- 23 Jan, 2018 22 commits
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Thomas Gleixner authored
commit 45d55e7b upstream. Keith reported the following warning: WARNING: CPU: 28 PID: 1420 at kernel/irq/matrix.c:222 irq_matrix_remove_managed+0x10f/0x120 x86_vector_free_irqs+0xa1/0x180 x86_vector_alloc_irqs+0x1e4/0x3a0 msi_domain_alloc+0x62/0x130 The reason for this is that if the vector allocation fails the error handling code tries to free the failed vector as well, which causes the above imbalance warning to trigger. Adjust the error path to handle this correctly. Fixes: b5dc8e6c ("x86/irq: Use hierarchical irqdomain to manage CPU interrupt vectors") Reported-by:
Keith Busch <keith.busch@intel.com> Signed-off-by:
Thomas Gleixner <tglx@linutronix.de> Tested-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Joe Lawrence authored
commit d3f14c48 upstream. round_pipe_size() contains a right-bit-shift expression which may overflow, which would cause undefined results in a subsequent roundup_pow_of_two() call. static inline unsigned int round_pipe_size(unsigned int size) { unsigned long nr_pages; nr_pages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT; return roundup_pow_of_two(nr_pages) << PAGE_SHIFT; } PAGE_SIZE is defined as (1UL << PAGE_SHIFT), so: - 4 bytes wide on 32-bit (0 to 0xffffffff) - 8 bytes wide on 64-bit (0 to 0xffffffffffffffff) That means that 32-bit round_pipe_size(), nr_pages may overflow to 0: size=0x00000000 nr_pages=0x0 size=0x00000001 nr_pages=0x1 size=0xfffff000 nr_pages=0xfffff size=0xfffff001 nr_pages=0x0 << ! size=0xffffffff nr_pages=0x0 << ! This is bad because roundup_pow_of_two(n) is undefined when n == 0! 64-bit is not a problem as the unsigned int size is 4 bytes wide (similar to 32-bit) and the larger, 8 byte wide unsigned long, is sufficient to handle the largest value of the bit shift expression: size=0xffffffff nr_pages=100000 Modify round_pipe_size() to return 0 if n == 0 and updates its callers to handle accordingly. Link: http://lkml.kernel.org/r/1507658689-11669-3-git-send-email-joe.lawrence@redhat.comSigned-off-by:
Joe Lawrence <joe.lawrence@redhat.com> Reported-by:
Mikulas Patocka <mpatocka@redhat.com> Reviewed-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Dong Jinguang <dongjinguang@huawei.com> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by:
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Len Brown authored
commit b5112030 upstream. The INTEL_FAM6_SKYLAKE_X hardcoded crystal_khz value of 25MHZ is problematic: - SKX workstations (with same model # as server variants) use a 24 MHz crystal. This results in a -4.0% time drift rate on SKX workstations. - SKX servers subject the crystal to an EMI reduction circuit that reduces its actual frequency by (approximately) -0.25%. This results in -1 second per 10 minute time drift as compared to network time. This issue can also trigger a timer and power problem, on configurations that use the LAPIC timer (versus the TSC deadline timer). Clock ticks scheduled with the LAPIC timer arrive a few usec before the time they are expected (according to the slow TSC). This causes Linux to poll-idle, when it should be in an idle power saving state. The idle and clock code do not graciously recover from this error, sometimes resulting in significant polling and measurable power impact. Stop using native_calibrate_tsc() for INTEL_FAM6_SKYLAKE_X. native_calibrate_tsc() will return 0, boot will run with tsc_khz = cpu_khz, and the TSC refined calibration will update tsc_khz to correct for the difference. [ tglx: Sanitized change log ] Fixes: 6baf3d61 ("x86/tsc: Add additional Intel CPU models to the crystal quirk list") Signed-off-by:
Len Brown <len.brown@intel.com> Signed-off-by:
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Eric W. Biederman authored
commit beacd6f7 upstream. SEGV_PKUERR is a signal specific si_code which happens to have the same numeric value as several others: BUS_MCEERR_AR, ILL_ILLTRP, FPE_FLTOVF, TRAP_HWBKPT, CLD_TRAPPED, POLL_ERR, SEGV_THREAD_ID, as such it is not safe to just test the si_code the signal number must also be tested to prevent a false positive in fill_sig_info_pkey. This error was by inspection, and BUS_MCEERR_AR appears to be a real candidate for confusion. So pass in si_signo and check for SIG_SEGV to verify that it is actually a SEGV_PKUERR Fixes: 019132ff ("x86/mm/pkeys: Fill in pkey field in siginfo") Signed-off-by:
"Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by:
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Andi Kleen authored
