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2022-01-27um: registers: Rename function names to avoid conflicts and build problemsRandy Dunlap3-5/+5
[ Upstream commit 077b7320942b64b0da182aefd83c374462a65535 ] The function names init_registers() and restore_registers() are used in several net/ethernet/ and gpu/drm/ drivers for other purposes (not calls to UML functions), so rename them. This fixes multiple build errors. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: linux-um@lists.infradead.org Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-12-08hugetlbfs: flush TLBs correctly after huge_pmd_unshareNadav Amit1-0/+12
commit a4a118f2eead1d6c49e00765de89878288d4b890 upstream. When __unmap_hugepage_range() calls to huge_pmd_unshare() succeed, a TLB flush is missing. This TLB flush must be performed before releasing the i_mmap_rwsem, in order to prevent an unshared PMDs page from being released and reused before the TLB flush took place. Arguably, a comprehensive solution would use mmu_gather interface to batch the TLB flushes and the PMDs page release, however it is not an easy solution: (1) try_to_unmap_one() and try_to_migrate_one() also call huge_pmd_unshare() and they cannot use the mmu_gather interface; and (2) deferring the release of the page reference for the PMDs page until after i_mmap_rwsem is dropeed can confuse huge_pmd_unshare() into thinking PMDs are shared when they are not. Fix __unmap_hugepage_range() by adding the missing TLB flush, and forcing a flush when unshare is successful. Fixes: 24669e58477e ("hugetlb: use mmu_gather instead of a temporary linked list for accumulating pages)" # 3.6 Signed-off-by: Nadav Amit <namit@vmware.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-20um: fix error return code in winch_tramp()Zhen Lei1-1/+2
[ Upstream commit ccf1236ecac476d9d2704866d9a476c86e387971 ] Fix to return a negative error code from the error handling case instead of 0, as done elsewhere in this function. Fixes: 89df6bfc0405 ("uml: DEBUG_SHIRQ fixes") Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Acked-By: anton.ivanov@cambridgegreys.com Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-20um: fix error return code in slip_open()Zhen Lei1-1/+2
[ Upstream commit b77e81fbe5f5fb4ad9a61ec80f6d1e30b6da093a ] Fix to return a negative error code from the error handling case instead of 0, as done elsewhere in this function. Fixes: a3c77c67a443 ("[PATCH] uml: slirp and slip driver cleanups and fixes") Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Acked-By: anton.ivanov@cambridgegreys.com Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-05-22um: Mark all kernel symbols as localJohannes Berg2-0/+12
[ Upstream commit d5027ca63e0e778b641cf23e3f5c6d6212cf412b ] Ritesh reported a bug [1] against UML, noting that it crashed on startup. The backtrace shows the following (heavily redacted): (gdb) bt ... #26 0x0000000060015b5d in sem_init () at ipc/sem.c:268 #27 0x00007f89906d92f7 in ?? () from /lib/x86_64-linux-gnu/libcom_err.so.2 #28 0x00007f8990ab8fb2 in call_init (...) at dl-init.c:72 ... #40 0x00007f89909bf3a6 in nss_load_library (...) at nsswitch.c:359 ... #44 0x00007f8990895e35 in _nss_compat_getgrnam_r (...) at nss_compat/compat-grp.c:486 #45 0x00007f8990968b85 in __getgrnam_r [...] #46 0x00007f89909d6b77 in grantpt [...] #47 0x00007f8990a9394e in __GI_openpty [...] #48 0x00000000604a1f65 in openpty_cb (...) at arch/um/os-Linux/sigio.c:407 #49 0x00000000604a58d0 in start_idle_thread (...) at arch/um/os-Linux/skas/process.c:598 #50 0x0000000060004a3d in start_uml () at arch/um/kernel/skas/process.c:45 #51 0x00000000600047b2 in linux_main (...) at arch/um/kernel/um_arch.c:334 #52 0x000000006000574f in main (...) at arch/um/os-Linux/main.c:144 indicating that the UML function openpty_cb() calls openpty(), which internally calls __getgrnam_r(), which causes the nsswitch machinery to get started. This loads, through lots of indirection that I snipped, the libcom_err.so.2 library, which (in an unknown function, "??") calls sem_init(). Now, of course it wants to get libpthread's sem_init(), since it's linked against libpthread. However, the dynamic linker looks up that symbol against the binary first, and gets the kernel's sem_init(). Hajime Tazaki noted that "objcopy -L" can localize a symbol, so the dynamic linker wouldn't do the lookup this way. I tried, but for some reason that didn't seem to work. Doing the same thing in the linker script instead does seem to work, though I cannot entirely explain - it *also* works if I just add "VERSION { { global: *; }; }" instead, indicating that something else is happening that I don't really understand. It may be that explicitly doing that marks them with some kind of empty version, and that's different from the default. Explicitly marking them with a version breaks kallsyms, so that doesn't seem to be possible. Marking all the symbols as local seems correct, and does seem to address the issue, so do that. Also do it for static link, nsswitch libraries could still be loaded there. [1] https://bugs.debian.org/983379 Reported-by: Ritesh Raj Sarraf <rrs@debian.org> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com> Tested-By: Ritesh Raj Sarraf <rrs@debian.org> Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-12-29um: chan_xterm: Fix fd leakAnton Ivanov1-0/+5
