| Message ID | 20180625173626.8046-5-emil.l.velikov@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Monday, 2018-06-25 17:39:14 +0000, Emil Velikov wrote: > From: Emil Velikov <emil.velikov@collabora.com> > > Introduce a helper which gets the real sysfs path for the given pci > device. > > In other words, instead opening the /sys/dev/char/*/device symlink, we > opt for the actual /sys/devices/pci*/*/ > > It folds three (nearly identical) snprintf's and paves the way of adding > extra devices (see next patch) a piece of pie. > > Signed-off-by: Emil Velikov <emil.velikov@collabora.com> > --- > xf86drm.c | 62 ++++++++++++++++++++++++++++++++++++++++++++----------- > 1 file changed, 50 insertions(+), 12 deletions(-) > > diff --git a/xf86drm.c b/xf86drm.c > index d4810740..8ccd528f 100644 > --- a/xf86drm.c > +++ b/xf86drm.c > @@ -2992,16 +2992,37 @@ static int drmParseSubsystemType(int maj, int min) > #endif > } > > +static char * > +get_real_pci_path(int maj, int min) > +{ > + char path[PATH_MAX + 1]; > + char *real_path = malloc(PATH_MAX); Why not allocate this on the stack and pass it in? It would avoid the error handling you had to add in this patch :) > + > + if (!real_path) > + return NULL; > + > + snprintf(path, sizeof(path), "/sys/dev/char/%d:%d/device", maj, min); > + if (!realpath(path, real_path)) { > + free(real_path); > + return NULL; > + } > + > + return real_path; > +} > + > static int drmParsePciBusInfo(int maj, int min, drmPciBusInfoPtr info) > { > #ifdef __linux__ > unsigned int domain, bus, dev, func; > - char path[PATH_MAX + 1], *value; > + char *real_path, *value; > int num; > > - snprintf(path, sizeof(path), "/sys/dev/char/%d:%d/device", maj, min); > + real_path = get_real_pci_path(maj, min); > + if (!real_path) > + return -ENOENT; > > - value = sysfs_uevent_get(path, "PCI_SLOT_NAME"); > + value = sysfs_uevent_get(real_path, "PCI_SLOT_NAME"); > + free(real_path); > if (!value) > return -ENOENT; > > @@ -3114,24 +3135,32 @@ static int parse_separate_sysfs_files(int maj, int min, > "subsystem_vendor", > "subsystem_device", > }; > - char path[PATH_MAX + 1]; > + char path[PATH_MAX + 1], *real_path; > unsigned int data[ARRAY_SIZE(attrs)]; > FILE *fp; > int ret; > > + real_path = get_real_pci_path(maj, min); > + if (!real_path) > + return -ENOENT; > + > for (unsigned i = ignore_revision ? 1 : 0; i < ARRAY_SIZE(attrs); i++) { > - snprintf(path, PATH_MAX, "/sys/dev/char/%d:%d/device/%s", maj, min, > - attrs[i]); > + snprintf(path, PATH_MAX, "%s/%s", real_path, attrs[i]); > fp = fopen(path, "r"); > - if (!fp) > + if (!fp) { > + free(real_path); > return -errno; > + } > > ret = fscanf(fp, "%x", &data[i]); > fclose(fp); > - if (ret != 1) > + if (ret != 1) { > + free(real_path); > return -errno; > + } > > } > + free(real_path); > > device->revision_id = ignore_revision ? 0xff : data[0] & 0xff; > device->vendor_id = data[1] & 0xffff; > @@ -3145,19 +3174,28 @@ static int parse_separate_sysfs_files(int maj, int min, > static int parse_config_sysfs_file(int maj, int min, > drmPciDeviceInfoPtr device) > { > - char path[PATH_MAX + 1]; > + char path[PATH_MAX + 1], *real_path; > unsigned char config[64]; > int fd, ret; > > - snprintf(path, PATH_MAX, "/sys/dev/char/%d:%d/device/config", maj, min); > + real_path = get_real_pci_path(maj, min); > + if (!real_path) > + return -ENOENT; > + > + snprintf(path, PATH_MAX, "%s/config", real_path); > fd = open(path, O_RDONLY); > - if (fd < 0) > + if (fd < 0) { > + free(real_path); > return -errno; > + } > > ret = read(fd, config, sizeof(config)); > close(fd); > - if (ret < 0) > + if (ret < 0) { > + free(real_path); > return -errno; > + } > + free(real_path); > > device->vendor_id = config[0] | (config[1] << 8); > device->device_id = config[2] | (config[3] << 8); > -- > 2.18.0 > > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel
