- 15 Apr, 2015 40 commits
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Rasmus Villemoes authored
When printf is given the format specifier %pE, it needs a way of obtaining the total output size that would be generated if the buffer was large enough, and string_escape_mem doesn't easily provide that. This is a refactorization of string_escape_mem in preparation of changing its external API to provide that information. The somewhat ugly early returns and subsequent seemingly redundant conditionals are to make the following patch touch as little as possible in string_helpers.c while still preserving the current behaviour of never outputting partial escape sequences. That behaviour must also change for %pE to work as one expects from every other printf specifier. Signed-off-by:
Rasmus Villemoes <linux@rasmusvillemoes.dk> Acked-by:
Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Rasmus Villemoes authored
The helper hex_string() is broken in two ways. First, it doesn't increment buf regardless of whether there is room to print, so callers such as kasprintf() that try to probe the correct storage to allocate will get a too small return value. But even worse, kasprintf() (and likely anyone else trying to find the size of the result) pass NULL for buf and 0 for size, so we also have end == NULL. But this means that the end-1 in hex_string() is (char*)-1, so buf < end-1 is true and we get a NULL pointer deref. I double-checked this with a trivial kernel module that just did a kasprintf(GFP_KERNEL, "%14ph", "CrashBoomBang"). Nobody seems to be using %ph with kasprintf, but we might as well fix it before it hits someone. Signed-off-by:
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Geert Uytterhoeven authored
Add format specifiers for printing struct clk: - '%pC' or '%pCn': name (Common Clock Framework) or address (legacy clock framework) of the clock, - '%pCr': rate of the clock. [akpm@linux-foundation.org: omit code if !CONFIG_HAVE_CLK] Signed-off-by:Geert Uytterhoeven <geert+renesas@glider.be> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Mike Turquette <mturquette@linaro.org> Cc: Stephen Boyd <sboyd@codeaurora.org> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by:
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Geert Uytterhoeven authored
Move the format types for 64-bit integers and configurable size integers to the top, so they're next to the other integer format types. While at it, add the missing format types for s32 and u32. Signed-off-by:
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Geert Uytterhoeven authored
This patch series improves the documentation for printk() formats, and adds support for printing clocks. The latter has always been a hassle if you wanted to support both the common and legacy clock frameworks. - '%pC' and '%pCn' print the name (Common Clock Framework) or address (legacy clock framework) of a clock, - '%pCr' prints the current clock rate. This patch (of 3): Make sure all %p extensions that take parameters by references are documented to do so. Signed-off-by: -
Rasmus Villemoes authored
Making ZEROPAD == '0'-' ', we can eliminate a few more instructions. Signed-off-by:
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Rasmus Villemoes authored
gcc doesn't merge or overlap const char[] objects with identical contents (probably language lawyers would also insist that these things have different addresses), but there's no reason to have the string "0123456789ABCDEF" occur in multiple places. hex_asc_upper is declared in kernel.h and defined in lib/hexdump.c, which is unconditionally compiled in. Signed-off-by:
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Rasmus Villemoes authored
At least since the initial git commit, when base was passed as a separate parameter, number() has only been called with bases 8, 10 and 16. I'm guessing that 66 was to accommodate 64 0/1, a sign and a '\0', but the buffer is only used for the actual digits. Octal digits carry 3 bits of information, so 24 is enough. Spell that 3*sizeof(num) so one less place needs to be changed should long long ever be 128 bits. Also remove the commented-out code that would handle an arbitrary base. Signed-off-by:
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Rasmus Villemoes authored
