OS-3923 lxbrand in-kernel chmod(2), fchmod(2) and fchmodat(2)

OS-3920 lxbrand use native *at(2) system calls for LX emulation
Reviewed by: Jerry Jelinek <jerry.jelinek@joyent.com>

11 files changed, 143 insertions, 79 deletions

diff --git a/usr/src/lib/brand/lx/lx_brand/common/file.c b/usr/src/lib/brand/lx/lx_brand/common/file.c
index 1f2c4032f5..a3fc081c53 100644
--- a/usr/src/lib/brand/lx/lx_brand/common/file.c
+++ b/usr/src/lib/brand/lx/lx_brand/common/file.c
@@ -316,29 +316,6 @@ lx_fchown(uintptr_t p1, uintptr_t p2, uintptr_t p3)
 }
 
 long
-lx_chmod(uintptr_t p1, uintptr_t p2)
-{
-	int ret;
-
-	ret = chmod((const char *)p1, (mode_t)p2);
-
-	if (ret < 0) {
-		/*
-		 * If chown() failed and we're in install mode, return success
-		 * if the the reason we failed was because the source file
-		 * didn't actually exist or if we're trying to modify /dev/pts.
-		 */
-		if ((lx_install != 0) &&
-		    ((errno == ENOENT) || (install_checkpath(p1) == 0)))
-			return (0);
-
-		return (-errno);
-	}
-
-	return (0);
-}
-
-long
 lx_utime(uintptr_t p1, uintptr_t p2)
 {
 	int ret;
@@ -868,23 +845,3 @@ lx_fchownat(uintptr_t ext1, uintptr_t p1, uintptr_t p2, uintptr_t p3,
 	else
 		return (lx_chown((uintptr_t)pathbuf, p2, p3));
 }
-
-/*ARGSUSED*/
-long
-lx_fchmodat(uintptr_t ext1, uintptr_t p1, uintptr_t p2, uintptr_t p3)
-{
-	int atfd = (int)ext1;
-	char pathbuf[MAXPATHLEN];
-	int ret;
-
-	/*
-	 * It seems that at least some versions of glibc do not set or clear
-	 * the flags arg, so checking them will result in random behaviour.
-	 */
-
-	ret = getpathat(atfd, p1, pathbuf, sizeof (pathbuf));
-	if (ret < 0)
-		return (ret);
-
-	return (lx_chmod((uintptr_t)pathbuf, p2));
-}
diff --git a/usr/src/lib/brand/lx/lx_brand/common/lx_brand.c b/usr/src/lib/brand/lx/lx_brand/common/lx_brand.c
index 5c5dd53fff..3b88397860 100644
--- a/usr/src/lib/brand/lx/lx_brand/common/lx_brand.c
+++ b/usr/src/lib/brand/lx/lx_brand/common/lx_brand.c
@@ -583,6 +583,8 @@ lx_init(int argc, char *argv[], char *envp[])
 	void		*vdso_hdr;
 #endif
 
+	bzero(&reg, sizeof (reg));
+
 	stack_bottom = 2 * sysconf(_SC_PAGESIZE);
 