[ Upstream commit 9431f7c199ab0d02da1482d62255e0b4621cb1b5 ] xterm serial channel was leaking a fd used in setting up the port helper This bug is prehistoric - it predates switching to git. The "fixes" header here is really just to mark all the versions we would like this to apply to which is "Anything from the Cretaceous period onwards". No dinosaurs were harmed in fixing this bug. Fixes: b40997b872cd ("um: drivers/xterm.c: fix a file descriptor leak") Signed-off-by: Anton Ivanov <anton.ivanov@cambridgegreys.com> Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-11-10um: change sigio_spinlock to a mutexJohannes Berg1-3/+3
[ Upstream commit f2d05059e15af3f70502074f4e3a504530af504a ] Lockdep complains at boot: ============================= [ BUG: Invalid wait context ] 5.7.0-05093-g46d91ecd597b #98 Not tainted ----------------------------- swapper/1 is trying to lock: 0000000060931b98 (&desc[i].request_mutex){+.+.}-{3:3}, at: __setup_irq+0x11d/0x623 other info that might help us debug this: context-{4:4} 1 lock held by swapper/1: #0: 000000006074fed8 (sigio_spinlock){+.+.}-{2:2}, at: sigio_lock+0x1a/0x1c stack backtrace: CPU: 0 PID: 1 Comm: swapper Not tainted 5.7.0-05093-g46d91ecd597b #98 Stack: 7fa4fab0 6028dfd1 0000002a 6008bea5 7fa50700 7fa50040 7fa4fac0 6028e016 7fa4fb50 6007f6da 60959c18 00000000 Call Trace: [<60023a0e>] show_stack+0x13b/0x155 [<6028e016>] dump_stack+0x2a/0x2c [<6007f6da>] __lock_acquire+0x515/0x15f2 [<6007eb50>] lock_acquire+0x245/0x273 [<6050d9f1>] __mutex_lock+0xbd/0x325 [<6050dc76>] mutex_lock_nested+0x1d/0x1f [<6008e27e>] __setup_irq+0x11d/0x623 [<6008e8ed>] request_threaded_irq+0x169/0x1a6 [<60021eb0>] um_request_irq+0x1ee/0x24b [<600234ee>] write_sigio_irq+0x3b/0x76 [<600383ca>] sigio_broken+0x146/0x2e4 [<60020bd8>] do_one_initcall+0xde/0x281 Because we hold sigio_spinlock and then get into requesting an interrupt with a mutex. Change the spinlock to a mutex to avoid that. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-05um: Make GCOV depend on !KCOVRichard Weinberger1-0/+1
[ Upstream commit 550ed0e2036663b35cec12374b835444f9c60454 ] Both do more or less the same thing and are mutually exclusive. If both are enabled the build will fail. Sooner or later we can kill UML's GCOV. Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-28um: Make line/tty semantics use true write IRQAnton Ivanov1-1/+1
[ Upstream commit 917e2fd2c53eb3c4162f5397555cbd394390d4bc ] This fixes a long standing bug where large amounts of output could freeze the tty (most commonly seen on stdio console). While the bug has always been there it became more pronounced after moving to the new interrupt controller. The line semantics are now changed to have true IRQ write semantics which should further improve the tty/line subsystem stability and performance Signed-off-by: Anton Ivanov <anton.ivanov@cambridgegreys.com> Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-08-04um: Silence lockdep complaint about mmap_semJohannes Berg1-1/+1
[ Upstream commit 80bf6ceaf9310b3f61934c69b382d4912deee049 ] When we get into activate_mm(), lockdep complains that we're doing something strange: WARNING: possible circular locking dependency detected 5.1.0-10252-gb00152307319-dirty #121 Not tainted ------------------------------------------------------ inside.sh/366 is trying to acquire lock: (____ptrval____) (&(&p->alloc_lock)->rlock){+.+.}, at: flush_old_exec+0x703/0x8d7 but task is already holding lock: (____ptrval____) (&mm->mmap_sem){++++}, at: flush_old_exec+0x6c5/0x8d7 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&mm->mmap_sem){++++}: [...] __lock_acquire+0x12ab/0x139f lock_acquire+0x155/0x18e down_write+0x3f/0x98 flush_old_exec+0x748/0x8d7 load_elf_binary+0x2ca/0xddb [...] -> #0 (&(&p->alloc_lock)->rlock){+.+.}: [...] __lock_acquire+0x12ab/0x139f lock_acquire+0x155/0x18e _raw_spin_lock+0x30/0x83 flush_old_exec+0x703/0x8d7 load_elf_binary+0x2ca/0xddb [...] other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&mm->mmap_sem); lock(&(&p->alloc_lock)->rlock); lock(&mm->mmap_sem); lock(&(&p->alloc_lock)->rlock); *** DEADLOCK *** 2 locks held by inside.sh/366: #0: (____ptrval____) (&sig->cred_guard_mutex){+.+.