[uml-devel] [PATCH 01/10] uml: cow_user.c warning corrections

[uml-devel] [PATCH 01/10] uml: cow_user.c warning corrections

[Richard Weinberger]

From: Vitaliy Ivanov <vitalivanov@gmail.com>

arch/um/drivers/cow_user.c: In function ‘absolutize’:
arch/um/drivers/cow_user.c:189:7: warning: ignoring return value of ‘chdir’, declared with attribute warn_unused_result

Signed-off-by: Vitaliy Ivanov <vitalivanov@gmail.com>
[richard@nod.at: happens only with -D_FORTIFY_SOURCE=2]
Signed-off-by: Richard Weinberger <richard@nod.at>
---
 arch/um/drivers/cow_user.c |    6 +++++-
 1 files changed, 5 insertions(+), 1 deletions(-)

diff --git a/arch/um/drivers/cow_user.c b/arch/um/drivers/cow_user.c
index 93f227a..9cbb426 100644
--- a/arch/um/drivers/cow_user.c
+++ b/arch/um/drivers/cow_user.c
@@ -186,7 +186,11 @@ static int absolutize(char *to, int size, char *from)
 		strcat(to, "/");
 		strcat(to, from);
 	}
-	chdir(save_cwd);
+	if (chdir(save_cwd)) {
+		cow_printf("absolutize : Can't cd to '%s' - "
+			   "errno = %d\n", save_cwd, errno);
+		return -1;
+	}
 	return 0;
 }
 
-- 
1.7.6


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[uml-devel] [PATCH 02/10] uml: helper.c warning corrections

[Richard Weinberger]

From: Vitaliy Ivanov <vitalivanov@gmail.com>

arch/um/os-Linux/helper.c: In function ‘helper_child’:
arch/um/os-Linux/helper.c:38:7: warning: ignoring return value of ‘write’, declared with attribute warn_unused_result

Signed-off-by: Vitaliy Ivanov <vitalivanov@gmail.com>
[richard@nod.at: happens only with -D_FORTIFY_SOURCE=2]
Signed-off-by: Richard Weinberger <richard@nod.at>
---
 arch/um/os-Linux/helper.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/um/os-Linux/helper.c b/arch/um/os-Linux/helper.c
index b6b1096..feff22d 100644
--- a/arch/um/os-Linux/helper.c
+++ b/arch/um/os-Linux/helper.c
@@ -28,14 +28,14 @@ static int helper_child(void *arg)
 {
 	struct helper_data *data = arg;
 	char **argv = data->argv;
-	int err;
+	int err, ret;
 
 	if (data->pre_exec != NULL)
 		(*data->pre_exec)(data->pre_data);
 	err = execvp_noalloc(data->buf, argv[0], argv);
 
 	/* If the exec succeeds, we don't get here */
-	write(data->fd, &err, sizeof(err));
+	CATCH_EINTR(ret = write(data->fd, &err, sizeof(err)));
 
 	return 0;
 }
-- 
1.7.6


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[uml-devel] [PATCH 03/10] uml: drivers/slip_user.c memory leak fix

[Richard Weinberger]

From: Vitaliy Ivanov <vitalivanov@gmail.com>

Do not free memory when you failed to allocate it.

Signed-off-by: Vitaliy Ivanov <vitalivanov@gmail.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
---
 arch/um/drivers/slip_user.c |    3 +--
 1 files changed, 1 insertions(+), 2 deletions(-)

diff --git a/arch/um/drivers/slip_user.c b/arch/um/drivers/slip_user.c
index a1c2d2c..cbacfc4 100644
--- a/arch/um/drivers/slip_user.c
+++ b/arch/um/drivers/slip_user.c
@@ -102,7 +102,7 @@ static int slip_tramp(char **argv, int fd)
 		       "buffer\n");
 		os_kill_process(pid, 1);
 		err = -ENOMEM;
-		goto out_free;
+		goto out_close;
 	}
 
 	close(fds[1]);
@@ -112,7 +112,6 @@ static int slip_tramp(char **argv, int fd)
 	err = helper_wait(pid);
 	close(fds[0]);
 
-out_free:
 	kfree(output);
 	return err;
 
-- 
1.7.6


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improve internal communications as well as offer faster, more efficient ways
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[uml-devel] [PATCH 04/10] uml: free resources

[Richard Weinberger]

From: Davidlohr Bueso <dave@gnu.org>

When creating the temp file there's a memory and file descriptor leak upon error.

Signed-off-by: Davidlohr Bueso <dave@gnu.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
Reviewed-by: Vitaliy Ivanov <vitalivanov@gmail.com>
---
 arch/um/os-Linux/mem.c |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/um/os-Linux/mem.c b/arch/um/os-Linux/mem.c
index e696144..62878cf 100644
--- a/arch/um/os-Linux/mem.c
+++ b/arch/um/os-Linux/mem.c
@@ -176,7 +176,7 @@ static int __init make_tempfile(const char *template, char **out_tempname,
 
 	find_tempdir();
 	if ((tempdir == NULL) || (strlen(tempdir) >= MAXPATHLEN))
-		return -1;
+		goto out;
 
 	if (template[0] != '/')
 		strcpy(tempname, tempdir);
@@ -191,13 +191,15 @@ static int __init make_tempfile(const char *template, char **out_tempname,
 	}
 	if (do_unlink && (unlink(tempname) < 0)) {
 		perror("unlink");
-		goto out;
+		goto close;
 	}
 	if (out_tempname) {
 		*out_tempname = tempname;
 	} else
 		free(tempname);
 	return fd;
+close:
+	close(fd);
 out:
 	free(tempname);
 	return -1;
-- 
1.7.6


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[uml-devel] [PATCH 05/10] um: Disable scan_elf_aux() on x86_64

[Richard Weinberger]

Reusing the host's vDSO makes only sense on x86_32.