 	/*
@@ -621,6 +623,7 @@ lx_init(int argc, char *argv[], char *envp[])
 	 * Are we in install mode?
 	 */
 	if (getenv("LX_INSTALL") != NULL) {
+		reg.lxbr_flags |= LX_PROC_INSTALL_MODE;
 		lx_install = 1;
 		lx_debug("INSTALL mode enabled.\n");
 	}
@@ -1049,8 +1052,8 @@ static lx_syscall_handler_t lx_handlers[] = {
 	lx_unlink,			/*  87: unlink */
 	lx_symlink,			/*  88: symlink */
 	lx_readlink,			/*  89: readlink */
-	lx_chmod,			/*  90: chmod */
-	lx_fchmod,			/*  91: fchmod */
+	NULL,				/*  90: chmod */
+	NULL,				/*  91: fchmod */
 	lx_chown,			/*  92: chown */
 	lx_fchown,			/*  93: fchown */
 	lx_lchown,			/*  94: lchown */
@@ -1227,7 +1230,7 @@ static lx_syscall_handler_t lx_handlers[] = {
 	lx_linkat,			/* 265: linkat */
 	lx_symlinkat,			/* 266: symlinkat */
 	lx_readlinkat,			/* 267: readlinkat */
-	lx_fchmodat,			/* 268: fchmodat */
+	NULL,				/* 268: fchmodat */
 	lx_faccessat,			/* 269: faccessat */
 	lx_pselect6,			/* 270: pselect6 */
 	lx_ppoll,			/* 271: ppoll */
@@ -1305,7 +1308,7 @@ static lx_syscall_handler_t lx_handlers[] = {
 	lx_chdir,			/*  12: chdir */
 	lx_time,			/*  13: time */
 	lx_mknod,			/*  14: mknod */
-	lx_chmod,			/*  15: chmod */
+	NULL,				/*  15: chmod */
 	lx_lchown16,			/*  16: lchown16 */
 	NULL,				/*  17: break */
 	NULL,				/*  18: stat */
@@ -1384,7 +1387,7 @@ static lx_syscall_handler_t lx_handlers[] = {
 	lx_munmap,			/*  91: munmap */
 	lx_truncate,			/*  92: truncate */
 	lx_ftruncate,			/*  93: ftruncate */
-	lx_fchmod,			/*  94: fchmod */
+	NULL,				/*  94: fchmod */
 	lx_fchown16,			/*  95: fchown16 */
 	lx_getpriority,			/*  96: getpriority */
 	lx_setpriority,			/*  97: setpriority */
@@ -1596,7 +1599,7 @@ static lx_syscall_handler_t lx_handlers[] = {
 	lx_linkat,			/* 303: linkat */
 	lx_symlinkat,			/* 304: symlinkat */
 	lx_readlinkat,			/* 305: readlinkat */
-	lx_fchmodat,			/* 306: fchmodat */
+	NULL,				/* 306: fchmodat */
 	lx_faccessat,			/* 307: faccessat */
 	lx_pselect6,			/* 308: pselect6 */
 	lx_ppoll,			/* 309: ppoll */
diff --git a/usr/src/lib/brand/lx/lx_brand/common/misc.c b/usr/src/lib/brand/lx/lx_brand/common/misc.c
index 7e16fb717e..e3bb34dadc 100644
--- a/usr/src/lib/brand/lx/lx_brand/common/misc.c
+++ b/usr/src/lib/brand/lx/lx_brand/common/misc.c
@@ -823,15 +823,6 @@ lx_fchdir(int fildes)
 	return ((r == -1) ? -errno : r);
 }
 
-long
-lx_fchmod(int fildes, mode_t mode)
-{
-	int r;
-
-	r = fchmod(fildes, mode);
-	return ((r == -1) ? -errno : r);
-}
-
 /*
  * We support neither the second argument (NUMA node), nor the third (obsolete
  * pre-2.6.24 caching functionality which was ultimately broken).
diff --git a/usr/src/lib/brand/lx/lx_brand/sys/lx_syscall.h b/usr/src/lib/brand/lx/lx_brand/sys/lx_syscall.h
index 4cc72ba0c6..7aed33752f 100644
--- a/usr/src/lib/brand/lx/lx_brand/sys/lx_syscall.h
+++ b/usr/src/lib/brand/lx/lx_brand/sys/lx_syscall.h
@@ -56,7 +56,6 @@ extern long lx_renameat(uintptr_t, uintptr_t, uintptr_t, uintptr_t);
 extern long lx_linkat(uintptr_t, uintptr_t, uintptr_t, uintptr_t, uintptr_t);
 extern long lx_symlinkat(uintptr_t, uintptr_t, uintptr_t);
 extern long lx_readlinkat(uintptr_t, uintptr_t, uintptr_t, uintptr_t);
-extern long lx_fchmodat(uintptr_t, uintptr_t, uintptr_t, uintptr_t);
 extern long lx_access(uintptr_t, uintptr_t);
 extern long lx_faccessat(uintptr_t, uintptr_t, uintptr_t, uintptr_t);
 
