Merge pull request #3825 from brauner/2021-05-04.fixes

src/lxc/attach.c

@@ -48,10 +48,6 @@
 #include "terminal.h"
 #include "utils.h"
 
-#if HAVE_SYS_PERSONALITY_H
-#include <sys/personality.h>
-#endif
-
 lxc_log_define(attach, lxc);
 
 /* Define default options if no options are supplied by the user. */
@@ -99,7 +95,7 @@ struct attach_context {
 	uid_t target_host_gid;
 	char *lsm_label;
 	struct lxc_container *container;
-	signed long personality;
+	personality_t personality;
 	unsigned long long capability_mask;
 	int ns_inherited;
 	int ns_fd[LXC_NS_MAX];
@@ -201,9 +197,10 @@ static struct attach_context *alloc_attach_context(void)
 }
 
 static int get_personality(const char *name, const char *lxcpath,
-			   signed long *personality)
+			   personality_t *personality)
 {
 	__do_free char *p = NULL;
+	int ret;
 	signed long per;
 
 	p = lxc_cmd_get_config_item(name, "lxc.arch", lxcpath);
@@ -212,9 +209,9 @@ static int get_personality(const char *name, const char *lxcpath,
 		return 0;
 	}
 
-	per = lxc_config_parse_arch(p);
-	if (per == LXC_ARCH_UNCHANGED)
-		return ret_errno(EINVAL);
+	ret = lxc_config_parse_arch(p, &per);
+	if (ret < 0)
+		return syserror("Failed to parse personality");
 
 	*personality = per;
 	return 0;
@@ -1147,24 +1144,22 @@ __noreturn static void do_attach(struct attach_payload *ap)
 	}
 
 	/* Now perform additional attachments. */
-#if HAVE_SYS_PERSONALITY_H
 	if (options->attach_flags & LXC_ATTACH_SET_PERSONALITY) {
 		long new_personality;
 
-		if (options->personality < 0)
+		if (options->personality == LXC_ATTACH_DETECT_PERSONALITY)
 			new_personality = ctx->personality;
 		else
 			new_personality = options->personality;
 
 		if (new_personality != LXC_ARCH_UNCHANGED) {
-			ret = personality(new_personality);
+			ret = lxc_personality(new_personality);
 			if (ret < 0)
 				goto on_error;
 
 			TRACE("Set new personality");
 		}
 	}
-#endif
 
 	if (options->attach_flags & LXC_ATTACH_DROP_CAPABILITIES) {
 		ret = drop_capabilities(ctx);

src/lxc/attach_options.h

@@ -82,6 +82,8 @@ typedef struct lxc_groups_t {
 	gid_t *list;
 } lxc_groups_t;
 
+#define LXC_ATTACH_DETECT_PERSONALITY ~0L
+
 /*!
  * LXC attach options for \ref lxc_container \c attach().
  */
@@ -92,7 +94,7 @@ typedef struct lxc_attach_options_t {
 	/*! The namespaces to attach to (CLONE_NEW... flags) */
 	int namespaces;
 
-	/*! Initial personality (\c -1 to autodetect).
+	/*! Initial personality (\c LXC_ATTACH_DETECT_PERSONALITY to autodetect).
 	 * \warning This may be ignored if lxc is compiled without personality
 	 * support)
 	 */
@@ -156,23 +158,23 @@ typedef struct lxc_attach_options_t {
 } lxc_attach_options_t;
 
 /*! Default attach options to use */
-#define LXC_ATTACH_OPTIONS_DEFAULT			\
-	{                                               \
-		.attach_flags	= LXC_ATTACH_DEFAULT,   \
-		.namespaces	= -1,                   \
-		.personality	= 0xffffffff,           \
-		.initial_cwd	= NULL,                 \
-		.uid		= (uid_t)-1,            \
-		.gid		= (gid_t)-1,            \
-		.env_policy	= LXC_ATTACH_KEEP_ENV,  \
-		.extra_env_vars = NULL,                 \
-		.extra_keep_env = NULL,                 \
-		.stdin_fd	= 0,                    \
-		.stdout_fd	= 1,                    \
-		.stderr_fd	= 2,                    \
-		.log_fd		= -EBADF,               \
-		.lsm_label	= NULL,			\
-		.groups		= {},			\
+#define LXC_ATTACH_OPTIONS_DEFAULT					\
+	{                                               		\
+		.attach_flags	= LXC_ATTACH_DEFAULT,   		\
+		.namespaces	= -1,					\
+		.personality	= LXC_ATTACH_DETECT_PERSONALITY,	\
+		.initial_cwd	= NULL,					\
+		.uid		= (uid_t)-1,            		\
+		.gid		= (gid_t)-1,            		\
+		.env_policy	= LXC_ATTACH_KEEP_ENV,  		\
+		.extra_env_vars = NULL,                 		\
+		.extra_keep_env = NULL,                 		\
+		.stdin_fd	= 0,                    		\
+		.stdout_fd	= 1,                    		\
+		.stderr_fd	= 2,                    		\
+		.log_fd		= -EBADF,               		\
+		.lsm_label	= NULL,					\
+		.groups		= {},					\
 	}
 
