREFIX)) { char *newpath; if (getrealpath(&newpath, path) < 0) return NULL; ret = realcanonicalize_file_name(newpath); VIR_FREE(newpath); } else { ret = realcanonicalize_file_name(path); } return ret; } int open(const char *path, int flags, ...) { int ret; char *newpath = NULL; init_syms(); if (STRPREFIX(path, PCI_SYSFS_PREFIX) && getrealpath(&newpath, path) < 0) return -1; if (flags & O_CREAT) { va_list ap; mode_t mode; va_start(ap, flags); mode = va_arg(ap, mode_t); va_end(ap); ret = realopen(newpath ? newpath : path, flags, mode); } else { ret = realopen(newpath ? newpath : path, flags); } /* Catch both: /sys/bus/pci/drivers/... and * /sys/bus/pci/device/.../driver/... */ if (ret >= 0 && STRPREFIX(path, PCI_SYSFS_PREFIX) && strstr(path, "driver") && add_fd(ret, path) < 0) { realclose(ret); ret = -1; } VIR_FREE(newpath); return ret; } DIR * opendir(const char *path) { DIR *ret; char *newpath = NULL; init_syms(); if (STRPREFIX(path, PCI_SYSFS_PREFIX) && getrealpath(&newpath, path) < 0) return NULL; ret = realopendir(newpath ? newpath : path); VIR_FREE(newpath); return ret; } int close(int fd) { if (remove_fd(fd) < 0) return -1; return realclose(fd); } #else /* Nothing to override on non-__linux__ platforms */ #endif