Signed-off-by: Richard Weinberger <richard@nod.at>
---
 arch/um/os-Linux/Makefile  |    4 +++-
 arch/um/os-Linux/elf_aux.c |    7 +------
 arch/um/os-Linux/main.c    |    4 ++++
 3 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/arch/um/os-Linux/Makefile b/arch/um/os-Linux/Makefile
index d66f038..b33f4df 100644
--- a/arch/um/os-Linux/Makefile
+++ b/arch/um/os-Linux/Makefile
@@ -3,10 +3,12 @@
 # Licensed under the GPL
 #
 
-obj-y = aio.o elf_aux.o execvp.o file.o helper.o irq.o main.o mem.o process.o \
+obj-y = aio.o execvp.o file.o helper.o irq.o main.o mem.o process.o \
 	registers.o sigio.o signal.o start_up.o time.o tty.o uaccess.o \
 	umid.o tls.o user_syms.o util.o drivers/ sys-$(SUBARCH)/ skas/
 
+obj-$(CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA) += elf_aux.o
+
 USER_OBJS := $(user-objs-y) aio.o elf_aux.o execvp.o file.o helper.o irq.o \
 	main.o mem.o process.o registers.o sigio.o signal.o start_up.o time.o \
 	tty.o tls.o uaccess.o umid.o util.o
diff --git a/arch/um/os-Linux/elf_aux.c b/arch/um/os-Linux/elf_aux.c
index 608784d..9533237 100644
--- a/arch/um/os-Linux/elf_aux.c
+++ b/arch/um/os-Linux/elf_aux.c
@@ -14,16 +14,11 @@
 #include "mem_user.h"
 #include <kern_constants.h>
 
-/* Use the one from the kernel - the host may miss it, if having old headers. */
-#if UM_ELF_CLASS == UM_ELFCLASS32
 typedef Elf32_auxv_t elf_auxv_t;
-#else
-typedef Elf64_auxv_t elf_auxv_t;
-#endif
 
 /* These are initialized very early in boot and never changed */
 char * elf_aux_platform;
-long elf_aux_hwcap;
+extern long elf_aux_hwcap;
 unsigned long vsyscall_ehdr;
 unsigned long vsyscall_end;
 unsigned long __kernel_vsyscall;
diff --git a/arch/um/os-Linux/main.c b/arch/um/os-Linux/main.c
index fb2a97a..8471b81 100644
--- a/arch/um/os-Linux/main.c
+++ b/arch/um/os-Linux/main.c
@@ -21,6 +21,8 @@
 #define STACKSIZE (8 * 1024 * 1024)
 #define THREAD_NAME_LEN (256)
 
+long elf_aux_hwcap;
+
 static void set_stklim(void)
 {
 	struct rlimit lim;
@@ -143,7 +145,9 @@ int __init main(int argc, char **argv, char **envp)
 	install_fatal_handler(SIGINT);
 	install_fatal_handler(SIGTERM);
 
+#ifdef CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA
 	scan_elf_aux(envp);
+#endif
 
 	do_uml_initcalls();
 	ret = linux_main(argc, argv);
-- 
1.7.6


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Unified Communications promises greater efficiencies for business. UC can 
improve internal communications as well as offer faster, more efficient ways
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[uml-devel] [PATCH 06/10] um: Set __HAVE_ARCH_GATE_AREA for i386

[Richard Weinberger]

When UML is unable to reuse the host's vDSO FIXADDR_USER_START
is zero.
To handle this special case correclty we have to implement custom
gate area helper methods.

Signed-off-by: Richard Weinberger <richard@nod.at>
---
 arch/um/sys-i386/Makefile  |    2 +-
 arch/um/sys-i386/asm/elf.h |    2 +
 arch/um/sys-i386/mem.c     |   62 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 65 insertions(+), 1 deletions(-)
 create mode 100644 arch/um/sys-i386/mem.c

diff --git a/arch/um/sys-i386/Makefile b/arch/um/sys-i386/Makefile
index b1da91c..daaea15 100644
--- a/arch/um/sys-i386/Makefile
+++ b/arch/um/sys-i386/Makefile
@@ -4,7 +4,7 @@
 
 obj-y = bug.o bugs.o checksum.o delay.o fault.o ksyms.o ldt.o ptrace.o \
 	ptrace_user.o setjmp.o signal.o stub.o stub_segv.o syscalls.o sysrq.o \
-	sys_call_table.o tls.o atomic64_cx8_32.o
+	sys_call_table.o tls.o atomic64_cx8_32.o mem.o
 
 obj-$(CONFIG_BINFMT_ELF) += elfcore.o
 
diff --git a/arch/um/sys-i386/asm/elf.h b/arch/um/sys-i386/asm/elf.h
index d964a41..4230555 100644
--- a/arch/um/sys-i386/asm/elf.h
+++ b/arch/um/sys-i386/asm/elf.h
@@ -105,6 +105,8 @@ extern unsigned long __kernel_vsyscall;
 #define FIXADDR_USER_START      VSYSCALL_BASE
 #define FIXADDR_USER_END        VSYSCALL_END
 