}, at: __do_execve_file+0x12d/0x869 #1: (____ptrval____) (&mm->mmap_sem){++++}, at: flush_old_exec+0x6c5/0x8d7 stack backtrace: CPU: 0 PID: 366 Comm: inside.sh Not tainted 5.1.0-10252-gb00152307319-dirty #121 Stack: [...] Call Trace: [<600420de>] show_stack+0x13b/0x155 [<6048906b>] dump_stack+0x2a/0x2c [<6009ae64>] print_circular_bug+0x332/0x343 [<6009c5c6>] check_prev_add+0x669/0xdad [<600a06b4>] __lock_acquire+0x12ab/0x139f [<6009f3d0>] lock_acquire+0x155/0x18e [<604a07e0>] _raw_spin_lock+0x30/0x83 [<60151e6a>] flush_old_exec+0x703/0x8d7 [<601a8eb8>] load_elf_binary+0x2ca/0xddb [...] I think it's because in exec_mmap() we have down_read(&old_mm->mmap_sem); ... task_lock(tsk); ... activate_mm(active_mm, mm); (which does down_write(&mm->mmap_sem)) I'm not really sure why lockdep throws in the whole knowledge about the task lock, but it seems that old_mm and mm shouldn't ever be the same (and it doesn't deadlock) so tell lockdep that they're different. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-07-10um: Compile with modern headersJason A. Donenfeld2-0/+3
commit 530ba6c7cb3c22435a4d26de47037bb6f86a5329 upstream. Recent libcs have gotten a bit more strict, so we actually need to include the right headers and use the right types. This enables UML to compile again. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Cc: stable@vger.kernel.org Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Alessio Balsini <balsini@android.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-20um: Avoid marking pages with "changed protection"Anton Ivanov1-1/+8
[ Upstream commit 8892d8545f2d0342b9c550defbfb165db237044b ] Changing protection is a very high cost operation in UML because in addition to an extra syscall it also interrupts mmap merge sequences generated by the tlb. While the condition is not particularly common it is worth avoiding. Signed-off-by: Anton Ivanov <anton.ivanov@cambridgegreys.com> Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Sasha Levin <sashal@kernel.org>
2018-11-27um: Give start_idle_thread() a return codeRichard Weinberger1-0/+5
[ Upstream commit 7ff1e34bbdc15acab823b1ee4240e94623d50ee8 ] Fixes: arch/um/os-Linux/skas/process.c:613:1: warning: control reaches end of non-void function [-Wreturn-type] longjmp() never returns but gcc still warns that the end of the function can be reached. Add a return code and debug aid to detect this impossible case. Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Sasha Levin <sashal@kernel.org>
2018-11-10um: Avoid longjmp/setjmp symbol clashes with libpthread.aFlorian Fainelli1-0/+4
[ Upstream commit f44f1e7da7c8e3f4575d5d61c4df978496903fcc ] Building a statically linked UML kernel on a Centos 6.9 host resulted in the following linking failure (GCC 4.4, glibc-2.12): /usr/lib/gcc/x86_64-redhat-linux/4.4.7/../../../../lib64/libpthread.a(libpthread.o): In function `siglongjmp': (.text+0x8490): multiple definition of `longjmp' arch/x86/um/built-in.o:/local/users/fainelli/openwrt/trunk/build_dir/target-x86_64_musl/linux-uml/linux-4.4.69/arch/x86/um/setjmp_64.S:44: first defined here /usr/lib/gcc/x86_64-redhat-linux/4.4.7/../../../../lib64/libpthread.a(libpthread.o): In function `sem_open': (.text+0x77cd): warning: the use of `mktemp' is dangerous, better use `mkstemp' collect2: ld returned 1 exit status make[4]: *** [vmlinux] Error 1 Adopt a solution similar to the one done for vmap where we define longjmp/setjmp to be kernel_longjmp/setjmp. In the process, make sure we do rename the functions in arch/x86/um/setjmp_*.S accordingly. Fixes: a7df4716d195 ("um: link with -lpthread") Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Sasha Levin <sashal@kernel.org>
2018-04-24um: Use POSIX ucontext_t instead of struct ucontextKrzysztof Mazur1-1/+1
commit 4d1a535b8ec5e74b42dfd9dc809142653b2597f6 upstream. glibc 2.26 removed the 'struct ucontext' to "improve" POSIX compliance and break programs, including User Mode Linux. Fix User Mode Linux by using POSIX ucontext_t. This fixes: arch/um/os-Linux/signal.c: In function 'hard_handler': arch/um/os-Linux/signal.c:163:22: error: dereferencing pointer to incomplete type 'struct ucontext' mcontext_t *mc = &uc->uc_mcontext; arch/x86/um/stub_segv.c: In function 'stub_segv_handler': arch/x86/um/stub_segv.c:16:13: error: dereferencing pointer to incomplete type 'struct ucontext' &uc->uc_mcontext); Cc: stable@vger.kernel.org Signed-off-by: Krzysztof Mazur <krzysiek@podlesie.net> Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-31um: link vmlinux with -no-pieThomas Meyer1-1/+1
commit 883354afbc109c57f925ccc19840055193da0cc0 upstream. Debian's gcc defaults to pie. The global Makefile already defines the -fno-pie option. Link UML dynamic kernel image also with -no-pie to fix the build. Signed-off-by: Thomas Meyer <thomas@m3y3r.de> Signed-off-by: Richard Weinberger <richard@nod.at> Cc: Bernie Innocenti <codewiz@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-07um: Don't discard .text.exit sectionAndrey Ryabinin1-1/+1