commit 6cfb521a upstream. Add a marker for retpoline to the module VERMAGIC. This catches the case when a non RETPOLINE compiled module gets loaded into a retpoline kernel, making it insecure. It doesn't handle the case when retpoline has been runtime disabled. Even in this case the match of the retcompile status will be enforced. This implies that even with retpoline run time disabled all modules loaded need to be recompiled. Signed-off-by:
Andi Kleen <ak@linux.intel.com> Signed-off-by:
David Woodhouse <dwmw@amazon.co.uk> Cc: rusty@rustcorp.com.au Cc: arjan.van.de.ven@intel.com Cc: jeyu@kernel.org Cc: torvalds@linux-foundation.org Link: https://lkml.kernel.org/r/20180116205228.4890-1-andi@firstfloor.orgSigned-off-by:
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Paolo Bonzini authored
commit 4fdec203 upstream. Processor tracing is already enumerated in word 9 (CPUID[7,0].EBX), so do not duplicate it in the scattered features word. Besides being more tidy, this will be useful for KVM when it presents processor tracing to the guests. KVM selects host features that are supported by both the host kernel (depending on command line options, CPU errata, or whatever) and KVM. Whenever a full feature word exists, KVM's code is written in the expectation that the CPUID bit number matches the X86_FEATURE_* bit number, but this is not the case for X86_FEATURE_INTEL_PT. Signed-off-by:
Paolo Bonzini <pbonzini@redhat.com> Cc: Borislav Petkov <bp@suse.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luwei Kang <luwei.kang@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kvm@vger.kernel.org Link: http://lkml.kernel.org/r/1516117345-34561-1-git-send-email-pbonzini@redhat.comSigned-off-by:
Ingo Molnar <mingo@kernel.org> Signed-off-by:
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Josh Poimboeuf authored
commit 385d11b1 upstream. If a nonexistent file is supplied to objtool, it complains with a non-helpful error: open: No such file or directory Improve it to: objtool: Can't open 'foo': No such file or directory Reported-by:
Markus <M4rkusXXL@web.de> Signed-off-by:
Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/406a3d00a21225eee2819844048e17f68523ccf6.1516025651.git.jpoimboe@redhat.comSigned-off-by:
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Tom Lendacky authored
commit 28d437d5 upstream. The PAUSE instruction is currently used in the retpoline and RSB filling macros as a speculation trap. The use of PAUSE was originally suggested because it showed a very, very small difference in the amount of cycles/time used to execute the retpoline as compared to LFENCE. On AMD, the PAUSE instruction is not a serializing instruction, so the pause/jmp loop will use excess power as it is speculated over waiting for return to mispredict to the correct target. The RSB filling macro is applicable to AMD, and, if software is unable to verify that LFENCE is serializing on AMD (possible when running under a hypervisor), the generic retpoline support will be used and, so, is also applicable to AMD. Keep the current usage of PAUSE for Intel, but add an LFENCE instruction to the speculation trap for AMD. The same sequence has been adopted by GCC for the GCC generated retpolines. Signed-off-by:
Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by:
Borislav Petkov <bp@alien8.de> Acked-by:
Arjan van de Ven <arjan@linux.intel.com> Cc: Rik van Riel <riel@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Paul Turner <pjt@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org> Cc: Kees Cook <keescook@google.com> Link: https://lkml.kernel.org/r/20180113232730.31060.36287.stgit@tlendack-t1.amdoffice.netSigned-off-by:
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David Woodhouse authored
commit c995efd5 upstream. On context switch from a shallow call stack to a deeper one, as the CPU does 'ret' up the deeper side it may encounter RSB entries (predictions for where the 'ret' goes to) which were populated in userspace. This is problematic if neither SMEP nor KPTI (the latter of which marks userspace pages as NX for the kernel) are active, as malicious code in userspace may then be executed speculatively. Overwrite the CPU's return prediction stack with calls which are predicted to return to an infinite loop, to "capture" speculation if this happens. This is required both for retpoline, and also in conjunction with IBRS for !SMEP && !KPTI. On Skylake+ the problem is slightly different, and an *underflow* of the RSB may cause errant branch predictions to occur. So there it's not so much overwrite, as *filling* the RSB to attempt to prevent it getting empty. This is only a partial solution for Skylake+ since there are many other conditions which may result in the RSB becoming empty. The full solution on Skylake+ is to use IBRS, which will prevent the problem even when the RSB becomes empty. With IBRS, the RSB-stuffing will not be required on context switch. [ tglx: Added missing vendor check and slighty massaged comments and changelog ] Signed-off-by:
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Xunlei Pang authored
commit ae83b56a upstream. When a contrained task is throttled by dl_check_constrained_dl(), it may carry the remaining positive runtime, as a result when dl_task_timer() fires and calls replenish_dl_entity(), it will not be replenished correctly due to the positive dl_se->runtime. This patch assigns its runtime to 0 if positive after throttling. Signed-off-by:
Xunlei Pang <xlpang@redhat.com> Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by:
Daniel Bristot de Oliveira <bristot@redhat.com> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luca Abeni <luca.abeni@santannapisa.it> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: df8eac8c ("sched/deadline: Throttle a constrained deadline task activated after the deadline) Link: http://lkml.kernel.org/r/1494421417-27550-1-git-send-email-xlpang@redhat.comSigned-off-by:
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Tomas Henzl authored
commit eb94588d upstream. In a previous patch a hpsa_scsi_dev_t.volume_offline update line has been removed, so let us put it back.. Fixes: 85b29008 (hpsa: update check for logical volume status) Signed-off-by:
Tomas Henzl <thenzl@redhat.com> Acked-by:
Don Brace <don.brace@microsemi.com> Signed-off-by:
Martin K. Petersen <martin.petersen@oracle.com> Cc: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by:
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Sagi Grimberg authored
commit cd52cb26 upstream. In case we fail to establish the connection we must drain our pre-posted login recieve work request before continuing safely with connection teardown. Fixes: a060b562 ("IB/core: generic RDMA READ/WRITE API") Reported-by:
Amrani, Ram <Ram.Amrani@cavium.com> Signed-off-by:
Sagi Grimberg <sagi@grimberg.me> Signed-off-by:
Doug Ledford <dledford@redhat.com> Signed-off-by:
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Eric Biggers authored
commit 4e765b49 upstream. If a message sent to a PF_KEY socket ended with an incomplete extension header (fewer than 4 bytes remaining), then parse_exthdrs() read past the end of the message, into uninitialized memory. Fix it by returning -EINVAL in this case. Reproducer: #include <linux/pfkeyv2.h> #include <sys/socket.h> #include <unistd.h> int main() { int sock = socket(PF_KEY, SOCK_RAW, PF_KEY_V2); char buf[17] = { 0 }; struct sadb_msg *msg = (void *)buf; msg->sadb_msg_version = PF_KEY_V2; msg->sadb_msg_type = SADB_DELETE; msg->sadb_msg_len = 2; write(sock, buf, 17); } Signed-off-by:
Eric Biggers <ebiggers@google.com> Signed-off-by:
Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by:
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Eric Biggers authored
commit 06b335cb upstream. If a message sent to a PF_KEY socket ended with one of the extensions that takes a 'struct sadb_address' but there were not enough bytes remaining in the message for the ->sa_family member of the 'struct sockaddr' which is supposed to follow, then verify_address_len() read past the end of the message, into uninitialized memory. Fix it by returning -EINVAL in this case. This bug was found using syzkaller with KMSAN. Reproducer: #include <linux/pfkeyv2.h> #include <sys/socket.h> #include <unistd.h> int main() { int sock = socket(PF_KEY, SOCK_RAW, PF_KEY_V2); char buf[24] = { 0 }; struct sadb_msg *msg = (void *)buf; struct sadb_address *addr = (void *)(msg + 1); msg->sadb_msg_version = PF_KEY_V2; msg->sadb_msg_type = SADB_DELETE; msg->sadb_msg_len = 3; addr->sadb_address_len = 1; addr->sadb_address_exttype = SADB_EXT_ADDRESS_SRC; write(sock, buf, 24); } Reported-by:
Alexander Potapenko <glider@google.com> Signed-off-by:
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Thomas Gleixner authored
commit ed4bbf79 upstream. When the timer base is checked for expired timers then the deferrable base must be checked as well. This was missed when making the deferrable base independent of base::nohz_active. Fixes: ced6d5c1 ("timers: Use deferrable base independent of base::nohz_active") Signed-off-by:
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Takashi Iwai authored
commit 031f335c upstream. iMac 14,1 requires the same quirk as iMac 12,2, using GPIO 2 and 3 for headphone and speaker output amps. Add the codec SSID quirk entry (106b:0600) accordingly. BugLink: http://lkml.kernel.org/r/CAEw6Zyteav09VGHRfD5QwsfuWv5a43r0tFBNbfcHXoNrxVz7ew@mail.gmail.comReported-by:
Freaky <freaky2000@gmail.com> Signed-off-by:
Takashi Iwai <tiwai@suse.de> Signed-off-by:
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Takashi Iwai authored
commit e4c9fd10 upstream. There is another Dell XPS 13 variant (SSID 1028:082a) that requires the existing fixup for reducing the headphone noise. This patch adds the quirk entry for that. BugLink: http://lkml.kernel.org/r/CAHXyb9ZCZJzVisuBARa+UORcjRERV8yokez=DP1_5O5isTz0ZA@mail.gmail.comReported-and-tested-by:
Francisco G. <frangio.1@gmail.com> Signed-off-by:
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Takashi Iwai authored
commit 23b19b7b upstream. muldiv32() contains a snd_BUG_ON() (which is morphed as WARN_ON() with debug option) for checking the case of 0 / 0. This would be helpful if this happens only as a logical error; however, since the hw refine is performed with any data set provided by user, the inconsistent values that can trigger such a condition might be passed easily. Actually, syzbot caught this by passing some zero'ed old hw_params ioctl. So, having snd_BUG_ON() there is simply superfluous and rather harmful to give unnecessary confusions. Let's get rid of it. Reported-by: syzbot+7e6ee55011deeebce15d@syzkaller.appspotmail.com Signed-off-by:
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Takashi Iwai authored
commit b3defb79 upstream. The ALSA sequencer ioctls have no protection against racy calls while the concurrent operations may lead to interfere with each other. As reported recently, for example, the concurrent calls of setting client pool with a combination of write calls may lead to either the unkillable dead-lock or UAF. As a slightly big hammer solution, this patch introduces the mutex to make each ioctl exclusive. Although this may reduce performance via parallel ioctl calls, usually it's not demanded for sequencer usages, hence it should be negligible. Reported-by:
Luo Quan <a4651386@163.com> Reviewed-by:
Kees Cook <keescook@chromium.org> Reviewed-by:
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Li Jinyue authored
commit fbe0e839 upstream. UBSAN reports signed integer overflow in kernel/futex.c: UBSAN: Undefined behaviour in kernel/futex.c:2041:18 signed integer overflow: 0 - -2147483648 cannot be represented in type 'int' Add a sanity check to catch negative values of nr_wake and nr_requeue. Signed-off-by:
Li Jinyue <lijinyue@huawei.com> Signed-off-by:
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Hannes Reinecke authored
commit 745dfa0d upstream. The ioctl SET_FORCE_LOW_DMA has never worked since the initial git check-in, and the respective setting is nowadays handled correctly. So disable it entirely. Signed-off-by:
Hannes Reinecke <hare@suse.com> Reviewed-by:
Johannes Thumshirn <jthumshirn@suse.de> Tested-by:
Christoph Hellwig <hch@lst.de> Signed-off-by:
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Vishal Verma authored
commit 24e3a7fb upstream. Due to a spec misinterpretation, the Linux implementation of the BTT log area had different padding scheme from other implementations, such as UEFI and NVML. This fixes the padding scheme, and defaults to it for new BTT layouts. We attempt to detect the padding scheme in use when probing for an existing BTT. If we detect the older/incompatible scheme, we continue using it. Reported-by:
Juston Li <juston.li@intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: <stable@vger.kernel.org> Fixes: 5212e11f ("nd_btt: atomic sector updates") Signed-off-by:
Vishal Verma <vishal.l.verma@intel.com> Signed-off-by:
Dan Williams <dan.j.williams@intel.com> Signed-off-by:
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- 17 Jan, 2018 18 commits
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Greg Kroah-Hartman authored
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Pavel Tatashin authored
The page table order must be increased for EFI table in order to avoid a bug where NMI tries to change the page table to kernel page table, while efi page table is active. For more disccussion about this bug, see this thread: http://lkml.iu.edu/hypermail/linux/kernel/1801.1/00951.htmlSigned-off-by:
Pavel Tatashin <pasha.tatashin@oracle.com> Reviewed-by:
Steven Sistare <steven.sistare@oracle.com> Acked-by:
Jiri Kosina <jkosina@suse.cz> Signed-off-by:
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Josh Poimboeuf authored
Objtool 1.0 (pre-ORC) produces the following warning when it encounters a retpoline: arch/x86/crypto/camellia-aesni-avx2-asm_64.o: warning: objtool: .altinstr_replacement+0xf: return instruction outside of a callable function That warning is meant to catch GCC bugs and missing ENTRY/ENDPROC annotations, neither of which are applicable to alternatives. Silence the warning for alternative instructions, just like objtool 2.0 already does. Reported-by:
David Woodhouse <dwmw2@infradead.org> Signed-off-by:
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Thomas Gleixner authored
commit b8b9ce4b upstream. Remove the compile time warning when CONFIG_RETPOLINE=y and the compiler does not have retpoline support. Linus rationale for this is: It's wrong because it will just make people turn off RETPOLINE, and the asm updates - and return stack clearing - that are independent of the compiler are likely the most important parts because they are likely the ones easiest to target. And it's annoying because most people won't be able to do anything about it. The number of people building their own compiler? Very small. So if their distro hasn't got a compiler yet (and pretty much nobody does), the warning is just annoying crap. It is already properly reported as part of the sysfs interface. The compile-time warning only encourages bad things. Fixes: 76b04384 ("x86/retpoline: Add initial retpoline support") Requested-by:
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Andy Lutomirski authored
commit 352909b4 upstream. This tests that the vsyscall entries do what they're expected to do. It also confirms that attempts to read the vsyscall page behave as expected. If changes are made to the vsyscall code or its memory map handling, running this test in all three of vsyscall=none, vsyscall=emulate, and vsyscall=native are helpful. (Because it's easy, this also compares the vsyscall results to their vDSO equivalents.) Note to KAISER backporters: please test this under all three vsyscall modes. Also, in the emulate and native modes, make sure that test_vsyscall_64 agrees with the command line or config option as to which mode you're in. It's quite easy to mess up the kernel such that native mode accidentally emulates or vice versa. Greg, etc: please backport this to all your Meltdown-patched kernels. It'll help make sure the patches didn't regress vsyscalls. CSigned-off-by:
Andy Lutomirski <luto@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Hugh Dickins <hughd@google.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/2b9c5a174c1d60fd7774461d518aa75598b1d8fd.1515719552.git.luto@kernel.orgSigned-off-by:
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David Woodhouse authored
commit 117cc7a9 upstream. In accordance with the Intel and AMD documentation, we need to overwrite all entries in the RSB on exiting a guest, to prevent malicious branch target predictions from affecting the host kernel. This is needed both for retpoline and for IBRS. [ak: numbers again for the RSB stuffing labels] Signed-off-by:
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Andi Kleen authored
commit 7614e913 upstream. Convert all indirect jumps in 32bit irq inline asm code to use non speculative sequences. Signed-off-by:
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David Woodhouse authored
commit 5096732f upstream. Convert all indirect jumps in 32bit checksum assembler code to use non-speculative sequences when CONFIG_RETPOLINE is enabled. Signed-off-by:
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David Woodhouse authored
commit ea08816d upstream. Convert indirect call in Xen hypercall to use non-speculative sequence, when CONFIG_RETPOLINE is enabled. Signed-off-by:
Juergen Gross <jgross@suse.com> Cc: gnomes@lxorguk.ukuu.org.uk Cc: Rik van Riel <riel@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: thomas.lendacky@amd.com Cc: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jiri Kosina <jikos@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Kees Cook <keescook@google.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org> Cc: Paul Turner <pjt@google.com> Link: https://lkml.kernel.org/r/1515707194-20531-10-git-send-email-dwmw@amazon.co.ukSigned-off-by:
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David Woodhouse authored
commit e70e5892 upstream. Convert all indirect jumps in hyperv inline asm code to use non-speculative sequences when CONFIG_RETPOLINE is enabled. Signed-off-by:
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David Woodhouse authored
commit 9351803b upstream. Convert all indirect jumps in ftrace assembler code to use non-speculative sequences when CONFIG_RETPOLINE is enabled. Signed-off-by:
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David Woodhouse authored
