- 10 Jan, 2018 9 commits
-
-
Anshuman Khandual authored
commit 4991c09c upstream. While testing on a large CPU system, detected the following RCU stall many times over the span of the workload. This problem is solved by adding a cond_resched() in the change_pmd_range() function. INFO: rcu_sched detected stalls on CPUs/tasks: 154-....: (670 ticks this GP) idle=022/140000000000000/0 softirq=2825/2825 fqs=612 (detected by 955, t=6002 jiffies, g=4486, c=4485, q=90864) Sending NMI from CPU 955 to CPUs 154: NMI backtrace for cpu 154 CPU: 154 PID: 147071 Comm: workload Not tainted 4.15.0-rc3+ #3 NIP: c0000000000b3f64 LR: c0000000000b33d4 CTR: 000000000000aa18 REGS: 00000000a4b0fb44 TRAP: 0501 Not tainted (4.15.0-rc3+) MSR: 8000000000009033 <SF,EE,ME,IR,DR,RI,LE> CR: 22422082 XER: 00000000 CFAR: 00000000006cf8f0 SOFTE: 1 GPR00: 0010000000000000 c00003ef9b1cb8c0 c0000000010cc600 0000000000000000 GPR04: 8e0000018c32b200 40017b3858fd6e00 8e0000018c32b208 40017b3858fd6e00 GPR08: 8e0000018c32b210 40017b3858fd6e00 8e0000018c32b218 40017b3858fd6e00 GPR12: ffffffffffffffff c00000000fb25100 NIP [c0000000000b3f64] plpar_hcall9+0x44/0x7c LR [c0000000000b33d4] pSeries_lpar_flush_hash_range+0x384/0x420 Call Trace: flush_hash_range+0x48/0x100 __flush_tlb_pending+0x44/0xd0 hpte_need_flush+0x408/0x470 change_protection_range+0xaac/0xf10 change_prot_numa+0x30/0xb0 task_numa_work+0x2d0/0x3e0 task_work_run+0x130/0x190 do_notify_resume+0x118/0x120 ret_from_except_lite+0x70/0x74 Instruction dump: 60000000 f8810028 7ca42b78 7cc53378 7ce63b78 7d074378 7d284b78 7d495378 e9410060 e9610068 e9810070 44000022 <7d806378> e9810028 f88c0000 f8ac0008 Link: http://lkml.kernel.org/r/20171214140551.5794-1-khandual@linux.vnet.ibm.comSigned-off-by:
Anshuman Khandual <khandual@linux.vnet.ibm.com> Suggested-by:
Nicholas Piggin <npiggin@gmail.com> Acked-by:
Michal Hocko <mhocko@suse.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>
-
Oleg Nesterov authored
commit 4d957015 upstream. As Tsukada explains, the time_is_before_jiffies(acct->needcheck) check is very wrong, we need time_is_after_jiffies() to make sys_acct() work. Ignoring the overflows, the code should "goto out" if needcheck > jiffies, while currently it checks "needcheck < jiffies" and thus in the likely case check_free_space() does nothing until jiffies overflow. In particular this means that sys_acct() is simply broken, acct_on() sets acct->needcheck = jiffies and expects that check_free_space() should set acct->active = 1 after the free-space check, but this won't happen if jiffies increments in between. This was broken by commit 32dc7308 ("get rid of timer in kern/acct.c") in 2011, then another (correct) commit 795a2f22 ("acct() should honour the limits from the very beginning") made the problem more visible. Link: http://lkml.kernel.org/r/20171213133940.GA6554@redhat.com Fixes: 32dc7308 ("get rid of timer in kern/acct.c") Reported-by:
TSUKADA Koutaro <tsukada@ascade.co.jp> Suggested-by:
Oleg Nesterov <oleg@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by:
-
Thomas Gleixner authored
commit de791821 upstream. Use the name associated with the particular attack which needs page table isolation for mitigation. Signed-off-by:
Thomas Gleixner <tglx@linutronix.de> Acked-by:
David Woodhouse <dwmw@amazon.co.uk> Cc: Alan Cox <gnomes@lxorguk.ukuu.org.uk> Cc: Jiri Koshina <jikos@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Andi Lutomirski <luto@amacapital.net> Cc: Andi Kleen <ak@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Paul Turner <pjt@google.com> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Greg KH <gregkh@linux-foundation.org> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Kees Cook <keescook@google.com> Link: https://lkml.kernel.org/r/alpine.DEB.2.20.1801051525300.1724@nanosSigned-off-by:
