Currently, a fixed-size array is used to store the configurations for all discovered iMC counters, which has several issues:
1. Fixed Overhead: The array is allocated a fixed size, even if the platform has fewer iMCs. 2. Out-of-Bounds Access: On platforms with more iMC counters than MAX_IMCS, the num_of_imcs() function can return a larger number, leading to an array index out-of-bounds access. 3. Reduced Maintainability: The need to statically define MAX_IMCS for different architectures and vendors makes the code harder to maintain. 4. Redundancy: The num_of_imcs() function dynamically discovers the actual number of counters, making the static size declaration unnecessary and redundant. To address these issues, this commit refactors resctrl_val.c to use a dynamic linked list. The num_of_imcs() function now allocates and configures an imc_counter_config structure for each discovered iMC and adds it to a global list (imc_counters_configs). This change ensures that only the required memory is used and prevents the out-of-bounds issue. Additionally, a corresponding cleanup_read_mem_bw_imc() function is added to iterate through the list and free all allocated memory, preventing leaks. All function signatures that previously accepted an integer index have been updated to accept a pointer to the imc_counter_config struct, and the calling code has been updated to traverse the new list. Signed-off-by: Yifan Wu <[email protected]> --- tools/testing/selftests/resctrl/resctrl.h | 1 + tools/testing/selftests/resctrl/resctrl_val.c | 132 ++++++++++-------- 2 files changed, 78 insertions(+), 55 deletions(-) diff --git a/tools/testing/selftests/resctrl/resctrl.h b/tools/testing/selftests/resctrl/resctrl.h index afe635b6e48d..75c595812e7d 100644 --- a/tools/testing/selftests/resctrl/resctrl.h +++ b/tools/testing/selftests/resctrl/resctrl.h @@ -24,6 +24,7 @@ #include <linux/perf_event.h> #include <linux/compiler.h> #include <linux/bits.h> +#include <linux/list.h> #include "kselftest.h" #define MB (1024 * 1024) diff --git a/tools/testing/selftests/resctrl/resctrl_val.c b/tools/testing/selftests/resctrl/resctrl_val.c index b0570c615aac..68e46c863474 100644 --- a/tools/testing/selftests/resctrl/resctrl_val.c +++ b/tools/testing/selftests/resctrl/resctrl_val.c @@ -11,7 +11,6 @@ #include "resctrl.h" #define DYN_PMU_PATH "/sys/bus/event_source/devices" -#define MAX_IMCS 20 #define MAX_TOKENS 5 #define CON_MBM_LOCAL_BYTES_PATH \ @@ -31,6 +30,7 @@ struct imc_counter_config { struct perf_event_attr pe; struct membw_read_format return_value; int fd; + struct list_head imc_list; }; struct membw_read_config { @@ -38,14 +38,18 @@ struct membw_read_config { const char *name; const char *event; double scale; + int (*num_of)(void); }; +static int num_of_imcs(void); + static struct membw_read_config membw_read_configs[] = { { .vendor_id = ARCH_INTEL | ARCH_AMD | ARCH_HYGON, .name = "uncore_imc", .event = "events/cas_count_read", .scale = 64.0 / MB, + .num_of = num_of_imcs, }, { .vendor_id = NULL @@ -53,37 +57,38 @@ static struct membw_read_config membw_read_configs[] = { }; static char mbm_total_path[1024]; -static int imcs; -static struct imc_counter_config imc_counters_config[MAX_IMCS]; +LIST_HEAD(imc_counters_configs); static const struct resctrl_test *current_test; static struct membw_read_config *current_config; -static void read_mem_bw_initialize_perf_event_attr(int i) +static void read_mem_bw_initialize_perf_event_attr(struct imc_counter_config *imc_counters_config) { - memset(&imc_counters_config[i].pe, 0, + memset(&imc_counters_config->pe, 0, sizeof(struct perf_event_attr)); - imc_counters_config[i].pe.type = imc_counters_config[i].type; - imc_counters_config[i].pe.size = sizeof(struct perf_event_attr); - imc_counters_config[i].pe.disabled = 1; - imc_counters_config[i].pe.inherit = 