[uml-devel] SKAS3 mode patch - newbie

[Pablo Pessolani <ppessolani@ho...>]

Hi:

   I am a  UML newbie .

   Is SKAS3 mode now included into the Linux kernel or it should be applied as a patch?

   Thanks in advance.

PAP

Re: [uml-devel] [UML] Question about arch/x86/um/vdso/vdso-syms.lds

[Richard Weinberger <richard@no...>]

Masahiro,

Am Mittwoch, 9. Mai 2018, 05:36:18 CEST schrieb Masahiro Yamada:
> Hi Richard,
> 
> 
> Please let me ask a question about vdso-syms.lds
> under arch/x86/um/vdso/.
> 
> This file exists since:
> 
> commit f1c2bb8b9964ed31de988910f8b1cfb586d30091
> Author: Richard Weinberger <richard@...>
> Date:   Mon Jul 25 17:12:54 2011 -0700
> 
>     um: implement a x86_64 vDSO
> 
> 
> So, I think you are the right person
> to reach out to.
> 
> 
> Originally, vdso-syms.lds was linked to vmlinux,
> but it is not since:
> 
> commit 827880ec260ba048f95fe646b96a205c394fa0f0
> Author: Nicholas Piggin <npiggin@...>
> Date:   Fri Jun 9 15:24:16 2017 +1000
> 
>     x86/um: thin archives build fix
> 
> 
> 
> Something may be missing from my thought,
> but I wonder what vdso-syms.lds is used for.

Hmm, I think we can kill it. In 2011 I used the x86 vdso
code as "template" this is how the file made it into UML.
AFAICT it was forgotten after all the vdso related refactoring
in um and x86.

Thanks,
//richard

[uml-devel] [REVIEW][PATCH 0/5] Improving siginfo_layout and fixing uml's relay_signal

[<ebiederm@xm...>]

This patchset is a respin of my latest patch to relay_signal for uml.

As I understand relay_signal it very carefully scrubs the signal
information it gets from the host kernel before passing it on.
Basically making certain it recognizes what it is dealing with.

This patchset updates siginfo_layout so that relay_signal and arm64's
force_signal_inject can reliably use it to verify the kind of signal
being processed, by recognizing the specializations of SIL_FAULT as
separate cases.

To make the siginfo_layout changes clean.  signalfd is first brought
into the modern world of using a single copy_to_user, no default case
statement (so gcc will flag missing cases), and handling SIGSYS for
seccomp.

The net is a simpler relay_signal is also more careful about which
signals it relays.

Eric

The changes are also available at:
  git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace.git siginfo-review3

Eric W. Biederman (5):
      signal/signalfd: Remove __put_user from signalfd_copyinfo
      signal/signalfd: Add support for SIGSYS
      signal: Remove unncessary #ifdef SEGV_PKUERR in 32bit compat code
      signal: Extend siginfo_layout with SIL_FAULT_{MCEERR|BNDERR|PKUERR}
      signal/um: More carefully relay signals in relay_signal.

 arch/um/kernel/trap.c         | 38 ++++++++------------
 fs/signalfd.c                 | 84 +++++++++++++++++++++++++------------------
 include/linux/signal.h        |  3 ++
 include/uapi/linux/signalfd.h |  6 +++-
 kernel/signal.c               | 82 +++++++++++++++++++++++++++---------------
 5 files changed, 125 insertions(+), 88 deletions(-)

Re: [uml-devel] [REVIEW][PATCH 19/22] signal/um: Use force_sig_fault in relay_signal.

[<ebiederm@xm...>]

Martin Pärtel <martin.partel@...> writes:

> And once more in plain text..
>
> On 25 April 2018 at 01:00, Martin Pärtel <martin.partel@...> wrote:
>>
>> Hi all,
>>
>> This was ages ago, but from what I remember...
>>
>>>
>>> Having a second look I really don't understand what relay_signal is
>>> trying to do.
>>>
>>> The function relay_signal does not pass siginfo through unchanged.
>>
>>
>> Just copying the entire struct would do the wrong thing. It was discussed here:
>> https://marc.info/?l=user-mode-linux-devel&m=133910707911999&w=2

So you are regnerating siginfo to ensure you don't copy unintended
things such as the host pid and host uid.

Then my analysis is correct that you simply missed filtering out the
si codes that are not signal specific and do not use the fault layout
in struct siginfo.

Is si_addr safe to copy across?  I presume so since the kernel just
ptraces an ordinary process, but I figure I should ask and double
check.

I am going to respin my patch.  I would say that you really need a
white-list of si_codes that whose use of struct siginfo that you know.
Otherwise you could get into the same problem of under or over copying
data.

Eric

Re: [uml-devel] [REVIEW][PATCH 19/22] signal/um: Use force_sig_fault in relay_signal.

[<ebiederm@xm...>]

Sigh I should have Cc'd Martin Partel as well as this bit is his
original code.

