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2018-10-18Linux 4.14.77v4.14.77Greg Kroah-Hartman
2018-10-18perf tools: Fix snprint warnings for gcc 8Jiri Olsa
commit 77f18153c080855e1c3fb520ca31a4e61530121d upstream. With gcc 8 we get new set of snprintf() warnings that breaks the compilation, one example: tests/mem.c: In function ‘check’: tests/mem.c:19:48: error: ‘%s’ directive output may be truncated writing \ up to 99 bytes into a region of size 89 [-Werror=format-truncation=] snprintf(failure, sizeof failure, "unexpected %s", out); The gcc docs says: To avoid the warning either use a bigger buffer or handle the function's return value which indicates whether or not its output has been truncated. Given that all these warnings are harmless, because the code either properly fails due to uncomplete file path or we don't care for truncated output at all, I'm changing all those snprintf() calls to scnprintf(), which actually 'checks' for the snprint return value so the gcc stays silent. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Link: http://lkml.kernel.org/r/20180319082902.4518-1-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Ignat Korchagin <ignat@cloudflare.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-18ARM: spectre-v1: mitigate user accessesRussell King
Commit a3c0f84765bb429ba0fd23de1c57b5e1591c9389 upstream. Spectre variant 1 attacks are about this sequence of pseudo-code: index = load(user-manipulated pointer); access(base + index * stride); In order for the cache side-channel to work, the access() must me made to memory which userspace can detect whether cache lines have been loaded. On 32-bit ARM, this must be either user accessible memory, or a kernel mapping of that same user accessible memory. The problem occurs when the load() speculatively loads privileged data, and the subsequent access() is made to user accessible memory. Any load() which makes use of a user-maniplated pointer is a potential problem if the data it has loaded is used in a subsequent access. This also applies for the access() if the data loaded by that access is used by a subsequent access. Harden the get_user() accessors against Spectre attacks by forcing out of bounds addresses to a NULL pointer. This prevents get_user() being used as the load() step above. As a side effect, put_user() will also be affected even though it isn't implicated. Also harden copy_from_user() by redoing the bounds check within the arm_copy_from_user() code, and NULLing the pointer if out of bounds. Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: David A. Long <dave.long@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-18ARM: spectre-v1: use get_user() for __get_user()Russell King
Commit b1cd0a14806321721aae45f5446ed83a3647c914 upstream. Fixing __get_user() for spectre variant 1 is not sane: we would have to add address space bounds checking in order to validate that the location should be accessed, and then zero the address if found to be invalid. Since __get_user() is supposed to avoid the bounds check, and this is exactly what get_user() does, there's no point having two different implementations that are doing the same thing. So, when the Spectre workarounds are required, make __get_user() an alias of get_user(). Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: David A. Long <dave.long@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-18ARM: use __inttype() in get_user()Russell King
Commit d09fbb327d670737ab40fd8bbb0765ae06b8b739 upstream. Borrow the x86 implementation of __inttype() to use in get_user() to select an integer type suitable to temporarily hold the result value. This is necessary to avoid propagating the volatile nature of the result argument, which can cause the following warning: lib/iov_iter.c:413:5: warning: optimization may eliminate reads and/or writes to register variables [-Wvolatile-register-var] Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: David A. Long <dave.long@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-18ARM: oabi-compat: copy semops using __copy_from_user()Russell King
Commit 8c8484a1c18e3231648f5ba7cc5ffb7fd70b3ca4 upstream. __get_user_error() is used as a fast accessor to make copying structure members as efficient as possible. However, with software PAN and the recent Spectre variant 1, the efficiency is reduced as these are no longer fast accessors. In the case of software PAN, it has to switch the domain register around each access, and with Spectre variant 1, it would have to repeat the access_ok() check for each access. Rather than using __get_user_error() to copy each semops element member, copy each semops element in full using __copy_from_user(). Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: David A. Long <dave.long@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-18ARM: vfp: use __copy_from_user() when restoring VFP stateRussell King