+#define __HAVE_ARCH_GATE_AREA 1
+
 /*
  * Architecture-neutral AT_ values in 0-17, leave some room
  * for more of them, start the x86-specific ones at 32.
diff --git a/arch/um/sys-i386/mem.c b/arch/um/sys-i386/mem.c
new file mode 100644
index 0000000..639900a
--- /dev/null
+++ b/arch/um/sys-i386/mem.c
@@ -0,0 +1,62 @@
+/*
+ * Copyright (C) 2011 Richard Weinberger <richrd@nod.at>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/mm.h>
+#include <asm/page.h>
+#include <asm/mman.h>
+
+static struct vm_area_struct gate_vma;
+
+static int __init gate_vma_init(void)
+{
+	if (!FIXADDR_USER_START)
+		return 0;
+
+	gate_vma.vm_mm = NULL;
+	gate_vma.vm_start = FIXADDR_USER_START;
+	gate_vma.vm_end = FIXADDR_USER_END;
+	gate_vma.vm_flags = VM_READ | VM_MAYREAD | VM_EXEC | VM_MAYEXEC;
+	gate_vma.vm_page_prot = __P101;
+
+	/*
+	 * Make sure the vDSO gets into every core dump.
+	 * Dumping its contents makes post-mortem fully interpretable later
+	 * without matching up the same kernel and hardware config to see
+	 * what PC values meant.
+	 */
+	gate_vma.vm_flags |= VM_ALWAYSDUMP;
+
+	return 0;
+}
+__initcall(gate_vma_init);
+
+struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
+{
+	return FIXADDR_USER_START ? &gate_vma : NULL;
+}
+
+int in_gate_area_no_mm(unsigned long addr)
+{
+	if (!FIXADDR_USER_START)
+		return 0;
+
+	if ((addr >= FIXADDR_USER_START) && (addr < FIXADDR_USER_END))
+		return 1;
+
+	return 0;
+}
+
+int in_gate_area(struct mm_struct *mm, unsigned long addr)
+{
+	struct vm_area_struct *vma = get_gate_vma(mm);
+
+	if (!vma)
+		return 0;
+
+	return (addr >= vma->vm_start) && (addr < vma->vm_end);
+}
-- 
1.7.6


------------------------------------------------------------------------------
5 Ways to Improve & Secure Unified Communications
Unified Communications promises greater efficiencies for business. UC can 
improve internal communications as well as offer faster, more efficient ways
to interact with customers and streamline customer service. Learn more!
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[uml-devel] [PATCH 07/10] um: Set __HAVE_ARCH_GATE_AREA for x86_64

[Richard Weinberger]

Implement arch_vma_name() and make get_gate_vma(),
in_gate_area() and in_gate_area_no_mm() a nop.

We need arch_vma_name() to support vDSO.

Signed-off-by: Richard Weinberger <richard@nod.at>
---
 arch/um/sys-x86_64/asm/elf.h |    1 +
 arch/um/sys-x86_64/mem.c     |   22 ++++++++++++++++++++++
 2 files changed, 23 insertions(+), 0 deletions(-)

diff --git a/arch/um/sys-x86_64/asm/elf.h b/arch/um/sys-x86_64/asm/elf.h
index d6d5af3..74eb0ac 100644
--- a/arch/um/sys-x86_64/asm/elf.h
+++ b/arch/um/sys-x86_64/asm/elf.h
@@ -119,4 +119,5 @@ extern long elf_aux_hwcap;
 
 #define SET_PERSONALITY(ex) do ; while(0)
 
+#define __HAVE_ARCH_GATE_AREA 1
 #endif
diff --git a/arch/um/sys-x86_64/mem.c b/arch/um/sys-x86_64/mem.c
index 3f8df8a..055cea0 100644
--- a/arch/um/sys-x86_64/mem.c
+++ b/arch/um/sys-x86_64/mem.c
@@ -14,3 +14,25 @@ unsigned long vm_data_default_flags = __VM_DATA_DEFAULT_FLAGS;
 unsigned long vm_data_default_flags32 = __VM_DATA_DEFAULT_FLAGS;
 unsigned long vm_force_exec32 = PROT_EXEC;
 
+const char *arch_vma_name(struct vm_area_struct *vma)
+{
+	if (vma->vm_mm && vma->vm_start == um_vdso_addr)
+		return "[vdso]";
+
+	return NULL;
+}
+
+struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
+{
+	return NULL;
+}
+
+int in_gate_area(struct mm_struct *mm, unsigned long addr)
+{
+	return 0;
+}
+
+int in_gate_area_no_mm(unsigned long addr)
+{
+	return 0;
+}
-- 
1.7.6


------------------------------------------------------------------------------
5 Ways to Improve & Secure Unified Communications
Unified Communications promises greater efficiencies for business. UC can 
improve internal communications as well as offer faster, more efficient ways
to interact with customers and streamline customer service. Learn more!
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Re: [PATCH 07/10] um: Set __HAVE_ARCH_GATE_AREA for x86_64

[Andrew Morton]

On Thu, 21 Jul 2011 11:18:31 +0200
Richard Weinberger <richard@nod.at> wrote:

> Implement arch_vma_name() and make get_gate_vma(),
> in_gate_area() and in_gate_area_no_mm() a nop.
> 
> We need arch_vma_name() to support vDSO.

Well this is awkward.

>  arch/um/sys-x86_64/asm/elf.h |    1 +
>  arch/um/sys-x86_64/mem.c     |   22 ++++++++++++++++++++++
>  2 files changed, 23 insertions(+), 0 deletions(-)

Your um-clean-up-vm-flagsh.patch deleted arch/um/sys-x86_64/mem.c.