-
David Woodhouse authored
commit b9e705ef upstream. Where an ALTERNATIVE is used in the middle of an inline asm block, this would otherwise lead to the following instruction being appended directly to the trailing ".popsection", and a failed compile. Fixes: 9cebed42 ("x86, alternative: Use .pushsection/.popsection") Signed-off-by:
-
Thomas Gleixner authored
commit 1e547681 upstream. The recent changes for PTI touch cpu_tlbstate from various tlb_flush inlines. cpu_tlbstate is exported as GPL symbol, so this causes a regression when building out of tree drivers for certain graphics cards. Aside of that the export was wrong since it was introduced as it should have been EXPORT_PER_CPU_SYMBOL_GPL(). Use the correct PER_CPU export and drop the _GPL to restore the previous state which allows users to utilize the cards they payed for. As always I'm really thrilled to make this kind of change to support the #friends (or however the hot hashtag of today is spelled) from that closet sauce graphics corp. Fixes: 1e02ce4c ("x86: Store a per-cpu shadow copy of CR4") Fixes: 6fd166aa ("x86/mm: Use/Fix PCID to optimize user/kernel switches") Reported-by:
Kees Cook <keescook@google.com> Signed-off-by:
-
Peter Zijlstra authored
commit 42f3bdc5 upstream. Thomas reported the following warning: BUG: using smp_processor_id() in preemptible [00000000] code: ovsdb-server/4498 caller is native_flush_tlb_single+0x57/0xc0 native_flush_tlb_single+0x57/0xc0 __set_pte_vaddr+0x2d/0x40 set_pte_vaddr+0x2f/0x40 cea_set_pte+0x30/0x40 ds_update_cea.constprop.4+0x4d/0x70 reserve_ds_buffers+0x159/0x410 x86_reserve_hardware+0x150/0x160 x86_pmu_event_init+0x3e/0x1f0 perf_try_init_event+0x69/0x80 perf_event_alloc+0x652/0x740 SyS_perf_event_open+0x3f6/0xd60 do_syscall_64+0x5c/0x190 set_pte_vaddr is used to map the ds buffers into the cpu entry area, but there are two problems with that: 1) The resulting flush is not supposed to be called in preemptible context 2) The cpu entry area is supposed to be per CPU, but the debug store buffers are mapped for all CPUs so these mappings need to be flushed globally. Add the necessary preemption protection across the mapping code and flush TLBs globally. Fixes: c1961a46 ("x86/events/intel/ds: Map debug buffers in cpu_entry_area") Reported-by:
Thomas Zeitlhofer <thomas.zeitlhofer+lkml@ze-it.at> Signed-off-by:
Peter Zijlstra <peterz@infradead.org> Signed-off-by:
-
Thomas Gleixner authored
commit 1dddd251 upstream. vaddr_end for KASLR is only documented in the KASLR code itself and is adjusted depending on config options. So it's not surprising that a change of the memory layout causes KASLR to have the wrong vaddr_end. This can map arbitrary stuff into other areas causing hard to understand problems. Remove the whole ifdef magic and define the start of the cpu_entry_area to be the end of the KASLR vaddr range. Add documentation to that effect. Fixes: 92a0f81d ("x86/cpu_entry_area: Move it out of the fixmap") Reported-by:
Benjamin Gilbert <benjamin.gilbert@coreos.com> Signed-off-by:
-
Thomas Gleixner authored
commit f2078904 upstream. There is no reason for 4 and 5 level pagetables to have a different layout. It just makes determining vaddr_end for KASLR harder than necessary. Fixes: 92a0f81d ("x86/cpu_entry_area: Move it out of the fixmap") Signed-off-by:
-
Andrey Ryabinin authored
