- 26 Aug, 2012 4 commits
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Daniel Vetter authored
commit 0d8957c8 upstream. We may only start to set up the new register values after having confirmed that the ring is truely off. Otherwise the hw might lose the newly written register values. This is caught later on in the init sequence, when we check whether the register writes have stuck. Reviewed-by:
Jani Nikula <jani.nikula@intel.com> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=50522Tested-by:
Yang Guang <guang.a.yang@intel.com> Signed-off-by:
Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Stefano Stabellini authored
commit b9e0d95c upstream. When the frontend and the backend reside on the same domain, even if we add pages to the m2p_override, these pages will never be returned by mfn_to_pfn because the check "get_phys_to_machine(pfn) != mfn" will always fail, so the pfn of the frontend will be returned instead (resulting in a deadlock because the frontend pages are already locked). INFO: task qemu-system-i38:1085 blocked for more than 120 seconds. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. qemu-system-i38 D ffff8800cfc137c0 0 1085 1 0x00000000 ffff8800c47ed898 0000000000000282 ffff8800be4596b0 00000000000137c0 ffff8800c47edfd8 ffff8800c47ec010 00000000000137c0 00000000000137c0 ffff8800c47edfd8 00000000000137c0 ffffffff82213020 ffff8800be4596b0 Call Trace: [<ffffffff81101ee0>] ? __lock_page+0x70/0x70 [<ffffffff81a0fdd9>] schedule+0x29/0x70 [<ffffffff81a0fe80>] io_schedule+0x60/0x80 [<ffffffff81101eee>] sleep_on_page+0xe/0x20 [<ffffffff81a0e1ca>] __wait_on_bit_lock+0x5a/0xc0 [<ffffffff81101ed7>] __lock_page+0x67/0x70 [<ffffffff8106f750>] ? autoremove_wake_function+0x40/0x40 [<ffffffff811867e6>] ? bio_add_page+0x36/0x40 [<ffffffff8110b692>] set_page_dirty_lock+0x52/0x60 [<ffffffff81186021>] bio_set_pages_dirty+0x51/0x70 [<ffffffff8118c6b4>] do_blockdev_direct_IO+0xb24/0xeb0 [<ffffffff811e71a0>] ? ext3_get_blocks_handle+0xe00/0xe00 [<ffffffff8118ca95>] __blockdev_direct_IO+0x55/0x60 [<ffffffff811e71a0>] ? ext3_get_blocks_handle+0xe00/0xe00 [<ffffffff811e91c8>] ext3_direct_IO+0xf8/0x390 [<ffffffff811e71a0>] ? ext3_get_blocks_handle+0xe00/0xe00 [<ffffffff81004b60>] ? xen_mc_flush+0xb0/0x1b0 [<ffffffff81104027>] generic_file_aio_read+0x737/0x780 [<ffffffff813bedeb>] ? gnttab_map_refs+0x15b/0x1e0 [<ffffffff811038f0>] ? find_get_pages+0x150/0x150 [<ffffffff8119736c>] aio_rw_vect_retry+0x7c/0x1d0 [<ffffffff811972f0>] ? lookup_ioctx+0x90/0x90 [<ffffffff81198856>] aio_run_iocb+0x66/0x1a0 [<ffffffff811998b8>] do_io_submit+0x708/0xb90 [<ffffffff81199d50>] sys_io_submit+0x10/0x20 [<ffffffff81a18d69>] system_call_fastpath+0x16/0x1b The explanation is in the comment within the code: We need to do this because the pages shared by the frontend (xen-blkfront) can be already locked (lock_page, called by do_read_cache_page); when the userspace backend tries to use them with direct_IO, mfn_to_pfn returns the pfn of the frontend, so do_blockdev_direct_IO is going to try to lock the same pages again resulting in a deadlock. A simplified call graph looks like this: pygrub QEMU ----------------------------------------------- do_read_cache_page io_submit | | lock_page ext3_direct_IO | bio_add_page | lock_page Internally the xen-blkback uses m2p_add_override to swizzle (temporarily) a 'struct page' to have a different MFN (so that it can point to another guest). It also can easily find out whether another pfn corresponding to the mfn exists in the m2p, and can set the FOREIGN bit in the p2m, making sure that mfn_to_pfn returns the pfn of the backend. This allows the backend to perform direct_IO on these pages, but as a side effect prevents the frontend from using get_user_pages_fast on them while they are being shared with the backend. Signed-off-by:
Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by:
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by:
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Zach Brown authored
commit fb6ccff6 upstream. Commit 7572777e attempted to verify that the total iovec from the client doesn't overflow iov_length() but it only checked the first element. The iovec could still overflow by starting with a small element. The obvious fix is to check all the elements. The overflow case doesn't look dangerous to the kernel as the copy is limited by the length after the overflow. This fix restores the intention of returning an error instead of successfully copying less than the iovec represented. I found this by code inspection. I built it but don't have a test case. I'm cc:ing stable because the initial commit did as well. Signed-off-by:
Zach Brown <zab@redhat.com> Signed-off-by:
Miklos Szeredi <mszeredi@suse.cz> Signed-off-by:
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Heiko Carstens authored
commit e8587121 upstream. The native 31 bit and the compat behaviour for the mmap system calls differ: In native 31 bit mode the passed in address for the mmap system call will be unmodified passed to sys_mmap_pgoff(). In compat mode however the passed in address will be modified with compat_ptr() which masks out the most significant bit. The result is that in native 31 bit mode each mmap request (with MAP_FIXED) will fail where the most significat bit is set, while in compat mode it may succeed. This odd behaviour was introduced with d3815898 "[S390] mmap: add missing compat_ptr conversion to both mmap compat syscalls". To restore a consistent behaviour accross native and compat mode this patch functionally reverts the above mentioned commit. Signed-off-by:
Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by:
Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by:
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- 15 Aug, 2012 36 commits
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Greg Kroah-Hartman authored
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Stanislaw Gruszka authored
commit deee0214 upstream. We can not pass NULL libconf->conf->channel to rt61pci_config() as it is dereferenced unconditionally in rt61pci_config_lna_gain() subroutine. Resolves: https://bugzilla.kernel.org/show_bug.cgi?id=44361 Reported-and-tested-by: <dolohow@gmail.com> Signed-off-by:
Stanislaw Gruszka <sgruszka@redhat.com> Signed-off-by:
John W. Linville <linville@tuxdriver.com> Signed-off-by:
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Chris Bagwell authored
commit 6dc46351 upstream. Bamboo One's with ID of 0x6a and 0x6b were added with correct indication of 1024 pressure levels but the Graphire packet routine was only looking at 9 bits. Increased to 10 bits. This bug caused these devices to roll over to zero pressure at half way mark. The other devices using this routine only support 256 or 512 range and look to fix unused bits at zero. Signed-off-by:
Chris Bagwell <chris@cnpbagwell.com> Reported-by:
Tushant Mirchandani <tushantin@gmail.com> Reviewed-by:
Ping Cheng <pingc@wacom.com> Signed-off-by:
Dmitry Torokhov <dtor@mail.ru> Signed-off-by:
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Tushar Dave authored
commit b7ec70be upstream. Found that commit d478eb44 was a bad commit. If the link partner is transmitting codeword (even if NULL codeword), then the RXCW.C bit will be set so check for RXCW.CW is unnecessary. Ref: RH BZ 840642 Reported-by:
Fabio Futigami <ffutigam@redhat.com> Signed-off-by:
Tushar Dave <tushar.n.dave@intel.com> CC: Marcelo Ricardo Leitner <mleitner@redhat.com> Tested-by:
Aaron Brown <aaron.f.brown@intel.com> Signed-off-by:
Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com> Signed-off-by:
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Liang Li authored
partial of commit 8e8b41f9 upstream. As part of commit 463454b5 ("cfg80211: fix interface combinations check"), this extra check was introduced: if ((all_iftypes & used_iftypes) != used_iftypes) goto cont; However, most wireless NIC drivers did not advertise ADHOC in wiphy.iface_combinations[i].limits[] and hence we'll get -EBUSY when we bring up a ADHOC wlan with commands similar to: # iwconfig wlan0 mode ad-hoc && ifconfig wlan0 up In commit 8e8b41f9 ("cfg80211: enforce lack of interface combinations"), the change below fixes the issue: if (total == 1) return 0; But it also introduces other dependencies for stable. For example, a full cherry pick of 8e8b41f9 would introduce additional regressions unless we also start cherry picking driver specific fixes like the following: 9b4760e3 ath5k: add possible wiphy interface combinations 1ae2fc25 mac80211_hwsim: advertise interface combinations 20c8e8dc ath9k: add possible wiphy interface combinations And the purpose of the 'if (total == 1)' is to cover the specific use case (IBSS, adhoc) that was mentioned above. So we just pick the specific part out from 8e8b41f9 here. Doing so gives stable kernels a way to fix the change introduced by 463454b5, without having to make cherry picks specific to various NIC drivers. Signed-off-by:
Liang Li <liang.li@windriver.com> Signed-off-by:
Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by:
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Daniel Drake authored