There's not really any appropriate .c file in arch/um/sys-x86_64 for
these functions so I changed the patch to reinstate mem.c.

Then I changed my maind and dropped it ;) Hopefully none of the other
patches depended on this one.

Then I looked at um-implement-a-x86_64-vdso.patch, got nervous and
undropped um-set-__have_arch_gate_area-for-x86_64.patch.

Re: [uml-devel] [PATCH 07/10] um: Set __HAVE_ARCH_GATE_AREA for x86_64

[Richard Weinberger]

Am Samstag 23 Juli 2011, 01:01:27 schrieb Andrew Morton:
> On Thu, 21 Jul 2011 11:18:31 +0200
> 
> Richard Weinberger <richard@nod.at> wrote:
> > Implement arch_vma_name() and make get_gate_vma(),
> > in_gate_area() and in_gate_area_no_mm() a nop.
> > 
> > We need arch_vma_name() to support vDSO.
> 
> Well this is awkward.

Why?
Without it UML's vDSO will have no name.
E.g. when reading /proc/<pid>/maps

> >  arch/um/sys-x86_64/asm/elf.h |    1 +
> >  arch/um/sys-x86_64/mem.c     |   22 ++++++++++++++++++++++
> >  2 files changed, 23 insertions(+), 0 deletions(-)
> 
> Your um-clean-up-vm-flagsh.patch deleted arch/um/sys-x86_64/mem.c.
> 
> There's not really any appropriate .c file in arch/um/sys-x86_64 for
> these functions so I changed the patch to reinstate mem.c.
> 
> Then I changed my maind and dropped it ;) Hopefully none of the other
> patches depended on this one.
> 
> Then I looked at um-implement-a-x86_64-vdso.patch, got nervous and
> undropped um-set-__have_arch_gate_area-for-x86_64.patch.

I see, you've had some fun with this patch. ;-)
Sorry for that, I completely forgot rebasing my patches to mmotm.

Thanks,
//richard

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[PATCH 08/10] um: Implement a x86_64 vDSO

[Richard Weinberger]

Until now UML had no x86_64 vDSO.
So glibc always used the vsyscall page for gettimeday()
and friends.
Calls to gettimeday() returned falsely the host time and
confused some programs.

This patch adds a vDSO which turns all __vdso_* calls into
a system call so that UML can trap them.

As glibc still uses the vsyscall page for static binaries this
patch improves the situation only for dynamic binaries.

Signed-off-by: Richard Weinberger <richard@nod.at>
---
 arch/um/sys-x86_64/Makefile               |    2 +
 arch/um/sys-x86_64/asm/elf.h              |    9 +++
 arch/um/sys-x86_64/vdso/Makefile          |   90 +++++++++++++++++++++++++++++
 arch/um/sys-x86_64/vdso/checkundef.sh     |   10 +++
 arch/um/sys-x86_64/vdso/um_vdso.c         |   71 +++++++++++++++++++++++
 arch/um/sys-x86_64/vdso/vdso-layout.lds.S |   64 ++++++++++++++++++++
 arch/um/sys-x86_64/vdso/vdso-note.S       |   12 ++++
 arch/um/sys-x86_64/vdso/vdso.S            |   10 +++
 arch/um/sys-x86_64/vdso/vdso.lds.S        |   32 ++++++++++
 arch/um/sys-x86_64/vdso/vma.c             |   74 +++++++++++++++++++++++
 10 files changed, 374 insertions(+), 0 deletions(-)
 create mode 100644 arch/um/sys-x86_64/vdso/Makefile
 create mode 100755 arch/um/sys-x86_64/vdso/checkundef.sh
 create mode 100644 arch/um/sys-x86_64/vdso/um_vdso.c
 create mode 100644 arch/um/sys-x86_64/vdso/vdso-layout.lds.S
 create mode 100644 arch/um/sys-x86_64/vdso/vdso-note.S
 create mode 100644 arch/um/sys-x86_64/vdso/vdso.S
 create mode 100644 arch/um/sys-x86_64/vdso/vdso.lds.S
 create mode 100644 arch/um/sys-x86_64/vdso/vma.c

diff --git a/arch/um/sys-x86_64/Makefile b/arch/um/sys-x86_64/Makefile
index c1ea9eb..cc70f7a 100644
--- a/arch/um/sys-x86_64/Makefile
+++ b/arch/um/sys-x86_64/Makefile
@@ -8,6 +8,8 @@ obj-y = bug.o bugs.o delay.o fault.o ldt.o mem.o ptrace.o ptrace_user.o \
 	setjmp.o signal.o stub.o stub_segv.o syscalls.o syscall_table.o \
 	sysrq.o ksyms.o tls.o
 
+obj-y += vdso/
+
 subarch-obj-y = lib/csum-partial_64.o lib/memcpy_64.o lib/thunk_64.o \
 		lib/rwsem_64.o
 subarch-obj-$(CONFIG_MODULES) += kernel/module.o
diff --git a/arch/um/sys-x86_64/asm/elf.h b/arch/um/sys-x86_64/asm/elf.h
index 74eb0ac..11a2bfb 100644
--- a/arch/um/sys-x86_64/asm/elf.h
+++ b/arch/um/sys-x86_64/asm/elf.h
@@ -120,4 +120,13 @@ extern long elf_aux_hwcap;
 #define SET_PERSONALITY(ex) do ; while(0)
 