1; - imc_counters_config[i].pe.exclude_guest = 0; - imc_counters_config[i].pe.config = - imc_counters_config[i].umask << 8 | - imc_counters_config[i].event; - imc_counters_config[i].pe.sample_type = PERF_SAMPLE_IDENTIFIER; - imc_counters_config[i].pe.read_format = + imc_counters_config->pe.type = imc_counters_config->type; + imc_counters_config->pe.size = sizeof(struct perf_event_attr); + imc_counters_config->pe.disabled = 1; + imc_counters_config->pe.inherit = 1; + imc_counters_config->pe.exclude_guest = 0; + imc_counters_config->pe.config = + imc_counters_config->umask << 8 | + imc_counters_config->event; + imc_counters_config->pe.sample_type = PERF_SAMPLE_IDENTIFIER; + imc_counters_config->pe.read_format = PERF_FORMAT_TOTAL_TIME_ENABLED | PERF_FORMAT_TOTAL_TIME_RUNNING; } -static void read_mem_bw_ioctl_perf_event_ioc_reset_enable(int i) +static void read_mem_bw_ioctl_perf_event_ioc_reset_enable(struct imc_counter_config + *imc_counters_config) { - ioctl(imc_counters_config[i].fd, PERF_EVENT_IOC_RESET, 0); - ioctl(imc_counters_config[i].fd, PERF_EVENT_IOC_ENABLE, 0); + ioctl(imc_counters_config->fd, PERF_EVENT_IOC_RESET, 0); + ioctl(imc_counters_config->fd, PERF_EVENT_IOC_ENABLE, 0); } -static void read_mem_bw_ioctl_perf_event_ioc_disable(int i) +static void read_mem_bw_ioctl_perf_event_ioc_disable(struct imc_counter_config + *imc_counters_config) { - ioctl(imc_counters_config[i].fd, PERF_EVENT_IOC_DISABLE, 0); + ioctl(imc_counters_config->fd, PERF_EVENT_IOC_DISABLE, 0); } /* @@ -91,7 +96,8 @@ static void read_mem_bw_ioctl_perf_event_ioc_disable(int i) * @cas_count_cfg: Config * @count: iMC number */ -static void get_read_event_and_umask(char *cas_count_cfg, int count) +static void get_read_event_and_umask(char *cas_count_cfg, struct imc_counter_config + *imc_counters_config) { char *token[MAX_TOKENS]; int i = 0; @@ -105,21 +111,21 @@ static void get_read_event_and_umask(char *cas_count_cfg, int count) if (!token[i]) break; if (strcmp(token[i], "event") == 0) - imc_counters_config[count].event = strtol(token[i + 1], NULL, 16); + imc_counters_config->event = strtol(token[i + 1], NULL, 16); if (strcmp(token[i], "umask") == 0) - imc_counters_config[count].umask = strtol(token[i + 1], NULL, 16); + imc_counters_config->umask = strtol(token[i + 1], NULL, 16); } } -static int open_perf_read_event(int i, int cpu_no) +static int open_perf_read_event(struct imc_counter_config *imc_counters_config, int cpu_no) { - imc_counters_config[i].fd = - perf_event_open(&imc_counters_config[i].pe, -1, cpu_no, -1, + imc_counters_config->fd = + perf_event_open(&imc_counters_config->pe, -1, cpu_no, -1, PERF_FLAG_FD_CLOEXEC); - if (imc_counters_config[i].fd == -1) { + if (imc_counters_config->fd == -1) { fprintf(stderr, "Error opening leader %llx\n", - imc_counters_config[i].pe.config); + imc_counters_config->pe.config); return -1; } @@ -128,7 +134,7 @@ static int open_perf_read_event(int i, int cpu_no) } /* Get type and config of an iMC counter's read event. */ -static int read_from_imc_dir(char *imc_dir, int count) +static int read_from_imc_dir(char *imc_dir, struct imc_counter_config *imc_counters_config) { char cas_count_cfg[1024], imc_counter_cfg[1024], imc_counter_type[1024]; FILE *fp; @@ -141,7 +147,7 @@ static int read_from_imc_dir(char *imc_dir, int count) return -1; } - if (fscanf(fp, "%u", &imc_counters_config[count].type) <= 0) { + if (fscanf(fp, "%u", &imc_counters_config->type) <= 0) { ksft_perror("Could not get iMC type"); fclose(fp); @@ -165,7 +171,7 @@ static int read_from_imc_dir(char *imc_dir, int count) } fclose(fp); - get_read_event_and_umask(cas_count_cfg, count); + get_read_event_and_umask(cas_count_cfg, imc_counters_config); return 0; } @@ -189,6 +195,7 @@ static int num_of_imcs(void) struct dirent *ep; int ret; DIR *dp; + struct imc_counter_config *imc_counters_config; dp = opendir(DYN_PMU_PATH); if (dp) { @@ -212,14 +219,17 @@ static int num_of_imcs(void) * first character is a numerical digit or not. */ if (temp[0] >= '0' && temp[0] <= '9') { + imc_counters_config = malloc(sizeof(struct imc_counter_config)); sprintf(imc_dir, "%s/%s/", DYN_PMU_PATH, ep->d_name); - ret = read_from_imc_dir(imc_dir, count); + ret = read_from_imc_dir(imc_dir, imc_counters_config); if (ret) { + free(imc_counters_config); closedir(dp); return ret; } + list_add(&imc_counters_config->imc_list, &imc_counters_configs); count++; } } @@ -240,26 +250,40 @@ static int num_of_imcs(void) int initialize_read_mem_bw_imc(void) { - int imc; + struct imc_counter_config *imc_counters_config; - imcs = num_of_imcs(); + int imcs = current_config->num_of(); if (imcs <= 0) return imcs; /* Initialize perf_event_attr structures for all iMC's */ - for (imc = 0; imc < imcs; imc++) - read_mem_bw_initialize_perf_event_attr(imc); + list_for_each_entry(imc_counters_config, &imc_counters_configs, imc_list) { + read_mem_bw_initialize_perf_event_attr(imc_counters_config); + } return 0; } +void cleanup_read_mem_bw_imc(void) +{ + struct imc_counter_config *imc_counters_config; + struct imc_counter_config *next_imc_counters_config; + + list_for_each_entry_safe(imc_counters_config, next_imc_counters_config, + &imc_counters_configs, imc_list) { + list_del(&imc_counters_config->imc_list); + free(imc_counters_config); + } + list_del_init(&imc_counters_configs); +} + static void perf_close_imc_read_mem_bw(void) { - int mc; + struct imc_counter_config *imc_counters_config; - for (mc = 0; mc < imcs; mc++) { - if (imc_counters_config[mc].fd != -1) - close(imc_counters_config[mc].fd); + list_for_each_entry(imc_counters_config, &imc_counters_configs, imc_list) { + if (imc_counters_config->fd != -1) + close(imc_counters_config->fd); } } @@ -271,13 +295,14 @@ static void perf_close_imc_read_mem_bw(void) */ static int perf_open_imc_read_mem_bw(int cpu_no) { - int imc, ret; + int ret; + struct imc_counter_config *imc_counters_config; - for (imc = 0; imc < imcs; imc++) - imc_counters_config[imc].fd = -1; + list_for_each_entry(imc_counters_config, &imc_counters_configs, imc_list) + imc_counters_config->fd = -1; - for (imc = 0; imc < imcs; imc++) { - ret = open_perf_read_event(imc, cpu_no); + list_for_each_entry(imc_counters_config, &imc_counters_configs, imc_list) { + ret = open_perf_read_event(imc_counters_config, cpu_no); if (ret) goto close_fds; } @@ -297,16 +322,16 @@ static int perf_open_imc_read_mem_bw(int cpu_no) */ static void do_imc_read_mem_bw_test(void) { - int imc; + struct imc_counter_config *imc_counters_config; - for (imc = 0; imc < imcs; imc++) - read_mem_bw_ioctl_perf_event_ioc_reset_enable(imc); + list_for_each_entry(imc_counters_config, &imc_counters_configs, imc_list) + read_mem_bw_ioctl_perf_event_ioc_reset_enable(imc_counters_config); sleep(1); /* Stop counters after a second to get results. */ - for (imc = 0; imc < imcs; imc++) - read_mem_bw_ioctl_perf_event_ioc_disable(imc); + list_for_each_entry(imc_counters_config, &imc_counters_configs, imc_list) + read_mem_bw_ioctl_perf_event_ioc_disable(imc_counters_config); } /* @@ -321,17 +346,14 @@ static void do_imc_read_mem_bw_test(void) static int get_read_mem_bw_imc(float *bw_imc) { float reads = 0, of_mul_read = 1; - int imc; + struct imc_counter_config *r; /* * Log read event values from all iMC counters into * struct imc_counter_config. * Take overflow into consideration before calculating total bandwidth. */ - for (imc = 0; imc < imcs; imc++) { - struct imc_counter_config *r = - &imc_counters_config[imc]; - + list_for_each_entry(r, &imc_counters_configs, imc_list) { if (read(r->fd, &r->return_value, sizeof(struct membw_read_format)) == -1) { ksft_perror("Couldn't get read bandwidth through iMC"); -- 2.33.0
