[PATCH 0/6] UML little patches for 2.6.16

[PATCH 0/6] UML little patches for 2.6.16

[Paolo 'Blaisorblade' Giarrusso]

I'm sending some little fixups for inclusion 2.6.16. I've held some other
fixes which need wider testing. Please merge now.

--
Inform me of my mistakes, so I can keep imitating Homer Simpson's "Doh!".
Paolo Giarrusso, aka Blaisorblade (Skype ID "PaoloGiarrusso", ICQ 215621894)
http://www.user-mode-linux.org/~blaisorblade

[PATCH 1/6] uml: correct error messages in COW driver

[Paolo 'Blaisorblade' Giarrusso]

Improve some error messages in the COW driver, and say V3, not V2, when talking
about V3 format. Also resync with our userspace code utility a bit more.

Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
---

 arch/um/drivers/cow_sys.h  |    2 +-
 arch/um/drivers/cow_user.c |   21 ++++++++++++---------
 2 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/arch/um/drivers/cow_sys.h b/arch/um/drivers/cow_sys.h
index c83fc5d..df25263 100644
--- a/arch/um/drivers/cow_sys.h
+++ b/arch/um/drivers/cow_sys.h
@@ -33,7 +33,7 @@ static inline int cow_file_size(char *fi
 	return(os_file_size(file, size_out));
 }
 
-static inline int cow_write_file(int fd, char *buf, int size)
+static inline int cow_write_file(int fd, void *buf, int size)
 {
 	return(os_write_file(fd, buf, size));
 }
diff --git a/arch/um/drivers/cow_user.c b/arch/um/drivers/cow_user.c
index fbe2217..d1c86bc 100644
--- a/arch/um/drivers/cow_user.c
+++ b/arch/um/drivers/cow_user.c
@@ -176,7 +176,7 @@ int write_cow_header(char *cow_file, int
 	err = -ENOMEM;
 	header = cow_malloc(sizeof(*header));
 	if(header == NULL){
-		cow_printf("Failed to allocate COW V3 header\n");
+		cow_printf("write_cow_header - failed to allocate COW V3 header\n");
 		goto out;
 	}
 	header->magic = htonl(COW_MAGIC);
@@ -196,15 +196,17 @@ int write_cow_header(char *cow_file, int
 
 	err = os_file_modtime(header->backing_file, &modtime);
 	if(err < 0){
-		cow_printf("Backing file '%s' mtime request failed, "
-			   "err = %d\n", header->backing_file, -err);
+		cow_printf("write_cow_header - backing file '%s' mtime "
+			   "request failed, err = %d\n", header->backing_file,
+			   -err);
 		goto out_free;
 	}
 
 	err = cow_file_size(header->backing_file, size);
 	if(err < 0){
-		cow_printf("Couldn't get size of backing file '%s', "
-			   "err = %d\n", header->backing_file, -err);
+		cow_printf("write_cow_header - couldn't get size of "
+			   "backing file '%s', err = %d\n",
+			   header->backing_file, -err);
 		goto out_free;
 	}
 
@@ -214,10 +216,11 @@ int write_cow_header(char *cow_file, int
 	header->alignment = htonl(alignment);
 	header->cow_format = COW_BITMAP;
 
-	err = os_write_file(fd, header, sizeof(*header));
+	err = cow_write_file(fd, header, sizeof(*header));
 	if(err != sizeof(*header)){
-		cow_printf("Write of header to new COW file '%s' failed, "
-			   "err = %d\n", cow_file, -err);
+		cow_printf("write_cow_header - write of header to "
+			   "new COW file '%s' failed, err = %d\n", cow_file,
+			   -err);
 		goto out_free;
 	}
 	err = 0;
@@ -299,7 +302,7 @@ int read_cow_header(int (*reader)(__u64,
 	}
 	else if(version == 3){
 		if(n < sizeof(header->v3)){
-			cow_printf("read_cow_header - failed to read V2 "
+			cow_printf("read_cow_header - failed to read V3 "
 				   "header\n");
 			goto out;
 		}

[PATCH 2/6] uml: fix usage of kernel_errno in place of errno

[Paolo 'Blaisorblade' Giarrusso]

From: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>

To avoid conflicts, in kernel files errno is expanded to kernel_errno, to
distinguish it from glibc errno. In this case, the code wants to use the libc
errno but the kernel one is used; in the other usage, we return errno in place
of -errno in case of an error.

Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
---

 arch/um/include/os.h       |    3 +++
 arch/um/os-Linux/process.c |   15 +++++++++++++++
 arch/um/sys-i386/ldt.c     |    9 +++------
 3 files changed, 21 insertions(+), 6 deletions(-)

diff --git a/arch/um/include/os.h b/arch/um/include/os.h
index eb1710b..2a1c64d 100644
--- a/arch/um/include/os.h
+++ b/arch/um/include/os.h
@@ -179,8 +179,11 @@ extern void os_stop_process(int pid);
 extern void os_kill_process(int pid, int reap_child);
 extern void os_kill_ptraced_process(int pid, int reap_child);
 extern void os_usr1_process(int pid);
+extern long os_ptrace_ldt(long pid, long addr, long data);
+
 extern int os_getpid(void);
 extern int os_getpgrp(void);
+
 extern void init_new_thread_stack(void *sig_stack, void (*usr1_handler)(int));
 extern void init_new_thread_signals(int altstack);
 extern int run_kernel_thread(int (*fn)(void *), void *arg, void **jmp_ptr);
diff --git a/arch/um/os-Linux/process.c b/arch/um/os-Linux/process.c
index 7f5e2da..49434a7 100644
--- a/arch/um/os-Linux/process.c
+++ b/arch/um/os-Linux/process.c
@@ -19,6 +19,7 @@
 #include "irq_user.h"
 #include "kern_util.h"
 #include "longjmp.h"
+#include "skas_ptrace.h"
 
 #define ARBITRARY_ADDR -1
 #define FAILURE_PID    -1
@@ -100,6 +101,20 @@ void os_kill_process(int pid, int reap_c
 		
 }
 
+/* This is here uniquely to have access to the userspace errno, i.e. the one
+ * used by ptrace in case of error.
+ */
+
+long os_ptrace_ldt(long pid, long addr, long data) {
+	int ret;
+
+	ret = ptrace(PTRACE_LDT, pid, addr, data);
+
+	if (ret < 0)
+		return -errno;
+	return ret;
+}
+
 /* Kill off a ptraced child by all means available.  kill it normally first,
  * then PTRACE_KILL it, then PTRACE_CONT it in case it's in a run state from
  * which it can't exit directly.
diff --git a/arch/um/sys-i386/ldt.c b/arch/um/sys-i386/ldt.c
index 1fa09a7..fe0877b 100644
--- a/arch/um/sys-i386/ldt.c
+++ b/arch/um/sys-i386/ldt.c
@@ -107,7 +107,7 @@ long write_ldt_entry(struct mm_id * mm_i
 		 * So we need to switch child's mm into our userspace, then
 		 * later switch back.
 		 *
-		 * Note: I'm unshure: should interrupts be disabled here?
+		 * Note: I'm unsure: should interrupts be disabled here?
 		 */
 		if(!current->active_mm || current->active_mm == &init_mm ||
 		   mm_idp != &current->active_mm->context.skas.id)
@@ -129,9 +129,7 @@ long write_ldt_entry(struct mm_id * mm_i
 			pid = userspace_pid[cpu];
 		}
 
-		res = ptrace(PTRACE_LDT, pid, 0, (unsigned long) &ldt_op);
-		if(res)
-			res = errno;
+		res = os_ptrace_ldt(pid, 0, (unsigned long) &ldt_op);
 
 		if(proc_mm)
 			put_cpu();
@@ -181,8 +179,7 @@ static long read_ldt_from_host(void __us
 	 */
 
 	cpu = get_cpu();
-	res = ptrace(PTRACE_LDT, userspace_pid[cpu], 0,
-		     (unsigned long) &ptrace_ldt);
+	res = os_ptrace_ldt(userspace_pid[cpu], 0, (unsigned long) &ptrace_ldt);
 	put_cpu();
 	if(res < 0)
 		goto out;

[PATCH 3/6] uml: fix ((unused)) attribute

[Paolo 'Blaisorblade' Giarrusso]

Use __attribute_used__ instead of __attribute__ ((unused)).
This will help with GCC > 3.2.

Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
---

 arch/um/include/init.h |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/um/include/init.h b/arch/um/include/init.h
index cbd79a8..d4de7c0 100644
--- a/arch/um/include/init.h
+++ b/arch/um/include/init.h
@@ -122,7 +122,7 @@ extern struct uml_param __uml_setup_star
 
 #define __exitcall(fn) static exitcall_t __exitcall_##fn __exit_call = fn
 
-#define __init_call __attribute__ ((unused,__section__ (".initcall.init")))
+#define __init_call	__attribute_used__ __attribute__ ((__section__ (".initcall.init")))
 
 #endif
 

[PATCH 4/6] uml: os_connect_socket error path fixup

[Paolo 'Blaisorblade' Giarrusso]

Fix an fd leak and a return of -1 instead of -errno in the error path - this
showed up in intensive testing of HPPFS, the os_connect_socket user.

Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
---

 arch/um/os-Linux/file.c |   19 ++++++++++++++-----
 1 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/arch/um/os-Linux/file.c b/arch/um/os-Linux/file.c
index f55773c..3bd10de 100644
--- a/arch/um/os-Linux/file.c
+++ b/arch/um/os-Linux/file.c
@@ -272,14 +272,23 @@ int os_connect_socket(char *name)
 	snprintf(sock.sun_path, sizeof(sock.sun_path), "%s", name);
 
 	fd = socket(AF_UNIX, SOCK_STREAM, 0);
-	if(fd < 0)
-		return(fd);
+	if(fd < 0) {
+		err = -errno;
+		goto out;
+	}
 
 	err = connect(fd, (struct sockaddr *) &sock, sizeof(sock));
-	if(err)
-		return(-errno);
+	if(err) {
+		err = -errno;
+		goto out_close;
+	}
 
-	return(fd);
+	return fd;
+
+out_close:
+	close(fd);
+out:
+	return err;
 }
 
 void os_close_file(int fd)

[PATCH 5/6] uml: better error reporting for read_output

[Paolo 'Blaisorblade' Giarrusso]

Do precise error handling: print precise error messages, distinguishing short
reads and read errors. This functions fails frequently enough for me so I
bothered doing this fix.

Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
---

 arch/um/drivers/net_user.c |   34 ++++++++++++++++++++++------------
 1 files changed, 22 insertions(+), 12 deletions(-)

diff --git a/arch/um/drivers/net_user.c b/arch/um/drivers/net_user.c
index 098fa65..0e2f061 100644
--- a/arch/um/drivers/net_user.c
+++ b/arch/um/drivers/net_user.c
@@ -47,10 +47,12 @@ void tap_check_ips(char *gate_addr, unsi
 	}
 }
 
+/* Do reliable error handling as this fails frequently enough. */
 void read_output(int fd, char *output, int len)
 {
-	int remain, n, actual;
+	int remain, ret, expected;
 	char c;
+	char *str;
 
 	if(output == NULL){
 		output = &c;
@@ -58,23 +60,31 @@ void read_output(int fd, char *output, i
 	}
 		
 	*output = '\0';
-	n = os_read_file(fd, &remain, sizeof(remain));
-	if(n != sizeof(remain)){
-		printk("read_output - read of length failed, err = %d\n", -n);
-		return;
+	ret = os_read_file(fd, &remain, sizeof(remain));
+
+	if (ret != sizeof(remain)) {
+		expected = sizeof(remain);
+		str = "length";
+		goto err;
 	}
 
 	while(remain != 0){
-		n = (remain < len) ? remain : len;
-		actual = os_read_file(fd, output, n);
-		if(actual != n){
-			printk("read_output - read of data failed, "
-			       "err = %d\n", -actual);
-			return;
+		expected = (remain < len) ? remain : len;
+		ret = os_read_file(fd, output, expected);
+		if (ret != expected) {
+			str = "data";
+			goto err;
 		}
-		remain -= actual;
+		remain -= ret;
 	}
+
 	return;
+
+err:
+	if (ret < 0)
+		printk("read_output - read of %s failed, errno = %d\n", str, -ret);
+	else
+		printk("read_output - read of %s failed, read only %d of %d bytes\n", str, ret, expected);
 }
 
 int net_read(int fd, void *buf, int len)