commit 1f6fc43e upstream. libertas currently calls cfg80211_disconnected() when it is being brought down. This causes an event to be allocated, but since the wdev is already removed from the rdev by the time that the event processing work executes, the event is never processed or freed. http://article.gmane.org/gmane.linux.kernel.wireless.general/95666 Fix this leak, and other possible situations, by processing the event queue when a device is being unregistered. Thanks to Johannes Berg for the suggestion. Signed-off-by:
Daniel Drake <dsd@laptop.org> Reviewed-by:
Johannes Berg <johannes@sipsolutions.net> Signed-off-by:
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Arnd Bergmann authored
commit 59ee93a5 upstream. The irq_to_gpio function was removed from the pxa platform in linux-3.2, and this driver has been broken since. There is actually no in-tree user of this driver that adds this platform device, but the driver can and does get enabled on some platforms. Without this patch, building ezx_defconfig results in: drivers/mfd/ezx-pcap.c: In function 'pcap_isr_work': drivers/mfd/ezx-pcap.c:205:2: error: implicit declaration of function 'irq_to_gpio' [-Werror=implicit-function-declaration] Signed-off-by:
Arnd Bergmann <arnd@arndb.de> Acked-by:
Haojian Zhuang <haojian.zhuang@gmail.com> Cc: Samuel Ortiz <sameo@linux.intel.com> Cc: Daniel Ribeiro <drwyrm@gmail.com> Signed-off-by:
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Marek Vasut authored
commit 3bed491c upstream. The CONFIG_DEFAULT_MMAP_MIN_ADDR was set to 65536 in mxs_defconfig, this caused severe breakage of userland applications since the upper limit for ARM is 32768. By default CONFIG_DEFAULT_MMAP_MIN_ADDR is set to 4096 and can also be changed via /proc/sys/vm/mmap_min_addr if needed. Quoting Russell King [1]: "4096 is also fine for ARM too. There's not much point in having defconfigs change it - that would just be pure noise in the config files." the CONFIG_DEFAULT_MMAP_MIN_ADDR can be removed from the defconfig altogether. This problem was introduced by commit cde7c41f (ARM: configs: add defconfig for mach-mxs). [1] http://marc.info/?l=linux-arm-kernel&m=134401593807820&w=2Signed-off-by:
Marek Vasut <marex@denx.de> Cc: Russell King <linux@arm.linux.org.uk> Cc: Wolfgang Denk <wd@denx.de> Signed-off-by:
Shawn Guo <shawn.guo@linaro.org> Signed-off-by:
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Mel Gorman authored
commit d833352a upstream. If a process creates a large hugetlbfs mapping that is eligible for page table sharing and forks heavily with children some of whom fault and others which destroy the mapping then it is possible for page tables to get corrupted. Some teardowns of the mapping encounter a "bad pmd" and output a message to the kernel log. The final teardown will trigger a BUG_ON in mm/filemap.c. This was reproduced in 3.4 but is known to have existed for a long time and goes back at least as far as 2.6.37. It was probably was introduced in 2.6.20 by [39dde65c: shared page table for hugetlb page]. The messages look like this; [ ..........] Lots of bad pmd messages followed by this [ 127.164256] mm/memory.c:391: bad pmd ffff880412e04fe8(80000003de4000e7). [ 127.164257] mm/memory.c:391: bad pmd ffff880412e04ff0(80000003de6000e7). [ 127.164258] mm/memory.c:391: bad pmd ffff880412e04ff8(80000003de0000e7). [ 127.186778] ------------[ cut here ]------------ [ 127.186781] kernel BUG at mm/filemap.c:134! [ 127.186782] invalid opcode: 0000 [#1] SMP [ 127.186783] CPU 7 [ 127.186784] Modules linked in: af_packet cpufreq_conservative cpufreq_userspace cpufreq_powersave acpi_cpufreq mperf ext3 jbd dm_mod coretemp crc32c_intel usb_storage ghash_clmulni_intel aesni_intel i2c_i801 r8169 mii uas sr_mod cdrom sg iTCO_wdt iTCO_vendor_support shpchp serio_raw cryptd aes_x86_64 e1000e pci_hotplug dcdbas aes_generic container microcode ext4 mbcache jbd2 crc16 sd_mod crc_t10dif i915 drm_kms_helper drm i2c_algo_bit ehci_hcd ahci libahci usbcore rtc_cmos usb_common button i2c_core intel_agp video intel_gtt fan processor thermal thermal_sys hwmon ata_generic pata_atiixp libata scsi_mod [ 127.186801] [ 127.186802] Pid: 9017, comm: hugetlbfs-test Not tainted 3.4.0-autobuild #53 Dell Inc. OptiPlex 990/06D7TR [ 127.186804] RIP: 0010:[<ffffffff810ed6ce>] [<ffffffff810ed6ce>] __delete_from_page_cache+0x15e/0x160 [ 127.186809] RSP: 0000:ffff8804144b5c08 EFLAGS: 00010002 [ 127.186810] RAX: 0000000000000001 RBX: ffffea000a5c9000 RCX: 00000000ffffffc0 [ 127.186811] RDX: 0000000000000000 RSI: 0000000000000009 RDI: ffff88042dfdad00 [ 127.186812] RBP: ffff8804144b5c18 R08: 0000000000000009 R09: 0000000000000003 [ 127.186813] R10: 0000000000000000 R11: 000000000000002d R12: ffff880412ff83d8 [ 127.186814] R13: ffff880412ff83d8 R14: 0000000000000000 R15: ffff880412ff83d8 [ 127.186815] FS: 00007fe18ed2c700(0000) GS:ffff88042dce0000(0000) knlGS:0000000000000000 [ 127.186816] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 127.186817] CR2: 00007fe340000503 CR3: 0000000417a14000 CR4: 00000000000407e0 [ 127.186818] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 127.186819] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [ 127.186820] Process hugetlbfs-test (pid: 9017, threadinfo ffff8804144b4000, task ffff880417f803c0) [ 127.186821] Stack: [ 127.186822] ffffea000a5c9000 0000000000000000 ffff8804144b5c48 ffffffff810ed83b [ 127.186824] ffff8804144b5c48 000000000000138a 0000000000001387 ffff8804144b5c98 [ 127.186825] ffff8804144b5d48 ffffffff811bc925 ffff8804144b5cb8 0000000000000000 [ 127.186827] Call Trace: [ 127.186829] [<ffffffff810ed83b>] delete_from_page_cache+0x3b/0x80 [ 127.186832] [<ffffffff811bc925>] truncate_hugepages+0x115/0x220 [ 127.186834] [<ffffffff811bca43>] hugetlbfs_evict_inode+0x13/0x30 [ 127.186837] [<ffffffff811655c7>] evict+0xa7/0x1b0 [ 127.186839] [<ffffffff811657a3>] iput_final+0xd3/0x1f0 [ 127.186840] [<ffffffff811658f9>] iput+0x39/0x50 [ 127.186842] [<ffffffff81162708>] d_kill+0xf8/0x130 [ 127.186843] [<ffffffff81162812>] dput+0xd2/0x1a0 [ 127.186845] [<ffffffff8114e2d0>] __fput+0x170/0x230 [ 127.186848] [<ffffffff81236e0e>] ? rb_erase+0xce/0x150 [ 127.186849] [<ffffffff8114e3ad>] fput+0x1d/0x30 [ 127.186851] [<ffffffff81117db7>] remove_vma+0x37/0x80 [ 127.186853] [<ffffffff81119182>] do_munmap+0x2d2/0x360 [ 127.186855] [<ffffffff811cc639>] sys_shmdt+0xc9/0x170 [ 127.186857] [<ffffffff81410a39>] system_call_fastpath+0x16/0x1b [ 127.186858] Code: 0f 1f 44 00 00 48 8b 43 08 48 8b 00 48 8b 40 28 8b b0 40 03 00 00 85 f6 0f 88 df fe ff ff 48 89 df e8 e7 cb 05 00 e9 d2 fe ff ff <0f> 0b 55 83 e2 fd 48 89 e5 48 83 ec 30 48 89 5d d8 4c 89 65 e0 [ 127.186868] RIP [<ffffffff810ed6ce>] __delete_from_page_cache+0x15e/0x160 [ 127.186870] RSP <ffff8804144b5c08> [ 127.186871] ---[ end trace 7cbac5d1db69f426 ]--- The bug is a race and not always easy to reproduce. To reproduce it I was doing the following on a single socket I7-based machine with 16G of RAM. $ hugeadm --pool-pages-max DEFAULT:13G $ echo $((18*1048576*1024)) > /proc/sys/kernel/shmmax $ echo $((18*1048576*1024)) > /proc/sys/kernel/shmall $ for i in `seq 1 9000`; do ./hugetlbfs-test; done On my particular machine, it usually triggers within 10 minutes but enabling debug options can change the timing such that it never hits. Once the bug is triggered, the machine is in trouble and needs to be rebooted. The machine will respond but processes accessing proc like "ps aux" will hang due to the BUG_ON. shutdown will also hang and needs a hard reset or a sysrq-b. The basic problem is a race between page table sharing and teardown. For the most part page table sharing depends on i_mmap_mutex. In some cases, it is also taking the mm->page_table_lock for the PTE updates but with shared page tables, it is the i_mmap_mutex that is more important. Unfortunately it appears to be also insufficient. Consider the following situation Process A Process B --------- --------- hugetlb_fault shmdt LockWrite(mmap_sem) do_munmap unmap_region unmap_vmas unmap_single_vma unmap_hugepage_range Lock(i_mmap_mutex) Lock(mm->page_table_lock) huge_pmd_unshare/unmap tables <--- (1) Unlock(mm->page_table_lock) Unlock(i_mmap_mutex) huge_pte_alloc ... Lock(i_mmap_mutex) ... vma_prio_walk, find svma, spte ... Lock(mm->page_table_lock) ... share spte ... Unlock(mm->page_table_lock) ... Unlock(i_mmap_mutex) ... hugetlb_no_page <--- (2) free_pgtables unlink_file_vma hugetlb_free_pgd_range remove_vma_list In this scenario, it is possible for Process A to share page tables with Process B that is trying to tear them down. The i_mmap_mutex on its own does not prevent Process A walking Process B's page tables. At (1) above, the page tables are not shared yet so it unmaps the PMDs. Process A sets up page table sharing and at (2) faults a new entry. Process B then trips up on it in free_pgtables. This patch fixes the problem by adding a new function __unmap_hugepage_range_final that is only called when the VMA is about to be destroyed. This function clears VM_MAYSHARE during unmap_hugepage_range() under the i_mmap_mutex. This makes the VMA ineligible for sharing and avoids the race. Superficially this looks like it would then be vunerable to truncate and madvise issues but hugetlbfs has its own truncate handlers so does not use unmap_mapping_range() and does not support madvise(DONTNEED). This should be treated as a -stable candidate if it is merged. Test program is as follows. The test case was mostly written by Michal Hocko with a few minor changes to reproduce this bug. ==== CUT