Anton Ivanov <anton.ivanov@...> writes:

> Hi Richard,
>
> There was a post to uml-devel during the days when the sourceforge mailing list
> was working in random drop mode which claimed that "this fixes the arm build".
>
> I have not kept it locally and I do not see it the archive (I do not see a few
> other posts there either - including some of mine).
>
> The joys of having a broken list :(
>
> Whoever posted it, if you are reading it, please re-post again so we can have a
> look.
>
> In the meantime we are as you said - x86 only.

The only case I can see my changed relay_signal affecting on arm is the
nasty hach where errno is set in conjunction with trap_trace.

Having a second look I really don't understand what relay_signal is
trying to do.

The function relay_signal does not pass siginfo through unchanged.
The function relay_signal does not handle cases where si_code is
not SI_USER or SI_KERNEL, or any of the other signal independent
si_codes.

In my change I believe I have preserved the character of relay_signal of
just passing through the fault.

Still even after reading the commit that upgraded relay_signal to
preserve si_code and si_addr I really don't understand the intended
logic.

Am I missing something subtle or have the subtle details of siginfo just
always been ignored?

commit d3c1cfcdb43e023ab1b1c7a555cd9e929026500a
Author: Martin Pärtel <martin.partel@...>
Date:   Thu Aug 2 00:49:17 2012 +0200

    um: pass siginfo to guest process
    
    UML guest processes now get correct siginfo_t for SIGTRAP, SIGFPE,
    SIGILL and SIGBUS. Specifically, si_addr and si_code are now correct
    where previously they were si_addr = NULL and si_code = 128.
    
    Signed-off-by: Martin Pärtel <martin.partel@...>
    Signed-off-by: Richard Weinberger <richard@...>

Eric

Re: [uml-devel] [REVIEW][PATCH 19/22] signal/um: Use force_sig_fault in relay_signal.

[Anton Ivanov <anton.ivanov@ko...>]

Hi Richard,

There was a post to uml-devel during the days when the sourceforge 
mailing list was working in random drop mode which claimed that "this 
fixes the arm build".

I have not kept it locally and I do not see it the archive (I do not see 
a few other posts there either - including some of mine).

The joys of having a broken list :(

Whoever posted it, if you are reading it, please re-post again so we can 
have a look.

In the meantime we are as you said - x86 only.

A.

On 04/24/18 09:32, Richard Weinberger wrote:
> On Fri, Apr 20, 2018 at 6:06 PM, Anton Ivanov
> <anton.ivanov@...> wrote:
>> On 04/20/18 15:38, Eric W. Biederman wrote:
>>> Today user mode linux only works on x86 and x86_64 and this allows
>>> simplifications of relay_signal.
>>
>> I believe someone recently fixed the ARM port. I have not had the time to
>> try the fixes though.
> Huh? UML is for ages x86 only.
>

Re: [uml-devel] [REVIEW][PATCH 19/22] signal/um: Use force_sig_fault in relay_signal.

[Richard Weinberger <richard.weinberger@gm...>]

On Fri, Apr 20, 2018 at 6:06 PM, Anton Ivanov
<anton.ivanov@...> wrote:
>
> On 04/20/18 15:38, Eric W. Biederman wrote:
>>
>> Today user mode linux only works on x86 and x86_64 and this allows
>> simplifications of relay_signal.
>
>
> I believe someone recently fixed the ARM port. I have not had the time to
> try the fixes though.

Huh? UML is for ages x86 only.

-- 
Thanks,
//richard

Re: [uml-devel] [PATCH] um: remove uml initcalls

[Richard Weinberger <richard@no...>]

Alexander,

Am Montag, 23. April 2018, 20:20:17 CEST schrieb Alexander Pateenok:
> __uml_initcall() is not used and .uml.initcall.init section is empty:
> 
> $ grep -r '__uml_initcall('
> arch/um/include/shared/init.h:#define __uml_initcall(fn)	\
> $ readelf -s ../umobj/linux | grep __uml_initcall
>  23214: 00000000603b75d8     0 NOTYPE  GLOBAL DEFAULT   32 __uml_initcall_start
>  25337: 00000000603b75d8     0 NOTYPE  GLOBAL DEFAULT   32 __uml_initcall_end
> 
> So it is unnecessary.

Right. The last user was removed almost 10 years ago by:
d2efa6d5ce14 ("uml: remove the dead TTY_LOG code")

Thanks,
//richard

Re: [uml-devel] [REVIEW][PATCH 19/22] signal/um: Use force_sig_fault in relay_signal.

[Anton Ivanov <anton.ivanov@ko...>]

On 04/20/18 15:38, Eric W. Biederman wrote:
> Today user mode linux only works on x86 and x86_64 and this allows
> simplifications of relay_signal.

I believe someone recently fixed the ARM port. I have not had the time 
to try the fixes though.