On Thursday, 2018-06-28 11:21:26 +0100, Eric Engestrom wrote: > On Monday, 2018-06-25 17:39:14 +0000, Emil Velikov wrote: > > From: Emil Velikov <emil.velikov@collabora.com> > > > > Introduce a helper which gets the real sysfs path for the given pci > > device. > > > > In other words, instead opening the /sys/dev/char/*/device symlink, we > > opt for the actual /sys/devices/pci*/*/ > > > > It folds three (nearly identical) snprintf's and paves the way of adding > > extra devices (see next patch) a piece of pie. > > > > Signed-off-by: Emil Velikov <emil.velikov@collabora.com> > > --- > > xf86drm.c | 62 ++++++++++++++++++++++++++++++++++++++++++++----------- > > 1 file changed, 50 insertions(+), 12 deletions(-) > > > > diff --git a/xf86drm.c b/xf86drm.c > > index d4810740..8ccd528f 100644 > > --- a/xf86drm.c > > +++ b/xf86drm.c > > @@ -2992,16 +2992,37 @@ static int drmParseSubsystemType(int maj, int min) > > #endif > > } > > > > +static char * > > +get_real_pci_path(int maj, int min) > > +{ > > + char path[PATH_MAX + 1]; > > + char *real_path = malloc(PATH_MAX); > > Why not allocate this on the stack and pass it in? > It would avoid the error handling you had to add in this patch :) Sorry, I forgot to add: with that amend, the series is Reviewed-by: Eric Engestrom <eric@engestrom.ch> > > > + > > + if (!real_path) > > + return NULL; > > + > > + snprintf(path, sizeof(path), "/sys/dev/char/%d:%d/device", maj, min); > > + if (!realpath(path, real_path)) { > > + free(real_path); > > + return NULL; > > + } > > + > > + return real_path; > > +} > > + > > static int drmParsePciBusInfo(int maj, int min, drmPciBusInfoPtr info) > > { > > #ifdef __linux__ > > unsigned int domain, bus, dev, func; > > - char path[PATH_MAX + 1], *value; > > + char *real_path, *value; > > int num; > > > > - snprintf(path, sizeof(path), "/sys/dev/char/%d:%d/device", maj, min); > > + real_path = get_real_pci_path(maj, min); > > + if (!real_path) > > + return -ENOENT; > > > > - value = sysfs_uevent_get(path, "PCI_SLOT_NAME"); > > + value = sysfs_uevent_get(real_path, "PCI_SLOT_NAME"); > > + free(real_path); > > if (!value) > > return -ENOENT; > > > > @@ -3114,24 +3135,32 @@ static int parse_separate_sysfs_files(int maj, int min, > > "subsystem_vendor", > > "subsystem_device", > > }; > > - char path[PATH_MAX + 1]; > > + char path[PATH_MAX + 1], *real_path; > > unsigned int data[ARRAY_SIZE(attrs)]; > > FILE *fp; > > int ret; > > > > + real_path = get_real_pci_path(maj, min); > > + if (!real_path) > > + return -ENOENT; > > + > > for (unsigned i = ignore_revision ? 1 : 0; i < ARRAY_SIZE(attrs); i++) { > > - snprintf(path, PATH_MAX, "/sys/dev/char/%d:%d/device/%s", maj, min, > > - attrs[i]); > > + snprintf(path, PATH_MAX, "%s/%s", real_path, attrs[i]); > > fp = fopen(path, "r"); > > - if (!fp) > > + if (!fp) { > > + free(real_path); > > return -errno; > > + } > > > > ret = fscanf(fp, "%x", &data[i]); > > fclose(fp); > > - if (ret != 1) > > + if (ret != 1) { > > + free(real_path); > > return -errno; > > + } > > > > } > > + free(real_path); > > > > device->revision_id = ignore_revision ? 0xff : data[0] & 0xff; > > device->vendor_id = data[1] & 0xffff; > > @@ -3145,19 +3174,28 @@ static int parse_separate_sysfs_files(int maj, int min, > > static int parse_config_sysfs_file(int maj, int min, > > drmPciDeviceInfoPtr device) > > { > > - char path[PATH_MAX + 1]; > > + char path[PATH_MAX + 1], *real_path; > > unsigned char config[64]; > > int fd, ret; > > > > - snprintf(path, PATH_MAX, "/sys/dev/char/%d:%d/device/config", maj, min); > > + real_path = get_real_pci_path(maj, min); > > + if (!real_path) > > + return -ENOENT; > > + > > + snprintf(path, PATH_MAX, "%s/config", real_path); > > fd = open(path, O_RDONLY); > > - if (fd < 0) > > + if (fd < 0) { > > + free(real_path); > > return -errno; > > + } > > > > ret = read(fd, config, sizeof(config)); > > close(fd); > > - if (ret < 0) > > + if (ret < 0) { > > + free(real_path); > > return -errno; > > + } > > + free(real_path); > > > > device->vendor_id = config[0] | (config[1] << 8); > > device->device_id = config[2] | (config[3] << 8); > > -- > > 2.18.0 > > > > _______________________________________________ > > dri-devel mailing list > > dri-devel@lists.freedesktop.org > > https://lists.freedesktop.org/mailman/listinfo/dri-devel
Feel free to add my r-b to this patch. On 2018-06-25 19:36, Emil Velikov wrote: > From: Emil Velikov <emil.velikov@collabora.com> > > Introduce a helper which gets the real sysfs path for the given pci > device. > > In other words, instead opening the /sys/dev/char/*/device symlink, we > opt for the actual /sys/devices/pci*/*/ > > It folds three (nearly identical) snprintf's and paves the way of adding > extra devices (see next patch) a piece of pie. > > Signed-off-by: Emil Velikov <emil.velikov@collabora.com> > --- > xf86drm.c | 62 ++++++++++++++++++++++++++++++++++++++++++++----------- > 1 file changed, 50 insertions(+), 12 deletions(-) > > diff --git a/xf86drm.c b/xf86drm.c > index d4810740..8ccd528f 100644 > --- a/xf86drm.c > +++ b/xf86drm.c > @@ -2992,16 +2992,37 @@ static int drmParseSubsystemType(int maj, int min) > #endif > } > > +static char * > +get_real_pci_path(int maj, int min) > +{ > + char path[PATH_MAX + 1]; > + char *real_path = malloc(PATH_MAX); > + > + if (!real_path) > + return NULL; > + > + snprintf(path, sizeof(path), "/sys/dev/char/%d:%d/device", maj, min); > + if (!realpath(path, real_path)) { > + free(real_path); > + return NULL; > + } > + > + return real_path; > +} > + > static int drmParsePciBusInfo(int maj, int min, drmPciBusInfoPtr info) > { > #ifdef __linux__ > unsigned int domain, bus, dev, func; > - char path[PATH_MAX + 1], *value; > + char *real_path, *value; > int num; > > - snprintf(path, sizeof(path), "/sys/dev/char/%d:%d/device", maj, min); > + real_path = get_real_pci_path(maj, min); > + if (!real_path) > + return -ENOENT; > > - value = sysfs_uevent_get(path, "PCI_SLOT_NAME"); > + value = sysfs_uevent_get(real_path, "PCI_SLOT_NAME"); > + free(real_path); > if (!value) > return -ENOENT; > > @@ -3114,24 +3135,32 @@ static int parse_separate_sysfs_files(int maj, int min, > "subsystem_vendor", > "subsystem_device", > }; > - char path[PATH_MAX + 1]; > + char path[PATH_MAX + 1], *real_path; > unsigned int data[ARRAY_SIZE(attrs)]; > FILE *fp; > int ret; > > + real_path = get_real_pci_path(maj, min); > + if (!real_path) > + return -ENOENT; > + > for (unsigned i = ignore_revision ? 1 : 0; i < ARRAY_SIZE(attrs); i++) { > - snprintf(path, PATH_MAX, "/sys/dev/char/%d:%d/device/%s", maj, min, > - attrs[i]); > + snprintf(path, PATH_MAX, "%s/%s", real_path, attrs[i]); > fp = fopen(path, "r"); > - if (!fp) > + if (!fp) { > + free(real_path); > return -errno; > + } > > ret = fscanf(fp, "%x", &data[i]); > fclose(fp); > - if (ret != 1) > + if (ret != 1) { > + free(real_path); > return -errno; > + } > > } > + free(real_path); > > device->revision_id = ignore_revision ? 0xff : data[0] & 0xff; > device->vendor_id = data[1] & 0xffff; > @@ -3145,19 +3174,28 @@ static int parse_separate_sysfs_files(int maj, int min, > static int parse_config_sysfs_file(int maj, int min, > drmPciDeviceInfoPtr device) > { > - char path[PATH_MAX + 1]; > + char path[PATH_MAX + 1], *real_path; > unsigned char config[64]; > int fd, ret; > > - snprintf(path, PATH_MAX, "/sys/dev/char/%d:%d/device/config", maj, min); > + real_path = get_real_pci_path(maj, min); > + if (!real_path) > + return -ENOENT; > + > + snprintf(path, PATH_MAX, "%s/config", real_path); > fd = open(path, O_RDONLY); > - if (fd < 0) > + if (fd < 0) { > + free(real_path); > return -errno; > + } > > ret = read(fd, config, sizeof(config)); > close(fd); > - if (ret < 0) > + if (ret < 0) { > + free(real_path); > return -errno; > + } > + free(real_path); > > device->vendor_id = config[0] | (config[1] << 8); > device->device_id = config[2] | (config[3] << 8); >
