diff --git a/include/qemu/selfmap.h b/include/qemu/selfmap.h new file mode 100644 index 0000000000..8382c4c779 --- /dev/null +++ b/include/qemu/selfmap.h @@ -0,0 +1,44 @@ +/* + * Utility functions to read our own memory map + * + * Copyright (c) 2020 Linaro Ltd + * + * SPDX-License-Identifier: GPL-2.0-or-later + */ + +#ifndef _SELFMAP_H_ +#define _SELFMAP_H_ + +typedef struct { + unsigned long start; + unsigned long end; + + /* flags */ + bool is_read; + bool is_write; + bool is_exec; + bool is_priv; + + unsigned long offset; + gchar *dev; + uint64_t inode; + gchar *path; +} MapInfo; + + +/** + * read_self_maps: + * + * Read /proc/self/maps and return a list of MapInfo structures. + */ +GSList *read_self_maps(void); + +/** + * free_self_maps: + * @info: a GSlist + * + * Free a list of MapInfo structures. + */ +void free_self_maps(GSList *info); + +#endif /* _SELFMAP_H_ */ diff --git a/linux-user/syscall.c b/linux-user/syscall.c index b679bc6b13..5f11787294 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -117,6 +117,7 @@ #include "qemu.h" #include "qemu/guest-random.h" +#include "qemu/selfmap.h" #include "user/syscall-trace.h" #include "qapi/error.h" #include "fd-trans.h" @@ -7232,45 +7233,45 @@ static int open_self_maps(void *cpu_env, int fd) { CPUState *cpu = env_cpu((CPUArchState *)cpu_env); TaskState *ts = cpu->opaque; - FILE *fp; - char *line = NULL; - size_t len = 0; - ssize_t read; + GSList *map_info = read_self_maps(); + GSList *s; - fp = fopen("/proc/self/maps", "r"); - if (fp == NULL) { - return -1; - } + for (s = map_info; s; s = g_slist_next(s)) { + MapInfo *e = (MapInfo *) s->data; - while ((read = getline(&line, &len, fp)) != -1) { - int fields, dev_maj, dev_min, inode; - uint64_t min, max, offset; - char flag_r, flag_w, flag_x, flag_p; - char path[512] = ""; - fields = sscanf(line, "%"PRIx64"-%"PRIx64" %c%c%c%c %"PRIx64" %x:%x %d" - " %512s", &min, &max, &flag_r, &flag_w, &flag_x, - &flag_p, &offset, &dev_maj, &dev_min, &inode, path); - - if ((fields < 10) || (fields > 11)) { - continue; - } - if (h2g_valid(min)) { + if (h2g_valid(e->start)) { + unsigned long min = e->start; + unsigned long max = e->end; int flags = page_get_flags(h2g(min)); - max = h2g_valid(max - 1) ? max : (uintptr_t)g2h(GUEST_ADDR_MAX) + 1; + const char *path; + + max = h2g_valid(max - 1) ? + max : (uintptr_t) g2h(GUEST_ADDR_MAX) + 1; + if (page_check_range(h2g(min), max - min, flags) == -1) { continue; } + if (h2g(min) == ts->info->stack_limit) { - pstrcpy(path, sizeof(path), " [stack]"); + path = " [stack]"; + } else { + path = e->path; } + dprintf(fd, TARGET_ABI_FMT_ptr "-" TARGET_ABI_FMT_ptr - " %c%c%c%c %08" PRIx64 " %02x:%02x %d %s%s\n", - h2g(min), h2g(max - 1) + 1, flag_r, flag_w, - flag_x, flag_p, offset, dev_maj, dev_min, inode, - path[0] ? " " : "", path); + " %c%c%c%c %08" PRIx64 " %s %"PRId64" %s%s\n", + h2g(min), h2g(max - 1) + 1, + e->is_read ? 'r' : '-', + e->is_write ? 'w' : '-', + e->is_exec ? 'x' : '-', + e->is_priv ? 'p' : '-', + (uint64_t) e->offset, e->dev, e->inode, + path ? " " : "", path ? path : ""); } } + free_self_maps(map_info); + #ifdef TARGET_VSYSCALL_PAGE /* * We only support execution from the vsyscall page. @@ -7281,9 +7282,6 @@ static int open_self_maps(void *cpu_env, int fd) TARGET_VSYSCALL_PAGE, TARGET_VSYSCALL_PAGE + TARGET_PAGE_SIZE); #endif - free(line); - fclose(fp); - return 0; } diff --git a/util/Makefile.objs b/util/Makefile.objs index 6718a38b61..fe339c2636 100644 --- a/util/Makefile.objs +++ b/util/Makefile.objs @@ -63,3 +63,4 @@ util-obj-y += guest-random.o util-obj-$(CONFIG_GIO) += dbus.o dbus.o-cflags = $(GIO_CFLAGS) dbus.o-libs = $(GIO_LIBS) +util-obj-$(CONFIG_USER_ONLY) += selfmap.o diff --git a/util/selfmap.c b/util/selfmap.c new file mode 100644 index 0000000000..2ec99dfdda --- /dev/null +++ b/util/selfmap.c @@ -0,0 +1,78 @@ +/* + * Utility function to get QEMU's own process map + * + * Copyright (c) 2020 Linaro Ltd + * + * SPDX-License-Identifier: GPL-2.0-or-later + */ + +#include "qemu/osdep.h" +#include "qemu/cutils.h" +#include "qemu/selfmap.h" + +GSList *read_self_maps(void) +{ + gchar *maps; + GSList *map_info = NULL; + + if (g_file_get_contents("/proc/self/maps", &maps, NULL, NULL)) { + gchar **lines = g_strsplit(maps, "\n", 0); + int i, entries = g_strv_length(lines); + + for (i = 0; i < entries; i++) { + gchar **fields = g_strsplit(lines[i], " ", 6); + if (g_strv_length(fields) > 4) { + MapInfo *e = g_new0(MapInfo, 1); + int errors; + const char *end; + + errors = qemu_strtoul(fields[0], &end, 16, &e->start); + errors += qemu_strtoul(end + 1, NULL, 16, &e->end); + + e->is_read = fields[1][0] == 'r'; + e->is_write = fields[1][1] == 'w'; + e->is_exec = fields[1][2] == 'x'; + e->is_priv = fields[1][3] == 'p'; + + errors += qemu_strtoul(fields[2], NULL, 16, &e->offset); + e->dev = g_strdup(fields[3]); + errors += qemu_strtou64(fields[4], NULL, 10, &e->inode); + + /* + * The last field may have leading spaces which we + * need to strip. + */ + if (g_strv_length(fields) == 6) { + e->path = g_strdup(g_strchug(fields[5])); + } + map_info = g_slist_prepend(map_info, e); + } + + g_strfreev(fields); + } + g_strfreev(lines); + g_free(maps); + } + + /* ensure the map data is in the same order we collected it */ + return g_slist_reverse(map_info); +} + +/** + * free_self_maps: + * @info: a GSlist + * + * Free a list of MapInfo structures. + */ +static void free_info(gpointer data) +{ + MapInfo *e = (MapInfo *) data; + g_free(e->dev); + g_free(e->path); + g_free(e); +} + +void free_self_maps(GSList *info) +{ + g_slist_free_full(info, &free_info); +}