I have added the new list we are migrating to the cc list.

A.



>
> - x86 always set si_errno to 0 in fault handlers.
> - x86 does not implement si_trapno.
> - Only si_codes between SI_USER and SI_KERNEL have a fault address.
>
> Therefore warn if si_errno is set (it should never be).
> Use force_sig_info in the case where we know we have a good fault.
>
> For signals whose content it is not clear how to relay use plain
> force_sig and let the signal sending code come up with an
> appropriate generic siginfo.
>
> Cc: Jeff Dike <jdike@...>
> Cc: Richard Weinberger <richard@...>
> Cc: user-mode-linux-devel@...
> Signed-off-by: "Eric W. Biederman" <ebiederm@...>
> ---
>   arch/um/kernel/trap.c | 28 +++++++++++++---------------
>   1 file changed, 13 insertions(+), 15 deletions(-)
>
> diff --git a/arch/um/kernel/trap.c b/arch/um/kernel/trap.c
> index d4d38520c4c6..5f0ff17cd790 100644
> --- a/arch/um/kernel/trap.c
> +++ b/arch/um/kernel/trap.c
> @@ -296,9 +296,6 @@ unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user,
>   
>   void relay_signal(int sig, struct siginfo *si, struct uml_pt_regs *regs)
>   {
> -	struct faultinfo *fi;
> -	struct siginfo clean_si;
> -
>   	if (!UPT_IS_USER(regs)) {
>   		if (sig == SIGBUS)
>   			printk(KERN_ERR "Bus error - the host /dev/shm or /tmp "
> @@ -308,29 +305,30 @@ void relay_signal(int sig, struct siginfo *si, struct uml_pt_regs *regs)
>   
>   	arch_examine_signal(sig, regs);
>   
> -	clear_siginfo(&clean_si);
> -	clean_si.si_signo = si->si_signo;
> -	clean_si.si_errno = si->si_errno;
> -	clean_si.si_code = si->si_code;
> +	if (unlikely(si->si_errno)) {
> +		printk(KERN_ERR "Attempted to relay signal %d (si_code = %d) with errno %d\n",
> +		       sig, si->si_code, si->si_errno);
> +	}
>   	switch (sig) {
>   	case SIGILL:
>   	case SIGFPE:
>   	case SIGSEGV:
>   	case SIGBUS:
>   	case SIGTRAP:
> -		fi = UPT_FAULTINFO(regs);
> -		clean_si.si_addr = (void __user *) FAULT_ADDRESS(*fi);
> -		current->thread.arch.faultinfo = *fi;
> -#ifdef __ARCH_SI_TRAPNO
> -		clean_si.si_trapno = si->si_trapno;
> -#endif
> -		break;
> +		if ((si->si_code > SI_USER) && (si->si_code < SI_KERNEL)) {
> +			struct faultinfo *fi = UPT_FAULTINFO(regs);
> +			current->thread.arch.faultinfo = *fi;
> +			force_sig_fault(sig, si->si_code,
> +					(void __user *)FAULT_ADDRESS(*fi),
> +					current);
> +			break;
> +		}
>   	default:
>   		printk(KERN_ERR "Attempted to relay unknown signal %d (si_code = %d)\n",
>   			sig, si->si_code);
>   	}
>   
> -	force_sig_info(sig, &clean_si, current);
> +	force_sig(sig, current);
>   }
>   
>   void bus_handler(int sig, struct siginfo *si, struct uml_pt_regs *regs)

[uml-devel] [REVIEW][PATCH 19/22] signal/um: Use force_sig_fault in relay_signal.

[Eric W. Biederman <ebiederm@xm...>]

Today user mode linux only works on x86 and x86_64 and this allows
simplifications of relay_signal.

- x86 always set si_errno to 0 in fault handlers.
- x86 does not implement si_trapno.
- Only si_codes between SI_USER and SI_KERNEL have a fault address.

Therefore warn if si_errno is set (it should never be).
Use force_sig_info in the case where we know we have a good fault.

For signals whose content it is not clear how to relay use plain
force_sig and let the signal sending code come up with an
appropriate generic siginfo.