commit dad2232844073295c64e9cc2d734a0ade043e0f6 upstream. Commit e41f501d3912 ("vmlinux.lds: account for destructor sections") added '.text.exit' to EXIT_TEXT which is discarded at link time by default. This breaks compilation of UML: `.text.exit' referenced in section `.fini_array' of /usr/lib/gcc/x86_64-linux-gnu/6/../../../x86_64-linux-gnu/libc.a(sdlerror.o): defined in discarded section `.text.exit' of /usr/lib/gcc/x86_64-linux-gnu/6/../../../x86_64-linux-gnu/libc.a(sdlerror.o) Apparently UML doesn't want to discard exit text, so let's place all EXIT_TEXT sections in .exit.text. Fixes: e41f501d3912 ("vmlinux.lds: account for destructor sections") Reported-by: Stefan Traby <stefan@hello-penguin.com> Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Acked-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-12fs/coredump: prevent fsuid=0 dumps into user-controlled directoriesJann Horn1-1/+1
commit 378c6520e7d29280f400ef2ceaf155c86f05a71a upstream. This commit fixes the following security hole affecting systems where all of the following conditions are fulfilled: - The fs.suid_dumpable sysctl is set to 2. - The kernel.core_pattern sysctl's value starts with "/". (Systems where kernel.core_pattern starts with "|/" are not affected.) - Unprivileged user namespace creation is permitted. (This is true on Linux >=3.8, but some distributions disallow it by default using a distro patch.) Under these conditions, if a program executes under secure exec rules, causing it to run with the SUID_DUMP_ROOT flag, then unshares its user namespace, changes its root directory and crashes, the coredump will be written using fsuid=0 and a path derived from kernel.core_pattern - but this path is interpreted relative to the root directory of the process, allowing the attacker to control where a coredump will be written with root privileges. To fix the security issue, always interpret core_pattern for dumps that are written under SUID_DUMP_ROOT relative to the root directory of init. Signed-off-by: Jann Horn <jann@thejh.net> Acked-by: Kees Cook <keescook@chromium.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-04uml: flush stdout before forkingVegard Nossum1-0/+2
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 <vegard.nossum@oracle.com> Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-09um: fix returns without va_endGeyslan G. Bem1-4/+6
When using va_list ensure that va_start will be followed by va_end. Signed-off-by: Geyslan G. Bem <geyslan@gmail.com> Signed-off-by: Richard Weinberger <richard@nod.at>
2015-12-09arch: um: fix error when linking vmlinux.Lorenzo Colitti1-1/+1
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 <lorenzo@google.com> Signed-off-by: Richard Weinberger <richard@nod.at>
2015-12-09um: Fix get_signal() usageRichard Weinberger1-1/+1
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: <stable@vger.kernel.org> # 3.10- Fixes: a610d6e672d ("pull clearing RESTORE_SIGMASK into block_sigmask()") Signed-off-by: Richard Weinberger <richard@nod.at>
2015-11-07um: Switch clocksource to hrtimersAnton Ivanov14-224/+255
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 <thomas@m3y3r.de> Signed-off-by: Anton Ivanov <aivanov@brocade.com> [rw: massaged commit message] Signed-off-by: Richard Weinberger <richard@nod.at>
2015-11-07um: net: replace GFP_KERNEL with GFP_ATOMIC when spinlock is heldSaurabh Sengar1-8/+9
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 <saurabh.truth@gmail.com> Signed-off-by: Richard Weinberger <richard@nod.at>
2015-11-07um: Report host OOM more nicelyRichard Weinberger1-1/+15
If UML runs on the host side out of memory, report this condition more nicely. Signed-off-by: Richard Weinberger <richard@nod.at>
2015-11-07um: Get rid of open coded NR_SYSCALLSRichard Weinberger1-5/+3
We can use __NR_syscall_max. Signed-off-by: Richard Weinberger <richard@nod.at>
2015-11-07um: Store syscall number after syscall_trace_enter()Richard Weinberger3-13/+11
To support changing syscall numbers we have to store it after syscall_trace_enter(). Signed-off-by: Richard Weinberger <richard@nod.at>
2015-11-07um: Define PTRACE_OLDSETOPTIONSRichard Weinberger1-0/+2
...such that processes within UML can do a ptrace(PTRACE_OLDSETOPTIONS, ...) Signed-off-by: Richard Weinberger <richard@nod.at>
2015-10-19um: Fix kernel mode fault conditionRichard Weinberger1-1/+1
We have to exclude memory locations <= PAGE_SIZE from the condition and let the kernel mode fault path catch it. Otherwise a kernel NULL pointer exception will be reported as a kernel user space access. Fixes: d2313084e2c (um: Catch unprotected user memory access) Signed-off-by: Richard Weinberger <richard@nod.at>