 #define __HAVE_ARCH_GATE_AREA 1
+#define ARCH_HAS_SETUP_ADDITIONAL_PAGES 1
+struct linux_binprm;
+extern int arch_setup_additional_pages(struct linux_binprm *bprm,
+	int uses_interp);
+
+extern unsigned long um_vdso_addr;
+#define AT_SYSINFO_EHDR 33
+#define ARCH_DLINFO	NEW_AUX_ENT(AT_SYSINFO_EHDR, um_vdso_addr)
+
 #endif
diff --git a/arch/um/sys-x86_64/vdso/Makefile b/arch/um/sys-x86_64/vdso/Makefile
new file mode 100644
index 0000000..5dffe6d
--- /dev/null
+++ b/arch/um/sys-x86_64/vdso/Makefile
@@ -0,0 +1,90 @@
+#
+# Building vDSO images for x86.
+#
+
+VDSO64-y		:= y
+
+vdso-install-$(VDSO64-y)	+= vdso.so
+
+
+# files to link into the vdso
+vobjs-y := vdso-note.o um_vdso.o
+
+# files to link into kernel
+obj-$(VDSO64-y)			+= vdso.o vma.o
+
+vobjs := $(foreach F,$(vobjs-y),$(obj)/$F)
+
+$(obj)/vdso.o: $(obj)/vdso.so
+
+targets += vdso.so vdso.so.dbg vdso.lds $(vobjs-y)
+
+export CPPFLAGS_vdso.lds += -P -C
+
+VDSO_LDFLAGS_vdso.lds = -m64 -Wl,-soname=linux-vdso.so.1 \
+       -Wl,-z,max-page-size=4096 -Wl,-z,common-page-size=4096
+
+$(obj)/vdso.o: $(src)/vdso.S $(obj)/vdso.so
+
+$(obj)/vdso.so.dbg: $(src)/vdso.lds $(vobjs) FORCE
+	$(call if_changed,vdso)
+
+$(obj)/%.so: OBJCOPYFLAGS := -S
+$(obj)/%.so: $(obj)/%.so.dbg FORCE
+	$(call if_changed,objcopy)
+
+#
+# Don't omit frame pointers for ease of userspace debugging, but do
+# optimize sibling calls.
+#
+CFL := $(PROFILING) -mcmodel=small -fPIC -O2 -fasynchronous-unwind-tables -m64 \
+       $(filter -g%,$(KBUILD_CFLAGS)) $(call cc-option, -fno-stack-protector) \
+       -fno-omit-frame-pointer -foptimize-sibling-calls
+
+$(vobjs): KBUILD_CFLAGS += $(CFL)
+
+#
+# vDSO code runs in userspace and -pg doesn't help with profiling anyway.
+#
+CFLAGS_REMOVE_vdso-note.o = -pg
+CFLAGS_REMOVE_um_vdso.o = -pg
+
+targets += vdso-syms.lds
+obj-$(VDSO64-y)			+= vdso-syms.lds
+
+#
+# Match symbols in the DSO that look like VDSO*; produce a file of constants.
+#
+sed-vdsosym := -e 's/^00*/0/' \
+	-e 's/^\([0-9a-fA-F]*\) . \(VDSO[a-zA-Z0-9_]*\)$$/\2 = 0x\1;/p'
+quiet_cmd_vdsosym = VDSOSYM $@
+define cmd_vdsosym
+	$(NM) $< | LC_ALL=C sed -n $(sed-vdsosym) | LC_ALL=C sort > $@
+endef
+
+$(obj)/%-syms.lds: $(obj)/%.so.dbg FORCE
+	$(call if_changed,vdsosym)
+
+#
+# The DSO images are built using a special linker script.
+#
+quiet_cmd_vdso = VDSO    $@
+      cmd_vdso = $(CC) -nostdlib -o $@ \
+		       $(VDSO_LDFLAGS) $(VDSO_LDFLAGS_$(filter %.lds,$(^F))) \
+		       -Wl,-T,$(filter %.lds,$^) $(filter %.o,$^) && \
+		 sh $(srctree)/$(src)/checkundef.sh '$(NM)' '$@'
+
+VDSO_LDFLAGS = -fPIC -shared $(call cc-ldoption, -Wl$(comma)--hash-style=sysv)
+GCOV_PROFILE := n
+
+#
+# Install the unstripped copy of vdso*.so listed in $(vdso-install-y).
+#
+quiet_cmd_vdso_install = INSTALL $@
+      cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/$@
+$(vdso-install-y): %.so: $(obj)/%.so.dbg FORCE
+	@mkdir -p $(MODLIB)/vdso
+	$(call cmd,vdso_install)
+
+PHONY += vdso_install $(vdso-install-y)
+vdso_install: $(vdso-install-y)
diff --git a/arch/um/sys-x86_64/vdso/checkundef.sh b/arch/um/sys-x86_64/vdso/checkundef.sh
new file mode 100755
index 0000000..7ee90a9
--- /dev/null
+++ b/arch/um/sys-x86_64/vdso/checkundef.sh
@@ -0,0 +1,10 @@
+#!/bin/sh
+nm="$1"
+file="$2"
+$nm "$file" | grep '^ *U' > /dev/null 2>&1
+if [ $? -eq 1 ]; then
+    exit 0
+else
+    echo "$file: undefined symbols found" >&2
+    exit 1
+fi
diff --git a/arch/um/sys-x86_64/vdso/um_vdso.c b/arch/um/sys-x86_64/vdso/um_vdso.c
new file mode 100644
index 0000000..7c441b5
--- /dev/null
+++ b/arch/um/sys-x86_64/vdso/um_vdso.c
@@ -0,0 +1,71 @@
+/*
+ * Copyright (C) 2011 Richard Weinberger <richrd@nod.at>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This vDSO turns all calls into a syscall so that UML can trap them.
+ */
+
+
+/* Disable profiling for userspace code */
+#define DISABLE_BRANCH_PROFILING
+
+#include <linux/time.h>
+#include <linux/getcpu.h>
+#include <asm/unistd.h>
+
+int __vdso_clock_gettime(clockid_t clock, struct timespec *ts)
+{
+	long ret;
+
+	asm("syscall" : "=a" (ret) :
+		"0" (__NR_clock_gettime), "D" (clock), "S" (ts) : "memory");
+
+	return ret;
+}
+int clock_gettime(clockid_t, struct timespec *)
+	__attribute__((weak, alias("__vdso_clock_gettime")));
+
+int __vdso_gettimeofday(struct timeval *tv, struct timezone *tz)
+{
+	long ret;
+
+	asm("syscall" : "=a" (ret) :
+		"0" (__NR_gettimeofday), "D" (tv), "S" (tz) : "memory");
+
+	return ret;
+}
+int gettimeofday(struct timeval *, struct timezone *)
+	__attribute__((weak, alias("__vdso_gettimeofday")));
+
+time_t __vdso_time(time_t *t)
+{
+	long secs;
+
+	asm volatile("syscall"
+		: "=a" (secs)
+		: "0" (__NR_time), "D" (t) : "cc", "r11", "cx", "memory");
+
+	return secs;
+}
+int time(time_t *t) __attribute__((weak, alias("__vdso_time")));
+
+long
+__vdso_getcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *unused)
+{
+	/*
+	 * UML does not support SMP, we can cheat here. :)
+	 */
+
+	if (cpu)
+		*cpu = 0;
+	if (node)
+		*node = 0;
+
+	return 0;
+}
+
+long getcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *tcache)
+	__attribute__((weak, alias("__vdso_getcpu")));