Cc: Jeff Dike <jdike@...>
Cc: Richard Weinberger <richard@...>
Cc: user-mode-linux-devel@...
Signed-off-by: "Eric W. Biederman" <ebiederm@...>
---
 arch/um/kernel/trap.c | 28 +++++++++++++---------------
 1 file changed, 13 insertions(+), 15 deletions(-)

diff --git a/arch/um/kernel/trap.c b/arch/um/kernel/trap.c
index d4d38520c4c6..5f0ff17cd790 100644
--- a/arch/um/kernel/trap.c
+++ b/arch/um/kernel/trap.c
@@ -296,9 +296,6 @@ unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user,
 
 void relay_signal(int sig, struct siginfo *si, struct uml_pt_regs *regs)
 {
-	struct faultinfo *fi;
-	struct siginfo clean_si;
-
 	if (!UPT_IS_USER(regs)) {
 		if (sig == SIGBUS)
 			printk(KERN_ERR "Bus error - the host /dev/shm or /tmp "
@@ -308,29 +305,30 @@ void relay_signal(int sig, struct siginfo *si, struct uml_pt_regs *regs)
 
 	arch_examine_signal(sig, regs);
 
-	clear_siginfo(&clean_si);
-	clean_si.si_signo = si->si_signo;
-	clean_si.si_errno = si->si_errno;
-	clean_si.si_code = si->si_code;
+	if (unlikely(si->si_errno)) {
+		printk(KERN_ERR "Attempted to relay signal %d (si_code = %d) with errno %d\n",
+		       sig, si->si_code, si->si_errno);
+	}
 	switch (sig) {
 	case SIGILL:
 	case SIGFPE:
 	case SIGSEGV:
 	case SIGBUS:
 	case SIGTRAP:
-		fi = UPT_FAULTINFO(regs);
-		clean_si.si_addr = (void __user *) FAULT_ADDRESS(*fi);
-		current->thread.arch.faultinfo = *fi;
-#ifdef __ARCH_SI_TRAPNO
-		clean_si.si_trapno = si->si_trapno;
-#endif
-		break;
+		if ((si->si_code > SI_USER) && (si->si_code < SI_KERNEL)) {
+			struct faultinfo *fi = UPT_FAULTINFO(regs);
+			current->thread.arch.faultinfo = *fi;
+			force_sig_fault(sig, si->si_code,
+					(void __user *)FAULT_ADDRESS(*fi),
+					current);
+			break;
+		}
 	default:
 		printk(KERN_ERR "Attempted to relay unknown signal %d (si_code = %d)\n",
 			sig, si->si_code);
 	}
 
-	force_sig_info(sig, &clean_si, current);
+	force_sig(sig, current);
 }
 
 void bus_handler(int sig, struct siginfo *si, struct uml_pt_regs *regs)
-- 
2.14.1

[uml-devel] [REVIEW][PATCH 20/22] signal/um: Use force_sig_fault where appropriate

[Eric W. Biederman <ebiederm@xm...>]

Filling in struct siginfo before calling force_sig_info a tedious and
error prone process, where once in a great while the wrong fields
are filled out, and siginfo has been inconsistently cleared.

Simplify this process by using the helper force_sig_fault.  Which
takes as a parameters all of the information it needs, ensures
all of the fiddly bits of filling in struct siginfo are done properly
and then calls force_sig_info.

In short about a 5 line reduction in code for every time force_sig_info
is called, which makes the calling function clearer.

Cc: Jeff Dike <jdike@...>
Cc: Richard Weinberger <richard@...>
Cc: user-mode-linux-devel@...
Signed-off-by: "Eric W. Biederman" <ebiederm@...>
---
 arch/um/kernel/ptrace.c | 13 +++----------
 arch/um/kernel/trap.c   | 26 ++++++++------------------
 2 files changed, 11 insertions(+), 28 deletions(-)

diff --git a/arch/um/kernel/ptrace.c b/arch/um/kernel/ptrace.c
index bc2a516c190f..1a1d88a4d940 100644
--- a/arch/um/kernel/ptrace.c
+++ b/arch/um/kernel/ptrace.c
@@ -115,17 +115,10 @@ long arch_ptrace(struct task_struct *child, long request,
 static void send_sigtrap(struct task_struct *tsk, struct uml_pt_regs *regs,
 		  int error_code)
 {
-	struct siginfo info;
-
-	memset(&info, 0, sizeof(info));
-	info.si_signo = SIGTRAP;
-	info.si_code = TRAP_BRKPT;
-
-	/* User-mode eip? */
-	info.si_addr = UPT_IS_USER(regs) ? (void __user *) UPT_IP(regs) : NULL;
-
 	/* Send us the fake SIGTRAP */
-	force_sig_info(SIGTRAP, &info, tsk);
+	force_sig_fault(SIGTRAP, TRAP_BRKPT,
+			/* User-mode eip? */
+			UPT_IS_USER(regs) ? (void __user *) UPT_IP(regs) : NULL, tsk);
 }
 