commit f5a40711 upstream. Since f06bdd40 ("x86/mm: Adapt MODULES_END based on fixmap section size") kasan_mem_to_shadow(MODULES_END) could be not aligned to a page boundary. So passing page unaligned address to kasan_populate_zero_shadow() have two possible effects: 1) It may leave one page hole in supposed to be populated area. After commit 21506525 ("x86/kasan/64: Teach KASAN about the cpu_entry_area") that hole happens to be in the shadow covering fixmap area and leads to crash: BUG: unable to handle kernel paging request at fffffbffffe8ee04 RIP: 0010:check_memory_region+0x5c/0x190 Call Trace: <NMI> memcpy+0x1f/0x50 ghes_copy_tofrom_phys+0xab/0x180 ghes_read_estatus+0xfb/0x280 ghes_notify_nmi+0x2b2/0x410 nmi_handle+0x115/0x2c0 default_do_nmi+0x57/0x110 do_nmi+0xf8/0x150 end_repeat_nmi+0x1a/0x1e Note, the crash likely disappeared after commit 92a0f81d, which changed kasan_populate_zero_shadow() call the way it was before commit 21506525. 2) Attempt to load module near MODULES_END will fail, because __vmalloc_node_range() called from kasan_module_alloc() will hit the WARN_ON(!pte_none(*pte)) in the vmap_pte_range() and bail out with error. To fix this we need to make kasan_mem_to_shadow(MODULES_END) page aligned which means that MODULES_END should be 8*PAGE_SIZE aligned. The whole point of commit f06bdd40 was to move MODULES_END down if NR_CPUS is big, so the cpu_entry_area takes a lot of space. But since 92a0f81d ("x86/cpu_entry_area: Move it out of the fixmap") the cpu_entry_area is no longer in fixmap, so we could just set MODULES_END to a fixed 8*PAGE_SIZE aligned address. Fixes: f06bdd40 ("x86/mm: Adapt MODULES_END based on fixmap section size") Reported-by:
Jakub Kicinski <kubakici@wp.pl> Signed-off-by:
Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by:
-
- 05 Jan, 2018 15 commits
-
-
Greg Kroah-Hartman authored
-
Troy Kisky authored
commit 05a03bf2 upstream. m41t80_sqw_set_rate will be called with the result from m41t80_sqw_round_rate, so might as well make m41t80_sqw_set_rate(n) same as m41t80_sqw_set_rate(m41t80_sqw_round_rate(n)) As Russell King wrote[1], "clk_round_rate() is supposed to tell you what you end up with if you ask clk_set_rate() to set the exact same value you passed in - but clk_round_rate() won't modify the hardware." [1] http://lists.infradead.org/pipermail/linux-arm-kernel/2012-January/080175.htmlSigned-off-by:
Troy Kisky <troy.kisky@boundarydevices.com> Signed-off-by:
Alexandre Belloni <alexandre.belloni@free-electrons.com> Cc: Christoph Fritz <chf.fritz@googlemail.com> Signed-off-by:
-
Troy Kisky authored
commit 13bb1d78 upstream. This is a little more efficient and avoids the warning WARNING: possible circular locking dependency detected 4.14.0-rc7-00010 #16 Not tainted ------------------------------------------------------ kworker/2:1/70 is trying to acquire lock: (prepare_lock){+.+.}, at: [<c049300c>] clk_prepare_lock+0x80/0xf4 but task is already holding lock: (i2c_register_adapter){+.+.}, at: [<c0690b04>] i2c_adapter_lock_bus+0x14/0x18 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (i2c_register_adapter){+.+.}: rt_mutex_lock+0x44/0x5c i2c_adapter_lock_bus+0x14/0x18 i2c_transfer+0xa8/0xbc i2c_smbus_xfer+0x20c/0x5d8 i2c_smbus_read_byte_data+0x38/0x48 m41t80_sqw_is_prepared+0x18/0x28 Signed-off-by:
-
Troy Kisky authored
commit 2cb90ed3 upstream. This is a little more efficient, and avoids the warning WARNING: possible circular locking dependency detected 4.14.0-rc7-00007 #14 Not tainted ------------------------------------------------------ alsactl/330 is trying to acquire lock: (prepare_lock){+.+.}, at: [<c049300c>] clk_prepare_lock+0x80/0xf4 but task is already holding lock: (i2c_register_adapter){+.+.}, at: [<c0690ae0>] i2c_adapter_lock_bus+0x14/0x18 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (i2c_register_adapter){+.+.}: rt_mutex_lock+0x44/0x5c i2c_adapter_lock_bus+0x14/0x18 i2c_transfer+0xa8/0xbc i2c_smbus_xfer+0x20c/0x5d8 i2c_smbus_read_byte_data+0x38/0x48 m41t80_sqw_recalc_rate+0x24/0x58 Signed-off-by:
-
Troy Kisky authored
commit c8384bb0 upstream. Previously it was returning the best of 32768, 8192, 1024, 64, 2, 0 Now, best of 32768, 8192, 4096, 2048, 1024, 512, 256, 128, 64, 32, 16, 8, 4, 2, 1, 0 Signed-off-by:
-
Troy Kisky authored
commit de6042d2 upstream. Previously it was returning -EINVAL upon success. Signed-off-by:
-
Steffen Klassert authored
commit 94802151 upstream. This reverts commit c9f3f813. This commit breaks transport mode when the policy template has widlcard addresses configured, so revert it. Signed-off-by:
Steffen Klassert <steffen.klassert@secunet.com> Cc: From: Derek Robson <robsonde@gmail.com> Signed-off-by:
-
Nick Desaulniers authored
commit 2fd9c41a upstream. cpu_tss_rw is declared with DECLARE_PER_CPU_PAGE_ALIGNED but then defined with DEFINE_PER_CPU_SHARED_ALIGNED leading to section mismatch warnings. Use DEFINE_PER_CPU_PAGE_ALIGNED consistently. This is necessary because it's mapped to the cpu entry area and must be page aligned. [ tglx: Massaged changelog a bit ] Fixes: 1a935bc3 ("x86/entry: Move SYSENTER_stack to the beginning of struct tss_struct") Suggested-by:
Nick Desaulniers <ndesaulniers@google.com> Signed-off-by:
-
Thomas Gleixner authored
commit d7732ba5 upstream. The preparation for PTI which added CR3 switching to the entry code misplaced the CR3 switch in entry_SYSCALL_compat(). With PTI enabled the entry code tries to access a per cpu variable after switching to kernel GS. This fails because that variable is not mapped to user space. This results in a double fault and in the worst case a kernel crash. Move the switch ahead of the access and clobber RSP which has been saved already. Fixes: 8a09317b ("x86/mm/pti: Prepare the x86/entry assembly code for entry/exit CR3 switching") Reported-by:
Lars Wendler <wendler.lars@web.de> Reported-by:
Laura Abbott <labbott@redhat.com> Signed-off-by:
-
Josh Poimboeuf authored
commit 3ffdeb1a upstream. In the stack dump code, if the frame after the starting pt_regs is also a regs frame, the registers don't get printed. Fix that. Reported-by:
Andy Lutomirski <luto@amacapital.net> Tested-by:
Alexander Tsoy <alexander@tsoy.me> Signed-off-by:
Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toralf Förster <toralf.foerster@gmx.de> Fixes: 3b3fa11b ("x86/dumpstack: Print any pt_regs found on the stack") Link: http://lkml.kernel.org/r/396f84491d2f0ef64eda4217a2165f5712f6a115.1514736742.git.jpoimboe@redhat.comSigned-off-by:
Ingo Molnar <mingo@kernel.org> Signed-off-by:
-
Josh Poimboeuf authored
commit a9cdbe72 upstream. The show_regs_safe() logic is wrong. When there's an iret stack frame, it prints the entire pt_regs -- most of which is random stack data -- instead of just the five registers at the end. show_regs_safe() is also poorly named: the on_stack() checks aren't for safety. Rename the function to show_regs_if_on_stack() and add a comment to explain why the checks are needed. These issues were introduced with the "partial register dump" feature of the following commit: b02fcf9b ("x86/unwinder: Handle stack overflows more gracefully") That patch had gone through a few iterations of development, and the above issues were artifacts from a previous iteration of the patch where 'regs' pointed directly to the iret frame rather than to the (partially empty) pt_regs. Tested-by:
-
Thomas Gleixner authored