HERE ==== static size_t huge_page_size = (2UL << 20); static size_t nr_huge_page_A = 512; static size_t nr_huge_page_B = 5632; unsigned int get_random(unsigned int max) { struct timeval tv; gettimeofday(&tv, NULL); srandom(tv.tv_usec); return random() % max; } static void play(void *addr, size_t size) { unsigned char *start = addr, *end = start + size, *a; start += get_random(size/2); /* we could itterate on huge pages but let's give it more time. */ for (a = start; a < end; a += 4096) *a = 0; } int main(int argc, char **argv) { key_t key = IPC_PRIVATE; size_t sizeA = nr_huge_page_A * huge_page_size; size_t sizeB = nr_huge_page_B * huge_page_size; int shmidA, shmidB; void *addrA = NULL, *addrB = NULL; int nr_children = 300, n = 0; if ((shmidA = shmget(key, sizeA, IPC_CREAT|SHM_HUGETLB|0660)) == -1) { perror("shmget:"); return 1; } if ((addrA = shmat(shmidA, addrA, SHM_R|SHM_W)) == (void *)-1UL) { perror("shmat"); return 1; } if ((shmidB = shmget(key, sizeB, IPC_CREAT|SHM_HUGETLB|0660)) == -1) { perror("shmget:"); return 1; } if ((addrB = shmat(shmidB, addrB, SHM_R|SHM_W)) == (void *)-1UL) { perror("shmat"); return 1; } fork_child: switch(fork()) { case 0: switch (n%3) { case 0: play(addrA, sizeA); break; case 1: play(addrB, sizeB); break; case 2: break; } break; case -1: perror("fork:"); break; default: if (++n < nr_children) goto fork_child; play(addrA, sizeA); break; } shmdt(addrA); shmdt(addrB); do { wait(NULL); } while (--n > 0); shmctl(shmidA, IPC_RMID, NULL); shmctl(shmidB, IPC_RMID, NULL); return 0; } [akpm@linux-foundation.org: name the declaration's args, fix CONFIG_HUGETLBFS=n build] Signed-off-by:
Hugh Dickins <hughd@google.com> Reviewed-by:
Michal Hocko <mhocko@suse.cz> Signed-off-by:
Mel Gorman <mgorman@suse.de> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by:
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Borislav Petkov authored
commit c9fc3f77 upstream. Microcode reloading in a per-core manner is a very bad idea for both major x86 vendors. And the thing is, we have such interface with which we can end up with different microcode versions applied on different cores of an otherwise homogeneous wrt (family,model,stepping) system. So turn off the possibility of doing that per core and allow it only system-wide. This is a minimal fix which we'd like to see in stable too thus the more-or-less arbitrary decision to allow system-wide reloading only on the BSP: $ echo 1 > /sys/devices/system/cpu/cpu0/microcode/reload ... and disable the interface on the other cores: $ echo 1 > /sys/devices/system/cpu/cpu23/microcode/reload -bash: echo: write error: Invalid argument Also, allowing the reload only from one CPU (the BSP in that case) doesn't allow the reload procedure to degenerate into an O(n^2) deal when triggering reloads from all /sys/devices/system/cpu/cpuX/microcode/reload sysfs nodes simultaneously. A more generic fix will follow. Signed-off-by:
Borislav Petkov <borislav.petkov@amd.com> Cc: Henrique de Moraes Holschuh <hmh@hmh.eng.br> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1340280437-7718-2-git-send-email-bp@amd64.orgSigned-off-by:
H. Peter Anvin <hpa@zytor.com> Signed-off-by:
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Shuah Khan authored
commit e826abd5 upstream. Change reload_for_cpu() in kernel/microcode_core.c to call kstrtoul() instead of calling obsoleted simple_strtoul(). Signed-off-by:
Shuah Khan <shuahkhan@gmail.com> Reviewed-by:
Borislav Petkov <bp@alien8.de> Link: http://lkml.kernel.org/r/1336324264.2897.9.camel@lorien2Signed-off-by:
H. Peter Anvin <hpa@linux.intel.com> Cc: Henrique de Moraes Holschuh <hmh@hmh.eng.br> Signed-off-by:
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H. Peter Anvin authored
commit d2e7c96a upstream. Mix in any architectural randomness in extract_buf() instead of xfer_secondary_buf(). This allows us to mix in more architectural randomness, and it also makes xfer_secondary_buf() faster, moving a tiny bit of additional CPU overhead to process which is extracting the randomness. [ Commit description modified by tytso to remove an extended advertisement for the RDRAND instruction. ] Signed-off-by:
Ingo Molnar <mingo@kernel.org> Cc: DJ Johnston <dj.johnston@intel.com> Signed-off-by:
Theodore Ts'o <tytso@mit.edu> Signed-off-by:
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Tony Luck authored
commit d114a333 upstream. Send the entire DMI (SMBIOS) table to the /dev/random driver to help seed its pools. Signed-off-by:
Tony Luck <tony.luck@intel.com> Signed-off-by:
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Tony Luck authored