Hi Eric, On 28 June 2018 at 11:21, Eric Engestrom <eric@engestrom.ch> wrote: >> @@ -2992,16 +2992,37 @@ static int drmParseSubsystemType(int maj, int min) >> #endif >> } >> >> +static char * >> +get_real_pci_path(int maj, int min) >> +{ >> + char path[PATH_MAX + 1]; >> + char *real_path = malloc(PATH_MAX); > > Why not allocate this on the stack and pass it in? > It would avoid the error handling you had to add in this patch :) > As always, thanks for having a look. I was mostly hesitant since some callers already have a char foo[PATH_MAX +1]. Thinking about it - the default stack size should be enough to accommodate an extra ~4k bytes. Will fix. Thanks Emil
diff --git a/xf86drm.c b/xf86drm.c index d4810740..8ccd528f 100644 --- a/xf86drm.c +++ b/xf86drm.c @@ -2992,16 +2992,37 @@ static int drmParseSubsystemType(int maj, int min) #endif } +static char * +get_real_pci_path(int maj, int min) +{ + char path[PATH_MAX + 1]; + char *real_path = malloc(PATH_MAX); + + if (!real_path) + return NULL; + + snprintf(path, sizeof(path), "/sys/dev/char/%d:%d/device", maj, min); + if (!realpath(path, real_path)) { + free(real_path); + return NULL; + } + + return real_path; +} + static int drmParsePciBusInfo(int maj, int min, drmPciBusInfoPtr info) { #ifdef __linux__ unsigned int domain, bus, dev, func; - char path[PATH_MAX + 1], *value; + char *real_path, *value; int num; - snprintf(path, sizeof(path), "/sys/dev/char/%d:%d/device", maj, min); + real_path = get_real_pci_path(maj, min); + if (!real_path) + return -ENOENT; - value = sysfs_uevent_get(path, "PCI_SLOT_NAME"); + value = sysfs_uevent_get(real_path, "PCI_SLOT_NAME"); + free(real_path); if (!value) return -ENOENT; @@ -3114,24 +3135,32 @@ static int parse_separate_sysfs_files(int maj, int min, "subsystem_vendor", "subsystem_device", }; - char path[PATH_MAX + 1]; + char path[PATH_MAX + 1], *real_path; unsigned int data[ARRAY_SIZE(attrs)]; FILE *fp; int ret; + real_path = get_real_pci_path(maj, min); + if (!real_path) + return -ENOENT; + for (unsigned i = ignore_revision ? 1 : 0; i < ARRAY_SIZE(attrs); i++) { - snprintf(path, PATH_MAX, "/sys/dev/char/%d:%d/device/%s", maj, min, - attrs[i]); + snprintf(path, PATH_MAX, "%s/%s", real_path, attrs[i]); fp = fopen(path, "r"); - if (!fp) + if (!fp) { + free(real_path); return -errno; + } ret = fscanf(fp, "%x", &data[i]); fclose(fp); - if (ret != 1) + if (ret != 1) { + free(real_path); return -errno; + } } + free(real_path); device->revision_id = ignore_revision ? 0xff : data[0] & 0xff; device->vendor_id = data[1] & 0xffff; @@ -3145,19 +3174,28 @@ static int parse_separate_sysfs_files(int maj, int min, static int parse_config_sysfs_file(int maj, int min, drmPciDeviceInfoPtr device) { - char path[PATH_MAX + 1]; + char path[PATH_MAX + 1], *real_path; unsigned char config[64]; int fd, ret; - snprintf(path, PATH_MAX, "/sys/dev/char/%d:%d/device/config", maj, min); + real_path = get_real_pci_path(maj, min); + if (!real_path) + return -ENOENT; + + snprintf(path, PATH_MAX, "%s/config", real_path); fd = open(path, O_RDONLY); - if (fd < 0) + if (fd < 0) { + free(real_path); return -errno; + } ret = read(fd, config, sizeof(config)); close(fd); - if (ret < 0) + if (ret < 0) { + free(real_path); return -errno; + } + free(real_path); device->vendor_id = config[0] | (config[1] << 8); device->device_id = config[2] | (config[3] << 8);