Since FORMAT_TYPE_INT is simply 1 more than FORMAT_TYPE_UINT, and similarly for BYTE/UBYTE, SHORT/USHORT, LONG/ULONG, we can eliminate a few instructions by making SIGN have the value 1 instead of 2, and then use arithmetic instead of branches for computing the right spec->type. It's a little hacky, but certainly in the same spirit as SMALL needing to have the value 0x20. For example for the spec->qualifier == 'l' case, gcc now generates 75e: 0f b6 53 01 movzbl 0x1(%rbx),%edx 762: 83 e2 01 and $0x1,%edx 765: 83 c2 09 add $0x9,%edx 768: 88 13 mov %dl,(%rbx) instead of 763: 0f b6 53 01 movzbl 0x1(%rbx),%edx 767: 83 e2 02 and $0x2,%edx 76a: 80 fa 01 cmp $0x1,%dl 76d: 19 d2 sbb %edx,%edx 76f: 83 c2 0a add $0xa,%edx 772: 88 13 mov %dl,(%rbx) Signed-off-by: -
Steven Rostedt authored
KERN_CONT is nicely commented in kern_levels.h, but pr_cont() is now used more often, and it lacks the comment stating what it is used for. It can be confused as continuing the log level, but that is not its purpose. Its purpose is to continue a line that had no newline enclosed. This should be documented by pr_cont() as well. Signed-off-by:
Steven Rostedt <rostedt@goodmis.org> Acked-by:
Borislav Petkov <bp@suse.de> Signed-off-by:
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Joel Stanley authored
Use orderly_reboot so userspace will to shut itself down via the reboot path. This is required for graceful reboot initiated by the BMC, such as when a user uses ipmitool to issue a 'chassis power cycle' command. Signed-off-by:
Joel Stanley <joel@jms.id.au> Acked-by:
Michael Ellerman <mpe@ellerman.id.au> Cc: Fabian Frederick <fabf@skynet.be> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Jeremy Kerr <jk@ozlabs.org> Cc: David S. Miller <davem@davemloft.net> Signed-off-by:
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Joel Stanley authored
The kernel has orderly_poweroff which allows the kernel to initiate a graceful shutdown of userspace, by running /sbin/poweroff. This adds orderly_reboot that will cause userspace to shut itself down by calling /sbin/reboot. This will be used for shutdown initiated by a system controller on platforms that do not use ACPI. orderly_reboot() should be used when the system wants to allow userspace to gracefully shut itself down. For cases where the system may imminently catch on fire, the existing emergency_restart() provides an immediate reboot without involving userspace. Signed-off-by:
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Joel Stanley authored
orderly_poweroff() unconditionally returns 0, so remove the dead code that checks the return value. A future patch will change the return type to void. Signed-off-by:
David S. Miller <davem@davemloft.net> Cc: Fabian Frederick <fabf@skynet.be> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Jeremy Kerr <jk@ozlabs.org> Signed-off-by:
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Aaron Tomlin authored
In check_hung_uninterruptible_tasks() avoid the use of deprecated while_each_thread(). The "max_count" logic will prevent a livelock - see commit 0c740d0a ("introduce for_each_thread() to replace the buggy while_each_thread()"). Having said this let's use for_each_process_thread(). Signed-off-by:
Aaron Tomlin <atomlin@redhat.com> Acked-by:
Oleg Nesterov <oleg@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Dave Wysochanski <dwysocha@redhat.com> Cc: Aaron Tomlin <atomlin@redhat.com> Signed-off-by:
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Jakub Sitnicki authored
All users of __check_region(), check_region(), and check_mem_region() are gone. We got rid of the last user in v4.0-rc1. Remove them. bloat-o-meter on x86_64 shows: add/remove: 0/3 grow/shrink: 0/0 up/down: 0/-102 (-102) function old new delta __kstrtab___check_region 15 - -15 __ksymtab___check_region 16 - -16 __check_region 71 - -71 Signed-off-by:
Jakub Sitnicki <jsitnicki@gmail.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by:
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Iulia Manda authored
There are a lot of embedded systems that run most or all of their functionality in init, running as root:root. For these systems, supporting multiple users is not necessary. This patch adds a new symbol, CONFIG_MULTIUSER, that makes support for non-root users, non-root groups, and capabilities optional. It is enabled under CONFIG_EXPERT menu. When this symbol is not defined, UID and GID are zero in any possible case and processes always have all capabilities. The following syscalls are compiled out: setuid, setregid, setgid, setreuid, setresuid, getresuid, setresgid, getresgid, setgroups, getgroups, setfsuid, setfsgid, capget, capset. Also, groups.c is compiled out completely. In kernel/capability.c, capable function was moved in order to avoid adding two ifdef blocks. This change saves about 25 KB on a defconfig build. The most minimal kernels have total text sizes in the high hundreds of kB rather than low MB. (The 25k goes down a bit with allnoconfig, but not that much. The kernel was booted in Qemu. All the common functionalities work. Adding users/groups is not possible, failing with -ENOSYS. Bloat-o-meter output: add/remove: 7/87 grow/shrink: 19/397 up/down: 1675/-26325 (-24650) [akpm@linux-foundation.org: coding-style fixes] Signed-off-by:
Iulia Manda <iulia.manda21@gmail.com> Reviewed-by:
Josh Triplett <josh@joshtriplett.org> Acked-by:
Geert Uytterhoeven <geert@linux-m68k.org> Tested-by:
Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by:
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Andi Kleen authored
const char *...[] is not const, but an array of pointer to const. So these arrays cannot be __initconst, but must be __initdata This fixes section conflicts with LTO. Signed-off-by:
Andi Kleen <ak@linux.intel.com> Signed-off-by:
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Dan Carpenter authored
The verbose module parameter can be set to 2 for extremely verbose messages so the type should be int instead of bool. Signed-off-by:
Dan Carpenter <dan.carpenter@oracle.com> Cc: Tim Waugh <tim@cyberelk.net> Signed-off-by:
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Rasmus Villemoes authored
Commit 607ca46e ("UAPI: (Scripted) Disintegrate include/linux") left behind some empty conditional blocks. Since they are useless and may cause a reader to wonder whether something is missing, remove them. Signed-off-by:
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Chen Hanxiao authored
If some issues occurred inside a container guest, host user could not know which process is in trouble just by guest pid: the users of container guest only knew the pid inside containers. This will bring obstacle for trouble shooting. This patch adds four fields: NStgid, NSpid, NSpgid and NSsid: a) In init_pid_ns, nothing changed; b) In one pidns, will tell the pid inside containers: NStgid: 21776 5 1 NSpid: 21776 5 1 NSpgid: 21776 5 1 NSsid: 21729 1 0 ** Process id is 21776 in level 0, 5 in level 1, 1 in level 2. c) If pidns is nested, it depends on which pidns are you in. NStgid: 5 1 NSpid: 5 1 NSpgid: 5 1 NSsid: 1 0 ** Views from level 1 [akpm@linux-foundation.org: add CONFIG_PID_NS ifdef] Signed-off-by:
Chen Hanxiao <chenhanxiao@cn.fujitsu.com> Acked-by:
Serge Hallyn <serge.hallyn@canonical.com> Acked-by:
"Eric W. Biederman" <ebiederm@xmission.com> Tested-by:
Nathan Scott <nathans@redhat.com> Signed-off-by:
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Julia Lawall authored
Return a negative error code on failure. A simplified version of the semantic match that finds this problem is as follows: (http://coccinelle.lip6.fr/) // <smpl> @@ identifier ret; expression e1,e2; @@ ( if (\(ret < 0\|ret != 0\)) { ... return ret; } | ret = 0 ) ... when != ret = e1 when != &ret *if(...) { ... when != ret = e2 when forall return ret; } // </smpl> Signed-off-by:
Julia Lawall <Julia.Lawall@lip6.fr> Cc: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Acked-by:
Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Signed-off-by:
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Sergey Senozhatsky authored
Do not perform cond_resched() before the busy compaction loop in __zs_compact(), because this loop does it when needed. Signed-off-by:
Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by:
Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by:
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Heesub Shin authored
There is no point in overriding the size class below. It causes fatal corruption on the next chunk on the 3264-bytes size class, which is the last size class that is not huge. For example, if the requested size was exactly 3264 bytes, current zsmalloc allocates and returns a chunk from the size class of 3264 bytes, not 4096. User access to this chunk may overwrite head of the next adjacent chunk. Here is the panic log captured when freelist was corrupted due to this: Kernel BUG at ffffffc00030659c [verbose debug info unavailable] Internal error: Oops - BUG: 96000006 [#1] PREEMPT SMP Modules linked in: exynos-snapshot: core register saved(CPU:5) CPUMERRSR: 0000000000000000, L2MERRSR: 0000000000000000 exynos-snapshot: context saved(CPU:5) exynos-snapshot: item - log_kevents is disabled CPU: 5 PID: 898 Comm: kswapd0 Not tainted 3.10.61-4497415-eng #1 task: ffffffc0b8783d80 ti: ffffffc0b71e8000 task.ti: ffffffc0b71e8000 PC is at obj_idx_to_offset+0x0/0x1c LR is at obj_malloc+0x44/0xe8 pc : [<ffffffc00030659c>] lr : [<ffffffc000306604>] pstate: a0000045 sp : ffffffc0b71eb790 x29: ffffffc0b71eb790 x28: ffffffc00204c000 x27: 000000000001d96f x26: 0000000000000000 x25: ffffffc098cc3500 x24: ffffffc0a13f2810 x23: ffffffc098cc3501 x22: ffffffc0a13f2800 x21: 000011e1a02006e3 x20: ffffffc0a13f2800 x19: ffffffbc02a7e000 x18: 0000000000000000 x17: 0000000000000000 x16: 0000000000000feb x15: 0000000000000000 x14: 00000000a01003e3 x13: 0000000000000020 x12: fffffffffffffff0 x11: ffffffc08b264000 x10: 00000000e3a01004 x9 : ffffffc08b263fea x8 : ffffffc0b1e611c0 x7 : ffffffc000307d24 x6 : 0000000000000000 x5 : 0000000000000038 x4 : 000000000000011e x3 : ffffffbc00003e90 x2 : 0000000000000cc0 x1 : 00000000d0100371 x0 : ffffffbc00003e90 Reported-by:Sooyong Suk <s.suk@samsung.com> Signed-off-by:
Heesub Shin <heesub.shin@samsung.com> Tested-by:
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Minchan Kim authored
In putback_zspage, we don't need to insert a zspage into list of zspage in size_class again to just fix fullness group. We could do directly without reinsertion so we could save some instuctions. Reported-by:
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Sergey Senozhatsky authored
A micro-optimization. Avoid additional branching and reduce (a bit) registry pressure (f.e. s_off += size; d_off += size; may be calculated twise: first for >= PAGE_SIZE check and later for offset update in "else" clause). scripts/bloat-o-meter shows some improvement add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-10 (-10) function old new delta zs_object_copy 550 540 -10 Signed-off-by:
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Sergey Senozhatsky authored
Do not synchronize rcu in zs_compact(). Neither zsmalloc not zram use rcu. Signed-off-by:
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Sergey Senozhatsky authored
Add Documentation/ABI/obsolete/sysfs-block-zram file and list obsolete and deprecated attributes there. The patch also adds additional information to zram documentation and describes the basic strategy: - the existing RW nodes will be downgraded to WO nodes (in 4.11) - deprecated RO sysfs nodes will eventually be removed (in 4.11) Users will be additionally notified about deprecated attr usage by pr_warn_once() (added to every deprecated attr _show()), as suggested by Minchan Kim. User space is advised to use zram<id>/stat, zram<id>/io_stat and zram<id>/mm_stat files. Signed-off-by:
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Sergey Senozhatsky authored
Per-device `zram<id>/mm_stat' file provides mm statistics of a particular zram device in a format similar to block layer statistics. The file consists of a single line and represents the following stats (separated by whitespace): orig_data_size compr_data_size mem_used_total mem_limit mem_used_max zero_pages num_migrated Signed-off-by: -
Sergey Senozhatsky authored
Per-device `zram<id>/io_stat' file provides accumulated I/O statistics of particular zram device in a format similar to block layer statistics. The file consists of a single line and represents the following stats (separated by whitespace): failed_reads failed_writes invalid_io notify_free Signed-off-by: -
Sergey Senozhatsky authored
Briefly describe exported device stat attrs in zram documentation. We will eventually get rid of per-stat sysfs nodes and, thus, clean up Documentation/ABI/testing/sysfs-block-zram file, which is the only source of information about device sysfs nodes. Add `num_migrated' description, since there is no independent `num_migrated' sysfs node (and no corresponding sysfs-block-zram entry), it will be exported via zram<id>/mm_stat file. At this point we can provide minimal description, because sysfs-block-zram still contains detailed information. Signed-off-by:
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Sergey Senozhatsky authored
Use bio generic_start_io_acct() and generic_end_io_acct() to account device's block layer statistics. This will let users to monitor zram activities using sysstat and similar packages/tools. Apart from the usual per-stat sysfs attr, zram IO stats are now also available in '/sys/block/zram<id>/stat' and '/proc/diskstats' files. We will slowly get rid of per-stat sysfs files. Signed-off-by:
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Sergey Senozhatsky authored
A cosmetic change. We have a new code layout and keep zram per-device sysfs store and show functions in one place. Move compact_store() to that handlers block to conform to current layout. Signed-off-by:
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Sergey Senozhatsky authored