 /*
diff --git a/arch/um/kernel/trap.c b/arch/um/kernel/trap.c
index 5f0ff17cd790..48b70dcb6963 100644
--- a/arch/um/kernel/trap.c
+++ b/arch/um/kernel/trap.c
@@ -162,14 +162,9 @@ static void show_segv_info(struct uml_pt_regs *regs)
 
 static void bad_segv(struct faultinfo fi, unsigned long ip)
 {
-	struct siginfo si;
-
-	clear_siginfo(&si);
-	si.si_signo = SIGSEGV;
-	si.si_code = SEGV_ACCERR;
-	si.si_addr = (void __user *) FAULT_ADDRESS(fi);
 	current->thread.arch.faultinfo = fi;
-	force_sig_info(SIGSEGV, &si, current);
+	force_sig_fault(SIGSEGV, SEGV_ACCERR, (void __user *) FAULT_ADDRESS(fi),
+			current);
 }
 
 void fatal_sigsegv(void)
@@ -215,13 +210,12 @@ void segv_handler(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs)
 unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user,
 		   struct uml_pt_regs *regs)
 {
-	struct siginfo si;
 	jmp_buf *catcher;
+	int si_code;
 	int err;
 	int is_write = FAULT_WRITE(fi);
 	unsigned long address = FAULT_ADDRESS(fi);
 
-	clear_siginfo(&si);
 	if (!is_user && regs)
 		current->thread.segv_regs = container_of(regs, struct pt_regs, regs);
 
@@ -241,7 +235,7 @@ unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user,
 
 	if (SEGV_IS_FIXABLE(&fi))
 		err = handle_page_fault(address, ip, is_write, is_user,
-					&si.si_code);
+					&si_code);
 	else {
 		err = -EFAULT;
 		/*
@@ -273,18 +267,14 @@ unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user,
 	show_segv_info(regs);
 
 	if (err == -EACCES) {
-		si.si_signo = SIGBUS;
-		si.si_errno = 0;
-		si.si_code = BUS_ADRERR;
-		si.si_addr = (void __user *)address;
 		current->thread.arch.faultinfo = fi;
-		force_sig_info(SIGBUS, &si, current);
+		force_sig_fault(SIGBUS, BUS_ADRERR, (void __user *)address,
+				current);
 	} else {
 		BUG_ON(err != -EFAULT);
-		si.si_signo = SIGSEGV;
-		si.si_addr = (void __user *) address;
 		current->thread.arch.faultinfo = fi;
-		force_sig_info(SIGSEGV, &si, current);
+		force_sig_fault(SIGSEGV, si_code, (void __user *) address,
+				current);
 	}
 
 out:
-- 
2.14.1

[uml-devel] [ANNOUNCE] New User Mode Linux Mailing List

[Richard Weinberger <richard@si...>]

Hi!

The new mailing list address is: linux-um@...

Please subscribe via web[0] or mail[1].

Thanks,
//richard

[0] http://lists.infradead.org/mailman/listinfo/linux-um
[1] linux-um-join@...

-- 
sigma star gmbh - Eduard-Bodem-Gasse 6 - 6020 Innsbruck - Austria
ATU66964118 - FN 374287y

[uml-devel] [PATCH] um: Update mailing list address

[Richard Weinberger <richard@no...>]

We have a new mailing list, so update the MAINTAINERS file.

Signed-off-by: Richard Weinberger <richard@...>
---
 MAINTAINERS | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/MAINTAINERS b/MAINTAINERS
index b60179d948bb..4834d1551248 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -14768,8 +14768,7 @@ F:	drivers/media/usb/zr364xx/
 USER-MODE LINUX (UML)
 M:	Jeff Dike <jdike@...>
 M:	Richard Weinberger <richard@...>
-L:	user-mode-linux-devel@...
-L:	user-mode-linux-user@...
+L:	linux-um@...
 W:	http://user-mode-linux.sourceforge.net
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml.git
 S:	Maintained
-- 
2.13.6

Re: [uml-devel] [PATCH] um: Fix return value of start_idle_thread

[Richard Weinberger <richard@no...>]

Am Donnerstag, 29. März 2018, 22:45:59 CEST schrieb Richard Weinberger:
> While the function will never returns, gcc will warns.
> Add a return statement to make gcc happy.
> Before f44f1e7da7c8 we never noticed because gcc knows that longjmp does
> not return.
> 
> arch/um/os-Linux/skas/process.c: In function ‘start_idle_thread’:
> arch/um/os-Linux/skas/process.c:613:1: warning: control reaches end of non-void function [-Wreturn-type]
> 
> Fixes: f44f1e7da7c8 ("um: Avoid longjmp/setjmp symbol clashes with libpthread.a")
> Signed-off-by: Richard Weinberger <richard@...>

Applied.

Thanks,
//richard

Re: [uml-devel] [PATCH] um: Add HAVE_DEBUG_BUGVERBOSE.

[Richard Weinberger <richard@no...>]

Am Donnerstag, 5. April 2018, 23:21:02 CEST schrieb Hernán Gonzalez:
> This option restores the DEBUG_BUGVERBOSE functionality as it was
> previous to commit 9a93848fe787 ("x86/debug: Implement __WARN() using
> UD0").
> 
> Signed-off-by: Hernán Gonzalez <hernan@...>

Applied.