Commit 42019fc50dfadb219f9e6ddf4c354f3837057d80 upstream. __get_user_error() is used as a fast accessor to make copying structure members in the signal handling path as efficient as possible. However, with software PAN and the recent Spectre variant 1, the efficiency is reduced as these are no longer fast accessors. In the case of software PAN, it has to switch the domain register around each access, and with Spectre variant 1, it would have to repeat the access_ok() check for each access. Use __copy_from_user() rather than __get_user_err() for individual members when restoring VFP state. Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: David A. Long <dave.long@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-18ARM: signal: copy registers using __copy_from_user()Russell King
Commit c32cd419d6650e42b9cdebb83c672ec945e6bd7e upstream. __get_user_error() is used as a fast accessor to make copying structure members in the signal handling path as efficient as possible. However, with software PAN and the recent Spectre variant 1, the efficiency is reduced as these are no longer fast accessors. In the case of software PAN, it has to switch the domain register around each access, and with Spectre variant 1, it would have to repeat the access_ok() check for each access. It becomes much more efficient to use __copy_from_user() instead, so let's use this for the ARM integer registers. Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: David A. Long <dave.long@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-18ARM: spectre-v1: fix syscall entryRussell King
Commit 10573ae547c85b2c61417ff1a106cffbfceada35 upstream. Prevent speculation at the syscall table decoding by clamping the index used to zero on invalid system call numbers, and using the csdb speculative barrier. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Acked-by: Mark Rutland <mark.rutland@arm.com> Boot-tested-by: Tony Lindgren <tony@atomide.com> Reviewed-by: Tony Lindgren <tony@atomide.com> Signed-off-by: David A. Long <dave.long@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-18ARM: spectre-v1: add array_index_mask_nospec() implementationRussell King
Commit 1d4238c56f9816ce0f9c8dbe42d7f2ad81cb6613 upstream. Add an implementation of the array_index_mask_nospec() function for mitigating Spectre variant 1 throughout the kernel. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Acked-by: Mark Rutland <mark.rutland@arm.com> Boot-tested-by: Tony Lindgren <tony@atomide.com> Reviewed-by: Tony Lindgren <tony@atomide.com> Signed-off-by: David A. Long <dave.long@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-18ARM: spectre-v1: add speculation barrier (csdb) macrosRussell King
Commit a78d156587931a2c3b354534aa772febf6c9e855 upstream. Add assembly and C macros for the new CSDB instruction. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Acked-by: Mark Rutland <mark.rutland@arm.com> Boot-tested-by: Tony Lindgren <tony@atomide.com> Reviewed-by: Tony Lindgren <tony@atomide.com> Signed-off-by: David A. Long <dave.long@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-18ARM: KVM: report support for SMCCC_ARCH_WORKAROUND_1Russell King
Commit add5609877c6785cc002c6ed7e008b1d61064439 upstream. Report support for SMCCC_ARCH_WORKAROUND_1 to KVM guests for affected CPUs. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Boot-tested-by: Tony Lindgren <tony@atomide.com> Reviewed-by: Tony Lindgren <tony@atomide.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: David A. Long <dave.long@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-18ARM: KVM: Add SMCCC_ARCH_WORKAROUND_1 fast handlingRussell King
Commit b800acfc70d9fb81fbd6df70f2cf5e20f70023d0 upstream. We want SMCCC_ARCH_WORKAROUND_1 to be fast. As fast as possible. So let's intercept it as early as we can by testing for the function call number as soon as we've identified a HVC call coming from the guest. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Boot-tested-by: Tony Lindgren <tony@atomide.com> Reviewed-by: Tony Lindgren <tony@atomide.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: David A. Long <dave.long@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-18ARM: spectre-v2: KVM: invalidate icache on guest exit for Brahma B15Russell King
Commit 3c908e16396d130608e831b7fac4b167a2ede6ba upstream. Include Brahma B15 in the Spectre v2 KVM workarounds. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Acked-by: Florian Fainelli <f.fainelli@gmail.com> Boot-tested-by: Tony Lindgren <tony@atomide.com> Reviewed-by: Tony Lindgren <tony@atomide.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: David A. Long <dave.long@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-18ARM: KVM: invalidate icache on guest exit for Cortex-A15Marc Zyngier
Commit 0c47ac8cd157727e7a532d665d6fb1b5fd333977 upstream. In order to avoid aliasing attacks against the branch predictor on Cortex-A15, let's invalidate the BTB on guest exit, which can only be done by invalidating the icache (with ACTLR[0] being set). We use the same hack as for A12/A17 to perform the vector decoding. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Boot-tested-by: Tony Lindgren <tony@atomide.com> Reviewed-by: Tony Lindgren <tony@atomide.com> Signed-off-by: David A. Long <dave.long@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-18ARM: KVM: invalidate BTB on guest exit for Cortex-A12/A17Marc Zyngier
