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2024-09-12um: Remove unused fields from thread_structTiwei Bie1-4/+4
These fields are no longer used since the removal of tt mode. Signed-off-by: Tiwei Bie <[email protected]> Signed-off-by: Richard Weinberger <[email protected]>
2024-07-03um: remove force_flush_all from fork_handlerBenjamin Berg1-2/+0
There should be no need for this. It may be that this used to work around another issue where after a clone the MM was in a bad state. Signed-off-by: Benjamin Berg <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Johannes Berg <[email protected]>
2024-07-03um: Remove /proc/sysemu support codeTiwei Bie1-67/+0
Currently /proc/sysemu will never be registered, as sysemu_supported is initialized to zero implicitly and no code updates it. And there is also nothing to configure via sysemu in UML anymore. Signed-off-by: Tiwei Bie <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Johannes Berg <[email protected]>
2024-04-30um: Stop tracking host PID in cpu_tasksTiwei Bie1-10/+2
The host PID tracked in 'cpu_tasks' is no longer used. Stopping tracking it will also save some cycles. Signed-off-by: Tiwei Bie <[email protected]> Signed-off-by: Richard Weinberger <[email protected]>
2024-04-22um: process: remove unused 'n' variableJohannes Berg1-2/+2
The return value of fn() wasn't used for a long time, so no need to assign it to a variable, addressing a W=1 warning. This seems to be - with patches from others posted to the list before - the last W=1 warning in arch/um/. Fixes: 22e2430d60db ("x86, um: convert to saner kernel_execve() semantics") Signed-off-by: Johannes Berg <[email protected]> Reviewed-by: Tiwei Bie <[email protected]> Signed-off-by: Richard Weinberger <[email protected]>
2024-04-22um: Move declarations to proper headersTiwei Bie1-2/+0
This will address below -Wmissing-prototypes warnings: arch/um/kernel/initrd.c:18:12: warning: no previous prototype for ‘read_initrd’ [-Wmissing-prototypes] arch/um/kernel/um_arch.c:408:19: warning: no previous prototype for ‘read_initrd’ [-Wmissing-prototypes] arch/um/os-Linux/start_up.c:301:12: warning: no previous prototype for ‘parse_iomem’ [-Wmissing-prototypes] arch/x86/um/ptrace_32.c:15:6: warning: no previous prototype for ‘arch_switch_to’ [-Wmissing-prototypes] arch/x86/um/ptrace_32.c:101:5: warning: no previous prototype for ‘poke_user’ [-Wmissing-prototypes] arch/x86/um/ptrace_32.c:153:5: warning: no previous prototype for ‘peek_user’ [-Wmissing-prototypes] arch/x86/um/ptrace_64.c:111:5: warning: no previous prototype for ‘poke_user’ [-Wmissing-prototypes] arch/x86/um/ptrace_64.c:171:5: warning: no previous prototype for ‘peek_user’ [-Wmissing-prototypes] arch/x86/um/syscalls_64.c:48:6: warning: no previous prototype for ‘arch_switch_to’ [-Wmissing-prototypes] arch/x86/um/tls_32.c:184:5: warning: no previous prototype for ‘arch_switch_tls’ [-Wmissing-prototypes] Signed-off-by: Tiwei Bie <[email protected]> Signed-off-by: Richard Weinberger <[email protected]>
2024-04-22um: Add missing headersTiwei Bie1-0/+2
This will address below -Wmissing-prototypes warnings: arch/um/kernel/mem.c:202:8: warning: no previous prototype for ‘pgd_alloc’ [-Wmissing-prototypes] arch/um/kernel/mem.c:215:7: warning: no previous prototype for ‘uml_kmalloc’ [-Wmissing-prototypes] arch/um/kernel/process.c:207:6: warning: no previous prototype for ‘arch_cpu_idle’ [-Wmissing-prototypes] arch/um/kernel/process.c:328:15: warning: no previous prototype for ‘arch_align_stack’ [-Wmissing-prototypes] arch/um/kernel/reboot.c:45:6: warning: no previous prototype for ‘machine_restart’ [-Wmissing-prototypes] arch/um/kernel/reboot.c:51:6: warning: no previous prototype for ‘machine_power_off’ [-Wmissing-prototypes] arch/um/kernel/reboot.c:57:6: warning: no previous prototype for ‘machine_halt’ [-Wmissing-prototypes] arch/um/kernel/skas/mmu.c:17:5: warning: no previous prototype for ‘init_new_context’ [-Wmissing-prototypes] arch/um/kernel/skas/mmu.c:60:6: warning: no previous prototype for ‘destroy_context’ [-Wmissing-prototypes] arch/um/kernel/skas/process.c:36:12: warning: no previous prototype for ‘start_uml’ [-Wmissing-prototypes] arch/um/kernel/time.c:807:15: warning: no previous prototype for ‘calibrate_delay_is_known’ [-Wmissing-prototypes] arch/um/kernel/tlb.c:594:6: warning: no previous prototype for ‘force_flush_all’ [-Wmissing-prototypes] arch/x86/um/bugs_32.c:22:6: warning: no previous prototype for ‘arch_check_bugs’ [-Wmissing-prototypes] arch/x86/um/bugs_32.c:44:6: warning: no previous prototype for ‘arch_examine_signal’ [-Wmissing-prototypes] arch/x86/um/bugs_64.c:9:6: warning: no previous prototype for ‘arch_check_bugs’ [-Wmissing-prototypes] arch/x86/um/bugs_64.c:13:6: warning: no previous prototype for ‘arch_examine_signal’ [-Wmissing-prototypes] arch/x86/um/elfcore.c:10:12: warning: no previous prototype for ‘elf_core_extra_phdrs’ [-Wmissing-prototypes] arch/x86/um/elfcore.c:15:5: warning: no previous prototype for ‘elf_core_write_extra_phdrs’ [-Wmissing-prototypes] arch/x86/um/elfcore.c:42:5: warning: no previous prototype for ‘elf_core_write_extra_data’ [-Wmissing-prototypes] arch/x86/um/elfcore.c:63:8: warning: no previous prototype for ‘elf_core_extra_data_size’ [-Wmissing-prototypes] arch/x86/um/fault.c:18:5: warning: no previous prototype for ‘arch_fixup’ [-Wmissing-prototypes] arch/x86/um/os-Linux/mcontext.c:7:6: warning: no previous prototype for ‘get_regs_from_mc’ [-Wmissing-prototypes] arch/x86/um/os-Linux/tls.c:22:6: warning: no previous prototype for ‘check_host_supports_tls’ [-Wmissing-prototypes] Signed-off-by: Tiwei Bie <[email protected]> Signed-off-by: Richard Weinberger <[email protected]>
2024-04-22um: Fix the return type of __switch_toTiwei Bie1-1/+2
Make it match the declaration in asm-generic/switch_to.h. And also include the header to allow the compiler to check it. Signed-off-by: Tiwei Bie <[email protected]> Signed-off-by: Richard Weinberger <[email protected]>
2024-04-22um: Remove unused functionsTiwei Bie1-21/+0
These functions are not used anymore. Removing them will also address below -Wmissing-prototypes warnings: arch/um/kernel/process.c:51:5: warning: no previous prototype for ‘pid_to_processor_id’ [-Wmissing-prototypes] arch/um/kernel/process.c:253:5: warning: no previous prototype for ‘copy_to_user_proc’ [-Wmissing-prototypes] arch/um/kernel/process.c:263:5: warning: no previous prototype for ‘clear_user_proc’ [-Wmissing-prototypes] arch/um/kernel/tlb.c:579:6: warning: no previous prototype for ‘flush_tlb_mm_range’ [-Wmissing-prototypes] Signed-off-by: Tiwei Bie <[email protected]> Signed-off-by: Richard Weinberger <[email protected]>
2024-04-22um: Make local functions and variables staticTiwei Bie1-4/+4
This will also fix the warnings like: warning: no previous prototype for ‘fork_handler’ [-Wmissing-prototypes] 140 | void fork_handler(void) | ^~~~~~~~~~~~ Signed-off-by: Tiwei Bie <[email protected]> Signed-off-by: Richard Weinberger <[email protected]>
2024-01-04um: Drop support for hosts without SYSEMU_SINGLESTEP supportBenjamin Berg1-10/+2
These features have existed since Linux 2.6.14 and can be considered widely available at this point. Also drop the backward compatibility code for PTRACE_SETOPTIONS. Signed-off-by: Benjamin Berg <[email protected]> ---- v2: * Continue to define PTRACE_SYSEMU_SINGLESTEP as glibc only added it in version 2.27. Signed-off-by: Richard Weinberger <[email protected]>
2024-01-04um: Fix naming clash between UML and schedulerAnton Ivanov1-1/+1
__cant_sleep was already used and exported by the scheduler. The name had to be changed to a UML specific one. Signed-off-by: Anton Ivanov <[email protected]> Reviewed-by: Peter Lafreniere <[email protected]> Signed-off-by: Richard Weinberger <[email protected]>
2023-01-13arch/idle: Change arch_cpu_idle() behavior: always exit with IRQs disabledPeter Zijlstra1-1/+0
Current arch_cpu_idle() is called with IRQs disabled, but will return with IRQs enabled. However, the very first thing the generic code does after calling arch_cpu_idle() is raw_local_irq_disable(). This means that architectures that can idle with IRQs disabled end up doing a pointless 'enable-disable' dance. Therefore, push this IRQ disabling into the idle function, meaning that those architectures can avoid the pointless IRQ state flipping. Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Signed-off-by: Ingo Molnar <[email protected]> Tested-by: Tony Lindgren <[email protected]> Tested-by: Ulf Hansson <[email protected]> Reviewed-by: Gautham R. Shenoy <[email protected]> Acked-by: Mark Rutland <[email protected]> [arm64] Acked-by: Rafael J. Wysocki <[email protected]> Acked-by: Guo Ren <[email protected]> Acked-by: Frederic Weisbecker <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2022-12-12Merge tag 'pull-elfcore' of ↵Linus Torvalds1-1/+2
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull elf coredumping updates from Al Viro: "Unification of regset and non-regset sides of ELF coredump handling. Collecting per-thread register values is the only thing that needs to be ifdefed there..." * tag 'pull-elfcore' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: [elf] get rid of get_note_info_size() [elf] unify regset and non-regset cases [elf][non-regset] use elf_core_copy_task_regs() for dumper as well [elf][non-regset] uninline elf_core_copy_task_fpregs() (and lose pt_regs argument) elf_core_copy_task_regs(): task_pt_regs is defined everywhere [elf][regset] simplify thread list handling in fill_note_info() [elf][regset] clean fill_note_info() a bit kill extern of vsyscall32_sysctl kill coredump_params->regs kill signal_pt_regs()
