OS-5356 su reports getcwd() error in LX zone

Reviewed by: Patrick Mooney <patrick.mooney@joyent.com>

7 files changed, 56 insertions, 61 deletions

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 e7d5ddccc3..7024a5d567 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
@@ -1042,7 +1042,7 @@ static lx_syscall_handler_t lx_handlers[] = {
 	lx_truncate,			/*  76: truncate */
 	lx_ftruncate,			/*  77: ftruncate */
 	NULL,				/*  78: getdents */
-	lx_getcwd,			/*  79: getcwd */
+	NULL,				/*  79: getcwd */
 	lx_chdir,			/*  80: chdir */
 	lx_fchdir,			/*  81: fchdir */
 	lx_rename,			/*  82: rename */
@@ -1477,7 +1477,7 @@ static lx_syscall_handler_t lx_handlers[] = {
 	NULL,				/* 180: pread64 */
 	NULL,				/* 181: pwrite64 */
 	NULL,				/* 182: chown16 */
-	lx_getcwd,			/* 183: getcwd */
+	NULL,				/* 183: getcwd */
 	lx_capget,			/* 184: capget */
 	lx_capset,			/* 185: capset */
 	lx_sigaltstack,			/* 186: sigaltstack */
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 378e766666..e8d60c4696 100644
--- a/usr/src/lib/brand/lx/lx_brand/common/misc.c
+++ b/usr/src/lib/brand/lx/lx_brand/common/misc.c
@@ -172,62 +172,6 @@ lx_reboot(uintptr_t p1, uintptr_t p2, uintptr_t p3, uintptr_t p4)
 }
 
 /*
- * getcwd() - Linux syscall semantics are slightly different; we need to return
- * the length of the pathname copied (+ 1 for the terminating NULL byte.)
- */
-long
-lx_getcwd(uintptr_t p1, uintptr_t p2)
-{
-	char *buf;
-	size_t buflen = (size_t)p2;
-	size_t copylen, local_len;
-	size_t len = 0;
-
-	if ((getcwd((char *)p1, (size_t)p2)) == NULL)
-		return (-errno);
-
-	/*
-	 * We need the length of the pathname getcwd() copied but we never want
-	 * to dereference a Linux pointer for any reason.
-	 *
-	 * Thus, to get the string length we will uucopy() up to copylen
-	 * bytes at a time into a local buffer and will walk each chunk looking
-	 * for the string-terminating NULL byte.
-	 *
-	 * We can use strlen() to find the length of the string in the
-	 * local buffer by delimiting the buffer with a NULL byte in the
-	 * last element that will never be overwritten.
-	 */
-	copylen = min(buflen, MAXPATHLEN + 1);
-	buf = SAFE_ALLOCA(copylen + 1);
-	if (buf == NULL)
-		return (-ENOMEM);
-	buf[copylen] = '\0';
-
-	for (;;) {
-		if (uucopy((char *)p1 + len, buf, copylen) != 0)
-			return (-errno);
-
-		local_len = strlen(buf);
-		len += local_len;
-
-		/*
-		 * If the strlen() is less than copylen, we found the
-		 * real end of the string -- not the NULL byte used to
-		 * delimit the end of our buffer.
-		 */
-		if (local_len != copylen)
-			break;
-
-		/* prepare to check the next chunk of the string */
-		buflen -= copylen;
-		copylen = min(buflen, copylen);
-	}
-
-	return (len + 1);
-}
-
-/*
  * {get,set}groups16() - Handle the conversion between 16-bit Linux gids and
  * 32-bit illumos gids.
  */
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 5c9c0d9d7f..4b2e23def8 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
@@ -142,7 +142,6 @@ extern long lx_llseek(uintptr_t, uintptr_t, uintptr_t, uintptr_t, uintptr_t);
 extern long lx_lseek(uintptr_t, uintptr_t, uintptr_t);
 extern long lx_sysfs(uintptr_t, uintptr_t, uintptr_t);
 
