dereference_symbol_descriptor() invokes appropriate ARCH specific
function descriptor dereference callbacks:
- dereference_kernel_function_descriptor() if the pointer is a
kernel symbol;
- dereference_module_function_descriptor() if the pointer is a
module symbol.
This is the last step needed to make '%pS/%ps' smart enough to
handle function descriptor dereference on affected ARCHs and
to retire '%pF/%pf'.
To refresh it:
Some architectures (ia64, ppc64, parisc64) use an indirect pointer
for C function pointers - the function pointer points to a function
descriptor and we need to dereference it to get the actual function
pointer.
Function descriptors live in .opd elf section and all affected
ARCHs (ia64, ppc64, parisc64) handle it properly for kernel and
modules. So we, technically, can decide if the dereference is
needed by simply looking at the pointer: if it belongs to .opd
section then we need to dereference it.
The kernel and modules have their own .opd sections, obviously,
that's why we need to split dereference_function_descriptor()
and use separate kernel and module dereference arch callbacks.
Link: http://lkml.kernel.org/r/20171206043649.GB15885@jagdpanzerIV
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: James Bottomley <jejb@parisc-linux.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-ia64@vger.kernel.org
Cc: linux-parisc@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-kernel@vger.kernel.org
Change-Id: I102222c3b164340bd683e29fe61cc963eb5106eb
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Tested-by: Tony Luck <tony.luck@intel.com> #ia64
Tested-by: Santosh Sivaraj <santosh@fossix.org> #powerpc
Tested-by: Helge Deller <deller@gmx.de> #parisc64
Signed-off-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Sorayukii <sorayukii69@gmail.com>
Sergey Senozhatskyauthored and Sorayukiicommited 2026-05-15 17:57:02 +07:00
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Merge 4.9.320 into android-4.9-q
Changes in 4.9.320
9p: missing chunk of "fs/9p: Don't update file type when updating file attributes"
random: remove stale maybe_reseed_primary_crng
random: remove stale urandom_init_wait
random: remove variable limit
random: fix comment for unused random_min_urandom_seed
random: convert get_random_int/long into get_random_u32/u64
random: move random_min_urandom_seed into CONFIG_SYSCTL ifdef block
random: invalidate batched entropy after crng init
random: silence compiler warnings and fix race
random: add wait_for_random_bytes() API
random: add get_random_{bytes,u32,u64,int,long,once}_wait family
random: warn when kernel uses unseeded randomness
random: do not ignore early device randomness
random: suppress spammy warnings about unseeded randomness
random: reorder READ_ONCE() in get_random_uXX
random: fix warning message on ia64 and parisc
random: use a different mixing algorithm for add_device_randomness()
random: set up the NUMA crng instances after the CRNG is fully initialized
random: fix possible sleeping allocation from irq context
random: rate limit unseeded randomness warnings
random: add a spinlock_t to struct batched_entropy
char/random: silence a lockdep splat with printk()
Revert "char/random: silence a lockdep splat with printk()"
random: always use batched entropy for get_random_u{32,64}
random: fix data race on crng_node_pool
crypto: chacha20 - Fix keystream alignment for chacha20_block()
random: always fill buffer in get_random_bytes_wait
random: optimize add_interrupt_randomness
drivers/char/random.c: remove unused dont_count_entropy
random: Fix whitespace pre random-bytes work
random: Return nbytes filled from hw RNG
random: add a config option to trust the CPU's hwrng
random: remove preempt disabled region
random: Make crng state queryable
random: make CPU trust a boot parameter
drivers/char/random.c: constify poolinfo_table
drivers/char/random.c: remove unused stuct poolinfo::poolbits
drivers/char/random.c: make primary_crng static
random: only read from /dev/random after its pool has received 128 bits
random: move rand_initialize() earlier
random: document get_random_int() family
latent_entropy: avoid build error when plugin cflags are not set
random: fix soft lockup when trying to read from an uninitialized blocking pool
random: Support freezable kthreads in add_hwgenerator_randomness()
fdt: add support for rng-seed
random: Use wait_event_freezable() in add_hwgenerator_randomness()
char/random: Add a newline at the end of the file
Revert "hwrng: core - Freeze khwrng thread during suspend"
crypto: Deduplicate le32_to_cpu_array() and cpu_to_le32_array()
crypto: blake2s - generic C library implementation and selftest
lib/crypto: blake2s: move hmac construction into wireguard
lib/crypto: sha1: re-roll loops to reduce code size
random: Don't wake crng_init_wait when crng_init == 1
random: Add a urandom_read_nowait() for random APIs that don't warn
random: add GRND_INSECURE to return best-effort non-cryptographic bytes
random: ignore GRND_RANDOM in getentropy(2)
random: make /dev/random be almost like /dev/urandom
random: fix crash on multiple early calls to add_bootloader_randomness()
random: remove the blocking pool
random: delete code to pull data into pools
random: remove kernel.random.read_wakeup_threshold
random: remove unnecessary unlikely()
random: convert to ENTROPY_BITS for better code readability
random: Add and use pr_fmt()
random: fix typo in add_timer_randomness()
random: remove some dead code of poolinfo
random: split primary/secondary crng init paths
random: avoid warnings for !CONFIG_NUMA builds
x86: Remove arch_has_random, arch_has_random_seed
powerpc: Remove arch_has_random, arch_has_random_seed