2015-10-19um: Fix waitpid() usage in helper codeRichard Weinberger1-3/+3
If UML is executing a helper program it is using waitpid() with the __WCLONE flag to wait for the program as the helper is executed from a clone()'ed thread. While using __WCLONE is perfectly fine for clone()'ed childs it won't detect terminated childs if the helper has issued an execve(). We have to use __WALL to wait for both clone()'ed and regular childs to detect the termination before and after an execve(). Reported-and-tested-by: Thomas Meyer <thomas@m3y3r.de> Signed-off-by: Richard Weinberger <richard@nod.at>
2015-10-19um: Fix out-of-tree buildRichard Weinberger1-2/+2
Commit 30b11ee9a (um: Remove copy&paste code from init.h) uncovered an issue wrt. out-of-tree builds. For out-of-tree builds, we must not rely on relative paths. Before 30b11ee9a it worked by chance as no host code included generated header files. Acked-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Richard Weinberger <richard@nod.at>
2015-10-04Merge branch 'strscpy' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile Pull strscpy string copy function implementation from Chris Metcalf. Chris sent this during the merge window, but I waffled back and forth on the pull request, which is why it's going in only now. The new "strscpy()" function is definitely easier to use and more secure than either strncpy() or strlcpy(), both of which are horrible nasty interfaces that have serious and irredeemable problems. strncpy() has a useless return value, and doesn't NUL-terminate an overlong result. To make matters worse, it pads a short result with zeroes, which is a performance disaster if you have big buffers. strlcpy(), by contrast, is a mis-designed "fix" for strlcpy(), lacking the insane NUL padding, but having a differently broken return value which returns the original length of the source string. Which means that it will read characters past the count from the source buffer, and you have to trust the source to be properly terminated. It also makes error handling fragile, since the test for overflow is unnecessarily subtle. strscpy() avoids both these problems, guaranteeing the NUL termination (but not excessive padding) if the destination size wasn't zero, and making the overflow condition very obvious by returning -E2BIG. It also doesn't read past the size of the source, and can thus be used for untrusted source data too. So why did I waffle about this for so long? Every time we introduce a new-and-improved interface, people start doing these interminable series of trivial conversion patches. And every time that happens, somebody does some silly mistake, and the conversion patch to the improved interface actually makes things worse. Because the patch is mindnumbing and trivial, nobody has the attention span to look at it carefully, and it's usually done over large swatches of source code which means that not every conversion gets tested. So I'm pulling the strscpy() support because it *is* a better interface. But I will refuse to pull mindless conversion patches. Use this in places where it makes sense, but don't do trivial patches to fix things that aren't actually known to be broken. * 'strscpy' of git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile: tile: use global strscpy() rather than private copy string: provide strscpy() Make asm/word-at-a-time.h available on all architectures
2015-09-02Merge branch 'timers-core-for-linus' of ↵Linus Torvalds1-24/+20
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer updates from Thomas Gleixner: "Rather large, but nothing exiting: - new range check for settimeofday() to prevent that boot time becomes negative. - fix for file time rounding - a few simplifications of the hrtimer code - fix for the proc/timerlist code so the output of clock realtime timers is accurate - more y2038 work - tree wide conversion of clockevent drivers to the new callbacks" * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (88 commits) hrtimer: Handle failure of tick_init_highres() gracefully hrtimer: Unconfuse switch_hrtimer_base() a bit hrtimer: Simplify get_target_base() by returning current base hrtimer: Drop return code of hrtimer_switch_to_hres() time: Introduce timespec64_to_jiffies()/jiffies_to_timespec64() time: Introduce current_kernel_time64() time: Introduce struct itimerspec64 time: Add the common weak version of update_persistent_clock() time: Always make sure wall_to_monotonic isn't positive time: Fix nanosecond file time rounding in timespec_trunc() timer_list: Add the base offset so remaining nsecs are accurate for non monotonic timers cris/time: Migrate to new 'set-state' interface kernel: broadcast-hrtimer: Migrate to new 'set-state' interface xtensa/time: Migrate to new 'set-state' interface unicore/time: Migrate to new 'set-state' interface um/time: Migrate to new 'set-state' interface sparc/time: Migrate to new 'set-state' interface sh/localtimer: Migrate to new 'set-state' interface score/time: Migrate to new 'set-state' interface s390/time: Migrate to new 'set-state' interface ...