Commit 3f7e8e2e1ebda787f156ce46e3f0a9ce2833fa4f upstream. In order to avoid aliasing attacks against the branch predictor, let's invalidate the BTB on guest exit. This is made complicated by the fact that we cannot take a branch before invalidating the BTB. We only apply this to A12 and A17, which are the only two ARM cores on which this useful. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Boot-tested-by: Tony Lindgren <tony@atomide.com> Reviewed-by: Tony Lindgren <tony@atomide.com> Signed-off-by: David A. Long <dave.long@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-18ARM: spectre-v2: warn about incorrect context switching functionsRussell King
Commit c44f366ea7c85e1be27d08f2f0880f4120698125 upstream. Warn at error level if the context switching function is not what we are expecting. This can happen with big.Little systems, which we currently do not support. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Boot-tested-by: Tony Lindgren <tony@atomide.com> Reviewed-by: Tony Lindgren <tony@atomide.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: David A. Long <dave.long@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-18ARM: spectre-v2: add firmware based hardeningRussell King
Commit 10115105cb3aa17b5da1cb726ae8dd5f6854bd93 upstream. Add firmware based hardening for cores that require more complex handling in firmware. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Boot-tested-by: Tony Lindgren <tony@atomide.com> Reviewed-by: Tony Lindgren <tony@atomide.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: David A. Long <dave.long@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-18ARM: spectre-v2: harden user aborts in kernel spaceRussell King
Commit f5fe12b1eaee220ce62ff9afb8b90929c396595f upstream. In order to prevent aliasing attacks on the branch predictor, invalidate the BTB or instruction cache on CPUs that are known to be affected when taking an abort on a address that is outside of a user task limit: Cortex A8, A9, A12, A17, A73, A75: flush BTB. Cortex A15, Brahma B15: invalidate icache. If the IBE bit is not set, then there is little point to enabling the workaround. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Boot-tested-by: Tony Lindgren <tony@atomide.com> Reviewed-by: Tony Lindgren <tony@atomide.com> Signed-off-by: David A. Long <dave.long@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-18ARM: spectre-v2: add Cortex A8 and A15 validation of the IBE bitRussell King
Commit e388b80288aade31135aca23d32eee93dd106795 upstream. When the branch predictor hardening is enabled, firmware must have set the IBE bit in the auxiliary control register. If this bit has not been set, the Spectre workarounds will not be functional. Add validation that this bit is set, and print a warning at alert level if this is not the case. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Boot-tested-by: Tony Lindgren <tony@atomide.com> Reviewed-by: Tony Lindgren <tony@atomide.com> Signed-off-by: David A. Long <dave.long@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-18ARM: spectre-v2: harden branch predictor on context switchesRussell King
Commit 06c23f5ffe7ad45b908d0fff604dae08a7e334b9 upstream. Required manual merge of arch/arm/mm/proc-v7.S. Harden the branch predictor against Spectre v2 attacks on context switches for ARMv7 and later CPUs. We do this by: Cortex A9, A12, A17, A73, A75: invalidating the BTB. Cortex A15, Brahma B15: invalidating the instruction cache. Cortex A57 and Cortex A72 are not addressed in this patch. Cortex R7 and Cortex R8 are also not addressed as we do not enforce memory protection on these cores. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Boot-tested-by: Tony Lindgren <tony@atomide.com> Reviewed-by: Tony Lindgren <tony@atomide.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: David A. Long <dave.long@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-18ARM: spectre: add Kconfig symbol for CPUs vulnerable to SpectreRussell King
Commit c58d237d0852a57fde9bc2c310972e8f4e3d155d upstream. Add a Kconfig symbol for CPUs which are vulnerable to the Spectre attacks. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Boot-tested-by: Tony Lindgren <tony@atomide.com> Reviewed-by: Tony Lindgren <tony@atomide.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: David A. Long <dave.long@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-18ARM: bugs: add support for per-processor bug checkingRussell King
Commit 9d3a04925deeabb97c8e26d940b501a2873e8af3 upstream. Add support for per-processor bug checking - each processor function descriptor gains a function pointer for this check, which must not be an __init function. If non-NULL, this will be called whenever a CPU enters the kernel via which ever path (boot CPU, secondary CPU startup, CPU resuming, etc.) This allows processor specific bug checks to validate that workaround bits are properly enabled by firmware via all entry paths to the kernel. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Boot-tested-by: Tony Lindgren <tony@atomide.com> Reviewed-by: Tony Lindgren <tony@atomide.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: David A. Long <dave.long@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-18ARM: bugs: hook processor bug checking into SMP and suspend pathsRussell King