2022-11-24[elf][non-regset] uninline elf_core_copy_task_fpregs() (and lose pt_regs ↵Al Viro1-1/+2
argument) Don't bother with pointless macros - we are not sharing it with aout coredumps anymore. Just convert the underlying functions to the same arguments (nobody uses regs, actually) and call them elf_core_copy_task_fpregs(). And unexport the entire bunch, while we are at it. [added missing includes in arch/{csky,m68k,um}/kernel/process.c to avoid extra warnings about the lack of externs getting added to huge piles for those files. Pointless, but...] Signed-off-by: Al Viro <[email protected]>
2022-11-18treewide: use get_random_u32_below() instead of deprecated functionJason A. Donenfeld1-1/+1
This is a simple mechanical transformation done by: @@ expression E; @@ - prandom_u32_max + get_random_u32_below (E) Reviewed-by: Kees Cook <[email protected]> Reviewed-by: Greg Kroah-Hartman <[email protected]> Acked-by: Darrick J. Wong <[email protected]> # for xfs Reviewed-by: SeongJae Park <[email protected]> # for damon Reviewed-by: Jason Gunthorpe <[email protected]> # for infiniband Reviewed-by: Russell King (Oracle) <[email protected]> # for arm Acked-by: Ulf Hansson <[email protected]> # for mmc Signed-off-by: Jason A. Donenfeld <[email protected]>
2022-10-11treewide: use prandom_u32_max() when possible, part 1Jason A. Donenfeld1-1/+1
Rather than incurring a division or requesting too many random bytes for the given range, use the prandom_u32_max() function, which only takes the minimum required bytes from the RNG and avoids divisions. This was done mechanically with this coccinelle script: @basic@ expression E; type T; identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32"; typedef u64; @@ ( - ((T)get_random_u32() % (E)) + prandom_u32_max(E) | - ((T)get_random_u32() & ((E) - 1)) + prandom_u32_max(E * XXX_MAKE_SURE_E_IS_POW2) | - ((u64)(E) * get_random_u32() >> 32) + prandom_u32_max(E) | - ((T)get_random_u32() & ~PAGE_MASK) + prandom_u32_max(PAGE_SIZE) ) @multi_line@ identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32"; identifier RAND; expression E; @@ - RAND = get_random_u32(); ... when != RAND - RAND %= (E); + RAND = prandom_u32_max(E); // Find a potential literal @literal_mask@ expression LITERAL; type T; identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32"; position p; @@ ((T)get_random_u32()@p & (LITERAL)) // Add one to the literal. @script:python add_one@ literal << literal_mask.LITERAL; RESULT; @@ value = None if literal.startswith('0x'): value = int(literal, 16) elif literal[0] in '123456789': value = int(literal, 10) if value is None: print("I don't know how to handle %s" % (literal)) cocci.include_match(False) elif value == 2**32 - 1 or value == 2**31 - 1 or value == 2**24 - 1 or value == 2**16 - 1 or value == 2**8 - 1: print("Skipping 0x%x for cleanup elsewhere" % (value)) cocci.include_match(False) elif value & (value + 1) != 0: print("Skipping 0x%x because it's not a power of two minus one" % (value)) cocci.include_match(False) elif literal.startswith('0x'): coccinelle.RESULT = cocci.make_expr("0x%x" % (value + 1)) else: coccinelle.RESULT = cocci.make_expr("%d" % (value + 1)) // Replace the literal mask with the calculated result. @plus_one@ expression literal_mask.LITERAL; position literal_mask.p; expression add_one.RESULT; identifier FUNC; @@ - (FUNC()@p & (LITERAL)) + prandom_u32_max(RESULT) @collapse_ret@ type T; identifier VAR; expression E; @@ { - T VAR; - VAR = (E); - return VAR; + return E; } @drop_var@ type T; identifier VAR; @@ { - T VAR; ... when != VAR } Reviewed-by: Greg Kroah-Hartman <[email protected]> Reviewed-by: Kees Cook <[email protected]> Reviewed-by: Yury Norov <[email protected]> Reviewed-by: KP Singh <[email protected]> Reviewed-by: Jan Kara <[email protected]> # for ext4 and sbitmap Reviewed-by: Christoph Böhmwalder <[email protected]> # for drbd Acked-by: Jakub Kicinski <[email protected]> Acked-by: Heiko Carstens <[email protected]> # for s390 Acked-by: Ulf Hansson <[email protected]> # for mmc Acked-by: Darrick J. Wong <[email protected]> # for xfs Signed-off-by: Jason A. Donenfeld <[email protected]>