 /*!

src/lxc/commands.c

@@ -126,7 +126,7 @@ static ssize_t lxc_cmd_rsp_recv_fds(int fd_sock, struct unix_fds *fds,
 
 	ret = lxc_abstract_unix_recv_fds(fd_sock, fds, rsp, sizeof(*rsp));
 	if (ret < 0)
-		return ret;
+		return log_error(ret, "Failed to receive file descriptors");
 
 	/*
 	 * If we end up here with fewer or more file descriptors the caller
@@ -135,18 +135,18 @@ static ssize_t lxc_cmd_rsp_recv_fds(int fd_sock, struct unix_fds *fds,
 	 */
 
 	if (fds->flags & UNIX_FDS_RECEIVED_EXACT)
-		return log_info(ret, "Received exact number of file descriptors %u == %u",
-				fds->fd_count_max, fds->fd_count_ret);
+		return log_debug(ret, "Received exact number of file descriptors %u == %u",
+				 fds->fd_count_max, fds->fd_count_ret);
 
 	if (fds->flags & UNIX_FDS_RECEIVED_LESS)
-		return log_info(ret, "Received less file descriptors %u < %u",
-				fds->fd_count_ret, fds->fd_count_max);
+		return log_debug(ret, "Received less file descriptors %u < %u",
+				 fds->fd_count_ret, fds->fd_count_max);
 
 	if (fds->flags & UNIX_FDS_RECEIVED_MORE)
-		return log_info(ret, "Received more file descriptors (excessive fds were automatically closed) %u > %u",
-				fds->fd_count_ret, fds->fd_count_max);
+		return log_debug(ret, "Received more file descriptors (excessive fds were automatically closed) %u > %u",
+				 fds->fd_count_ret, fds->fd_count_max);
 
-	INFO("Command \"%s\" received response", cur_cmdstr);
+	DEBUG("Command \"%s\" received response", cur_cmdstr);
 	return ret;
 }
 

src/lxc/conf.c

@@ -80,10 +80,6 @@
 #include <sys/capability.h>
 #endif
 
-#if HAVE_SYS_PERSONALITY_H
-#include <sys/personality.h>
-#endif
-
 #ifndef HAVE_STRLCAT
 #include "include/strlcat.h"
 #endif
@@ -1732,21 +1728,18 @@ static int lxc_setup_devpts_child(struct lxc_handler *handler)
 	return 0;
 }
 
-static int setup_personality(int persona)
+static int setup_personality(personality_t persona)
 {
 	int ret;
 
-#if HAVE_SYS_PERSONALITY_H
-	if (persona == -1)
-		return 0;
+	if (persona == LXC_ARCH_UNCHANGED)
+		return log_debug(0, "Retaining original personality");
 
-	ret = personality(persona);
+	ret = lxc_personality(persona);
 	if (ret < 0)
-		return log_error_errno(-1, errno, "Failed to set personality to \"0x%x\"", persona);
-
-	INFO("Set personality to \"0x%x\"", persona);
-#endif
+		return syserror("Failed to set personality to \"0lx%lx\"", persona);
 
+	INFO("Set personality to \"0lx%lx\"", persona);
 	return 0;
 }
 
@@ -2806,7 +2799,7 @@ struct lxc_conf *lxc_conf_init(void)
 		return NULL;
 
 	new->loglevel = LXC_LOG_LEVEL_NOTSET;
-	new->personality = -1;
+	new->personality = LXC_ARCH_UNCHANGED;
 	new->autodev = 1;
 	new->console.buffer_size = 0;
 	new->console.log_path = NULL;
@@ -3737,7 +3730,7 @@ int lxc_setup(struct lxc_handler *handler)
 
 	ret = setup_personality(lxc_conf->personality);
 	if (ret < 0)
-		return log_error(-1, "Failed to set personality");
+		return syserror("Failed to set personality");
 