commit 52994c25 upstream. Meelis reported that his K8 Athlon64 emits MCE warnings when PTI is enabled: [Hardware Error]: Error Addr: 0x0000ffff81e000e0 [Hardware Error]: MC1 Error: L1 TLB multimatch. [Hardware Error]: cache level: L1, tx: INSN The address is in the entry area, which is mapped into kernel _AND_ user space. That's special because we switch CR3 while we are executing there. User mapping: 0xffffffff81e00000-0xffffffff82000000 2M ro PSE GLB x pmd Kernel mapping: 0xffffffff81000000-0xffffffff82000000 16M ro PSE x pmd So the K8 is complaining that the TLB entries differ. They differ in the GLB bit. Drop the GLB bit when installing the user shared mapping. Fixes: 6dc72c3c ("x86/mm/pti: Share entry text PMD") Reported-by:
Meelis Roos <mroos@linux.ee> Signed-off-by:
-
Tom Lendacky authored
commit 694d99d4 upstream. AMD processors are not subject to the types of attacks that the kernel page table isolation feature protects against. The AMD microarchitecture does not allow memory references, including speculative references, that access higher privileged data when running in a lesser privileged mode when that access would result in a page fault. Disable page table isolation by default on AMD processors by not setting the X86_BUG_CPU_INSECURE feature, which controls whether X86_FEATURE_PTI is set. Signed-off-by:
Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by:
Borislav Petkov <bp@suse.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20171227054354.20369.94587.stgit@tlendack-t1.amdoffice.netSigned-off-by:
-
Eric Biggers authored
commit dc32b5c3 upstream. If userspace attempted to set a "security.capability" xattr shorter than 4 bytes (e.g. 'setfattr -n security.capability -v x file'), then cap_convert_nscap() read past the end of the buffer containing the xattr value because it accessed the ->magic_etc field without verifying that the xattr value is long enough to contain that field. Fix it by validating the xattr value size first. This bug was found using syzkaller with KASAN. The KASAN report was as follows (cleaned up slightly): BUG: KASAN: slab-out-of-bounds in cap_convert_nscap+0x514/0x630 security/commoncap.c:498 Read of size 4 at addr ffff88002d8741c0 by task syz-executor1/2852 CPU: 0 PID: 2852 Comm: syz-executor1 Not tainted 4.15.0-rc6-00200-gcc0aac99d977 #253 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-20171110_100015-anatol 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0xe3/0x195 lib/dump_stack.c:53 print_address_description+0x73/0x260 mm/kasan/report.c:252 kasan_report_error mm/kasan/report.c:351 [inline] kasan_report+0x235/0x350 mm/kasan/report.c:409 cap_convert_nscap+0x514/0x630 security/commoncap.c:498 setxattr+0x2bd/0x350 fs/xattr.c:446 path_setxattr+0x168/0x1b0 fs/xattr.c:472 SYSC_setxattr fs/xattr.c:487 [inline] SyS_setxattr+0x36/0x50 fs/xattr.c:483 entry_SYSCALL_64_fastpath+0x18/0x85 Fixes: 8db6c34f ("Introduce v3 namespaced file capabilities") Signed-off-by:
Eric Biggers <ebiggers@google.com> Reviewed-by:
Serge Hallyn <serge@hallyn.com> Signed-off-by:
James Morris <james.l.morris@oracle.com> Signed-off-by:
-
Kees Cook authored
commit e816c201 upstream. This is a logical revert of commit e37fdb78 ("exec: Use secureexec for setting dumpability") This weakens dumpability back to checking only for uid/gid changes in current (which is useless), but userspace depends on dumpability not being tied to secureexec. https://bugzilla.redhat.com/show_bug.cgi?id=1528633Reported-by:
Tom Horsley <horsley1953@gmail.com> Fixes: e37fdb78 ("exec: Use secureexec for setting dumpability") Signed-off-by:
Kees Cook <keescook@chromium.org> Signed-off-by:
-
- 02 Jan, 2018 16 commits
-
-
Greg Kroah-Hartman authored
-
Johan Hovold authored
commit e7e51dcf upstream. The tty_ldisc_receive_buf() helper returns the number of bytes processed so drop the bogus "not" from the kernel doc comment. Fixes: 8d082cd3 ("tty: Unify receive_buf() code paths") Signed-off-by:
Johan Hovold <johan@kernel.org> Signed-off-by:
-
Linus Torvalds authored
commit 966031f3 upstream. We added support for EXTPROC back in 2010 in commit 26df6d13 ("tty: Add EXTPROC support for LINEMODE") and the intent was to allow it to override some (all?) ICANON behavior. Quoting from that original commit message: There is a new bit in the termios local flag word, EXTPROC. When this bit is set, several aspects of the terminal driver are disabled. Input line editing, character echo, and mapping of signals are all disabled. This allows the telnetd to turn off these functions when in linemode, but still keep track of what state the user wants the terminal to be in. but the problem turns out that "several aspects of the terminal driver are disabled" is a bit ambiguous, and you can really confuse the n_tty layer by setting EXTPROC and then causing some of the ICANON invariants to no longer be maintained. This fixes at least one such case (TIOCINQ) becoming unhappy because of the confusion over whether ICANON really means ICANON when EXTPROC is set. This basically makes TIOCINQ match the case of read: if EXTPROC is set, we ignore ICANON. Also, make sure to reset the ICANON state ie EXTPROC changes, not just if ICANON changes. Fixes: 26df6d13 ("tty: Add EXTPROC support for LINEMODE") Reported-by:
Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Reported-by:
syzkaller <syzkaller@googlegroups.com> Cc: Jiri Slaby <jslaby@suse.com> Signed-off-by:
-
Thomas Gleixner authored
commit 7f414195 upstream. Andy prefers to be paranoid about the pagetable free in the error path of write_ldt(). Make it conditional and warn whenever the installment of a secondary LDT fails. Requested-by:
-
Thomas Gleixner authored
commit a62d6985 upstream. The error path in write_ldt() tries to free 'old_ldt' instead of the newly allocated 'new_ldt', resulting in a memory leak. It also misses to clean up a half populated LDT pagetable, which is not a leak as it gets cleaned up when the process exits. Free both the potentially half populated LDT pagetable and the newly allocated LDT struct. This can be done unconditionally because once an LDT is mapped subsequent maps will succeed, because the PTE page is already populated and the two LDTs fit into that single page. Reported-by:
Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by:
-
Andy Lutomirski authored
commit c739f930 upstream. Using PGDIR_SHIFT to identify espfix64 addresses on 5-level systems was wrong, and it resulted in panics due to unhandled double faults. Use P4D_SHIFT instead, which is correct on 4-level and 5-level machines. This fixes a panic when running x86 selftests on 5-level machines. Signed-off-by:
Andy Lutomirski <luto@kernel.org> Acked-by:
Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: David Laight <David.Laight@aculab.com> Cc: Kees Cook <keescook@chromium.org> Cc: Kirill A. Shutemov <kirill@shutemov.name> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 1d33b219 ("x86/espfix: Add support for 5-level paging") Link: http://lkml.kernel.org/r/24c898b4f44fdf8c22d93703850fb384ef87cfdc.1513035461.git.luto@kernel.orgSigned-off-by:
-
Linus Torvalds authored
commit ac461122 upstream. Commit e802a51e ("x86/idt: Consolidate IDT invalidation") cleaned up and unified the IDT invalidation that existed in a couple of places. It changed no actual real code. Despite not changing any actual real code, it _did_ change code generation: by implementing the common idt_invalidate() function in archx86/kernel/idt.c, it made the use of the function in arch/x86/kernel/machine_kexec_32.c be a real function call rather than an (accidental) inlining of the function. That, in turn, exposed two issues: - in load_segments(), we had