commit cbc96b75 upstream. Many platforms have per-machine instance data (serial numbers, asset tags, etc.) squirreled away in areas that are accessed during early system bringup. Mixing this data into the random pools has a very high value in providing better random data, so we should allow (and even encourage) architecture code to call add_device_randomness() from the setup_arch() paths. However, this limits our options for internal structure of the random driver since random_initialize() is not called until long after setup_arch(). Add a big fat comment to rand_initialize() spelling out this requirement. Suggested-by:
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Theodore Ts'o authored
commit c5857ccf upstream. With the new interrupt sampling system, we are no longer using the timer_rand_state structure in the irq descriptor, so we can stop initializing it now. [ Merged in fixes from Sedat to find some last missing references to rand_initialize_irq() ] Signed-off-by:
Sedat Dilek <sedat.dilek@gmail.com> Signed-off-by:
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Mark Brown authored
commit 27130f0c upstream. wm831x devices contain a unique ID value. Feed this into the newly added device_add_randomness() to add some per device seed data to the pool. Signed-off-by:
Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by:
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Mark Brown authored
commit 9dccf55f upstream. The tamper evident features of the RTC include the "write counter" which is a pseudo-random number regenerated whenever we set the RTC. Since this value is unpredictable it should provide some useful seeding to the random number generator. Only do this on boot since the goal is to seed the pool rather than add useful entropy. Signed-off-by:
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Theodore Ts'o authored
commit 330e0a01 upstream. Matt Mackall stepped down as the /dev/random driver maintainer last year, so Theodore Ts'o is taking back the /dev/random driver. Cc: Matt Mackall <mpm@selenic.com> Signed-off-by:
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Theodore Ts'o authored
commit 00ce1db1 upstream. Signed-off-by:
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Theodore Ts'o authored
commit c2557a30 upstream. Create a new function, get_random_bytes_arch() which will use the architecture-specific hardware random number generator if it is present. Change get_random_bytes() to not use the HW RNG, even if it is avaiable. The reason for this is that the hw random number generator is fast (if it is present), but it requires that we trust the hardware manufacturer to have not put in a back door. (For example, an increasing counter encrypted by an AES key known to the NSA.) It's unlikely that Intel (for example) was paid off by the US Government to do this, but it's impossible for them to prove otherwise --- especially since Bull Mountain is documented to use AES as a whitener. Hence, the output of an evil, trojan-horse version of RDRAND is statistically indistinguishable from an RDRAND implemented to the specifications claimed by Intel. Short of using a tunnelling electronic microscope to reverse engineer an Ivy Bridge chip and disassembling and analyzing the CPU microcode, there's no way for us to tell for sure. Since users of get_random_bytes() in the Linux kernel need to be able to support hardware systems where the HW RNG is not present, most time-sensitive users of this interface have already created their own cryptographic RNG interface which uses get_random_bytes() as a seed. So it's much better to use the HW RNG to improve the existing random number generator, by mixing in any entropy returned by the HW RNG into /dev/random's entropy pool, but to always _use_ /dev/random's entropy pool. This way we get almost of the benefits of the HW RNG without any potential liabilities. The only benefits we forgo is the speed/performance enhancements --- and generic kernel code can't depend on depend on get_random_bytes() having the speed of a HW RNG anyway. For those places that really want access to the arch-specific HW RNG, if it is available, we provide get_random_bytes_arch(). Signed-off-by:
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Theodore Ts'o authored
commit e6d4947b upstream. If the CPU supports a hardware random number generator, use it in xfer_secondary_pool(), where it will significantly improve things and where we can afford it. Also, remove the use of the arch-specific rng in add_timer_randomness(), since the call is significantly slower than get_cycles(), and we're much better off using it in xfer_secondary_pool() anyway. Signed-off-by:
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Theodore Ts'o authored