2022-06-03Merge tag 'ptrace_stop-cleanup-for-v5.19' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull ptrace_stop cleanups from Eric Biederman: "While looking at the ptrace problems with PREEMPT_RT and the problems Peter Zijlstra was encountering with ptrace in his freezer rewrite I identified some cleanups to ptrace_stop that make sense on their own and move make resolving the other problems much simpler. The biggest issue is the habit of the ptrace code to change task->__state from the tracer to suppress TASK_WAKEKILL from waking up the tracee. No other code in the kernel does that and it is straight forward to update signal_wake_up and friends to make that unnecessary. Peter's task freezer sets frozen tasks to a new state TASK_FROZEN and then it stores them by calling "wake_up_state(t, TASK_FROZEN)" relying on the fact that all stopped states except the special stop states can tolerate spurious wake up and recover their state. The state of stopped and traced tasked is changed to be stored in task->jobctl as well as in task->__state. This makes it possible for the freezer to recover tasks in these special states, as well as serving as a general cleanup. With a little more work in that direction I believe TASK_STOPPED can learn to tolerate spurious wake ups and become an ordinary stop state. The TASK_TRACED state has to remain a special state as the registers for a process are only reliably available when the process is stopped in the scheduler. Fundamentally ptrace needs acess to the saved register values of a task. There are bunch of semi-random ptrace related cleanups that were found while looking at these issues. One cleanup that deserves to be called out is from commit 57b6de08b5f6 ("ptrace: Admit ptrace_stop can generate spuriuos SIGTRAPs"). This makes a change that is technically user space visible, in the handling of what happens to a tracee when a tracer dies unexpectedly. According to our testing and our understanding of userspace nothing cares that spurious SIGTRAPs can be generated in that case" * tag 'ptrace_stop-cleanup-for-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: sched,signal,ptrace: Rework TASK_TRACED, TASK_STOPPED state ptrace: Always take siglock in ptrace_resume ptrace: Don't change __state ptrace: Admit ptrace_stop can generate spuriuos SIGTRAPs ptrace: Document that wait_task_inactive can't fail ptrace: Reimplement PTRACE_KILL by always sending SIGKILL signal: Use lockdep_assert_held instead of assert_spin_locked ptrace: Remove arch_ptrace_attach ptrace/xtensa: Replace PT_SINGLESTEP with TIF_SINGLESTEP ptrace/um: Replace PT_DTRACE with TIF_SINGLESTEP signal: Replace __group_send_sig_info with send_signal_locked signal: Rename send_signal send_signal_locked
2022-05-11ptrace/um: Replace PT_DTRACE with TIF_SINGLESTEPEric W. Biederman1-1/+1
User mode linux is the last user of the PT_DTRACE flag. Using the flag to indicate single stepping is a little confusing and worse changing tsk->ptrace without locking could potentionally cause problems. So use a thread info flag with a better name instead of flag in tsk->ptrace. Remove the definition PT_DTRACE as uml is the last user. Cc: [email protected] Acked-by: Johannes Berg <[email protected]> Tested-by: Kees Cook <[email protected]> Reviewed-by: Oleg Nesterov <[email protected]> Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: "Eric W. Biederman" <[email protected]>
2022-05-07fork: Generalize PF_IO_WORKER handlingEric W. Biederman1-6/+4
Add fn and fn_arg members into struct kernel_clone_args and test for them in copy_thread (instead of testing for PF_KTHREAD | PF_IO_WORKER). This allows any task that wants to be a user space task that only runs in kernel mode to use this functionality. The code on x86 is an exception and still retains a PF_KTHREAD test because x86 unlikely everything else handles kthreads slightly differently than user space tasks that start with a function. The functions that created tasks that start with a function have been updated to set ".fn" and ".fn_arg" instead of ".stack" and ".stack_size". These functions are fork_idle(), create_io_thread(), kernel_thread(), and user_mode_thread(). Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: "Eric W. Biederman" <[email protected]>
2022-05-07fork: Pass struct kernel_clone_args into copy_threadEric W. Biederman1-2/+5
With io_uring we have started supporting tasks that are for most purposes user space tasks that exclusively run code in kernel mode. The kernel task that exec's init and tasks that exec user mode helpers are also user mode tasks that just run kernel code until they call kernel execve. Pass kernel_clone_args into copy_thread so these oddball tasks can be supported more cleanly and easily. v2: Fix spelling of kenrel_clone_args on h8300 Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: "Eric W. Biederman" <[email protected]>
2022-03-10resume_user_mode: Move to resume_user_mode.hEric W. Biederman1-2/+2