incorrectly reset all the segment registers, which then made the stack canary load (which gcc does using offset of %gs) cause a trap. Instead of %gs pointing to the stack canary, it will be the normal zero-based kernel segment, and the stack canary load will take a page fault at address 0x14. - to make this even harder to debug, we had invalidated the GDT just before calling idt_invalidate(), which meant that the fault happened with an invalid GDT, which in turn causes a triple fault and immediate reboot. Fix this by (a) not reloading the special segments in load_segments(). We currently don't do any percpu accesses (which would require %fs on x86-32) in this area, but there's no reason to think that we might not want to do them, and like %gs, it's pointless to break it. (b) doing idt_invalidate() before invalidating the GDT, to keep things at least _slightly_ more debuggable for a bit longer. Without a IDT, traps will not work. Without a GDT, traps also will not work, but neither will any segment loads etc. So in a very real sense, the GDT is even more core than the IDT. Fixes: e802a51e ("x86/idt: Consolidate IDT invalidation") Reported-and-tested-by:
Alexandru Chirvasitu <achirvasub@gmail.com> Signed-off-by:
-
Thomas Gleixner authored
commit decab088 upstream. The preempt_disable/enable() pair in __native_flush_tlb() was added in commit: 5cf0791d ("x86/mm: Disable preemption during CR3 read+write") ... to protect the UP variant of flush_tlb_mm_range(). That preempt_disable/enable() pair should have been added to the UP variant of flush_tlb_mm_range() instead. The UP variant was removed with commit: ce4a4e56 ("x86/mm: Remove the UP asm/tlbflush.h code, always use the (formerly) SMP code") ... but the preempt_disable/enable() pair stayed around. The latest change to __native_flush_tlb() in commit: 6fd166aa ("x86/mm: Use/Fix PCID to optimize user/kernel switches") ... added an access to a per CPU variable outside the preempt disabled regions, which makes no sense at all. __native_flush_tlb() must always be called with at least preemption disabled. Remove the preempt_disable/enable() pair and add a WARN_ON_ONCE() to catch bad callers independent of the smp_processor_id() debugging. Signed-off-by:
-
Thomas Gleixner authored
commit 322f8b8b upstream. smpboot_setup_warm_reset_vector() and smpboot_restore_warm_reset_vector() invoke local_flush_tlb() for no obvious reason. Digging in history revealed that the original code in the 2.1 era added those because the code manipulated a swapper_pg_dir pagetable entry. The pagetable manipulation was removed long ago in the 2.3 timeframe, but the TLB flush invocations stayed around forever. Remove them along with the pointless pr_debug()s which come from the same 2.1 change. Reported-by:
Dominik Brodowski <linux@dominikbrodowski.net> Signed-off-by:
-
Thomas Gleixner authored
commit 5d62c183 upstream. The conditions in irq_exit() to invoke tick_nohz_irq_exit() which subsequently invokes tick_nohz_stop_sched_tick() are: if ((idle_cpu(cpu) && !need_resched()) || tick_nohz_full_cpu(cpu)) If need_resched() is not set, but a timer softirq is pending then this is an indication that the softirq code punted and delegated the execution to softirqd. need_resched() is not true because the current interrupted task takes precedence over softirqd. Invoking tick_nohz_irq_exit() in this case can cause an endless loop of timer interrupts because the timer wheel contains an expired timer, but softirqs are not yet executed. So it returns an immediate expiry request, which causes the timer to fire immediately again. Lather, rinse and repeat.... Prevent that by adding a check for a pending timer soft interrupt to the conditions in tick_nohz_stop_sched_tick() which avoid calling get_next_timer_interrupt(). That keeps the tick sched timer on the tick and prevents a repetitive programming of an already expired timer. Reported-by:
Sebastian Siewior <bigeasy@linutronix.d> Signed-off-by:
Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Paul McKenney <paulmck@linux.vnet.ibm.com> Cc: Anna-Maria Gleixner <anna-maria@linutronix.de> Cc: Sebastian Siewior <bigeasy@linutronix.de> Link: https://lkml.kernel.org/r/alpine.DEB.2.20.1712272156050.2431@nanosSigned-off-by:
-
Sushmita Susheelendra authored
commit d6b246bb upstream. Use the direction argument passed into begin_cpu_access and end_cpu_access when calling the dma_sync_sg_for_cpu/device. The actual cache primitive called depends on the direction passed in. Signed-off-by:
Sushmita Susheelendra <ssusheel@codeaurora.org> Acked-by:
-
Sudeep Holla authored
commit f57ab9a0 upstream. Commit dfea747d ("drivers: base: cacheinfo: support DT overrides for cache properties") doesn't initialise the cache type if it's present only in DT and the architecture is not aware of it. They are unified system level cache which are generally transparent. This patch check if the cache type is set to NOCACHE but the DT node indicates that it's unified cache and sets the cache type accordingly. Fixes: dfea747d ("drivers: base: cacheinfo: support DT overrides for cache properties") Reported-and-tested-by:
Tan Xiaojun <tanxiaojun@huawei.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by:
Sudeep Holla <sudeep.holla@arm.com> Signed-off-by:
-
Johan Hovold authored
commit 04604673 upstream. Fix child-node lookups during probe, which ended up searching the whole device tree depth-first starting at the parents rather than just matching on their children. To make things worse, some parent nodes could end up being being prematurely freed (by tegra_xusb_pad_register()) as of_find_node_by_name() drops a reference to its first argument. Fixes: 53d2a715 ("phy: Add Tegra XUSB pad controller support") Cc: Thierry Reding <treding@nvidia.com> Signed-off-by:
Kishon Vijay Abraham I <kishon@ti.com> Signed-off-by:
-
Todd Kjos authored
commit 7f3dc008 upstream. proc->files cleanup is initiated by binder_vma_close. Therefore a reference on the binder_proc is not enough to prevent the files_struct from being released while the binder_proc still has a reference. This can lead to an attempt to dereference the stale pointer obtained from proc->files prior to proc->files cleanup. This has been seen once in task_get_unused_fd_flags() when __alloc_fd() is called with a stale "files". The fix is to protect proc->files with a mutex to prevent cleanup while in use. Signed-off-by:
Todd Kjos <tkjos@google.com> Signed-off-by:
-
Thomas Gleixner authored
commit 26456f87 upstream. The timer wheel bases are not (re)initialized on CPU hotplug. That leaves them with a potentially stale clk and next_expiry valuem, which can cause trouble then the CPU is plugged. Add a prepare callback which forwards the clock, sets next_expiry to far in the future and reset the control flags to a known state. Set base->must_forward_clk so the first timer which is queued will try to forward the clock to current jiffies. Fixes: 500462a9 ("timers: Switch to a non-cascading wheel") Reported-by:
Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by:
-
Thomas Gleixner authored
commit fd45bb77 upstream. The timer start debug function is called before the proper timer base is set. As a consequence the trace data contains the stale CPU and flags values. Call the debug function after setting the new base and flags. Fixes: 500462a9 ("timers: Switch to a non-cascading wheel") Signed-off-by:
-