2015-08-10um/time: Migrate to new 'set-state' interfaceViresh Kumar1-24/+20
Migrate um driver to the new 'set-state' interface provided by clockevents core, the earlier 'set-mode' interface is marked obsolete now. This also enables us to implement callbacks for new states of clockevent devices, for example: ONESHOT_STOPPED. Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Cc: user-mode-linux-devel@lists.sourceforge.net Cc: user-mode-linux-user@lists.sourceforge.net Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2015-07-31Merge branch 'x86/urgent' into x86/asm, before applying dependent patchesIngo Molnar2-15/+1
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-07-18mm: clean up per architecture MM hook header filesLaurent Dufour2-15/+1
Commit 2ae416b142b6 ("mm: new mm hook framework") introduced an empty header file (mm-arch-hooks.h) for every architecture, even those which doesn't need to define mm hooks. As suggested by Geert Uytterhoeven, this could be cleaned through the use of a generic header file included via each per architecture asm/include/Kbuild file. The PowerPC architecture is not impacted here since this architecture has to defined the arch_remap MM hook. Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com> Suggested-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Vineet Gupta <vgupta@synopsys.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-07-08Make asm/word-at-a-time.h available on all architecturesChris Metcalf1-0/+1
Added the x86 implementation of word-at-a-time to the generic version, which previously only supported big-endian. Omitted the x86-specific load_unaligned_zeropad(), which in any case is also not present for the existing BE-only implementation of a word-at-a-time, and is only used under CONFIG_DCACHE_WORD_ACCESS. Added as a "generic-y" to the Kbuilds of all architectures that didn't previously have it. Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com>
2015-07-07um: Fix do_signal() prototypeIngo Molnar5-12/+9
Once x86 exports its do_signal(), the prototypes will clash. Fix the clash and also improve the code a bit: remove the unnecessary kern_do_signal() indirection. This allows interrupt_end() to share the 'regs' parameter calculation. Also remove the unused return code to match x86. Minimally build and boot tested. Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Denys Vlasenko <vda.linux@googlemail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Richard Weinberger <richard.weinberger@gmail.com> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: paulmck@linux.vnet.ibm.com Link: http://lkml.kernel.org/r/67c57eac09a589bac3c6c5ff22f9623ec55a184a.1435952415.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-07-01Merge tag 'modules-next-for-linus' of ↵Linus Torvalds1-10/+10
git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux Pull module updates from Rusty Russell: "Main excitement here is Peter Zijlstra's lockless rbtree optimization to speed module address lookup. He found some abusers of the module lock doing that too. A little bit of parameter work here too; including Dan Streetman's breaking up the big param mutex so writing a parameter can load another module (yeah, really). Unfortunately that broke the usual suspects, !CONFIG_MODULES and !CONFIG_SYSFS, so those fixes were appended too" * tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: (26 commits) modules: only use mod->param_lock if CONFIG_MODULES param: fix module param locks when !CONFIG_SYSFS. rcu: merge fix for Convert ACCESS_ONCE() to READ_ONCE() and WRITE_ONCE() module: add per-module param_lock module: make perm const params: suppress unused variable error, warn once just in case code changes. modules: clarify CONFIG_MODULE_COMPRESS help, suggest 'N'. kernel/module.c: avoid ifdefs for sig_enforce declaration kernel/workqueue.c: remove ifdefs over wq_power_efficient kernel/params.c: export param_ops_bool_enable_only kernel/params.c: generalize bool_enable_only kernel/module.c: use generic module param operaters for sig_enforce kernel/params: constify struct kernel_param_ops uses sysfs: tightened sysfs permission checks module: Rework module_addr_{min,max} module: Use __module_address() for module_address_lookup() module: Make the mod_tree stuff conditional on PERF_EVENTS || TRACING module: Optimize __module_address() using a latched RB-tree rbtree: Implement generic latch_tree seqlock: Introduce raw_read_seqcount_latch() ...