Thanks,
//richard

[uml-devel] [GIT PULL] UML changes for 4.17-rc1

[Richard Weinberger <richard@no...>]

Linus,

The following changes since commit 91ab883eb21325ad80f3473633f794c78ac87f51:

  Linux 4.16-rc2 (2018-02-18 17:29:42 -0800)

are available in the git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml.git 

for you to fetch changes up to e40238dedb484c8a19f8257e4ef5d77d038f9ad8:

  Fix vector raw inintialization logic (2018-03-29 22:18:02 +0200)

----------------------------------------------------------------
This pull request contains:
- A new and faster epoll based IRQ controller and NIC driver
- Misc fixes and janitorial updates

----------------------------------------------------------------
Anton Ivanov (5):
      Epoll based IRQ controller
      High Performance UML Vector Network Driver
      um: Add missing EXPORT for free_irq_by_fd()
      Migrate vector timers to new timer API
      Fix vector raw inintialization logic

Arnd Bergmann (1):
      um: time: Use timespec64 for persistent clock

Christophe JAILLET (2):
      um: vector: Fix a memory allocation check
      um: vector: Fix an error handling path in 'vector_parse()'

Geert Uytterhoeven (1):
      um: Restore symbol versions for __memcpy and memcpy

Jason A. Donenfeld (1):
      um: Compile with modern headers

Krzysztof Mazur (1):
      um: Use POSIX ucontext_t instead of struct ucontext

Wei Yongjun (1):
      um: vector: fix missing unlock on error in vector_net_open()

 arch/um/Kconfig.net                  |   11 +
 arch/um/drivers/Makefile             |    4 +-
 arch/um/drivers/chan_kern.c          |   53 +-
 arch/um/drivers/line.c               |    2 +-
 arch/um/drivers/net_kern.c           |    4 +-
 arch/um/drivers/random.c             |   11 +-
 arch/um/drivers/ubd_kern.c           |    4 +-
 arch/um/drivers/vector_kern.c        | 1633 ++++++++++++++++++++++++++++++++++
 arch/um/drivers/vector_kern.h        |  130 +++
 arch/um/drivers/vector_transports.c  |  458 ++++++++++
 arch/um/drivers/vector_user.c        |  590 ++++++++++++
 arch/um/drivers/vector_user.h        |  100 +++
 arch/um/include/asm/asm-prototypes.h |    1 +
 arch/um/include/asm/irq.h            |   12 +
 arch/um/include/shared/irq_user.h    |   12 +-
 arch/um/include/shared/net_kern.h    |    2 +
 arch/um/include/shared/os.h          |   17 +-
 arch/um/kernel/irq.c                 |  461 ++++++----
 arch/um/kernel/time.c                |    6 +-
 arch/um/os-Linux/file.c              |    1 +
 arch/um/os-Linux/irq.c               |  202 +++--
 arch/um/os-Linux/signal.c            |    3 +-
 arch/x86/um/stub_segv.c              |    3 +-
 23 files changed, 3395 insertions(+), 325 deletions(-)
 create mode 100644 arch/um/drivers/vector_kern.c
 create mode 100644 arch/um/drivers/vector_kern.h
 create mode 100644 arch/um/drivers/vector_transports.c
 create mode 100644 arch/um/drivers/vector_user.c
 create mode 100644 arch/um/drivers/vector_user.h
 create mode 100644 arch/um/include/asm/asm-prototypes.h

[uml-devel] [PATCH] um: Add HAVE_DEBUG_BUGVERBOSE.

[Hernán Gonzalez <hernan@va...>]

This option restores the DEBUG_BUGVERBOSE functionality as it was
previous to commit 9a93848fe787 ("x86/debug: Implement __WARN() using
UD0").

Signed-off-by: Hernán Gonzalez <hernan@...>
---
 arch/um/Kconfig.common | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/um/Kconfig.common b/arch/um/Kconfig.common
index c68add8..bf2a70f 100644
--- a/arch/um/Kconfig.common
+++ b/arch/um/Kconfig.common
@@ -8,6 +8,7 @@ config UML
 	select HAVE_UID16
 	select HAVE_FUTEX_CMPXCHG if FUTEX
 	select HAVE_DEBUG_KMEMLEAK
+	select HAVE_DEBUG_BUGVERBOSE
 	select GENERIC_IRQ_SHOW
 	select GENERIC_CPU_DEVICES
 	select GENERIC_CLOCKEVENTS
-- 
2.7.4

[uml-devel] [PATCH] um: Fix return value of start_idle_thread

[Richard Weinberger <richard@no...>]

While the function will never returns, gcc will warns.
Add a return statement to make gcc happy.
Before f44f1e7da7c8 we never noticed because gcc knows that longjmp does
not return.

arch/um/os-Linux/skas/process.c: In function ‘start_idle_thread’:
arch/um/os-Linux/skas/process.c:613:1: warning: control reaches end of non-void function [-Wreturn-type]