@@ -184,7 +183,6 @@ extern long lx_fchown16(uintptr_t, uintptr_t, uintptr_t);
 extern long lx_lchown16(uintptr_t, uintptr_t, uintptr_t);
 extern long lx_chown(uintptr_t, uintptr_t, uintptr_t);
 extern long lx_fchown(uintptr_t, uintptr_t, uintptr_t);
-extern long lx_chmod(uintptr_t, uintptr_t);
 extern long lx_rename(uintptr_t, uintptr_t);
 extern long lx_utime(uintptr_t, uintptr_t);
 extern long lx_llseek(uintptr_t, uintptr_t, uintptr_t, uintptr_t, uintptr_t);
@@ -319,7 +317,6 @@ extern long lx_epoll_wait(int, void *, int, int);
 extern long lx_eventfd(unsigned int);
 extern long lx_eventfd2(unsigned int, int);
 extern long lx_fchdir(int);
-extern long lx_fchmod(int, mode_t);
 extern long lx_getgid(void);
 extern long lx_getgroups(int, gid_t *);
 extern long lx_getitimer(int, struct itimerval *);
diff --git a/usr/src/uts/common/brand/lx/os/lx_brand.c b/usr/src/uts/common/brand/lx/os/lx_brand.c
index fc9aaa6055..a2f38da9dd 100644
--- a/usr/src/uts/common/brand/lx/os/lx_brand.c
+++ b/usr/src/uts/common/brand/lx/os/lx_brand.c
@@ -805,6 +805,7 @@ lx_brandsys(int cmd, int64_t *rval, uintptr_t arg1, uintptr_t arg2,
 			reg.lxbr_version = (uint_t)reg32.lxbr_version;
 			reg.lxbr_handler =
 			    (void *)(uintptr_t)reg32.lxbr_handler;
+			reg.lxbr_flags = reg32.lxbr_flags;
 		}
 #endif
 
@@ -814,10 +815,17 @@ lx_brandsys(int cmd, int64_t *rval, uintptr_t arg1, uintptr_t arg2,
 			return (EINVAL);
 		}
 
+		if ((reg.lxbr_flags & ~LX_PROC_ALL) != 0) {
+			lx_print("Invalid brand flags (%u)\n",
+			    reg.lxbr_flags);
+			return (EINVAL);
+		}
+
 		lx_print("Assigning brand 0x%p and handler 0x%p to proc 0x%p\n",
 		    (void *)&lx_brand, (void *)reg.lxbr_handler, (void *)p);
 		pd = p->p_brand_data;
 		pd->l_handler = (uintptr_t)reg.lxbr_handler;
+		pd->l_flags = reg.lxbr_flags;
 
 		return (0);
 