Move set_notify_resume and tracehook_notify_resume into resume_user_mode.h. While doing that rename tracehook_notify_resume to resume_user_mode_work. Update all of the places that included tracehook.h for these functions to include resume_user_mode.h instead. Update all of the callers of tracehook_notify_resume to call resume_user_mode_work. Reviewed-by: Kees Cook <[email protected]> Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: "Eric W. Biederman" <[email protected]>
2021-12-21um: kill unused cpu()Al Viro1-5/+0
Signed-off-by: Al Viro <[email protected]> Signed-off-by: Richard Weinberger <[email protected]>
2021-12-21um: stop polluting the namespace with registers.h contentsAl Viro1-0/+1
Only one extern in there is needed in processor-generic.h, and it's not needed anywhere else. So move it over there and get rid of the include in processor-generic.h, adding includes of registers.h to the few files that need the declarations in it. Signed-off-by: Al Viro <[email protected]> Signed-off-by: Richard Weinberger <[email protected]>
2021-10-15sched: Add wrapper for get_wchan() to keep task blockedKees Cook1-4/+1
Having a stable wchan means the process must be blocked and for it to stay that way while performing stack unwinding. Suggested-by: Peter Zijlstra <[email protected]> Signed-off-by: Kees Cook <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Acked-by: Geert Uytterhoeven <[email protected]> Acked-by: Russell King (Oracle) <[email protected]> [arm] Tested-by: Mark Rutland <[email protected]> [arm64] Link: https://lkml.kernel.org/r/[email protected]
2021-06-18sched: Introduce task_is_running()Peter Zijlstra1-1/+1
Replace a bunch of 'p->state == TASK_RUNNING' with a new helper: task_is_running(p). Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Acked-by: Davidlohr Bueso <[email protected]> Acked-by: Geert Uytterhoeven <[email protected]> Acked-by: Will Deacon <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2021-02-21arch: setup PF_IO_WORKER threads like PF_KTHREADJens Axboe1-1/+1
PF_IO_WORKER are kernel threads too, but they aren't PF_KTHREAD in the sense that we don't assign ->set_child_tid with our own structure. Just ensure that every arch sets up the PF_IO_WORKER threads like kthreads in the arch implementation of copy_thread(). Signed-off-by: Jens Axboe <[email protected]>
2021-01-26Revert "um: allocate a guard page to helper threads"Johannes Berg1-7/+4
This reverts commit ef4459a6da09 ("um: allocate a guard page to helper threads"), it's broken in multiple ways: 1) the free no longer matches the alloc; and 2) more importantly, the set_memory_ro() causes allocation of page tables for the normal memory that doesn't have any, and that later causes corruption and crashes (usually but not always in vfree()). We could fix the first bug and use vmalloc() to work around the second, but set_memory_ro() actually doesn't do anything either so I'll just revert that as well. Reported-by: Benjamin Berg <[email protected]> Fixes: ef4459a6da09 ("um: allocate a guard page to helper threads") Signed-off-by: Johannes Berg <[email protected]> Signed-off-by: Richard Weinberger <[email protected]>
2020-12-13um: allocate a guard page to helper threadsJohannes Berg1-4/+7
We've been running into stack overflows in helper threads corrupting memory (e.g. because somebody put printf() or os_info() there), so to avoid those causing hard-to-debug issues later on, allocate a guard page for helper thread stacks and mark it read-only. Unfortunately, the crash dump at that point is useless as the stack tracer will try to backtrace the *kernel* thread, not the helper thread, but at least we don't survive to a random issue caused by corruption. Signed-off-by: Johannes Berg <[email protected]> Signed-off-by: Richard Weinberger <[email protected]>
2020-12-13um: Support suspend to RAMJohannes Berg1-1/+1
With all the previous bits in place, we can now also support suspend to RAM, in the sense that everything is suspended, not just most, including userspace, processes like in s2idle. Since um_idle_sleep() now waits forever, we can simply call that to "suspend" the system. As before, you can wake it up using SIGUSR1 since we're just in a pause() call that only needs to return. In order to implement selective resume from certain devices, and not have any arbitrary device interrupt wake up, suspend interrupts by removing SIGIO notification (O_ASYNC) from all the FDs that are not supposed to wake up the system. However, swap out the handler so we don't actually handle the SIGIO as an interrupt. Since we're in pause(), the mere act of receiving SIGIO wakes us up, and then after things have been restored enough, re-set O_ASYNC for all previously suspended FDs, reinstall the proper SIGIO handler, and send SIGIO to self to process anything that might now be pending. Signed-off-by: Johannes Berg <[email protected]> Signed-off-by: Richard Weinberger <[email protected]>