 	/* Set sysctl value to a path under /proc/sys as determined from the
 	 * key. For e.g. net.ipv4.ip_forward translated to

src/lxc/conf.h

@@ -26,6 +26,7 @@
 #include "start.h"
 #include "storage/storage.h"
 #include "string_utils.h"
+#include "syscall_wrappers.h"
 #include "terminal.h"
 
 #if HAVE_SYS_RESOURCE_H
@@ -36,6 +37,8 @@
 typedef void * scmp_filter_ctx;
 #endif
 
+typedef signed long personality_t;
+
 /* worth moving to configure.ac? */
 #define subuidfile "/etc/subuid"
 #define subgidfile "/etc/subgid"
@@ -327,7 +330,7 @@ struct lxc_conf {
 	const char *name;
 	bool is_execute;
 	int reboot;
-	signed long personality;
+	personality_t personality;
 	struct utsname *utsname;
 
 	struct {
@@ -628,4 +631,12 @@ static inline void lxc_clear_cgroup2_devices(struct bpf_devices *bpf_devices)
 	lxc_list_init(&bpf_devices->device_item);
 }
 
+static inline int lxc_personality(personality_t persona)
+{
+	if (persona < 0)
+		return ret_errno(EINVAL);
+
+	return personality(persona);
+}
+
 #endif /* __LXC_CONF_H */

src/lxc/confile.c

@@ -39,10 +39,6 @@
 #include "storage/storage.h"
 #include "utils.h"
 
-#if HAVE_SYS_PERSONALITY_H
-#include <sys/personality.h>
-#endif
-
 #ifndef HAVE_STRLCPY
 #include "include/strlcpy.h"
 #endif
@@ -1392,14 +1388,14 @@ static int set_config_hooks_version(const char *key, const char *value,
 static int set_config_personality(const char *key, const char *value,
 				  struct lxc_conf *lxc_conf, void *data)
 {
-	signed long personality;
+	int ret;
+	personality_t personality;
 
-	personality = lxc_config_parse_arch(value);
-	if (personality >= 0)
-		lxc_conf->personality = personality;
-	else
-		WARN("Unsupported personality \"%s\"", value);
+	ret = lxc_config_parse_arch(value, &personality);
+	if (ret < 0)
+		return syserror("Unsupported personality \"%s\"", value);
 
+	lxc_conf->personality = personality;
 	return 0;
 }
 
@@ -3213,10 +3209,9 @@ void lxc_config_define_free(struct lxc_list *defines)
 	}
 }
 
-signed long lxc_config_parse_arch(const char *arch)
+int lxc_config_parse_arch(const char *arch, signed long *persona)
 {
-#if HAVE_SYS_PERSONALITY_H
-	struct per_name {
+	static struct per_name {
 		char *name;
 		unsigned long per;
 	} pername[] = {
@@ -3247,14 +3242,16 @@ signed long lxc_config_parse_arch(const char *arch)
 		{ "s390x",     PER_LINUX   },
 		{ "x86_64",    PER_LINUX   },
 	};
-	size_t len = sizeof(pername) / sizeof(pername[0]);
 
-	for (int i = 0; i < len; i++)
-		if (strequal(pername[i].name, arch))
-			return pername[i].per;
-#endif
+	for (int i = 0; i < ARRAY_SIZE(pername); i++) {
+		if (!strequal(pername[i].name, arch))
+			continue;
+
+		*persona = pername[i].per;
+		return 0;
+	}
 
-	return LXC_ARCH_UNCHANGED;
+	return ret_errno(EINVAL);
 }
 
 int lxc_fill_elevated_privileges(char *flaglist, int *flags)
@@ -3735,7 +3732,6 @@ static int get_config_personality(const char *key, char *retv, int inlen,
 	else
 		memset(retv, 0, inlen);
 