diff --git a/usr/src/uts/common/brand/lx/os/lx_syscall.c b/usr/src/uts/common/brand/lx/os/lx_syscall.c
index 09a3e9bbba..eb4ce1e8f6 100644
--- a/usr/src/uts/common/brand/lx/os/lx_syscall.c
+++ b/usr/src/uts/common/brand/lx/os/lx_syscall.c
@@ -441,7 +441,7 @@ lx_sysent_t lx_sysent32[] = {
 	{"chdir",	NULL,			0,		1}, /* 12 */
 	{"time",	NULL,			0,		1}, /* 13 */
 	{"mknod",	NULL,			0,		3}, /* 14 */
-	{"chmod",	NULL,			0,		2}, /* 15 */
+	{"chmod",	lx_chmod,		0,		2}, /* 15 */
 	{"lchown16",	NULL,			0,		3}, /* 16 */
 	{"break",	NULL,			NOSYS_OBSOLETE,	0}, /* 17 */
 	{"stat",	NULL,			NOSYS_OBSOLETE,	0}, /* 18 */
@@ -520,7 +520,7 @@ lx_sysent_t lx_sysent32[] = {
 	{"munmap",	NULL,			0,		2}, /* 91 */
 	{"truncate",	NULL,			0,		2}, /* 92 */
 	{"ftruncate",	NULL,			0,		2}, /* 93 */
-	{"fchmod",	NULL,			0,		2}, /* 94 */
+	{"fchmod",	lx_fchmod,		0,		2}, /* 94 */
 	{"fchown16",	NULL,			0,		3}, /* 95 */
 	{"getpriority",	NULL,			0,		2}, /* 96 */
 	{"setpriority",	NULL,			0,		3}, /* 97 */
@@ -736,7 +736,7 @@ lx_sysent_t lx_sysent32[] = {
 	{"linkat",	NULL,			0,		5}, /* 303 */
 	{"symlinkat",	NULL,			0,		3}, /* 304 */
 	{"readlinkat",	NULL,			0,		4}, /* 305 */
-	{"fchmodat",	NULL,			0,		4}, /* 306 */
+	{"fchmodat",	lx_fchmodat,		0,		3}, /* 306 */
 	{"faccessat",	NULL,			0,		4}, /* 307 */
 	{"pselect6",	NULL,			LX_SYS_EBPARG6,	6}, /* 308 */
 	{"ppoll",	NULL,			0,		5}, /* 309 */
@@ -887,8 +887,8 @@ lx_sysent_t lx_sysent64[] = {
 	{"unlink",	NULL,			0,		1}, /* 87 */
 	{"symlink",	NULL,			0,		2}, /* 88 */
 	{"readlink",	NULL,			0,		3}, /* 89 */
-	{"chmod",	NULL,			0,		2}, /* 90 */
-	{"fchmod",	NULL,			0,		2}, /* 91 */
+	{"chmod",	lx_chmod,		0,		2}, /* 90 */
+	{"fchmod",	lx_fchmod,		0,		2}, /* 91 */
 	{"chown",	NULL,			0,		3}, /* 92 */
 	{"fchown",	NULL,			0,		3}, /* 93 */
 	{"lchown",	NULL,			0,		3}, /* 94 */
@@ -1065,7 +1065,7 @@ lx_sysent_t lx_sysent64[] = {
 	{"linkat",	NULL,			0,		5}, /* 265 */
 	{"symlinkat",	NULL,			0,		3}, /* 266 */
 	{"readlinkat",	NULL,			0,		4}, /* 267 */
-	{"fchmodat",	NULL,			0,		4}, /* 268 */
+	{"fchmodat",	lx_fchmodat,		0,		3}, /* 268 */
 	{"faccessat",	NULL,			0,		4}, /* 269 */
 	{"pselect6",	NULL,			0,		6}, /* 270 */
 	{"ppoll",	NULL,			0,		5}, /* 271 */
diff --git a/usr/src/uts/common/brand/lx/sys/lx_brand.h b/usr/src/uts/common/brand/lx/sys/lx_brand.h
index 543373b5fa..f3c46dd7fd 100644
--- a/usr/src/uts/common/brand/lx/sys/lx_brand.h
+++ b/usr/src/uts/common/brand/lx/sys/lx_brand.h
@@ -203,11 +203,13 @@ extern struct brand lx_brand;
 typedef struct lx_brand_registration {
 	uint_t lxbr_version;		/* version number */
 	void *lxbr_handler;		/* base address of handler */
+	uint32_t lxbr_flags;		/* LX_PROC_* registration flags */
 } lx_brand_registration_t;
 
 typedef struct lx_brand_registration32 {
 	uint_t lxbr_version;		/* version number */
 	uint32_t lxbr_handler;		/* base address of handler */
+	uint32_t lxbr_flags;		/* LX_PROC_* registration flags */
 } lx_brand_registration32_t;
 
 #ifdef __amd64
@@ -392,6 +394,12 @@ typedef lx_elf_data64_t lx_elf_data_t;
 typedef lx_elf_data32_t lx_elf_data_t;
 #endif
 