[PATCH 6/6] uml: tidying COW code

[Paolo 'Blaisorblade' Giarrusso]

Improve (especially for coherence) some prototypes, and return code of
init_cow_file in error case - for a short write return -EINVAL, otherwise return
the error we got!

Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
---

 arch/um/drivers/cow.h      |    2 +-
 arch/um/drivers/cow_sys.h  |    4 ++--
 arch/um/drivers/cow_user.c |    3 ++-
 arch/um/drivers/ubd_kern.c |    2 +-
 4 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/arch/um/drivers/cow.h b/arch/um/drivers/cow.h
index dc36b22..04e3958 100644
--- a/arch/um/drivers/cow.h
+++ b/arch/um/drivers/cow.h
@@ -46,7 +46,7 @@ extern int file_reader(__u64 offset, cha
 extern int read_cow_header(int (*reader)(__u64, char *, int, void *),
 			   void *arg, __u32 *version_out,
 			   char **backing_file_out, time_t *mtime_out,
-			   unsigned long long *size_out, int *sectorsize_out,
+			   __u64 *size_out, int *sectorsize_out,
 			   __u32 *align_out, int *bitmap_offset_out);
 
 extern int write_cow_header(char *cow_file, int fd, char *backing_file,
diff --git a/arch/um/drivers/cow_sys.h b/arch/um/drivers/cow_sys.h
index df25263..94de4ea 100644
--- a/arch/um/drivers/cow_sys.h
+++ b/arch/um/drivers/cow_sys.h
@@ -23,12 +23,12 @@ static inline char *cow_strdup(char *str
 	return(uml_strdup(str));
 }
 
-static inline int cow_seek_file(int fd, unsigned long long offset)
+static inline int cow_seek_file(int fd, __u64 offset)
 {
 	return(os_seek_file(fd, offset));
 }
 
-static inline int cow_file_size(char *file, unsigned long long *size_out)
+static inline int cow_file_size(char *file, __u64 *size_out)
 {
 	return(os_file_size(file, size_out));
 }
diff --git a/arch/um/drivers/cow_user.c b/arch/um/drivers/cow_user.c
index d1c86bc..61951b7 100644
--- a/arch/um/drivers/cow_user.c
+++ b/arch/um/drivers/cow_user.c
@@ -362,7 +362,8 @@ int init_cow_file(int fd, char *cow_file
 	if(err != sizeof(zero)){
 		cow_printf("Write of bitmap to new COW file '%s' failed, "
 			   "err = %d\n", cow_file, -err);
-		err = -EINVAL;
+		if (err >= 0)
+			err = -EINVAL;
 		goto out;
 	}
 
diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c
index f93af66..59f9890 100644
--- a/arch/um/drivers/ubd_kern.c
+++ b/arch/um/drivers/ubd_kern.c
@@ -1141,7 +1141,7 @@ static int path_requires_switch(char *fr
 static int backing_file_mismatch(char *file, __u64 size, time_t mtime)
 {
 	unsigned long modtime;
-	long long actual;
+	unsigned long long actual;
 	int err;
 
 	err = os_file_modtime(file, &modtime);

Re: [PATCH 0/6] UML little patches for 2.6.16

[Jeff Dike]

On Tue, Feb 21, 2006 at 06:15:35PM +0100, Paolo 'Blaisorblade' Giarrusso wrote:
> I'm sending some little fixups for inclusion 2.6.16. I've held some other
> fixes which need wider testing. Please merge now.

Acked-by: Jeff Dike <jdike@addtoit.com>