commit 2641f08b upstream. Convert indirect jumps in core 32/64bit entry assembler code to use non-speculative sequences when CONFIG_RETPOLINE is enabled. Don't use CALL_NOSPEC in entry_SYSCALL_64_fastpath because the return address after the 'call' instruction must be *precisely* at the .Lentry_SYSCALL_64_after_fastpath label for stub_ptregs_64 to work, and the use of alternatives will mess that up unless we play horrid games to prepend with NOPs and make the variants the same length. It's not worth it; in the case where we ALTERNATIVE out the retpoline, the first instruction at __x86.indirect_thunk.rax is going to be a bare jmp *%rax anyway. Signed-off-by:
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David Woodhouse authored
commit 9697fa39 upstream. Convert all indirect jumps in crypto assembler code to use non-speculative sequences when CONFIG_RETPOLINE is enabled. Signed-off-by:
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David Woodhouse authored
commit da285121 upstream. Add a spectre_v2= option to select the mitigation used for the indirect branch speculation vulnerability. Currently, the only option available is retpoline, in its various forms. This will be expanded to cover the new IBRS/IBPB microcode features. The RETPOLINE_AMD feature relies on a serializing LFENCE for speculation control. For AMD hardware, only set RETPOLINE_AMD if LFENCE is a serializing instruction, which is indicated by the LFENCE_RDTSC feature. [ tglx: Folded back the LFENCE/AMD fixes and reworked it so IBRS integration becomes simple ] Signed-off-by:
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David Woodhouse authored
commit 76b04384 upstream. Enable the use of -mindirect-branch=thunk-extern in newer GCC, and provide the corresponding thunks. Provide assembler macros for invoking the thunks in the same way that GCC does, from native and inline assembler. This adds X86_FEATURE_RETPOLINE and sets it by default on all CPUs. In some circumstances, IBRS microcode features may be used instead, and the retpoline can be disabled. On AMD CPUs if lfence is serialising, the retpoline can be dramatically simplified to a simple "lfence; jmp *\reg". A future patch, after it has been verified that lfence really is serialising in all circumstances, can enable this by setting the X86_FEATURE_RETPOLINE_AMD feature bit in addition to X86_FEATURE_RETPOLINE. Do not align the retpoline in the altinstr section, because there is no guarantee that it stays aligned when it's copied over the oldinstr during alternative patching. [ Andi Kleen: Rename the macros, add CONFIG_RETPOLINE option, export thunks] [ tglx: Put actual function CALL/JMP in front of the macros, convert to symbolic labels ] [ dwmw2: Convert back to numeric labels, merge objtool fixes ] Signed-off-by:
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Andrey Ryabinin authored
commit 196bd485 upstream. Currently we use current_stack_pointer() function to get the value of the stack pointer register. Since commit: f5caf621 ("x86/asm: Fix inline asm call constraints for Clang") ... we have a stack register variable declared. It can be used instead of current_stack_pointer() function which allows to optimize away some excessive "mov %rsp, %<dst>" instructions: -mov %rsp,%rdx -sub %rdx,%rax -cmp $0x3fff,%rax -ja ffffffff810722fd <ist_begin_non_atomic+0x2d> +sub %rsp,%rax +cmp $0x3fff,%rax +ja ffffffff810722fa <ist_begin_non_atomic+0x2a> Remove current_stack_pointer(), rename __asm_call_sp to current_stack_pointer and use it instead of the removed function. Signed-off-by:
Andrey Ryabinin <aryabinin@virtuozzo.com> Reviewed-by:
David Woodhouse <dwmw@amazon.co.ku> Signed-off-by:
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Josh Poimboeuf authored
commit 258c7605 upstream. Getting objtool to understand retpolines is going to be a bit of a challenge. For now, take advantage of the fact that retpolines are patched in with alternatives. Just read the original (sane) non-alternative instruction, and ignore the patched-in retpoline. This allows objtool to understand the control flow *around* the retpoline, even if it can't yet follow what's inside. This means the ORC unwinder will fail to unwind from inside a retpoline, but will work fine otherwise. Signed-off-by:
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Josh Poimboeuf authored
commit 39b73533 upstream. A direct jump to a retpoline thunk is really an indirect jump in disguise. Change the objtool instruction type accordingly. Objtool needs to know where indirect branches are so it can detect switch statement jump tables. This fixes a bunch of warnings with CONFIG_RETPOLINE like: arch/x86/events/intel/uncore_nhmex.o: warning: objtool: nhmex_rbox_msr_enable_event()+0x44: sibling call from callable instruction with modified stack frame kernel/signal.o: warning: objtool: copy_siginfo_to_user()+0x91: sibling call from callable instruction with modified stack frame ... Signed-off-by:
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