+typedef enum lx_proc_flags {
+	LX_PROC_INSTALL_MODE = 0x01
+} lx_proc_flags_t;
+
+#define	LX_PROC_ALL	LX_PROC_INSTALL_MODE
+
 #ifdef	_KERNEL
 
 typedef struct lx_proc_data {
@@ -401,6 +409,7 @@ typedef struct lx_proc_data {
 	lx_elf_data_t l_elf_data; /* ELF data for linux executable */
 	int l_signal;		/* signal to deliver to parent when this */
 				/* thread group dies */
+	lx_proc_flags_t l_flags;
 } lx_proc_data_t;
 
 #endif	/* _KERNEL */
diff --git a/usr/src/lib/brand/lx/lx_brand/sys/lx_fcntl.h b/usr/src/uts/common/brand/lx/sys/lx_fcntl.h
index 06e05cbf5c..f3b472e7ff 100644
--- a/usr/src/lib/brand/lx/lx_brand/sys/lx_fcntl.h
+++ b/usr/src/uts/common/brand/lx/sys/lx_fcntl.h
@@ -21,7 +21,7 @@
 /*
  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
- * Copyright 2014 Joyent, Inc.  All rights reserved.
+ * Copyright 2015 Joyent, Inc.
  */
 
 #ifndef _SYS_LX_FCNTL_H
@@ -94,7 +94,7 @@ extern "C" {
  * AT_REMOVEDIR is used only by unlinkat and AT_EACCESS is used only by
  * faccessat.
  */
-#define	LX_AT_FDCWD		-100
+#define	LX_AT_FDCWD		(-100)
 #define	LX_AT_SYMLINK_NOFOLLOW	0x100
 #define	LX_AT_REMOVEDIR		0x200
 #define	LX_AT_EACCESS		0x200
@@ -102,21 +102,46 @@ extern "C" {
 #define	LX_AT_NO_AUTOMOUNT	0x800
 #define	LX_AT_EMPTY_PATH	0x1000
 
-struct lx_flock {
+typedef struct lx_flock {
 	short		l_type;
 	short		l_whence;
 	long		l_start;
 	long		l_len;
 	int		l_pid;
-};
+} lx_flock_t;
 
-struct lx_flock64 {
+typedef struct lx_flock64 {
 	short		l_type;
 	short		l_whence;
 	long long	l_start;
 	long long	l_len;
 	int		l_pid;
-};
+} lx_flock64_t;
+
+#if defined(_KERNEL) && defined(_SYSCALL32_IMPL)
+
+/*
+ * 64-bit kernel view of 32-bit usermode structs.
+ */
+#pragma pack(4)
+typedef struct lx_flock32 {
+	int16_t		l_type;
+	int16_t		l_whence;
+	int32_t		l_start;
+	int32_t		l_len;
+	int32_t		l_pid;
+} lx_flock32_t;
+
+typedef struct lx_flock64_32 {
+	int16_t		l_type;
+	int16_t		l_whence;
+	int64_t		l_start;
+	int64_t		l_len;
+	int32_t		l_pid;
+} lx_flock64_32_t;
+#pragma pack()
+
+#endif /* _KERNEL && _SYSCALL32_IMPL */
 
 #ifdef	__cplusplus
 }
diff --git a/usr/src/uts/common/brand/lx/sys/lx_syscalls.h b/usr/src/uts/common/brand/lx/sys/lx_syscalls.h
index 2d9abf2fe6..6943b40310 100644
--- a/usr/src/uts/common/brand/lx/sys/lx_syscalls.h
+++ b/usr/src/uts/common/brand/lx/sys/lx_syscalls.h
@@ -36,19 +36,20 @@ extern "C" {
 