commit 7bf23575 upstream. Signed-off-by:
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Theodore Ts'o authored
commit b04b3156 upstream. Send the USB device's serial, product, and manufacturer strings to the /dev/random driver to help seed its pools. Cc: Linus Torvalds <torvalds@linux-foundation.org> Acked-by:
Greg KH <greg@kroah.com> Signed-off-by:
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Linus Torvalds authored
commit a2080a67 upstream. Add a new interface, add_device_randomness() for adding data to the random pool that is likely to differ between two devices (or possibly even per boot). This would be things like MAC addresses or serial numbers, or the read-out of the RTC. This does *not* add any actual entropy to the pool, but it initializes the pool to different values for devices that might otherwise be identical and have very little entropy available to them (particularly common in the embedded world). [ Modified by tytso to mix in a timestamp, since there may be some variability caused by the time needed to detect/configure the hardware in question. ] Signed-off-by:
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Theodore Ts'o authored
commit 902c098a upstream. The real-time Linux folks don't like add_interrupt_randomness() taking a spinlock since it is called in the low-level interrupt routine. This also allows us to reduce the overhead in the fast path, for the random driver, which is the interrupt collection path. Signed-off-by:
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Theodore Ts'o authored
commit 775f4b29 upstream. We've been moving away from add_interrupt_randomness() for various reasons: it's too expensive to do on every interrupt, and flooding the CPU with interrupts could theoretically cause bogus floods of entropy from a somewhat externally controllable source. This solves both problems by limiting the actual randomness addition to just once a second or after 64 interrupts, whicever comes first. During that time, the interrupt cycle data is buffered up in a per-cpu pool. Also, we make sure the the nonblocking pool used by urandom is initialized before we start feeding the normal input pool. This assures that /dev/urandom is returning unpredictable data as soon as possible. (Based on an original patch by Linus, but significantly modified by tytso.) Tested-by:
Eric Wustrow <ewust@umich.edu> Reported-by:
Nadia Heninger <nadiah@cs.ucsd.edu> Reported-by:
Zakir Durumeric <zakir@umich.edu> Reported-by:
J. Alex Halderman <jhalderm@umich.edu> Signed-off-by:
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Mathieu Desnoyers authored
commit 44e4360f upstream. /proc/sys/kernel/random/boot_id can be read concurrently by userspace processes. If two (or more) user-space processes concurrently read boot_id when sysctl_bootid is not yet assigned, a race can occur making boot_id differ between the reads. Because the whole point of the boot id is to be unique across a kernel execution, fix this by protecting this operation with a spinlock. Given that this operation is not frequently used, hitting the spinlock on each call should not be an issue. Signed-off-by:
Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Matt Mackall <mpm@selenic.com> Signed-off-by:
Eric Dumazet <eric.dumazet@gmail.com> Cc: Greg Kroah-Hartman <greg@kroah.com> Signed-off-by:
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H. Peter Anvin authored
commit 2dac8e54 upstream. When we are initializing using arch_get_random_long() we only need to loop enough times to touch all the bytes in the buffer; using poolwords for that does twice the number of operations necessary on a 64-bit machine, since in the random number generator code "word" means 32 bits. Signed-off-by:
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Theodore Ts'o authored
commit 3e88bdff upstream. If there is an architecture-specific random number generator (such as RDRAND for Intel architectures), use it to initialize /dev/random's entropy stores. Even in the worst case, if RDRAND is something like AES(NSA_KEY, counter++), it won't hurt, and it will definitely help against any other adversaries. Signed-off-by:
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Linus Torvalds authored