Commit 26602161b5ba795928a5a719fe1d5d9f2ab5c3ef upstream. Check for CPU bugs when secondary processors are being brought online, and also when CPUs are resuming from a low power mode. This gives an opportunity to check that processor specific bug workarounds are correctly enabled for all paths that a CPU re-enters the kernel. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Boot-tested-by: Tony Lindgren <tony@atomide.com> Reviewed-by: Tony Lindgren <tony@atomide.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: David A. Long <dave.long@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-18ARM: bugs: prepare processor bug infrastructureRussell King
Commit a5b9177f69329314721aa7022b7e69dab23fa1f0 upstream. Prepare the processor bug infrastructure so that it can be expanded to check for per-processor bugs. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Boot-tested-by: Tony Lindgren <tony@atomide.com> Reviewed-by: Tony Lindgren <tony@atomide.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: David A. Long <dave.long@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-18ARM: add more CPU part numbers for Cortex and Brahma B15 CPUsRussell King
Commit f5683e76f35b4ec5891031b6a29036efe0a1ff84 upstream. Add CPU part numbers for Cortex A53, A57, A72, A73, A75 and the Broadcom Brahma B15 CPU. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Acked-by: Florian Fainelli <f.fainelli@gmail.com> Boot-tested-by: Tony Lindgren <tony@atomide.com> Reviewed-by: Tony Lindgren <tony@atomide.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: David A. Long <dave.long@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-18mm: don't show nr_indirectly_reclaimable in /proc/vmstatRoman Gushchin
commit 7aaf7727235870f497eb928f728f7773d6df3b40 upstream. Don't show nr_indirectly_reclaimable in /proc/vmstat, because there is no need to export this vm counter to userspace, and some changes are expected in reclaimable object accounting, which can alter this counter. Link: http://lkml.kernel.org/r/20180425191422.9159-1-guro@fb.com Signed-off-by: Roman Gushchin <guro@fb.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: David Rientjes <rientjes@google.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>
2018-10-18mm: treat indirectly reclaimable memory as free in overcommit logicRoman Gushchin
commit d79f7aa496fc94d763f67b833a1f36f4c171176f upstream. Indirectly reclaimable memory can consume a significant part of total memory and it's actually reclaimable (it will be released under actual memory pressure). So, the overcommit logic should treat it as free. Otherwise, it's possible to cause random system-wide memory allocation failures by consuming a significant amount of memory by indirectly reclaimable memory, e.g. dentry external names. If overcommit policy GUESS is used, it might be used for denial of service attack under some conditions. The following program illustrates the approach. It causes the kernel to allocate an unreclaimable kmalloc-256 chunk for each stat() call, so that at some point the overcommit logic may start blocking large allocation system-wide. int main() { char buf[256]; unsigned long i; struct stat statbuf; buf[0] = '/'; for (i = 1; i < sizeof(buf); i++) buf[i] = '_'; for (i = 0; 1; i++) { sprintf(&buf[248], "%8lu", i); stat(buf, &statbuf); } return 0; } This patch in combination with related indirectly reclaimable memory patches closes this issue. Link: http://lkml.kernel.org/r/20180313130041.8078-1-guro@fb.com Signed-off-by: Roman Gushchin <guro@fb.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> 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>
2018-10-18dcache: account external names as indirectly reclaimable memoryRoman Gushchin
commit f1782c9bc547754f4bd3043fe8cfda53db85f13f upstream. I received a report about suspicious growth of unreclaimable slabs on some machines. I've found that it happens on machines with low memory pressure, and these unreclaimable slabs are external names attached to dentries. External names are allocated using generic kmalloc() function, so they are accounted as unreclaimable. But they are held by dentries, which are reclaimable, and they will be reclaimed under the memory pressure. In particular, this breaks MemAvailable calculation, as it doesn't take unreclaimable slabs into account. This leads to a silly situation, when a machine is almost idle, has no memory pressure and therefore has a big dentry cache. And the resulting MemAvailable is too low to start a new workload. To address the issue, the NR_INDIRECTLY_RECLAIMABLE_BYTES counter is used to track the amount of memory, consumed by external names. The counter is increased in the dentry allocation path, if an external name structure is allocated; and it's decreased in the dentry freeing path. To reproduce the problem I've used the following Python script: import os for iter in range (0, 10000000): try: name = ("/some_long_name_%d" % iter) + "_" * 220 os.stat(name) except Exception: pass Without this patch: $ cat /proc/meminfo | grep MemAvailable MemAvailable: 7811688 kB $ python indirect.py $ cat /proc/meminfo | grep MemAvailable MemAvailable: 2753052 kB With the patch: $ cat /proc/meminfo | grep MemAvailable MemAvailable: 7809516 kB $ python indirect.py $ cat /proc/meminfo | grep MemAvailable MemAvailable: 7749144 kB [guro@fb.com: fix indirectly reclaimable memory accounting for CONFIG_SLOB] Link: http://lkml.kernel.org/r/20180312194140.19517-1-guro@fb.com [guro@fb.com: fix indirectly reclaimable memory accounting] Link: http://lkml.kernel.org/r/20180313125701.7955-1-guro@fb.com Link: http://lkml.kernel.org/r/20180305133743.12746-5-guro@fb.com Signed-off-by: Roman Gushchin <guro@fb.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@techsingularity.net> 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>