2015-06-28Merge branch 'for-linus-4.2-rc1' of ↵Linus Torvalds28-282/+130
git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml Pull UML updates from Richard Weinberger: - remove hppfs ("HonePot ProcFS") - initial support for musl libc - uaccess cleanup - random cleanups and bug fixes all over the place * 'for-linus-4.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml: (21 commits) um: Don't pollute kernel namespace with uapi um: Include sys/types.h for makedev(), major(), minor() um: Do not use stdin and stdout identifiers for struct members um: Do not use __ptr_t type for stack_t's .ss pointer um: Fix mconsole dependency um: Handle tracehook_report_syscall_entry() result um: Remove copy&paste code from init.h um: Stop abusing __KERNEL__ um: Catch unprotected user memory access um: Fix warning in setup_signal_stack_si() um: Rework uaccess code um: Add uaccess.h to ldt.c um: Add uaccess.h to syscalls_64.c um: Add asm/elf.h to vma.c um: Cleanup mem_32/64.c headers um: Remove hppfs um: Move syscall() declaration into os.h um: kernel: ksyms: Export symbol syscall() for fixing modpost issue um/os-Linux: Use char[] for syscall_stub declarations um: Use char[] for linker script address declarations ...
2015-06-27Merge tag 'char-misc-4.2-rc1' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc Pull char/misc driver updates from Greg KH: "Here's the big char/misc driver pull request for 4.2-rc1. Lots of mei, extcon, coresight, uio, mic, and other driver updates in here. Full details in the shortlog. All of these have been in linux-next for some time with no reported problems" * tag 'char-misc-4.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (176 commits) mei: me: wait for power gating exit confirmation mei: reset flow control on the last client disconnection MAINTAINERS: mei: add mei_cl_bus.h to maintained file list misc: sram: sort and clean up included headers misc: sram: move reserved block logic out of probe function misc: sram: add private struct device and virt_base members misc: sram: report correct SRAM pool size misc: sram: bump error message level on unclean driver unbinding misc: sram: fix device node reference leak on error misc: sram: fix enabled clock leak on error path misc: mic: Fix reported static checker warning misc: mic: Fix randconfig build error by including errno.h uio: pruss: Drop depends on ARCH_DAVINCI_DA850 from config uio: pruss: Add CONFIG_HAS_IOMEM dependence uio: pruss: Include <linux/sizes.h> extcon: Redefine the unique id of supported external connectors without 'enum extcon' type char:xilinx_hwicap:buffer_icap - change 1/0 to true/false for bool type variable in function buffer_icap_set_configuration(). Drivers: hv: vmbus: Allocate ring buffer memory in NUMA aware fashion parport: check exclusive access before register w1: use correct lock on error in w1_seq_show() ...