commit cf833d0b upstream. We still don't use rdrand in /dev/random, which just seems stupid. We accept the *cycle*counter* as a random input, but we don't accept rdrand? That's just broken. Sure, people can do things in user space (write to /dev/random, use rdrand in addition to /dev/random themselves etc etc), but that *still* seems to be a particularly stupid reason for saying "we shouldn't bother to try to do better in /dev/random". And even if somebody really doesn't trust rdrand as a source of random bytes, it seems singularly stupid to trust the cycle counter *more*. So I'd suggest the attached patch. I'm not going to even bother arguing that we should add more bits to the entropy estimate, because that's not the point - I don't care if /dev/random fills up slowly or not, I think it's just stupid to not use the bits we can get from rdrand and mix them into the strong randomness pool. Link: http://lkml.kernel.org/r/CA%2B55aFwn59N1=m651QAyTy-1gO1noGbK18zwKDwvwqnravA84A@mail.gmail.comAcked-by:
"David S. Miller" <davem@davemloft.net> Acked-by:
Herbert Xu <herbert@gondor.apana.org.au> Cc: Matt Mackall <mpm@selenic.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by:
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Luck, Tony authored
commit bd29e568 upstream. If there is an architecture-specific random number generator we use it to acquire randomness one "long" at a time. We should put these random words into consecutive words in the result buffer - not just overwrite the first word again and again. Signed-off-by:
Thomas Gleixner <tglx@linutronix.de> Signed-off-by:
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H. Peter Anvin authored
commit 63d77173 upstream. Add support for architecture-specific hooks into the kernel-directed random number generator interfaces. This patchset does not use the architecture random number generator interfaces for the userspace-directed interfaces (/dev/random and /dev/urandom), thus eliminating the need to distinguish between them based on a pool pointer. Changes in version 3: - Moved the hooks from extract_entropy() to get_random_bytes(). - Changes the hooks to inlines. Signed-off-by:
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Alan Cox authored
commit d6250a3f upstream. The Intel case falls through into the generic case which then changes the values. For cases like the P6 it doesn't do the right thing so this seems to be a screwup. Signed-off-by:
Alan Cox <alan@linux.intel.com> Link: http://lkml.kernel.org/n/tip-lww2uirad4skzjlmrm0vru8o@git.kernel.orgSigned-off-by:
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Johannes Berg authored
commit dd4c9260 upstream. The mesh path timer needs to be canceled when leaving the mesh as otherwise it could fire after the interface has been removed already. Signed-off-by:
Johannes Berg <johannes.berg@intel.com> Signed-off-by:
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Xiao Guangrong authored
commit 3ad3d901 upstream. mmu_notifier_release() is called when the process is exiting. It will delete all the mmu notifiers. But at this time the page belonging to the process is still present in page tables and is present on the LRU list, so this race will happen: CPU 0 CPU 1 mmu_notifier_release: try_to_unmap: hlist_del_init_rcu(&mn->hlist); ptep_clear_flush_notify: mmu nofifler not found free page !!!!!! /* * At the point, the page has been * freed, but it is still mapped in * the secondary MMU. */ mn->ops->release(mn, mm); Then the box is not stable and sometimes we can get this bug: [ 738.075923] BUG: Bad page state in process migrate-perf pfn:03bec [ 738.075931] page:ffffea00000efb00 count:0 mapcount:0 mapping: (null) index:0x8076 [ 738.075936] page flags: 0x20000000000014(referenced|dirty) The same issue is present in mmu_notifier_unregister(). We can call ->release before deleting the notifier to ensure the page has been unmapped from the secondary MMU before it is freed. Signed-off-by:
Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Cc: Avi Kivity <avi@redhat.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by:
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Will Deacon authored
commit b74253f7 upstream. The vivt_flush_cache_{range,page} functions check that the mm_struct of the VMA being flushed has been active on the current CPU before performing the cache maintenance. The gate_vma has a NULL mm_struct pointer and, as such, will cause a kernel fault if we try to flush it with the above operations. This happens during ELF core dumps, which include the gate_vma as it may be useful for debugging purposes. This patch adds checks to the VIVT cache flushing functions so that VMAs with a NULL mm_struct are flushed unconditionally (the vectors page may be dirty if we use it to store the current TLS pointer). Reported-by:
Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org> Tested-by:
Uros Bizjak <ubizjak@gmail.com> Signed-off-by:
Will Deacon <will.deacon@arm.com> Signed-off-by:
Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by:
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