This patch introduces rework to zram stats. We have per-stat sysfs nodes, and it makes things a bit hard to use in user space: it doesn't give an immediate stats 'snapshot', it requires user space to use more syscalls - open, read, close for every stat file, with appropriate error checks on every step, etc. First, zram now accounts block layer statistics, available in /sys/block/zram<id>/stat and /proc/diskstats files. So some new stats are available (see Documentation/block/stat.txt), besides, zram's activities now can be monitored by sysstat's iostat or similar tools. Example: cat /sys/block/zram0/stat 248 0 1984 0 251029 0 2008232 5120 0 5116 5116 Second, group currently exported on per-stat basis nodes into two categories (files): -- zram<id>/io_stat accumulates device's IO stats, that are not accounted by block layer, and contains: failed_reads failed_writes invalid_io notify_free Example: cat /sys/block/zram0/io_stat 0 0 0 652572 -- zram<id>/mm_stat accumulates zram mm stats and contains: orig_data_size compr_data_size mem_used_total mem_limit mem_used_max zero_pages num_migrated Example: cat /sys/block/zram0/mm_stat 434634752 270288572 279158784 0 579895296 15060 0 per-stat sysfs nodes are now considered to be deprecated and we plan to remove them (and clean up some of the existing stat code) in two years (as of now, there is no warning printed to syslog about deprecated stats being used). User space is advised to use the above mentioned 3 files. This patch (of 7): Remove sysfs `num_migrated' attribute. We are moving away from per-stat device attrs towards 3 stat files that will accumulate io and mm stats in a format similar to block layer statistics in /sys/block/<dev>/stat. That will be easier to use in user space, and reduce the number of syscalls needed to read zram device statistics. `num_migrated' will return back in zram<id>/mm_stat file. Signed-off-by: -
Yinghao Xie authored
Signed-off-by:
Yinghao Xie <yinghao.xie@sumsung.com> Suggested-by:
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Minchan Kim authored
Create zsmalloc doc which explains design concept and stat information. Signed-off-by:
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Minchan Kim authored
During investigating compaction, fullness information of each class is helpful for investigating how the compaction works well. With that, we could know how compaction works well more clear on each size class. Signed-off-by:
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Minchan Kim authored
We store handle on header of each allocated object so it increases the size of each object by sizeof(unsigned long). If zram stores 4096 bytes to zsmalloc(ie, bad compression), zsmalloc needs 4104B-class to add handle. However, 4104B-class has 1-pages_per_zspage so wasted size by internal fragment is 8192 - 4104, which is terrible. So this patch records the handle in page->private on such huge object(ie, pages_per_zspage == 1 && maxobj_per_zspage == 1) instead of header of each object so we could use 4096B-class, not 4104B-class. Signed-off-by:
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Minchan Kim authored
Now that zsmalloc supports compaction, zram can use it. For the first step, this patch exports compact knob via sysfs so user can do compaction via "echo 1 > /sys/block/zram0/compact". Signed-off-by:
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Minchan Kim authored
Curretly, zsmalloc regards a zspage as ZS_ALMOST_EMPTY if the zspage has under 1/4 used objects(ie, fullness_threshold_frac). It could make result in loose packing since zsmalloc migrates only ZS_ALMOST_EMPTY zspage out. This patch changes the rule so that zsmalloc makes zspage which has above 3/4 used object ZS_ALMOST_FULL so it could make tight packing. Signed-off-by:
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Minchan Kim authored
This patch provides core functions for migration of zsmalloc. Migraion policy is simple as follows. for each size class { while { src_page = get zs_page from ZS_ALMOST_EMPTY if (!src_page) break; dst_page = get zs_page from ZS_ALMOST_FULL if (!dst_page) dst_page = get zs_page from ZS_ALMOST_EMPTY if (!dst_page) break; migrate(from src_page, to dst_page); } } For migration, we need to identify which objects in zspage are allocated to migrate them out. We could know it by iterating of freed objects in a zspage because first_page of zspage keeps free objects singly-linked list but it's not efficient. Instead, this patch adds a tag(ie, OBJ_ALLOCATED_TAG) in header of each object(ie, handle) so we could check whether the object is allocated easily. This patch adds another status bit in handle to synchronize between user access through zs_map_object and migration. During migration, we cannot move objects user are using due to data coherency between old object and new object. [akpm@linux-foundation.org: zsmalloc.c needs sched.h for cond_resched()] Signed-off-by:
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