[PATCH 0/4] Uml: basic fixups for 2.6.15

[PATCH 0/4] Uml: basic fixups for 2.6.15

[Paolo 'Blaisorblade' Giarrusso]

These are some important fixes for 2.6.15 to merge. A couple of them are
already in -mm, but I'm resending them anyway since they haven't been merged,
and since akpm is "non-functional". They are:

uml-arch-um-scripts-makefilerules-remove-duplicated-code.patch
uml-fix-dynamic-linking-on-some-64-bit-distros.patch

--
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 1/4] uml: arch/um/scripts/Makefile.rules - remove duplicated code

[Paolo 'Blaisorblade' Giarrusso]

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

Duplicated code - the patch adding it was probably applied twice without enough
care.

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

 arch/um/scripts/Makefile.rules |    5 -----
 1 files changed, 0 insertions(+), 5 deletions(-)

diff --git a/arch/um/scripts/Makefile.rules b/arch/um/scripts/Makefile.rules
index b3fbf12..2e41cab 100644
--- a/arch/um/scripts/Makefile.rules
+++ b/arch/um/scripts/Makefile.rules
@@ -21,11 +21,6 @@ define unprofile
 endef
 
 
-# The stubs and unmap.o can't try to call mcount or update basic block data
-define unprofile
-	$(patsubst -pg,,$(patsubst -fprofile-arcs -ftest-coverage,,$(1)))
-endef
-
 # cmd_make_link checks to see if the $(foo-dir) variable starts with a /.  If
 # so, it's considered to be a path relative to $(srcdir) rather than
 # $(srcdir)/arch/$(SUBARCH).  This is because x86_64 wants to get ldt.c from

[PATCH 2/4] uml: fix dynamic linking on some 64-bit distros

[Paolo 'Blaisorblade' Giarrusso]

From: Rob Landley <rob@landley.net>, Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>

The current UML build assumes that on x86-64 systems, /lib is a symlink 
to /lib64, but in some distributions (like PLD and CentOS) they are separate 
directories, so the 64 bit library loader isn't found.  This patch 
inserts /lib64 at the start of the rpath on x86-64 UML builds.

Signed-off-by: Rob Landley <rob@landley.net>
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
---

 arch/um/Makefile-x86_64 |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/arch/um/Makefile-x86_64 b/arch/um/Makefile-x86_64
index 4f118d5..38df311 100644
--- a/arch/um/Makefile-x86_64
+++ b/arch/um/Makefile-x86_64
@@ -12,3 +12,7 @@ CHECKFLAGS  += -m64
 
 ELF_ARCH := i386:x86-64
 ELF_FORMAT := elf64-x86-64
+
+# Not on all 64-bit distros /lib is a symlink to /lib64. PLD is an example.
+
+LINK-$(CONFIG_LD_SCRIPT_DYN) += -Wl,-rpath,/lib64

[PATCH 3/4] uml - fix some funkiness in Kconfig

[Paolo 'Blaisorblade' Giarrusso]

So you may have seen the miniconfig stuff wander by, which means that my build
script exits if there's a .config error, and we have this:

fs/Kconfig:1749:warning: 'select' used by config symbol 'CIFS_UPCALL' refer to
undefined symbol 'CONNECTOR'

This makes it shut up.

Signed-off-by: Rob Landley <rob@landley.net>

Verified it makes sense.

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

 arch/um/Kconfig |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/arch/um/Kconfig b/arch/um/Kconfig
index 563301f..1eb21de 100644
--- a/arch/um/Kconfig
+++ b/arch/um/Kconfig
@@ -289,6 +289,8 @@ source "arch/um/Kconfig.net"
 
 source "drivers/net/Kconfig"
 
+source "drivers/connector/Kconfig"
+
 source "fs/Kconfig"
 
 source "security/Kconfig"

[PATCH 4/4] uml skas0: stop gcc's insanity

[Paolo 'Blaisorblade' Giarrusso]

From: Jeff Dike <jdike@addtoit.com>, Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>

UML skas0 stub has been miscompiling for many people (incidentally not the
authors), depending on the used GCC versions.

I think (and testing on some GCC versions shows) this patch avoids the
fundamental issue which is behind this, namely gcc using the stack when we have
just replaced it, behind gcc's back. The remapping and storage of the return
value is hidden in a blob of asm, hopefully giving gcc no room for creativity.

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

 arch/um/include/sysdep-i386/stub.h   |   29 ++++++++++++++++-------------
 arch/um/include/sysdep-x86_64/stub.h |   30 +++++++++++++++++-------------
 arch/um/kernel/skas/clone.c          |   23 +++++++++++++----------
 3 files changed, 46 insertions(+), 36 deletions(-)

diff --git a/arch/um/include/sysdep-i386/stub.h b/arch/um/include/sysdep-i386/stub.h
index 6ba8cbb..b492b12 100644
--- a/arch/um/include/sysdep-i386/stub.h
+++ b/arch/um/include/sysdep-i386/stub.h
@@ -6,8 +6,12 @@
 #ifndef __SYSDEP_STUB_H
 #define __SYSDEP_STUB_H
 
+#include <sys/mman.h>
 #include <asm/ptrace.h>
 #include <asm/unistd.h>
+#include "stub-data.h"
+#include "kern_constants.h"
+#include "uml-config.h"
 
 extern void stub_segv_handler(int sig);
 extern void stub_clone_handler(void);
@@ -76,23 +80,22 @@ static inline long stub_syscall5(long sy
 	return ret;
 }
 