-#if HAVE_SYS_PERSONALITY_H
 	int len = 0;
 
 	switch (c->personality) {
@@ -3748,7 +3744,6 @@ static int get_config_personality(const char *key, char *retv, int inlen,
 	default:
 		break;
 	}
-#endif
 
 	return fulllen;
 }

src/lxc/confile.h

@@ -84,11 +84,10 @@ __hidden extern void lxc_config_define_free(struct lxc_list *defines);
 
 #define LXC_ARCH_UNCHANGED 0xffffffffL
 /*
- * Parse personality of the container. Returns LXC_ARCH_UNCHANGED if the
- * personality is not know.
- * (Used during attach.)
+ * Parse personality of the container. Returns 0 if personality is valid,
+ * negative errno otherwise.
  */
-__hidden extern signed long lxc_config_parse_arch(const char *arch);
+__hidden extern int lxc_config_parse_arch(const char *arch, signed long *persona);
 
 __hidden extern int lxc_fill_elevated_privileges(char *flaglist, int *flags);
 

src/lxc/macro.h

@@ -22,6 +22,7 @@
 #include <unistd.h>
 
 #include "compiler.h"
+#include "config.h"
 
 #ifndef PATH_MAX
 #define PATH_MAX 4096
@@ -741,4 +742,9 @@ enum {
 #define BITS_PER_TYPE(type) (sizeof(type) * 8)
 #define LAST_BIT_PER_TYPE(type) (BITS_PER_TYPE(type) - 1)
 
+#ifndef HAVE_SYS_PERSONALITY_H
+#define PER_LINUX	0x0000
+#define PER_LINUX32	0x0008
+#endif
+
 #endif /* __LXC_MACRO_H */

src/lxc/syscall_numbers.h

@@ -700,4 +700,43 @@
 	#endif
 #endif
 
+#ifndef __NR_personality
+	#if defined __alpha__
+		#define __NR_personality 324
+	#elif defined __m68k__
+		#define __NR_personality 136
+	#elif defined __i386__
+		#define __NR_personality 136
+	#elif defined __x86_64__
+		#define __NR_personality 135
+	#elif defined __arm__
+		#define __NR_personality 136
+	#elif defined __aarch64__
+		#define __NR_personality 92
+	#elif defined __s390__
+		#define __NR_personality 136
+	#elif defined __powerpc__
+		#define __NR_personality 136
+	#elif defined __riscv
+		#define __NR_personality -1
+	#elif defined __sparc__
+		#define __NR_personality 191
+	#elif defined __ia64__
+		#define __NR_personality (116 + 1024)
+	#elif defined _MIPS_SIM
+		#if _MIPS_SIM == _MIPS_SIM_ABI32	/* o32 */
+			#define __NR_personality (136 + 4000)
+		#endif
+		#if _MIPS_SIM == _MIPS_SIM_NABI32	/* n32 */
+			#define __NR_personality (132 + 6000)
+		#endif
+		#if _MIPS_SIM == _MIPS_SIM_ABI64	/* n64 */
+			#define __NR_personality (132 + 5000)
+		#endif
+	#else
+		#define -1
+		#warning "__NR_personality not defined for your architecture"
+	#endif
+#endif
+
 #endif /* __LXC_SYSCALL_NUMBERS_H */

src/lxc/syscall_wrappers.h

@@ -31,6 +31,10 @@
 #include <linux/openat2.h>
 #endif
 
+#if HAVE_SYS_PERSONALITY_H
+#include <sys/personality.h>
+#endif
+
 typedef int32_t key_serial_t;
 
 #if !HAVE_KEYCTL
@@ -317,4 +321,11 @@ static inline int close_range(unsigned int fd, unsigned int max_fd, unsigned int
 }
 #endif
 
+#ifndef HAVE_SYS_PERSONALITY_H
+static inline int personality(unsigned long persona)
+{
+	return syscall(__NR_personality, persona);
+}
+#endif
+
 #endif /* __LXC_SYSCALL_WRAPPER_H */

src/lxc/tools/lxc_attach.c

@@ -154,8 +154,8 @@ static int my_parser(struct lxc_arguments *args, int c, char *arg)
 		break;
 	case 'R': remount_sys_proc = 1; break;
 	case 'a':
-		new_personality = lxc_config_parse_arch(arg);
-		if (new_personality < 0) {
+		ret = lxc_config_parse_arch(arg, &new_personality);
+		if (ret < 0) {
 			ERROR("Invalid architecture specified: %s", arg);
 			return -1;
 		}