diff options
Diffstat (limited to 'arch/um/os-Linux/util.c')
| -rw-r--r-- | arch/um/os-Linux/util.c | 26 |
1 files changed, 20 insertions, 6 deletions
diff --git a/arch/um/os-Linux/util.c b/arch/um/os-Linux/util.c index fc0f2a9dee5a..e3ad71a0d13c 100644 --- a/arch/um/os-Linux/util.c +++ b/arch/um/os-Linux/util.c @@ -20,8 +20,7 @@ void stack_protections(unsigned long address) { - if (mprotect((void *) address, UM_THREAD_SIZE, - PROT_READ | PROT_WRITE | PROT_EXEC) < 0) + if (mprotect((void *) address, UM_THREAD_SIZE, PROT_READ | PROT_WRITE) < 0) panic("protecting stack failed, errno = %d", errno); } @@ -52,8 +51,8 @@ void setup_machinename(char *machine_out) struct utsname host; uname(&host); -#ifdef UML_CONFIG_UML_X86 -# ifndef UML_CONFIG_64BIT +#if IS_ENABLED(CONFIG_UML_X86) +# if !IS_ENABLED(CONFIG_64BIT) if (!strcmp(host.machine, "x86_64")) { strcpy(machine_out, "i686"); return; @@ -173,23 +172,38 @@ __uml_setup("quiet", quiet_cmd_param, "quiet\n" " Turns off information messages during boot.\n\n"); +/* + * The os_info/os_warn functions will be called by helper threads. These + * have a very limited stack size and using the libc formatting functions + * may overflow the stack. + * So pull in the kernel vscnprintf and use that instead with a fixed + * on-stack buffer. + */ +int vscnprintf(char *buf, size_t size, const char *fmt, va_list args); + void os_info(const char *fmt, ...) { + char buf[256]; va_list list; + int len; if (quiet_info) return; va_start(list, fmt); - vfprintf(stderr, fmt, list); + len = vscnprintf(buf, sizeof(buf), fmt, list); + fwrite(buf, len, 1, stderr); va_end(list); } void os_warn(const char *fmt, ...) { + char buf[256]; va_list list; + int len; va_start(list, fmt); - vfprintf(stderr, fmt, list); + len = vscnprintf(buf, sizeof(buf), fmt, list); + fwrite(buf, len, 1, stderr); va_end(list); } |