-static inline long stub_syscall6(long syscall, long arg1, long arg2, long arg3,
-				 long arg4, long arg5, long arg6)
+static inline void trap_myself(void)
 {
-	long ret;
-
-	__asm__ volatile ("push %%ebp ; movl %%eax,%%ebp ; movl %1,%%eax ; "
-			"int $0x80 ; pop %%ebp"
-			: "=a" (ret)
-			: "g" (syscall), "b" (arg1), "c" (arg2), "d" (arg3),
-			  "S" (arg4), "D" (arg5), "0" (arg6));
-
-	return ret;
+	__asm("int3");
 }
 
-static inline void trap_myself(void)
+static inline void remap_stack(int fd, unsigned long offset)
 {
-	__asm("int3");
+	__asm__ volatile ("movl %%eax,%%ebp ; movl %0,%%eax ; int $0x80 ;"
+			  "movl %7, %%ebx ; movl %%eax, (%%ebx)"
+			  : : "g" (STUB_MMAP_NR), "b" (UML_CONFIG_STUB_DATA), 
+			    "c" (UM_KERN_PAGE_SIZE), 
+			    "d" (PROT_READ | PROT_WRITE),
+			    "S" (MAP_FIXED | MAP_SHARED), "D" (fd), 
+			    "a" (offset), 
+			    "i" (&((struct stub_data *) UML_CONFIG_STUB_DATA)->err) 
+			  : "memory");
 }
 
 #endif
diff --git a/arch/um/include/sysdep-x86_64/stub.h b/arch/um/include/sysdep-x86_64/stub.h
index c41689c..92e989f 100644
--- a/arch/um/include/sysdep-x86_64/stub.h
+++ b/arch/um/include/sysdep-x86_64/stub.h
@@ -6,8 +6,12 @@
 #ifndef __SYSDEP_STUB_H
 #define __SYSDEP_STUB_H
 
+#include <sys/mman.h>
 #include <asm/unistd.h>
 #include <sysdep/ptrace_user.h>
+#include "stub-data.h"
+#include "kern_constants.h"
+#include "uml-config.h"
 
 extern void stub_segv_handler(int sig);
 extern void stub_clone_handler(void);
@@ -81,23 +85,23 @@ static inline long stub_syscall5(long sy
 	return ret;
 }
 
-static inline long stub_syscall6(long syscall, long arg1, long arg2, long arg3,
-				 long arg4, long arg5, long arg6)
+static inline void trap_myself(void)
 {
-	long ret;
-
-	__asm__ volatile ("movq %5,%%r10 ; movq %6,%%r8 ; "
-		"movq %7, %%r9; " __syscall : "=a" (ret)
-		: "0" (syscall), "D" (arg1), "S" (arg2), "d" (arg3),
-		  "g" (arg4), "g" (arg5), "g" (arg6)
-		: __syscall_clobber, "r10", "r8", "r9" );
-
-	return ret;
+	__asm("int3");
 }
 
-static inline void trap_myself(void)
+static inline void remap_stack(long fd, unsigned long offset)
 {
-	__asm("int3");
+	__asm__ volatile ("movq %4,%%r10 ; movq %5,%%r8 ; "
+			  "movq %6, %%r9; " __syscall "; movq %7, %%rbx ; "
+			  "movq %%rax, (%%rbx)": 
+			  : "a" (STUB_MMAP_NR), "D" (UML_CONFIG_STUB_DATA), 
+			    "S" (UM_KERN_PAGE_SIZE), 
+			    "d" (PROT_READ | PROT_WRITE), 
+                            "g" (MAP_FIXED | MAP_SHARED), "g" (fd), 
+			    "g" (offset),
+			    "i" (&((struct stub_data *) UML_CONFIG_STUB_DATA)->err)
+			  : __syscall_clobber, "r10", "r8", "r9" );
 }
 
 #endif
diff --git a/arch/um/kernel/skas/clone.c b/arch/um/kernel/skas/clone.c
index cb37ce9..47b812b 100644
--- a/arch/um/kernel/skas/clone.c
+++ b/arch/um/kernel/skas/clone.c
@@ -18,11 +18,10 @@
  * on some systems.
  */
 
-#define STUB_DATA(field) (((struct stub_data *) UML_CONFIG_STUB_DATA)->field)
-
 void __attribute__ ((__section__ (".__syscall_stub")))
 stub_clone_handler(void)
 {
+	struct stub_data *data = (struct stub_data *) UML_CONFIG_STUB_DATA;
 	long err;
 
 	err = stub_syscall2(__NR_clone, CLONE_PARENT | CLONE_FILES | SIGCHLD,
@@ -35,17 +34,21 @@ stub_clone_handler(void)
 	if(err)
 		goto out;
 
-	err = stub_syscall3(__NR_setitimer, ITIMER_VIRTUAL,
-			    (long) &STUB_DATA(timer), 0);
+	err = stub_syscall3(__NR_setitimer, ITIMER_VIRTUAL, 
+			    (long) &data->timer, 0);
 	if(err)
 		goto out;
 
-	err = stub_syscall6(STUB_MMAP_NR, UML_CONFIG_STUB_DATA,
-			    UM_KERN_PAGE_SIZE, PROT_READ | PROT_WRITE,
-			    MAP_FIXED | MAP_SHARED, STUB_DATA(fd),
-			    STUB_DATA(offset));
+	remap_stack(data->fd, data->offset);
+	goto done;
+
  out:
-	/* save current result. Parent: pid; child: retcode of mmap */
-	STUB_DATA(err) = err;
+	/* save current result. 
+	 * Parent: pid; 
+	 * child: retcode of mmap already saved and it jumps around this 
+	 * assignment
+	 */
+	data->err = err;
+ done:
 	trap_myself();
 }