2018-10-18mm: treat indirectly reclaimable memory as available in MemAvailableRoman Gushchin
commit 034ebf65c3c21d85b963d39f992258a64a85e3a9 upstream. Adjust /proc/meminfo MemAvailable calculation by adding the amount of indirectly reclaimable memory (rounded to the PAGE_SIZE). Link: http://lkml.kernel.org/r/20180305133743.12746-4-guro@fb.com Signed-off-by: Roman Gushchin <guro@fb.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@techsingularity.net> 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>
2018-10-18mm: introduce NR_INDIRECTLY_RECLAIMABLE_BYTESRoman Gushchin
commit eb59254608bc1d42c4c6afdcdce9c0d3ce02b318 upstream. Patch series "indirectly reclaimable memory", v2. This patchset introduces the concept of indirectly reclaimable memory and applies it to fix the issue of when a big number of dentries with external names can significantly affect the MemAvailable value. This patch (of 3): Introduce a concept of indirectly reclaimable memory and adds the corresponding memory counter and /proc/vmstat item. Indirectly reclaimable memory is any sort of memory, used by the kernel (except of reclaimable slabs), which is actually reclaimable, i.e. will be released under memory pressure. The counter is in bytes, as it's not always possible to count such objects in pages. The name contains BYTES by analogy to NR_KERNEL_STACK_KB. Link: http://lkml.kernel.org/r/20180305133743.12746-2-guro@fb.com Signed-off-by: Roman Gushchin <guro@fb.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@techsingularity.net> 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>
2018-10-18xhci: Don't print a warning when setting link state for disabled portsMathias Nyman
commit 1208d8a84fdcae6b395c57911cdf907450d30e70 upstream. When disabling a USB3 port the hub driver will set the port link state to U3 to prevent "ejected" or "safely removed" devices that are still physically connected from immediately re-enumerating. If the device was really unplugged, then error messages were printed as the hub tries to set the U3 link state for a port that is no longer enabled. xhci-hcd ee000000.usb: Cannot set link state. usb usb8-port1: cannot disable (err = -32) Don't print error message in xhci-hub if hub tries to set port link state for a disabled port. Return -ENODEV instead which also silences hub driver. Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Tested-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Signed-off-by: Ross Zwisler <zwisler@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-18i2c: i2c-scmi: fix for i2c_smbus_write_block_dataEdgar Cherkasov
commit 08d9db00fe0e300d6df976e6c294f974988226dd upstream. The i2c-scmi driver crashes when the SMBus Write Block transaction is executed: WARNING: CPU: 9 PID: 2194 at mm/page_alloc.c:3931 __alloc_pages_slowpath+0x9db/0xec0 Call Trace: ? get_page_from_freelist+0x49d/0x11f0 ? alloc_pages_current+0x6a/0xe0 ? new_slab+0x499/0x690 __alloc_pages_nodemask+0x265/0x280 alloc_pages_current+0x6a/0xe0 kmalloc_order+0x18/0x40 kmalloc_order_trace+0x24/0xb0 ? acpi_ut_allocate_object_desc_dbg+0x62/0x10c __kmalloc+0x203/0x220 acpi_os_allocate_zeroed+0x34/0x36 acpi_ut_copy_eobject_to_iobject+0x266/0x31e acpi_evaluate_object+0x166/0x3b2 acpi_smbus_cmi_access+0x144/0x530 [i2c_scmi] i2c_smbus_xfer+0xda/0x370 i2cdev_ioctl_smbus+0x1bd/0x270 i2cdev_ioctl+0xaa/0x250 do_vfs_ioctl+0xa4/0x600 SyS_ioctl+0x79/0x90 do_syscall_64+0x73/0x130 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 ACPI Error: Evaluating _SBW: 4 (20170831/smbus_cmi-185) This problem occurs because the length of ACPI Buffer object is not defined/initialized in the code before a corresponding ACPI method is called. The obvious patch below fixes this issue. Signed-off-by: Edgar Cherkasov <echerkasov@dev.rtsoft.ru> Acked-by: Viktor Krasnov <vkrasnov@dev.rtsoft.ru> Acked-by: Michael Brunner <Michael.Brunner@kontron.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-18mm: Preserve _PAGE_DEVMAP across mprotect() callsJan Kara
commit 4628a64591e6cee181237060961e98c615c33966 upstream. Currently _PAGE_DEVMAP bit is not preserved in mprotect(2) calls. As a result we will see warnings such as: BUG: Bad page map in process JobWrk0013 pte:800001803875ea25 pmd:7624381067 addr:00007f0930720000 vm_flags:280000f9 anon_vma: (null) mapping:ffff97f2384056f0 index:0 file:457-000000fe00000030-00000009-000000ca-00000001_2001.fileblock fault:xfs_filemap_fault [xfs] mmap:xfs_file_mmap [xfs] readpage: (null) CPU: 3 PID: 15848 Comm: JobWrk0013 Tainted: G W 4.12.14-2.g7573215-default #1 SLE12-SP4 (unreleased) Hardware name: Intel Corporation S2600WFD/S2600WFD, BIOS SE5C620.86B.01.00.0833.051120182255 05/11/2018 Call Trace: dump_stack+0x5a/0x75 print_bad_pte+0x217/0x2c0 ? enqueue_task_fair+0x76/0x9f0 _vm_normal_page+0xe5/0x100 zap_pte_range+0x148/0x740 unmap_page_range+0x39a/0x4b0 unmap_vmas+0x42/0x90 unmap_region+0x99/0xf0 ? vma_gap_callbacks_rotate+0x1a/0x20 do_munmap+0x255/0x3a0 vm_munmap+0x54/0x80 SyS_munmap+0x1d/0x30 do_syscall_64+0x74/0x150 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 ... when mprotect(2) gets used on DAX mappings. Also there is a wide variety of other failures that can result from the missing _PAGE_DEVMAP flag when the area gets used by get_user_pages() later. Fix the problem by including _PAGE_DEVMAP in a set of flags that get preserved by mprotect(2). Fixes: 69660fd797c3 ("x86, mm: introduce _PAGE_DEVMAP") Fixes: ebd31197931d ("powerpc/mm: Add devmap support for ppc64") Cc: <stable@vger.kernel.org> Signed-off-by: Jan Kara <jack@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-18mm/thp: fix call to mmu_notifier in set_pmd_migration_entry() v2Jérôme Glisse