Fixes: f44f1e7da7c8 ("um: Avoid longjmp/setjmp symbol clashes with libpthread.a")
Signed-off-by: Richard Weinberger <richard@...>
---
 arch/um/os-Linux/skas/process.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/um/os-Linux/skas/process.c b/arch/um/os-Linux/skas/process.c
index c94c3bd70ccd..d41fdf686a5f 100644
--- a/arch/um/os-Linux/skas/process.c
+++ b/arch/um/os-Linux/skas/process.c
@@ -610,6 +610,10 @@ int start_idle_thread(void *stack, jmp_buf *switch_buf)
 		fatal_sigsegv();
 	}
 	longjmp(*switch_buf, 1);
+
+	/* unreachable */
+	fatal_sigsegv();
+	return 0;
 }
 
 void initial_thread_cb_skas(void (*proc)(void *), void *arg)
-- 
2.13.6

Re: [uml-devel] [0/9] UML vector network driver: Adjustments for three function implementations

[Anton Ivanov <anton.ivanov@ko...>]

Yes,

Next version though, I have some tweaks enqueued for the socket initialization. We can combine them with these. 

On 29 March 2018 20:51:55 BST, SF Markus Elfring <elfring@...> wrote:
>> Date: Sun, 11 Mar 2018 16:06:16 +0100
>> 
>> Some update suggestions were taken into account
>> from static source code analysis.
>…
>>   Delete unnecessary code in user_init_raw_fds()
>>   Less checks in user_init_raw_fds() after error detection
>>   Adjust an error message in user_init_socket_fds()
>>   Delete an unnecessary check before kfree() in
>user_init_socket_fds()
>>   Delete two unnecessary checks before freeaddrinfo() in
>user_init_socket_fds()
>>   Less checks in user_init_socket_fds() after error detection
>>   Adjust an error message in user_init_tap_fds()
>>   Less checks in user_init_tap_fds() after error detection
>>   Delete an unnecessary variable initialisation in
>user_init_tap_fds()
>…
>
>Would you like to pick any idea up from this patch series?
>	
>Regards,
>Markus

-- 
Sent from my Android device with K-9 Mail. Please excuse my brevity.

Re: [uml-devel] UML hangs with hrtimer test module

[Richard Weinberger <richard@no...>]

Am Donnerstag, 29. März 2018, 22:20:47 CEST schrieb Joel Fernandes:
> Thanks a lot! I am wondering why the same compiler works when running
> the test for a regular image. Maybe different compiler flags. Anyway
> good to learn this.
> 
> Also one more slightly OT question, why is UML only doing UP ? Is it
> extremely hard to do SMP for UML?

Long story short, nobody implemented SMP so far. :-)
Because SKAS3/0 we had a SMP implementation of TT mode.

In terms of UML implementing SMP means having multiple threads
that handle the userspace loop in arch/um/os-Linux/skas/process.c.

We could also do a poor man's SMP implementation first, where only user 
processes run in parallel.
IOW userspace() in arch/um/os-Linux/skas/process.c is still a single thread 
but it let's run up to N user space thread and only if the call into the 
kernel we degrade to UP.

Adding SMP is not extremely hard but it requires a lot of re-work of the UML 
core and introduces tons of new issues.

That said, volunteers are welcome!

Thanks,
//richard

Re: [uml-devel] UML hangs with hrtimer test module

[Joel Fernandes <agnel.joel@gm...>]

On Wed, Mar 28, 2018 at 11:04 PM, Geert Uytterhoeven
<geert@...> wrote:
> On Thu, Mar 29, 2018 at 12:35 AM, Richard Weinberger <richard@...> wrote:
>> Am Donnerstag, 29. März 2018, 00:19:39 CEST schrieb Joel Fernandes:
>>> On Wed, Mar 28, 2018 at 6:19 AM, Richard Weinberger <richard@...> wrote:
>>> > Am Mittwoch, 28. März 2018, 15:11:29 CEST schrieb Geert Uytterhoeven:
>>> >> On Wed, Mar 28, 2018 at 12:28 PM, Joel Fernandes <agnel.joel@...>
>>> > wrote:
>>> >> >         while(release_now == 0);
>>> >>
>>> >> while (release_now == 0)
>>> >>         cpu_relax();
>>> >
>>> > Not sure whether a cpu_relax() fixes the problem.
>>> > I guess the root of the problem is that UML is UP and non-preemptive.
>>> > Therefore the loop is never interrupted.
>>> > To verify I asked for the full source.
>>> >
>>>
>>> cpu_relax actually worked!
>>
>> Interesting.
>>
>>> Any thoughts on why it helps? Even if its non-preemptive, I did
>>> receive the timer interrupt, so I expected the variable to be set.
>>
>> Timers trigger also with preempt off, I forgot...
>> I think the cpu_relax() issues internally a barrier such that the
>> release_now variable is read again.
>> Can you try barrier() instead of cpu_relax()? I bet it works too.
>> Same if you mark release_now as volatile.
>
> Without cpu_relax()/barrier()/volatile, the compiler can assume release_now
> never changes, and thus may "optimize" the loop to an infinite loop.
>

Thanks a lot! I am wondering why the same compiler works when running
the test for a regular image. Maybe different compiler flags. Anyway
good to learn this.

