From 1a49ef2ad3c1c3c50e6aea348260412f98ea862d Mon Sep 17 00:00:00 2001 From: Alexander Graf Date: Tue, 1 May 2012 16:30:28 +0100 Subject: [PATCH] linux-user: fix emulation of /proc/self/maps Improve the emulation of /proc/self/maps by reading the underlying host maps file and passing lines through with addresses adjusted to be guest addresses. This is necessary to avoid false triggers of the glibc check that a format string containing '%n' is not in writable memory. (For an example see the bug reported in https://bugs.launchpad.net/qemu-linaro/+bug/947888 where gpg aborts.) Signed-off-by: Alexander Graf Signed-off-by: Peter Maydell Signed-off-by: Riku Voipio --- linux-user/syscall.c | 42 +++++++++++++++++++++++++++++++++++++++++- 1 file changed, 41 insertions(+), 1 deletion(-) diff --git a/linux-user/syscall.c b/linux-user/syscall.c index 801b8ed..20d2a74 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -4866,13 +4866,53 @@ int get_osversion(void) static int open_self_maps(void *cpu_env, int fd) { +#if defined(TARGET_ARM) || defined(TARGET_M68K) || defined(TARGET_UNICORE32) TaskState *ts = ((CPUArchState *)cpu_env)->opaque; +#endif + FILE *fp; + char *line = NULL; + size_t len = 0; + ssize_t read; + + fp = fopen("/proc/self/maps", "r"); + if (fp == NULL) { + return -EACCES; + } + 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 (!strncmp(path, "[stack]", 7)) { + continue; + } + if (h2g_valid(min) && h2g_valid(max)) { + dprintf(fd, TARGET_ABI_FMT_lx "-" TARGET_ABI_FMT_lx + " %c%c%c%c %08" PRIx64 " %02x:%02x %d%s%s\n", + h2g(min), h2g(max), flag_r, flag_w, + flag_x, flag_p, offset, dev_maj, dev_min, inode, + path[0] ? " " : "", path); + } + } + + free(line); + fclose(fp); + +#if defined(TARGET_ARM) || defined(TARGET_M68K) || defined(TARGET_UNICORE32) dprintf(fd, "%08llx-%08llx rw-p %08llx 00:00 0 [stack]\n", (unsigned long long)ts->info->stack_limit, (unsigned long long)(ts->stack_base + (TARGET_PAGE_SIZE - 1)) & TARGET_PAGE_MASK, - (unsigned long long)ts->stack_base); + (unsigned long long)0); +#endif return 0; } -- 2.7.4