diff options
| -rw-r--r-- | tools/testing/selftests/proc/proc-maps-race.c | 119 |
1 files changed, 100 insertions, 19 deletions
diff --git a/tools/testing/selftests/proc/proc-maps-race.c b/tools/testing/selftests/proc/proc-maps-race.c index a734553718da..5eb350c23da4 100644 --- a/tools/testing/selftests/proc/proc-maps-race.c +++ b/tools/testing/selftests/proc/proc-maps-race.c @@ -39,6 +39,13 @@ #include <sys/types.h> #include <sys/wait.h> +#define min(a, b) \ + ({ \ + typeof(a) _a = (a); \ + typeof(b) _b = (b); \ + _a < _b ? _a : _b; \ + }) + /* /proc/pid/maps parsing routines */ struct page_content { char *data; @@ -77,6 +84,7 @@ FIXTURE(proc_maps_race) struct line_content first_line; unsigned long duration_sec; int shared_mem_size; + int skip_pages; int page_size; int vma_count; bool verbose; @@ -105,38 +113,102 @@ struct vma_modifier_info { void *child_mapped_addr[]; }; - -static bool read_two_pages(FIXTURE_DATA(proc_maps_race) *self) +static bool read_page(FIXTURE_DATA(proc_maps_race) *self, + struct page_content *page) { ssize_t bytes_read; - if (lseek(self->maps_fd, 0, SEEK_SET) < 0) + bytes_read = read(self->maps_fd, page->data, self->page_size); + if (bytes_read <= 0) return false; - bytes_read = read(self->maps_fd, self->page1.data, self->page_size); - if (bytes_read <= 0) + /* Make sure data always ends with a newline character. */ + if (page->data[bytes_read - 1] != '\n') return false; - self->page1.size = bytes_read; + page->size = bytes_read; - bytes_read = read(self->maps_fd, self->page2.data, self->page_size); - if (bytes_read <= 0) + return true; +} + +static bool parse_vma_line(char *line_start, char *line_end, + unsigned long *start, unsigned long *end) +{ + bool found; + + *line_end = '\0'; /* stop sscanf at the EOL */ + found = (sscanf(line_start, "%lx-%lx", start, end) == 2); + *line_end = '\n'; + + return found; +} + +static int locate_containing_page(FIXTURE_DATA(proc_maps_race) *self, + unsigned long addr, unsigned long size) +{ + unsigned long start, end; + int page = 0; + + if (lseek(self->maps_fd, 0, SEEK_SET) < 0) + return -1; + + while (true) { + char *curr_pos; + char *end_pos; + + if (!read_page(self, &self->page1)) + return -1; + + curr_pos = self->page1.data; + end_pos = self->page1.data + self->page1.size; + while (curr_pos < end_pos) { + char *line_end; + + line_end = strchr(curr_pos, '\n'); + if (!line_end) + break; + + if (parse_vma_line(curr_pos, line_end, &start, &end) && + start == addr && end == addr + size) + return page; + + curr_pos = line_end + 1; + } + page++; + } + + return 0; +} + +static bool read_two_pages(FIXTURE_DATA(proc_maps_race) *self) +{ + if (lseek(self->maps_fd, 0, SEEK_SET) < 0) return false; - self->page2.size = bytes_read; + for (int i = 0; i < self->skip_pages; i++) + if (!read_page(self, &self->page1)) + return false; - return true; + return read_page(self, &self->page1) && read_page(self, &self->page2); } -static void copy_first_line(struct page_content *page, char *first_line) +static void copy_line(const char *line_start, const char *line_end, + char *buf, size_t buf_size) { - char *pos = strchr(page->data, '\n'); + size_t len = min(line_end - line_start, buf_size - 1); - strncpy(first_line, page->data, pos - page->data); - first_line[pos - page->data] = '\0'; + strncpy(buf, line_start, len); + buf[len] = '\0'; } -static void copy_last_line(struct page_content *page, char *last_line) +static void copy_first_line(struct page_content *page, char *first_line, + size_t line_size) +{ + copy_line(page->data, strchr(page->data, '\n'), first_line, line_size); +} + +static void copy_last_line(struct page_content *page, char *last_line, + size_t line_size) { /* Get the last line in the first page */ const char *end = page->data + page->size - 1; @@ -146,8 +218,8 @@ static void copy_last_line(struct page_content *page, char *last_line) /* search previous newline */ while (pos[-1] != '\n') pos--; - strncpy(last_line, pos, end - pos); - last_line[end - pos] = '\0'; + + copy_line(pos, end, last_line, line_size); } /* Read the last line of the first page and the first line of the second page */ @@ -158,8 +230,8 @@ static bool read_boundary_lines(FIXTURE_DATA(proc_maps_race) *self, if (!read_two_pages(self)) return false; - copy_last_line(&self->page1, last_line->text); - copy_first_line(&self->page2, first_line->text); + copy_last_line(&self->page1, last_line->text, LINE_MAX_SIZE); + copy_first_line(&self->page2, first_line->text, LINE_MAX_SIZE); return sscanf(last_line->text, "%lx-%lx", &last_line->start_addr, &last_line->end_addr) == 2 && @@ -418,6 +490,8 @@ FIXTURE_SETUP(proc_maps_race) struct vma_modifier_info *mod_info; pthread_mutexattr_t mutex_attr; pthread_condattr_t cond_attr; + unsigned long first_map_addr; + unsigned long last_map_addr; unsigned long duration_sec; char fname[32]; @@ -502,6 +576,13 @@ FIXTURE_SETUP(proc_maps_race) self->page2.data = malloc(self->page_size); ASSERT_NE(self->page2.data, NULL); + first_map_addr = (unsigned long)mod_info->child_mapped_addr[0]; + last_map_addr = (unsigned long)mod_info->child_mapped_addr[mod_info->vma_count - 1]; + + self->skip_pages = locate_containing_page(self, + min(first_map_addr, last_map_addr), + self->page_size * 3); + ASSERT_NE(self->skip_pages, -1); ASSERT_TRUE(read_boundary_lines(self, &self->last_line, &self->first_line)); /* |