commit bfba8e5cf28f413aa05571af493871d74438979f upstream. Inside set_pmd_migration_entry() we are holding page table locks and thus we can not sleep so we can not call invalidate_range_start/end() So remove call to mmu_notifier_invalidate_range_start/end() because they are call inside the function calling set_pmd_migration_entry() (see try_to_unmap_one()). Link: http://lkml.kernel.org/r/20181012181056.7864-1-jglisse@redhat.com Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Reported-by: Andrea Arcangeli <aarcange@redhat.com> Reviewed-by: Zi Yan <zi.yan@cs.rutgers.edu> Acked-by: Michal Hocko <mhocko@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: David Nellans <dnellans@nvidia.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Minchan Kim <minchan@kernel.org> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-18arm64: perf: Reject stand-alone CHAIN events for PMUv3Will Deacon
commit ca2b497253ad01c80061a1f3ee9eb91b5d54a849 upstream. It doesn't make sense for a perf event to be configured as a CHAIN event in isolation, so extend the arm_pmu structure with a ->filter_match() function to allow the backend PMU implementation to reject CHAIN events early. Cc: <stable@vger.kernel.org> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-18pinctrl: mcp23s08: fix irq and irqchip setup orderMarco Felsch
commit f259f896f2348f0302f6f88d4382378cf9d23a7e upstream. Since 'commit 02e389e63e35 ("pinctrl: mcp23s08: fix irq setup order")' the irq request isn't the last devm_* allocation. Without a deeper look at the irq and testing this isn't a good solution. Since this driver relies on the devm mechanism, requesting a interrupt should be the last thing to avoid memory corruptions during unbinding. 'Commit 02e389e63e35 ("pinctrl: mcp23s08: fix irq setup order")' fixed the order for the interrupt-controller use case only. The mcp23s08_irq_setup() must be split into two to fix it for the interrupt-controller use case and to register the irq at last. So the irq will be freed first during unbind. Cc: stable@vger.kernel.org Cc: Jan Kundrát <jan.kundrat@cesnet.cz> Cc: Dmitry Mastykin <mastichi@gmail.com> Cc: Sebastian Reichel <sebastian.reichel@collabora.co.uk> Fixes: 82039d244f87 ("pinctrl: mcp23s08: add pinconf support") Fixes: 02e389e63e35 ("pinctrl: mcp23s08: fix irq setup order") Signed-off-by: Marco Felsch <m.felsch@pengutronix.de> Tested-by: Phil Reid <preid@electromag.com.au> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-18mmc: block: avoid multiblock reads for the last sector in SPI modeChris Boot
commit 41591b38f5f8f78344954b68582b5f00e56ffe61 upstream. On some SD cards over SPI, reading with the multiblock read command the last sector will leave the card in a bad state. Remove last sectors from the multiblock reading cmd. Signed-off-by: Chris Boot <bootc@bootc.net> Signed-off-by: Clément Péron <peron.clem@gmail.com> Cc: stable@vger.kernel.org # v4.10+ Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-18cgroup: Fix dom_cgrp propagation when enabling threaded modeTejun Heo
commit 479adb89a97b0a33e5a9d702119872cc82ca21aa upstream. A cgroup which is already a threaded domain may be converted into a threaded cgroup if the prerequisite conditions are met. When this happens, all threaded descendant should also have their ->dom_cgrp updated to the new threaded domain cgroup. Unfortunately, this propagation was missing leading to the following failure. # cd /sys/fs/cgroup/unified # cat cgroup.subtree_control # show that no controllers are enabled # mkdir -p mycgrp/a/b/c # echo threaded > mycgrp/a/b/cgroup.type At this point, the hierarchy looks as follows: mycgrp [d] a [dt] b [t] c [inv] Now let's make node "a" threaded (and thus "mycgrp" s made "domain threaded"): # echo threaded > mycgrp/a/cgroup.type By this point, we now have a hierarchy that looks as follows: mycgrp [dt] a [t] b [t] c [inv] But, when we try to convert the node "c" from "domain invalid" to "threaded", we get ENOTSUP on the write(): # echo threaded > mycgrp/a/b/c/cgroup.type sh: echo: write error: Operation not supported This patch fixes the problem by * Moving the opencoded ->dom_cgrp save and restoration in cgroup_enable_threaded() into cgroup_{save|restore}_control() so that mulitple cgroups can be handled. * Updating all threaded descendants' ->dom_cgrp to point to the new dom_cgrp when enabling threaded mode. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-and-tested-by: "Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com> Reported-by: Amin Jamali <ajamali@pivotal.io> Reported-by: Joao De Almeida Pereira <jpereira@pivotal.io> Link: https://lore.kernel.org/r/CAKgNAkhHYCMn74TCNiMJ=ccLd7DcmXSbvw3CbZ1YREeG7iJM5g@mail.gmail.com Fixes: 454000adaa2a ("cgroup: introduce cgroup->dom_cgrp and threaded css_set handling") Cc: stable@vger.kernel.org # v4.14+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-18dm linear: fix linear_end_io conditional definitionDamien Le Moal