diff --git a/arch/um/sys-x86_64/vdso/vdso-layout.lds.S b/arch/um/sys-x86_64/vdso/vdso-layout.lds.S
new file mode 100644
index 0000000..634a2cf
--- /dev/null
+++ b/arch/um/sys-x86_64/vdso/vdso-layout.lds.S
@@ -0,0 +1,64 @@
+/*
+ * Linker script for vDSO.  This is an ELF shared object prelinked to
+ * its virtual address, and with only one read-only segment.
+ * This script controls its layout.
+ */
+
+SECTIONS
+{
+	. = VDSO_PRELINK + SIZEOF_HEADERS;
+
+	.hash		: { *(.hash) }			:text
+	.gnu.hash	: { *(.gnu.hash) }
+	.dynsym		: { *(.dynsym) }
+	.dynstr		: { *(.dynstr) }
+	.gnu.version	: { *(.gnu.version) }
+	.gnu.version_d	: { *(.gnu.version_d) }
+	.gnu.version_r	: { *(.gnu.version_r) }
+
+	.note		: { *(.note.*) }		:text	:note
+
+	.eh_frame_hdr	: { *(.eh_frame_hdr) }		:text	:eh_frame_hdr
+	.eh_frame	: { KEEP (*(.eh_frame)) }	:text
+
+	.dynamic	: { *(.dynamic) }		:text	:dynamic
+
+	.rodata		: { *(.rodata*) }		:text
+	.data		: {
+	      *(.data*)
+	      *(.sdata*)
+	      *(.got.plt) *(.got)
+	      *(.gnu.linkonce.d.*)
+	      *(.bss*)
+	      *(.dynbss*)
+	      *(.gnu.linkonce.b.*)
+	}
+
+	.altinstructions	: { *(.altinstructions) }
+	.altinstr_replacement	: { *(.altinstr_replacement) }
+
+	/*
+	 * Align the actual code well away from the non-instruction data.
+	 * This is the best thing for the I-cache.
+	 */
+	. = ALIGN(0x100);
+
+	.text		: { *(.text*) }			:text	=0x90909090
+}
+
+/*
+ * Very old versions of ld do not recognize this name token; use the constant.
+ */
+#define PT_GNU_EH_FRAME	0x6474e550
+
+/*
+ * We must supply the ELF program headers explicitly to get just one
+ * PT_LOAD segment, and set the flags explicitly to make segments read-only.
+ */
+PHDRS
+{
+	text		PT_LOAD		FLAGS(5) FILEHDR PHDRS; /* PF_R|PF_X */
+	dynamic		PT_DYNAMIC	FLAGS(4);		/* PF_R */
+	note		PT_NOTE		FLAGS(4);		/* PF_R */
+	eh_frame_hdr	PT_GNU_EH_FRAME;
+}
diff --git a/arch/um/sys-x86_64/vdso/vdso-note.S b/arch/um/sys-x86_64/vdso/vdso-note.S
new file mode 100644
index 0000000..79a071e
--- /dev/null
+++ b/arch/um/sys-x86_64/vdso/vdso-note.S
@@ -0,0 +1,12 @@
+/*
+ * This supplies .note.* sections to go into the PT_NOTE inside the vDSO text.
+ * Here we can supply some information useful to userland.
+ */
+
+#include <linux/uts.h>
+#include <linux/version.h>
+#include <linux/elfnote.h>
+
+ELFNOTE_START(Linux, 0, "a")
+	.long LINUX_VERSION_CODE
+ELFNOTE_END
diff --git a/arch/um/sys-x86_64/vdso/vdso.S b/arch/um/sys-x86_64/vdso/vdso.S
new file mode 100644
index 0000000..ec82c16
--- /dev/null
+++ b/arch/um/sys-x86_64/vdso/vdso.S
@@ -0,0 +1,10 @@
+#include <linux/init.h>
+
+__INITDATA
+
+	.globl vdso_start, vdso_end
+vdso_start:
+	.incbin "arch/um/sys-x86_64/vdso/vdso.so"
+vdso_end:
+
+__FINIT
diff --git a/arch/um/sys-x86_64/vdso/vdso.lds.S b/arch/um/sys-x86_64/vdso/vdso.lds.S
new file mode 100644
index 0000000..b96b267
--- /dev/null
+++ b/arch/um/sys-x86_64/vdso/vdso.lds.S
@@ -0,0 +1,32 @@
+/*
+ * Linker script for 64-bit vDSO.
+ * We #include the file to define the layout details.
+ * Here we only choose the prelinked virtual address.
+ *
+ * This file defines the version script giving the user-exported symbols in
+ * the DSO.  We can define local symbols here called VDSO* to make their
+ * values visible using the asm-x86/vdso.h macros from the kernel proper.
+ */
+
+#define VDSO_PRELINK 0xffffffffff700000
+#include "vdso-layout.lds.S"
+
+/*
+ * This controls what userland symbols we export from the vDSO.
+ */
+VERSION {
+	LINUX_2.6 {
+	global:
+		clock_gettime;
+		__vdso_clock_gettime;
+		gettimeofday;
+		__vdso_gettimeofday;
+		getcpu;
+		__vdso_getcpu;
+		time;
+		__vdso_time;
+	local: *;
+	};
+}
+
+VDSO64_PRELINK = VDSO_PRELINK;
diff --git a/arch/um/sys-x86_64/vdso/vma.c b/arch/um/sys-x86_64/vdso/vma.c
new file mode 100644
index 0000000..9495c8d
--- /dev/null
+++ b/arch/um/sys-x86_64/vdso/vma.c
@@ -0,0 +1,74 @@
+/*
+ * Copyright (C) 2011 Richard Weinberger <richrd@nod.at>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <asm/page.h>
+#include <linux/init.h>
+
+unsigned int __read_mostly vdso_enabled = 1;
+unsigned long um_vdso_addr;
+
+extern unsigned long task_size;
+extern char vdso_start[], vdso_end[];
+
+static struct page **vdsop;
+
+static int __init init_vdso(void)
+{
+	struct page *um_vdso;
+
+	BUG_ON(vdso_end - vdso_start > PAGE_SIZE);
+
+	um_vdso_addr = task_size - PAGE_SIZE;
+
+	vdsop = kmalloc(GFP_KERNEL, sizeof(struct page *));
+	if (!vdsop)
+		goto oom;
+
+	um_vdso = alloc_page(GFP_KERNEL);
+	if (!um_vdso) {
+		kfree(vdsop);
+
+		goto oom;
+	}
+
+	copy_page(page_address(um_vdso), vdso_start);
+	*vdsop = um_vdso;
+
+	return 0;
+
+oom:
+	printk(KERN_ERR "Cannot allocate vdso\n");
+	vdso_enabled = 0;
+
+	return -ENOMEM;
+}
+subsys_initcall(init_vdso);
+
+int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
+{
+	int err;
+	struct mm_struct *mm = current->mm;
+
+	if (!vdso_enabled)
+		return 0;
+
+	down_write(&mm->mmap_sem);
+
+	err = install_special_mapping(mm, um_vdso_addr, PAGE_SIZE,
+		VM_READ|VM_EXEC|
+		VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC|
+		VM_ALWAYSDUMP,
+		vdsop);
+
+	up_write(&mm->mmap_sem);
+
+	return err;
+}
-- 
1.7.6

