user/sven/linux.git/arch/um, branch v4.4.4

uml: flush stdout before forking

2016-03-03T23:07:12Z

commit 0754fb298f2f2719f0393491d010d46cfb25d043 upstream. I was seeing some really weird behaviour where piping UML's output somewhere would cause output to get duplicated: $ ./vmlinux | head -n 40 Checking that ptrace can change system call numbers...Core dump limits : soft - 0 hard - NONE OK Checking syscall emulation patch for ptrace...Core dump limits : soft - 0 hard - NONE OK Checking advanced syscall emulation patch for ptrace...Core dump limits : soft - 0 hard - NONE OK Core dump limits : soft - 0 hard - NONE This is because these tests do a fork() which duplicates the non-empty stdout buffer, then glibc flushes the duplicated buffer as each child exits. A simple workaround is to flush before forking. Signed-off-by: Vegard Nossum Signed-off-by: Richard Weinberger Signed-off-by: Greg Kroah-Hartman

um: fix returns without va_end

2015-12-08T21:26:00Z

When using va_list ensure that va_start will be followed by va_end. Signed-off-by: Geyslan G. Bem Signed-off-by: Richard Weinberger

arch: um: fix error when linking vmlinux.

2015-12-08T21:25:13Z

On gcc Ubuntu 4.8.4-2ubuntu1~14.04, linking vmlinux fails with: arch/um/os-Linux/built-in.o: In function `os_timer_create': /android/kernel/android/arch/um/os-Linux/time.c:51: undefined reference to `timer_create' arch/um/os-Linux/built-in.o: In function `os_timer_set_interval': /android/kernel/android/arch/um/os-Linux/time.c:84: undefined reference to `timer_settime' arch/um/os-Linux/built-in.o: In function `os_timer_remain': /android/kernel/android/arch/um/os-Linux/time.c:109: undefined reference to `timer_gettime' arch/um/os-Linux/built-in.o: In function `os_timer_one_shot': /android/kernel/android/arch/um/os-Linux/time.c:132: undefined reference to `timer_settime' arch/um/os-Linux/built-in.o: In function `os_timer_disable': /android/kernel/android/arch/um/os-Linux/time.c:145: undefined reference to `timer_settime' This is because -lrt appears in the generated link commandline after arch/um/os-Linux/built-in.o. Fix this by removing -lrt from arch/um/Makefile and adding it to the UM-specific section of scripts/link-vmlinux.sh. Signed-off-by: Lorenzo Colitti Signed-off-by: Richard Weinberger

um: Fix get_signal() usage

2015-12-08T21:23:30Z

If get_signal() returns us a signal to post we must not call it again, otherwise the already posted signal will be overridden. Before commit a610d6e672d this was the case as we stopped the while after a successful handle_signal(). Cc: # 3.10- Fixes: a610d6e672d ("pull clearing RESTORE_SIGMASK into block_sigmask()") Signed-off-by: Richard Weinberger

um: Switch clocksource to hrtimers

2015-11-06T21:54:49Z

UML is using an obsolete itimer call for all timers and "polls" for kernel space timer firing in its userspace portion resulting in a long list of bugs and incorrect behaviour(s). It also uses ITIMER_VIRTUAL for its timer which results in the timer being dependent on it running and the cpu load. This patch fixes this by moving to posix high resolution timers firing off CLOCK_MONOTONIC and relaying the timer correctly to the UML userspace. Fixes: - crashes when hosts suspends/resumes - broken userspace timers - effecive ~40Hz instead of what they should be. Note - this modifies skas behavior by no longer setting an itimer per clone(). Timer events are relayed instead. - kernel network packet scheduling disciplines - tcp behaviour especially under load - various timer related corner cases Finally, overall responsiveness of userspace is better. Signed-off-by: Thomas Meyer Signed-off-by: Anton Ivanov [rw: massaged commit message] Signed-off-by: Richard Weinberger

um: net: replace GFP_KERNEL with GFP_ATOMIC when spinlock is held

2015-11-06T21:51:00Z

since GFP_KERNEL with GFP_ATOMIC while spinlock is held, as code while holding a spinlock should be atomic. GFP_KERNEL may sleep and can cause deadlock, where as GFP_ATOMIC may fail but certainly avoids deadlockdex f70dd54..d898f6c 100644 Signed-off-by: Saurabh Sengar Signed-off-by: Richard Weinberger

um: Report host OOM more nicely

2015-11-06T21:49:12Z

If UML runs on the host side out of memory, report this condition more nicely. Signed-off-by: Richard Weinberger

um: Get rid of open coded NR_SYSCALLS

2015-11-06T21:49:10Z

We can use __NR_syscall_max. Signed-off-by: Richard Weinberger

um: Store syscall number after syscall_trace_enter()

2015-11-06T21:49:09Z

To support changing syscall numbers we have to store it after syscall_trace_enter(). Signed-off-by: Richard Weinberger

um: Define PTRACE_OLDSETOPTIONS

2015-11-06T21:49:09Z

...such that processes within UML can do a ptrace(PTRACE_OLDSETOPTIONS, ...) Signed-off-by: Richard Weinberger