2020-12-13um: Simplify os_idle_sleep() and sleep longerJohannes Berg1-7/+4
There really is no reason to pass the amount of time we should sleep, especially since it's just hard-coded to one second. Additionally, one second isn't really all that long, and as we are expecting to be woken up by a signal, we can sleep longer and avoid doing some work every second, so replace the current clock_nanosleep() with just an empty select() that can _only_ be woken up by a signal. We can also remove the deliver_alarm() since we don't need to do that when we got e.g. SIGIO that woke us up, and if we got SIGALRM the signal handler will actually (have) run, so it's just unnecessary extra work. Similarly, in time-travel mode, just program the wakeup event from idle to be S64_MAX, which is basically the most you could ever simulate to. Of course, you should already have an event in the list that's earlier and will cause a wakeup, normally that's the regular timer interrupt, though in suspend it may (later) also be an RTC event. Since actually getting to this point would be a bug and you can't ever get out again, panic() on it in the time control code. Signed-off-by: Johannes Berg <[email protected]> Acked-By: Anton Ivanov <[email protected]> Signed-off-by: Richard Weinberger <[email protected]>
2020-12-13um: Add support for TIF_NOTIFY_SIGNALJens Axboe1-1/+2
Wire up TIF_NOTIFY_SIGNAL handling for um. Cc: [email protected] Signed-off-by: Jens Axboe <[email protected]> Acked-By: Anton Ivanov <[email protected]> Signed-off-by: Richard Weinberger <[email protected]>
2020-11-24sched/idle: Fix arch_cpu_idle() vs tracingPeter Zijlstra1-1/+1
We call arch_cpu_idle() with RCU disabled, but then use local_irq_{en,dis}able(), which invokes tracing, which relies on RCU. Switch all arch_cpu_idle() implementations to use raw_local_irq_{en,dis}able() and carefully manage the lockdep,rcu,tracing state like we do in entry. (XXX: we really should change arch_cpu_idle() to not return with interrupts enabled) Reported-by: Sven Schnelle <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Reviewed-by: Mark Rutland <[email protected]> Tested-by: Mark Rutland <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-10-17tracehook: clear TIF_NOTIFY_RESUME in tracehook_notify_resume()Jens Axboe1-1/+1
All the callers currently do this, clean it up and move the clearing into tracehook_notify_resume() instead. Reviewed-by: Oleg Nesterov <[email protected]> Reviewed-by: Thomas Gleixner <[email protected]> Signed-off-by: Jens Axboe <[email protected]>
2020-07-04arch: rename copy_thread_tls() back to copy_thread()Christian Brauner1-1/+1
Now that HAVE_COPY_THREAD_TLS has been removed, rename copy_thread_tls() back simply copy_thread(). It's a simpler name, and doesn't imply that only tls is copied here. This finishes an outstanding chunk of internal process creation work since we've added clone3(). Cc: [email protected] Acked-by: Thomas Bogendoerfer <[email protected]>A Acked-by: Stafford Horne <[email protected]> Acked-by: Greentime Hu <[email protected]> Acked-by: Geert Uytterhoeven <[email protected]>A Reviewed-by: Kees Cook <[email protected]> Signed-off-by: Christian Brauner <[email protected]>
2020-06-09mm: don't include asm/pgtable.h if linux/mm.h is already includedMike Rapoport1-1/+0
Patch series "mm: consolidate definitions of page table accessors", v2. The low level page table accessors (pXY_index(), pXY_offset()) are duplicated across all architectures and sometimes more than once. For instance, we have 31 definition of pgd_offset() for 25 supported architectures. Most of these definitions are actually identical and typically it boils down to, e.g. static inline unsigned long pmd_index(unsigned long address) { return (address >> PMD_SHIFT) & (PTRS_PER_PMD - 1); } static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address) { return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(address); } These definitions can be shared among 90% of the arches provided XYZ_SHIFT, PTRS_PER_XYZ and xyz_page_vaddr() are defined. For architectures that really need a custom version there is always possibility to override the generic version with the usual ifdefs magic. These patches introduce include/linux/pgtable.h that replaces include/asm-generic/pgtable.h and add the definitions of the page table accessors to the new header. This patch (of 12): The linux/mm.h header includes <asm/pgtable.h> to allow inlining of the functions involving page table manipulations, e.g. pte_alloc() and