[uml-devel] [PATCH 09/10] um: Ajdust size of pid_buf

[Richard Weinberger]

Linux can have pids up to 4*1024*1024.
To handle such huge numbers pid_buf needs to be larger.

Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
---
 arch/um/drivers/harddog_user.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/um/drivers/harddog_user.c b/arch/um/drivers/harddog_user.c
index b56f8e0..84dce3f 100644
--- a/arch/um/drivers/harddog_user.c
+++ b/arch/um/drivers/harddog_user.c
@@ -32,7 +32,7 @@ int start_watchdog(int *in_fd_ret, int *out_fd_ret, char *sock)
 {
 	struct dog_data data;
 	int in_fds[2], out_fds[2], pid, n, err;
-	char pid_buf[sizeof("nnnnn\0")], c;
+	char pid_buf[sizeof("nnnnnnn\0")], c;
 	char *pid_args[] = { "/usr/bin/uml_watchdog", "-pid", pid_buf, NULL };
 	char *mconsole_args[] = { "/usr/bin/uml_watchdog", "-mconsole", NULL,
 				  NULL };
-- 
1.7.6


------------------------------------------------------------------------------
5 Ways to Improve & Secure Unified Communications
Unified Communications promises greater efficiencies for business. UC can 
improve internal communications as well as offer faster, more efficient ways
to interact with customers and streamline customer service. Learn more!
http://www.accelacomm.com/jaw/sfnl/114/51426253/
_______________________________________________
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Re: [uml-devel] [PATCH 09/10] um: Ajdust size of pid_buf

[Geert Uytterhoeven]