commit 118aa47c7072bce05fc39bd40a1c0a90caed72ab upstream. The dm-linear target is independent of the dm-zoned target. For code requiring support for zoned block devices, use CONFIG_BLK_DEV_ZONED instead of CONFIG_DM_ZONED. While at it, similarly to dm linear, also enable the DM_TARGET_ZONED_HM feature in dm-flakey only if CONFIG_BLK_DEV_ZONED is defined. Fixes: beb9caac211c1 ("dm linear: eliminate linear_end_io call if CONFIG_DM_ZONED disabled") Fixes: 0be12c1c7fce7 ("dm linear: add support for zoned block devices") Cc: stable@vger.kernel.org Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-18dm linear: eliminate linear_end_io call if CONFIG_DM_ZONED disabledMike Snitzer
commit beb9caac211c1be1bc118bb62d5cf09c4107e6a5 upstream. It is best to avoid any extra overhead associated with bio completion. DM core will indirectly call a DM target's .end_io if it is defined. In the case of DM linear, there is no need to do so (for every bio that completes) if CONFIG_DM_ZONED is not enabled. Avoiding an extra indirect call for every bio completion is very important for ensuring DM linear doesn't incur more overhead that further widens the performance gap between dm-linear and raw block devices. Fixes: 0be12c1c7fce7 ("dm linear: add support for zoned block devices") Cc: stable@vger.kernel.org Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-18dm: fix report zone remapping to account for partition offsetDamien Le Moal
commit 9864cd5dc54cade89fd4b0954c2e522841aa247c upstream. If dm-linear or dm-flakey are layered on top of a partition of a zoned block device, remapping of the start sector and write pointer position of the zones reported by a report zones BIO must be modified to account for the target table entry mapping (start offset within the device and entry mapping with the dm device). If the target's backing device is a partition of a whole disk, the start sector on the physical device of the partition must also be accounted for when modifying the zone information. However, dm_remap_zone_report() was not considering this last case, resulting in incorrect zone information remapping with targets using disk partitions. Fix this by calculating the target backing device start sector using the position of the completed report zones BIO and the unchanged position and size of the original report zone BIO. With this value calculated, the start sector and write pointer position of the target zones can be correctly remapped. Fixes: 10999307c14e ("dm: introduce dm_remap_zone_report()") Cc: stable@vger.kernel.org Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-18dm cache: destroy migration_cache if cache target registration failedShenghui Wang
commit c7cd55504a5b0fc826a2cd9540845979d24ae542 upstream. Commit 7e6358d244e47 ("dm: fix various targets to dm_register_target after module __init resources created") inadvertently introduced this bug when it moved dm_register_target() after the call to KMEM_CACHE(). Fixes: 7e6358d244e47 ("dm: fix various targets to dm_register_target after module __init resources created") Cc: stable@vger.kernel.org Signed-off-by: Shenghui Wang <shhuiw@foxmail.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-18s390/cio: Fix how vfio-ccw checks pinned pagesEric Farman
commit 24abf2901b18bf941b9f21ea2ce5791f61097ae4 upstream. We have two nested loops to check the entries within the pfn_array_table arrays. But we mistakenly use the outer array as an index in our check, and completely ignore the indexing performed by the inner loop. Cc: stable@vger.kernel.org Signed-off-by: Eric Farman <farman@linux.ibm.com> Message-Id: <20181002010235.42483-1-farman@linux.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-18perf script python: Fix export-to-sqlite.py sample columnsAdrian Hunter
commit d005efe18db0b4a123dd92ea8e77e27aee8f99fd upstream. With the "branches" export option, not all sample columns are exported. However the unwanted columns are not at the end of the tuple, as assumed by the code. Fix by taking the first 15 and last 3 values, instead of the first 18. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/20180911114504.28516-3-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-18perf script python: Fix export-to-postgresql.py occasional failureAdrian Hunter
commit 25e11700b54c7b6b5ebfc4361981dae12299557b upstream. Occasional export failures were found to be caused by truncating 64-bit pointers to 32-bits. Fix by explicitly setting types for all ctype arguments and results. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/20180911114504.28516-2-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-18percpu: stop leaking bitmap metadata blocksMike Rapoport