pmd_alloc(). So, there is no point to explicitly include <asm/pgtable.h> in the files that include <linux/mm.h>. The include statements in such cases are remove with a simple loop: for f in $(git grep -l "include <linux/mm.h>") ; do sed -i -e '/include <asm\/pgtable.h>/ d' $f done Signed-off-by: Mike Rapoport <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Cc: Arnd Bergmann <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Brian Cain <[email protected]> Cc: Catalin Marinas <[email protected]> Cc: Chris Zankel <[email protected]> Cc: "David S. Miller" <[email protected]> Cc: Geert Uytterhoeven <[email protected]> Cc: Greentime Hu <[email protected]> Cc: Greg Ungerer <[email protected]> Cc: Guan Xuetao <[email protected]> Cc: Guo Ren <[email protected]> Cc: Heiko Carstens <[email protected]> Cc: Helge Deller <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Ley Foon Tan <[email protected]> Cc: Mark Salter <[email protected]> Cc: Matthew Wilcox <[email protected]> Cc: Matt Turner <[email protected]> Cc: Max Filippov <[email protected]> Cc: Michael Ellerman <[email protected]> Cc: Michal Simek <[email protected]> Cc: Mike Rapoport <[email protected]> Cc: Nick Hu <[email protected]> Cc: Paul Walmsley <[email protected]> Cc: Richard Weinberger <[email protected]> Cc: Rich Felker <[email protected]> Cc: Russell King <[email protected]> Cc: Stafford Horne <[email protected]> Cc: Thomas Bogendoerfer <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Tony Luck <[email protected]> Cc: Vincent Chen <[email protected]> Cc: Vineet Gupta <[email protected]> Cc: Will Deacon <[email protected]> Cc: Yoshinori Sato <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Linus Torvalds <[email protected]>
2020-03-29um: time-travel: Rewrite as an event schedulerJohannes Berg1-37/+0
Instead of tracking all the various timer configurations, modify the time-travel mode to have an event scheduler and use a timer event on the scheduler to handle the different timer configurations. This doesn't change the function right now, but it prepares the code for having different kinds of events in the future (i.e. interrupts coming from other devices that are part of co-simulation.) While at it, also move time_travel_sleep() to time.c to reduce the externally visible API surface. Also, we really should mark time-travel as incompatible with SMP, even if UML doesn't support SMP yet. Finally, I noticed a bug while developing this - if we move time forward due to consuming time while reading the clock, we might move across the next event and that would cause us to go backward in time when we then handle that event. Fix that by invoking the whole event machine in this case, but in order to simplify this, make reading the clock only cost something when interrupts are not disabled. Otherwise, we'd have to hook into the interrupt delivery machinery etc. and that's somewhat intrusive. Signed-off-by: Johannes Berg <[email protected]> Signed-off-by: Richard Weinberger <[email protected]>
2020-03-29um: Move timer-internal.h to non-sharedJohannes Berg1-1/+1
This file isn't really shared, it's only used on the kernel side, not on the user side. Remove the include from the user-side and move the file to a better place. While at it, rename it to time-internal.h, it's not really just timers but all kinds of things related to timekeeping. Signed-off-by: Johannes Berg <[email protected]> Signed-off-by: Richard Weinberger <[email protected]>
2020-02-04proc: convert everything to "struct proc_ops"Alexey Dobriyan1-8/+7
The most notable change is DEFINE_SHOW_ATTRIBUTE macro split in seq_file.h. Conversion rule is: llseek => proc_lseek unlocked_ioctl => proc_ioctl xxx => proc_xxx delete ".owner = THIS_MODULE" line [[email protected]: fix drivers/isdn/capi/kcapi_proc.c] [[email protected]: fix kernel/sched/psi.c] Link: http://lkml.kernel.org/r/[email protected] Link: http://lkml.kernel.org/r/20191225172546.GB13378@avx2 Signed-off-by: Alexey Dobriyan <[email protected]> Signed-off-by: Stephen Rothwell <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2020-01-07um: Implement copy_thread_tlsAmanieu d'Antras1-3/+3
This is required for clone3 which passes the TLS value through a struct rather than a register. Signed-off-by: Amanieu d'Antras <[email protected]> Cc: [email protected] Cc: <[email protected]> # 5.3.x Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Christian Brauner <[email protected]>
2019-09-15um: Add SPDX headers to files in arch/um/kernel/Alex Dewar1-1/+1
Convert files to use SPDX header. All files are licensed under the GPLv2. Signed-off-by: Alex Dewar <[email protected]> Signed-off-by: Richard Weinberger <[email protected]>