 extern long lx_arch_prctl();
 extern long lx_brk();
+extern long lx_chmod();
+extern long lx_fchmod();
+extern long lx_fchmodat();
+extern long lx_futex();
+extern long lx_get_thread_area();
 extern long lx_getpid();
 extern long lx_getppid();
+extern long lx_gettid();
+extern long lx_ioctl();
 extern long lx_kill();
-extern long lx_tkill();
-extern long lx_tgkill();
 extern long lx_modify_ldt();
 extern long lx_pipe();
 extern long lx_pipe2();
 extern long lx_read();
-extern long lx_ioctl();
-extern long lx_gettid();
-extern long lx_futex();
-extern long lx_get_thread_area();
 extern long lx_sched_getparam();
 extern long lx_sched_getscheduler();
 extern long lx_sched_rr_get_interval();
@@ -63,6 +64,8 @@ extern long lx_setresuid();
 extern long lx_setresuid16();
 extern long lx_sysinfo32();
 extern long lx_sysinfo64();
+extern long lx_tgkill();
+extern long lx_tkill();
 extern long lx_wait4();
 extern long lx_waitid();
 extern long lx_waitpid();
diff --git a/usr/src/uts/common/brand/lx/syscall/lx_chmod.c b/usr/src/uts/common/brand/lx/syscall/lx_chmod.c
new file mode 100644
index 0000000000..66a4e35a63
--- /dev/null
+++ b/usr/src/uts/common/brand/lx/syscall/lx_chmod.c
@@ -0,0 +1,70 @@
+/*
+ * This file and its contents are supplied under the terms of the
+ * Common Development and Distribution License ("CDDL"), version 1.0.
+ * You may only use this file in accordance with the terms of version
+ * 1.0 of the CDDL.
+ *
+ * A full copy of the text of the CDDL should have accompanied this
+ * source.  A copy of the CDDL is also available via the Internet at
+ * http://www.illumos.org/license/CDDL.
+ */
+
+/*
+ * Copyright 2015 Joyent, Inc.
+ */
+
+#include <sys/fcntl.h>
+#include <sys/thread.h>
+#include <sys/klwp.h>
+#include <sys/lx_brand.h>
+#include <sys/lx_fcntl.h>
+
+/*
+ * From "uts/common/syscall/chmod.c":
+ */
+extern int fchmodat(int, char *, int, int);
+
+static long
+lx_fchmodat_wrapper(int fd, char *path, int mode, int flag)
+{
+	long rval;
+
+	if (fd == LX_AT_FDCWD) {
+		fd = AT_FDCWD;
+	}
+
+	if ((rval = fchmodat(fd, path, mode, flag)) != 0) {
+		lx_proc_data_t *pd = ttolxproc(curthread);
+		klwp_t *lwp = ttolwp(curthread);
+
+		/*
+		 * If the process is in "install mode", return success
+		 * if the operation failed due to an absent file.
+		 */
+		if ((pd->l_flags & LX_PROC_INSTALL_MODE) &&
+		    lwp->lwp_errno == ENOENT) {
+			lwp->lwp_errno = 0;
+			return (0);
+		}
+	}
+
+	return (rval);
+}
+
+long
+lx_fchmodat(int fd, char *path, int mode)
+{
+	return (lx_fchmodat_wrapper(fd, path, mode, 0));
+}
+
+long
+lx_fchmod(int fd, int mode)
+{
+	return (lx_fchmodat_wrapper(fd, NULL, mode, 0));
+}
+
+long
+lx_chmod(char *path, int mode)
+{
+	return (lx_fchmodat_wrapper(AT_FDCWD, path, mode, 0));
+}
diff --git a/usr/src/uts/intel/Makefile.files b/usr/src/uts/intel/Makefile.files
index 7eefb1c062..0b99fc7e9c 100644
--- a/usr/src/uts/intel/Makefile.files
+++ b/usr/src/uts/intel/Makefile.files
@@ -279,6 +279,7 @@ LX_BRAND_OBJS  =		\
 	lx_archdep.o		\
 	lx_brand.o		\
 	lx_brk.o		\
+	lx_chmod.o		\
 	lx_clone.o		\
 	lx_futex.o		\
 	lx_getpid.o		\