Also one more slightly OT question, why is UML only doing UP ? Is it
extremely hard to do SMP for UML?

I also happen to notice Qemu has one thread per emulated core...

thanks,

- Joel

Re: [uml-devel] [PATCH v2] Fix vector raw inintialization logic

[Richard Weinberger <richard@no...>]

Am Montag, 5. März 2018, 14:29:05 CEST schrieb anton.ivanov@...:
> From: Anton Ivanov <anton.ivanov@...>
> 
> Vector RAW in UML needs to BPF filter its own MAC only
> if QDISC_BYPASS has failed. If QDISC_BYPASS is successful, the
> frames originated locally are not visible to readers on the
> raw socket.
> 
> Signed-off-by: Anton Ivanov <anton.ivanov@...>

Applied.

Thanks,
//richard

Re: [uml-devel] [PATCH] Migrate vector timers to new timer API

[Richard Weinberger <richard@no...>]

Am Montag, 5. März 2018, 11:41:42 CEST schrieb anton.ivanov@...:
> From: Anton Ivanov <anton.ivanov@...>
> 
> The patches for the UML vector drivers were in-flight when
> the timer changes happened and were not covered by them.
> 
> This change migrates vector_kern.c to use the new timer API.
> 
> Signed-off-by: Anton Ivanov <anton.ivanov@...>

Applied.

Thanks,
//richard

Re: [uml-devel] UML hangs with hrtimer test module

[Geert Uytterhoeven <geert@li...>]

On Thu, Mar 29, 2018 at 12:35 AM, Richard Weinberger <richard@...> wrote:
> Am Donnerstag, 29. März 2018, 00:19:39 CEST schrieb Joel Fernandes:
>> On Wed, Mar 28, 2018 at 6:19 AM, Richard Weinberger <richard@...> wrote:
>> > Am Mittwoch, 28. März 2018, 15:11:29 CEST schrieb Geert Uytterhoeven:
>> >> On Wed, Mar 28, 2018 at 12:28 PM, Joel Fernandes <agnel.joel@...>
>> > wrote:
>> >> >         while(release_now == 0);
>> >>
>> >> while (release_now == 0)
>> >>         cpu_relax();
>> >
>> > Not sure whether a cpu_relax() fixes the problem.
>> > I guess the root of the problem is that UML is UP and non-preemptive.
>> > Therefore the loop is never interrupted.
>> > To verify I asked for the full source.
>> >
>>
>> cpu_relax actually worked!
>
> Interesting.
>
>> Any thoughts on why it helps? Even if its non-preemptive, I did
>> receive the timer interrupt, so I expected the variable to be set.
>
> Timers trigger also with preempt off, I forgot...
> I think the cpu_relax() issues internally a barrier such that the
> release_now variable is read again.
> Can you try barrier() instead of cpu_relax()? I bet it works too.
> Same if you mark release_now as volatile.

Without cpu_relax()/barrier()/volatile, the compiler can assume release_now
never changes, and thus may "optimize" the loop to an infinite loop.

Gr{oetje,eeting}s,

                        Geert

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

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] UML hangs with hrtimer test module

[Richard Weinberger <richard@no...>]

Am Donnerstag, 29. März 2018, 00:19:39 CEST schrieb Joel Fernandes:
> Thanks for the quick reply.
> 
> On Wed, Mar 28, 2018 at 6:19 AM, Richard Weinberger <richard@...> wrote:
> > Am Mittwoch, 28. März 2018, 15:11:29 CEST schrieb Geert Uytterhoeven:
> >> On Wed, Mar 28, 2018 at 12:28 PM, Joel Fernandes <agnel.joel@...>
> > wrote:
> >> >         while(release_now == 0);
> >>
> >> while (release_now == 0)
> >>         cpu_relax();
> >
> > Not sure whether a cpu_relax() fixes the problem.
> > I guess the root of the problem is that UML is UP and non-preemptive.
> > Therefore the loop is never interrupted.
> > To verify I asked for the full source.
> >
> 
> cpu_relax actually worked!

Interesting.
 
> Any thoughts on why it helps? Even if its non-preemptive, I did
> receive the timer interrupt, so I expected the variable to be set.

Timers trigger also with preempt off, I forgot...
I think the cpu_relax() issues internally a barrier such that the
release_now variable is read again.
Can you try barrier() instead of cpu_relax()? I bet it works too.
Same if you mark release_now as volatile.

Thanks,
//richard