2015-06-26Merge branch 'for-4.2/sg' of git://git.kernel.dk/linux-blockLinus Torvalds1-1/+0
Pull asm/scatterlist.h removal from Jens Axboe: "We don't have any specific arch scatterlist anymore, since parisc finally switched over. Kill the include" * 'for-4.2/sg' of git://git.kernel.dk/linux-block: remove scatterlist.h generation from arch Kbuild files remove <asm/scatterlist.h>
2015-06-25um: Don't pollute kernel namespace with uapiRichard Weinberger2-1/+1
Don't include ptrace uapi stuff in arch headers, it will pollute the kernel namespace and conflict with existing stuff. In this case it fixes clashes with common names like R8. Signed-off-by: Richard Weinberger <richard@nod.at>
2015-06-25um: Include sys/types.h for makedev(), major(), minor()Hans-Werner Hilse1-0/+1
The functions in question are not part of the POSIX standard, documentation however hints that the corresponding header shall be sys/types.h. C libraries other than glibc, namely musl, did not include that header via other ways and complained. Signed-off-by: Hans-Werner Hilse <hwhilse@gmail.com> Signed-off-by: Richard Weinberger <richard@nod.at>
2015-06-25um: Do not use stdin and stdout identifiers for struct membersHans-Werner Hilse5-30/+30
stdin, stdout and stderr are macros according to C89/C99. Thus do not use them as struct member identifiers to avoid bad results from macro expansion. Signed-off-by: Hans-Werner Hilse <hwhilse@gmail.com> Signed-off-by: Richard Weinberger <richard@nod.at>
2015-06-25um: Do not use __ptr_t type for stack_t's .ss pointerHans-Werner Hilse1-3/+5
__ptr_t type is a glibc-specific type, while the generally documented type is a void*. That's what other C libraries use, too. Signed-off-by: Hans-Werner Hilse <hwhilse@gmail.com> Signed-off-by: Richard Weinberger <richard@nod.at>
2015-06-25mm: new mm hook frameworkLaurent Dufour1-0/+15
CRIU is recreating the process memory layout by remapping the checkpointee memory area on top of the current process (criu). This includes remapping the vDSO to the place it has at checkpoint time. However some architectures like powerpc are keeping a reference to the vDSO base address to build the signal return stack frame by calling the vDSO sigreturn service. So once the vDSO has been moved, this reference is no more valid and the signal frame built later are not usable. This patch serie is introducing a new mm hook framework, and a new arch_remap hook which is called when mremap is done and the mm lock still hold. The next patch is adding the vDSO remap and unmap tracking to the powerpc architecture. This patch (of 3): This patch introduces a new set of header file to manage mm hooks: - per architecture empty header file (arch/x/include/asm/mm-arch-hooks.h) - a generic header (include/linux/mm-arch-hooks.h) The architecture which need to overwrite a hook as to redefine it in its header file, while architecture which doesn't need have nothing to do. The default hooks are defined in the generic header and are used in the case the architecture is not defining it. In a next step, mm hooks defined in include/asm-generic/mm_hooks.h should be moved here. Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com> Suggested-by: Andrew Morton <akpm@linux-foundation.org> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-23module: add per-module param_lockDan Streetman1-10/+10
Add a "param_lock" mutex to each module, and update params.c to use the correct built-in or module mutex while locking kernel params. Remove the kparam_block_sysfs_r/w() macros, replace them with direct calls to kernel_param_[un]lock(module). The kernel param code currently uses a single mutex to protect modification of any and all kernel params. While this generally works, there is one specific problem with it; a module callback function cannot safely load another module, i.e. with request_module() or even with indirect calls such as crypto_has_alg(). If the module to be loaded has any of its params configured (e.g. with a /etc/modprobe.d/* config file), then the attempt will result in a deadlock between the first module param callback waiting for modprobe, and modprobe trying to lock the single kernel param mutex to set the new module's param. This fixes that by using per-module mutexes, so that each individual module is protected against concurrent changes in its own kernel params, but is not blocked by changes to other module params. All built-in modules continue to use the built-in mutex, since they will always be loaded at runtime and references (e.g. request_module(), crypto_has_alg()) to them will never cause load-time param changing. This also simplifies the interface used by modules to block sysfs access to their params; while there are currently functions to block and unblock sysfs param access which are split up by read and write and expect a single kernel param to be passed, their actual operation is identical and applies to all params, not just the one passed to them; they simply lock and unlock the global param mutex. They are replaced with direct calls to kernel_param_[un]lock(THIS_MODULE), which locks THIS_MODULE's param_lock, or if the module is built-in, it locks the built-in mutex. Suggested-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Dan Streetman <ddstreet@ieee.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-06-01um: Fix mconsole dependencyRichard Weinberger1-0/+1
mconsole depends on CONFIG_PROC_FS. Signed-off-by: Richard Weinberger <richard@nod.at>
2015-05-31um: Handle tracehook_report_syscall_entry() resultRichard Weinberger3-5/+9
tracehook_report_syscall_entry() is allowed to fail, in case of failure we have to abort the current syscall. Signed-off-by: Richard Weinberger <richard@nod.at>