diff options
| -rw-r--r-- | tools/vm/page-types.c | 35 |
1 files changed, 32 insertions, 3 deletions
diff --git a/tools/vm/page-types.c b/tools/vm/page-types.c index 05654f5e48d5..c4d6d2e20e0d 100644 --- a/tools/vm/page-types.c +++ b/tools/vm/page-types.c @@ -32,6 +32,8 @@ #include <assert.h> #include <ftw.h> #include <time.h> +#include <setjmp.h> +#include <signal.h> #include <sys/types.h> #include <sys/errno.h> #include <sys/fcntl.h> @@ -824,21 +826,38 @@ static void show_file(const char *name, const struct stat *st) atime, now - st->st_atime); } +static sigjmp_buf sigbus_jmp; + +static void * volatile sigbus_addr; + +static void sigbus_handler(int sig, siginfo_t *info, void *ucontex) +{ + (void)sig; + (void)ucontex; + sigbus_addr = info ? info->si_addr : NULL; + siglongjmp(sigbus_jmp, 1); +} + +static struct sigaction sigbus_action = { + .sa_sigaction = sigbus_handler, + .sa_flags = SA_SIGINFO, +}; + static void walk_file(const char *name, const struct stat *st) { uint8_t vec[PAGEMAP_BATCH]; uint64_t buf[PAGEMAP_BATCH], flags; unsigned long nr_pages, pfn, i; + off_t off, end = st->st_size; int fd; - off_t off; ssize_t len; void *ptr; int first = 1; fd = checked_open(name, O_RDONLY|O_NOATIME|O_NOFOLLOW); - for (off = 0; off < st->st_size; off += len) { - nr_pages = (st->st_size - off + page_size - 1) / page_size; + for (off = 0; off < end; off += len) { + nr_pages = (end - off + page_size - 1) / page_size; if (nr_pages > PAGEMAP_BATCH) nr_pages = PAGEMAP_BATCH; len = nr_pages * page_size; @@ -855,11 +874,19 @@ static void walk_file(const char *name, const struct stat *st) if (madvise(ptr, len, MADV_RANDOM)) fatal("madvice failed: %s", name); + if (sigsetjmp(sigbus_jmp, 1)) { + end = off + sigbus_addr ? sigbus_addr - ptr : 0; + fprintf(stderr, "got sigbus at offset %lld: %s\n", + (long long)end, name); + goto got_sigbus; + } + /* populate ptes */ for (i = 0; i < nr_pages ; i++) { if (vec[i] & 1) (void)*(volatile int *)(ptr + i * page_size); } +got_sigbus: /* turn off harvesting reference bits */ if (madvise(ptr, len, MADV_SEQUENTIAL)) @@ -910,6 +937,7 @@ static void walk_page_cache(void) kpageflags_fd = checked_open(PROC_KPAGEFLAGS, O_RDONLY); pagemap_fd = checked_open("/proc/self/pagemap", O_RDONLY); + sigaction(SIGBUS, &sigbus_action, NULL); if (stat(opt_file, &st)) fatal("stat failed: %s\n", opt_file); @@ -925,6 +953,7 @@ static void walk_page_cache(void) close(kpageflags_fd); close(pagemap_fd); + signal(SIGBUS, SIG_DFL); } static void parse_file(const char *name) |