2019-09-15um: time-travel: Restrict time update in IRQ handlerJohannes Berg1-3/+6
We currently do the time updates in the timer handler, even if we just call the timer handler ourselves. In basic mode we must in fact do it there since otherwise the OS timer signal won't move time forward, but in inf-cpu mode we don't need to, and it's harder to understand. Restrict the update there to basic mode, adding a comment, and do it before calling the timer_handler() in inf-cpu mode. Signed-off-by: Johannes Berg <[email protected]> Signed-off-by: Richard Weinberger <[email protected]>
2019-09-15um: time-travel: Fix periodic timersJohannes Berg1-1/+6
Periodic timers are broken, because the also only fire once. As it happens, Linux doesn't care because it only sets the timer to periodic very briefly during boot, and then switches it only between one-shot and off later. Nevertheless, fix the logic (we shouldn't even be looking at time_travel_timer_expiry unless the timer is enabled) and change the code to fire the timer periodically in periodic mode, in case it ever gets used in the future. Signed-off-by: Johannes Berg <[email protected]> Signed-off-by: Richard Weinberger <[email protected]>
2019-08-23um: fix time travel modeJohannes Berg1-1/+1
Unfortunately, my build fix for when time travel mode isn't enabled broke time travel mode, because I forgot that we need to use the timer time after the timer has been marked disabled, and thus need to leave the time stored instead of zeroing it. Fix that by splitting the inline into two, so we can call only the _mode() one in the relevant code path. Fixes: b482e48d29f1 ("um: fix build without CONFIG_UML_TIME_TRAVEL_SUPPORT") Signed-off-by: Johannes Berg <[email protected]> Signed-off-by: Richard Weinberger <[email protected]>
2019-07-04um: fix build without CONFIG_UML_TIME_TRAVEL_SUPPORTJohannes Berg1-1/+1
When CONFIG_UML_TIME_TRAVEL_SUPPORT isn't set, the build was broken. Fix this. Fixes: 065038706f77 ("um: Support time travel mode") Signed-off-by: Johannes Berg <[email protected]> Signed-off-by: Richard Weinberger <[email protected]>
2019-07-02um: Support time travel modeJohannes Berg1-1/+41
Sometimes it can be useful to run with "time travel" inside the UML instance, for example for testing. For example, some tests for the wireless subsystem and userspace are based on hwsim, a virtual wireless adapter. Some tests can take a long time to run because they e.g. wait for 120 seconds to elapse for some regulatory checks. This obviously goes faster if it need not actually wait that long, but time inside the test environment just "bumps up" when there's nothing to do. Add CONFIG_UML_TIME_TRAVEL_SUPPORT to enable code to support such modes at runtime, selected on the command line: * just "time-travel", in which time inside the UML instance can move faster than real time, if there's nothing to do * "time-travel=inf-cpu" in which time also moves slower and any CPU processing takes no time at all, which allows to implement consistent behaviour regardless of host CPU load (or speed) or debug overhead. An additional "time-travel-start=<seconds>" parameter is also supported in this case to start the wall clock at this time (in unix epoch). With this enabled, the test mentioned above goes from a runtime of about 140 seconds (with startup overhead and all) to being CPU bound and finishing in 15 seconds (on my slow laptop). Signed-off-by: Johannes Berg <[email protected]> Signed-off-by: Richard Weinberger <[email protected]>
2017-09-13um: Fix FP register size for XSTATE/XSAVEThomas Meyer1-2/+2
Hard code max size. Taken from https://sourceware.org/git/?p=binutils-gdb.git;a=blob;f=gdb/common/x86-xstate.h Signed-off-by: Thomas Meyer <[email protected]> Signed-off-by: Richard Weinberger <[email protected]>
2017-05-15kill strlen_user()Al Viro1-5/+0
no callers, no consistent semantics, no sane way to use it... Signed-off-by: Al Viro <[email protected]>
2017-03-02sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar1-0/+1
<linux/sched/task_stack.h> We are going to split <linux/sched/task_stack.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/task_stack.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <[email protected]> Cc: Mike Galbraith <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Signed-off-by: Ingo Molnar <[email protected]>
2017-03-02sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar1-0/+1
<linux/sched/task.h> We are going to split <linux/sched/task.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/task.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <[email protected]> Cc: Mike Galbraith <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Signed-off-by: Ingo Molnar <[email protected]>