On Thu, Jul 21, 2011 at 11:18, Richard Weinberger <richard@nod.at> wrote:
> Linux can have pids up to 4*1024*1024.
> To handle such huge numbers pid_buf needs to be larger.
>
> Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
> Signed-off-by: Richard Weinberger <richard@nod.at>
> ---
>  arch/um/drivers/harddog_user.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/arch/um/drivers/harddog_user.c b/arch/um/drivers/harddog_user.c
> index b56f8e0..84dce3f 100644
> --- a/arch/um/drivers/harddog_user.c
> +++ b/arch/um/drivers/harddog_user.c
> @@ -32,7 +32,7 @@ int start_watchdog(int *in_fd_ret, int *out_fd_ret, char *sock)
>  {
>        struct dog_data data;
>        int in_fds[2], out_fds[2], pid, n, err;
> -       char pid_buf[sizeof("nnnnn\0")], c;
> +       char pid_buf[sizeof("nnnnnnn\0")], c;

Why not make it handle the full 32-bit? That's just a few bytes extra
on the stack...

>        char *pid_args[] = { "/usr/bin/uml_watchdog", "-pid", pid_buf, NULL };
>        char *mconsole_args[] = { "/usr/bin/uml_watchdog", "-mconsole", NULL,
>                                  NULL };
> --
> 1.7.6

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [uml-devel] [PATCH 09/10] um: Ajdust size of pid_buf

[Richard Weinberger]

Am Donnerstag 21 Juli 2011, 11:38:11 schrieb Geert Uytterhoeven:
> On Thu, Jul 21, 2011 at 11:18, Richard Weinberger <richard@nod.at> wrote:
> > Linux can have pids up to 4*1024*1024.
> > To handle such huge numbers pid_buf needs to be larger.
> > 
> > Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
> > Signed-off-by: Richard Weinberger <richard@nod.at>
> > ---
> >  arch/um/drivers/harddog_user.c |    2 +-
> >  1 files changed, 1 insertions(+), 1 deletions(-)
> > 
> > diff --git a/arch/um/drivers/harddog_user.c
> > b/arch/um/drivers/harddog_user.c index b56f8e0..84dce3f 100644
> > --- a/arch/um/drivers/harddog_user.c
> > +++ b/arch/um/drivers/harddog_user.c
> > @@ -32,7 +32,7 @@ int start_watchdog(int *in_fd_ret, int *out_fd_ret,
> > char *sock) {
> >        struct dog_data data;
> >        int in_fds[2], out_fds[2], pid, n, err;
> > -       char pid_buf[sizeof("nnnnn\0")], c;
> > +       char pid_buf[sizeof("nnnnnnn\0")], c;
> 
> Why not make it handle the full 32-bit? That's just a few bytes extra
> on the stack...

True.
The sizeof("nnnnnnn\0") crap will anyway go away.
ASAP I'll submit a patch which removes all sizeof("nnnnnnn\0") and replaces
sprintf() with snprintf().

Thanks,
//richard

[uml-devel] [PATCH 10/10] um: Remove dead code

[Richard Weinberger]

GCC 4.6's -Wunused-but-set-variable found some dead code.

Signed-off-by: Richard Weinberger <richard@nod.at>
---
 arch/um/drivers/chan_kern.c |    3 +--
 arch/um/drivers/line.c      |    3 +--
 arch/um/kernel/reboot.c     |    3 +--
 3 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/arch/um/drivers/chan_kern.c b/arch/um/drivers/chan_kern.c
index 25e1965..d4191fe 100644
--- a/arch/um/drivers/chan_kern.c
+++ b/arch/um/drivers/chan_kern.c
@@ -543,11 +543,10 @@ int parse_chan_pair(char *str, struct line *line, int device,
 		    const struct chan_opts *opts, char **error_out)
 {
 	struct list_head *chans = &line->chan_list;
-	struct chan *new, *chan;
+	struct chan *new;
 	char *in, *out;
 
 	if (!list_empty(chans)) {
-		chan = list_entry(chans->next, struct chan, list);
 		free_chan(chans, 0);
 		INIT_LIST_HEAD(chans);
 	}
diff --git a/arch/um/drivers/line.c b/arch/um/drivers/line.c
index 35dd0b8..d51c404 100644
--- a/arch/um/drivers/line.c
+++ b/arch/um/drivers/line.c
@@ -176,10 +176,9 @@ void line_flush_buffer(struct tty_struct *tty)
 {
 	struct line *line = tty->driver_data;
 	unsigned long flags;
-	int err;
 
 	spin_lock_irqsave(&line->lock, flags);
-	err = flush_buffer(line);
+	flush_buffer(line);
 	spin_unlock_irqrestore(&line->lock, flags);
 }
 
diff --git a/arch/um/kernel/reboot.c b/arch/um/kernel/reboot.c
index 869bec9..4d93dff 100644
--- a/arch/um/kernel/reboot.c
+++ b/arch/um/kernel/reboot.c
@@ -20,9 +20,8 @@ static void kill_off_processes(void)
 		os_kill_ptraced_process(userspace_pid[0], 1);
 	else {
 		struct task_struct *p;
-		int pid, me;
+		int pid;
 
-		me = os_getpid();
 		for_each_process(p) {
 			if (p->mm == NULL)
 				continue;
-- 
1.7.6


------------------------------------------------------------------------------
5 Ways to Improve & Secure Unified Communications
Unified Communications promises greater efficiencies for business. UC can 
improve internal communications as well as offer faster, more efficient ways
to interact with customers and streamline customer service. Learn more!
http://www.accelacomm.com/jaw/sfnl/114/51426253/
_______________________________________________
User-mode-linux-devel mailing list
User-mode-linux-devel@lists.sourceforge.net
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