commit 6685b357363bfe295e3ae73665014db4aed62c58 upstream. The commit ca460b3c9627 ("percpu: introduce bitmap metadata blocks") introduced bitmap metadata blocks. These metadata blocks are allocated whenever a new chunk is created, but they are never freed. Fix it. Fixes: ca460b3c9627 ("percpu: introduce bitmap metadata blocks") Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: stable@vger.kernel.org Signed-off-by: Dennis Zhou <dennis@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-18mach64: detect the dot clock divider correctly on sparcMikulas Patocka
commit 76ebebd2464c5c8a4453c98b6dbf9c95a599e810 upstream. On Sun Ultra 5, it happens that the dot clock is not set up properly for some videomodes. For example, if we set the videomode "r1024x768x60" in the firmware, Linux would incorrectly set a videomode with refresh rate 180Hz when booting (suprisingly, my LCD monitor can display it, although display quality is very low). The reason is this: Older mach64 cards set the divider in the register VCLK_POST_DIV. The register has four 2-bit fields (the field that is actually used is specified in the lowest two bits of the register CLOCK_CNTL). The 2 bits select divider "1, 2, 4, 8". On newer mach64 cards, there's another bit added - the top four bits of PLL_EXT_CNTL extend the divider selection, so we have possible dividers "1, 2, 4, 8, 3, 5, 6, 12". The Linux driver clears the top four bits of PLL_EXT_CNTL and never sets them, so it can work regardless if the card supports them. However, the sparc64 firmware may set these extended dividers during boot - and the mach64 driver detects incorrect dot clock in this case. This patch makes the driver read the additional divider bit from PLL_EXT_CNTL and calculate the initial refresh rate properly. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Cc: stable@vger.kernel.org Acked-by: David S. Miller <davem@davemloft.net> Reviewed-by: Ville Syrjälä <syrjala@sci.fi> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-18MIPS: VDSO: Always map near top of user memoryPaul Burton
commit ea7e0480a4b695d0aa6b3fa99bd658a003122113 upstream. When using the legacy mmap layout, for example triggered using ulimit -s unlimited, get_unmapped_area() fills memory from bottom to top starting from a fairly low address near TASK_UNMAPPED_BASE. This placement is suboptimal if the user application wishes to allocate large amounts of heap memory using the brk syscall. With the VDSO being located low in the user's virtual address space, the amount of space available for access using brk is limited much more than it was prior to the introduction of the VDSO. For example: # ulimit -s unlimited; cat /proc/self/maps 00400000-004ec000 r-xp 00000000 08:00 71436 /usr/bin/coreutils 004fc000-004fd000 rwxp 000ec000 08:00 71436 /usr/bin/coreutils 004fd000-0050f000 rwxp 00000000 00:00 0 00cc3000-00ce4000 rwxp 00000000 00:00 0 [heap] 2ab96000-2ab98000 r--p 00000000 00:00 0 [vvar] 2ab98000-2ab99000 r-xp 00000000 00:00 0 [vdso] 2ab99000-2ab9d000 rwxp 00000000 00:00 0 ... Resolve this by adjusting STACK_TOP to reserve space for the VDSO & providing an address hint to get_unmapped_area() causing it to use this space even when using the legacy mmap layout. We reserve enough space for the VDSO, plus 1MB or 256MB for 32 bit & 64 bit systems respectively within which we randomize the VDSO base address. Previously this randomization was taken care of by the mmap base address randomization performed by arch_mmap_rnd(). The 1MB & 256MB sizes are somewhat arbitrary but chosen such that we have some randomization without taking up too much of the user's virtual address space, which is often in short supply for 32 bit systems. With this the VDSO is always mapped at a high address, leaving lots of space for statically linked programs to make use of brk: # ulimit -s unlimited; cat /proc/self/maps 00400000-004ec000 r-xp 00000000 08:00 71436 /usr/bin/coreutils 004fc000-004fd000 rwxp 000ec000 08:00 71436 /usr/bin/coreutils 004fd000-0050f000 rwxp 00000000 00:00 0 00c28000-00c49000 rwxp 00000000 00:00 0 [heap] ... 7f67c000-7f69d000 rwxp 00000000 00:00 0 [stack] 7f7fc000-7f7fd000 rwxp 00000000 00:00 0 7fcf1000-7fcf3000 r--p 00000000 00:00 0 [vvar] 7fcf3000-7fcf4000 r-xp 00000000 00:00 0 [vdso] Signed-off-by: Paul Burton <paul.burton@mips.com> Reported-by: Huacai Chen <chenhc@lemote.com> Fixes: ebb5e78cc634 ("MIPS: Initial implementation of a VDSO") Cc: Huacai Chen <chenhc@lemote.com> Cc: linux-mips@linux-mips.org Cc: stable@vger.kernel.org # v4.4+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-18mm/vmstat.c: fix outdated vmstat_textJann Horn
commit 28e2c4bb99aa40f9d5f07ac130cbc4da0ea93079 upstream. 7a9cdebdcc17 ("mm: get rid of vmacache_flush_all() entirely") removed the VMACACHE_FULL_FLUSHES statistics, but didn't remove the corresponding entry in vmstat_text. This causes an out-of-bounds access in vmstat_show(). Luckily this only affects kernels with CONFIG_DEBUG_VM_VMACACHE=y, which is probably very rare. Link: http://lkml.kernel.org/r/20181001143138.95119-1-jannh@google.com Fixes: 7a9cdebdcc17 ("mm: get rid of vmacache_flush_all() entirely") Signed-off-by: Jann Horn <jannh@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Roman Gushchin <guro@fb.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Christoph Lameter <clameter@sgi.com> Cc: Kemi Wang <kemi.wang@intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>