-extern long lx_getcwd(uintptr_t, uintptr_t);
 extern long lx_uname(uintptr_t);
 extern long lx_reboot(uintptr_t, uintptr_t, uintptr_t, uintptr_t);
 extern long lx_getgroups16(uintptr_t, uintptr_t);
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 5e0f03cc5c..23010b8234 100644
--- a/usr/src/uts/common/brand/lx/os/lx_syscall.c
+++ b/usr/src/uts/common/brand/lx/os/lx_syscall.c
@@ -799,7 +799,7 @@ lx_sysent_t lx_sysent32[] = {
 	{"pread64",	lx_pread32,		0,		5}, /* 180 */
 	{"pwrite64",	lx_pwrite32,		0,		5}, /* 181 */
 	{"chown16",	lx_chown16,		0,		3}, /* 182 */
-	{"getcwd",	NULL,			0,		2}, /* 183 */
+	{"getcwd",	lx_getcwd,		0,		2}, /* 183 */
 	{"capget",	NULL,			0,		2}, /* 184 */
 	{"capset",	NULL,			0,		2}, /* 185 */
 	{"sigaltstack",	NULL,			0,		2}, /* 186 */
@@ -1066,7 +1066,7 @@ lx_sysent_t lx_sysent64[] = {
 	{"truncate",	NULL,			0,		2}, /* 76 */
 	{"ftruncate",	NULL,			0,		2}, /* 77 */
 	{"getdents",	lx_getdents_64,		0,		3}, /* 78 */
-	{"getcwd",	NULL,			0,		2}, /* 79 */
+	{"getcwd",	lx_getcwd,		0,		2}, /* 79 */
 	{"chdir",	NULL,			0,		1}, /* 80 */
 	{"fchdir",	NULL,			0,		1}, /* 81 */
 	{"rename",	NULL,			0,		2}, /* 82 */
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 f932c70bb9..001be273cd 100644
--- a/usr/src/uts/common/brand/lx/sys/lx_syscalls.h
+++ b/usr/src/uts/common/brand/lx/sys/lx_syscalls.h
@@ -70,6 +70,7 @@ extern long lx_futex();
 extern long lx_get_robust_list();
 extern long lx_get_thread_area();
 extern long lx_getcpu();
+extern long lx_getcwd();
 extern long lx_getdents_32();
 extern long lx_getdents_64();
 extern long lx_getdents64();
diff --git a/usr/src/uts/common/brand/lx/syscall/lx_getcwd.c b/usr/src/uts/common/brand/lx/syscall/lx_getcwd.c
new file mode 100644
index 0000000000..7fcc594d81
--- /dev/null
+++ b/usr/src/uts/common/brand/lx/syscall/lx_getcwd.c
@@ -0,0 +1,50 @@
+/*
+ * 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 2016 Joyent, Inc.
+ */
+
+#include <sys/systm.h>
+#include <sys/types.h>
+#include <sys/proc.h>
+#include <sys/vnode.h>
+#include <sys/pathname.h>
+
+/*
+ * getcwd() - Linux syscall semantics are slightly different; we need to return
+ * the length of the pathname copied (+ 1 for the terminating NULL byte.)
+ */
+long
+lx_getcwd(char *buf, int size)
+{
+	int len;
+	int error;
+	vnode_t *vp;
+	char path[MAXPATHLEN + 1];
+
+	vp = PTOU(curproc)->u_cdir;
+	VN_HOLD(vp);
+	if ((error = vnodetopath(NULL, vp, path, sizeof (path), CRED())) != 0) {
+		VN_RELE(vp);
+		return (set_errno(error));
+	}
+	VN_RELE(vp);
+
+	len = strlen(path) + 1;
+	if (len > size)
+		return (set_errno(ERANGE));
+
+	if (copyout(path, buf, len) != 0)
+		return (set_errno(EFAULT));
+
+	return (len);
+}
diff --git a/usr/src/uts/intel/Makefile.files b/usr/src/uts/intel/Makefile.files
index a3812170c9..81326bb74a 100644
--- a/usr/src/uts/intel/Makefile.files
+++ b/usr/src/uts/intel/Makefile.files
@@ -305,6 +305,7 @@ LX_BRAND_OBJS  =		\
 	lx_fallocate.o		\
 	lx_fcntl.o		\
 	lx_futex.o		\
+	lx_getcwd.o		\
 	lx_getdents.o		\
 	lx_getpid.o		\
 	lx_getrandom.o		\