linux/random.h: Remove arch_has_random, arch_has_random_seed
linux/random.h: Use false with bool
linux/random.h: Mark CONFIG_ARCH_RANDOM functions __must_check
powerpc: Use bool in archrandom.h
random: add arch_get_random_*long_early()
random: avoid arch_get_random_seed_long() when collecting IRQ randomness
random: remove dead code left over from blocking pool
MAINTAINERS: co-maintain random.c
crypto: blake2s - include <linux/bug.h> instead of <asm/bug.h>
crypto: blake2s - adjust include guard naming
random: document add_hwgenerator_randomness() with other input functions
random: remove unused irq_flags argument from add_interrupt_randomness()
random: use BLAKE2s instead of SHA1 in extraction
random: do not sign extend bytes for rotation when mixing
random: do not re-init if crng_reseed completes before primary init
random: mix bootloader randomness into pool
random: harmonize "crng init done" messages
random: use IS_ENABLED(CONFIG_NUMA) instead of ifdefs
random: initialize ChaCha20 constants with correct endianness
random: early initialization of ChaCha constants
random: avoid superfluous call to RDRAND in CRNG extraction
random: don't reset crng_init_cnt on urandom_read()
random: fix typo in comments
random: cleanup poolinfo abstraction
crypto: chacha20 - Fix chacha20_block() keystream alignment (again)
random: cleanup integer types
random: remove incomplete last_data logic
random: remove unused extract_entropy() reserved argument
random: try to actively add entropy rather than passively wait for it
random: rather than entropy_store abstraction, use global
random: remove unused OUTPUT_POOL constants
random: de-duplicate INPUT_POOL constants
random: prepend remaining pool constants with POOL_
random: cleanup fractional entropy shift constants
random: access input_pool_data directly rather than through pointer
random: simplify arithmetic function flow in account()
random: continually use hwgenerator randomness
random: access primary_pool directly rather than through pointer
random: only call crng_finalize_init() for primary_crng
random: use computational hash for entropy extraction
random: simplify entropy debiting
random: use linear min-entropy accumulation crediting
random: always wake up entropy writers after extraction
random: make credit_entropy_bits() always safe
random: remove use_input_pool parameter from crng_reseed()
random: remove batched entropy locking
random: fix locking in crng_fast_load()
random: use RDSEED instead of RDRAND in entropy extraction
random: inline leaves of rand_initialize()
random: ensure early RDSEED goes through mixer on init
random: do not xor RDRAND when writing into /dev/random
random: absorb fast pool into input pool after fast load
random: use hash function for crng_slow_load()
random: remove outdated INT_MAX >> 6 check in urandom_read()
random: zero buffer after reading entropy from userspace
random: tie batched entropy generation to base_crng generation
random: remove ifdef'd out interrupt bench
random: remove unused tracepoints
random: add proper SPDX header
random: deobfuscate irq u32/u64 contributions
random: introduce drain_entropy() helper to declutter crng_reseed()
random: remove useless header comment
random: remove whitespace and reorder includes
random: group initialization wait functions
random: group entropy extraction functions
random: group entropy collection functions
random: group userspace read/write functions
random: group sysctl functions
random: rewrite header introductory comment
workqueue: make workqueue available early during boot
random: defer fast pool mixing to worker
random: do not take pool spinlock at boot
random: unify early init crng load accounting
random: check for crng_init == 0 in add_device_randomness()
hwrng: core - do not use multiple blank lines
hwrng: core - rewrite better comparison to NULL
hwrng: core - Rewrite the header
hwrng: core - Move hwrng miscdev minor number to include/linux/miscdevice.h
hwrng: core - remove unused PFX macro
hwrng: use rng source with best quality
hwrng: remember rng chosen by user
random: pull add_hwgenerator_randomness() declaration into random.h
random: clear fast pool, crng, and batches in cpuhp bring up
random: round-robin registers as ulong, not u32
random: only wake up writers after zap if threshold was passed
random: cleanup UUID handling
random: unify cycles_t and jiffies usage and types
random: do crng pre-init loading in worker rather than irq
random: give sysctl_random_min_urandom_seed a more sensible value
random: don't let 644 read-only sysctls be written to
random: replace custom notifier chain with standard one
random: use SipHash as interrupt entropy accumulator
random: make consistent usage of crng_ready()
random: reseed more often immediately after booting
random: check for signal and try earlier when generating entropy
random: skip fast_init if hwrng provides large chunk of entropy
random: treat bootloader trust toggle the same way as cpu trust toggle
random: re-add removed comment about get_random_{u32,u64} reseeding
random: mix build-time latent entropy into pool at init
random: do not split fast init input in add_hwgenerator_randomness()
random: do not allow user to keep crng key around on stack
random: check for signal_pending() outside of need_resched() check
random: check for signals every PAGE_SIZE chunk of /dev/[u]random
random: make random_get_entropy() return an unsigned long
random: document crng_fast_key_erasure() destination possibility
random: fix sysctl documentation nits
init: call time_init() before rand_initialize()
ia64: define get_cycles macro for arch-override
s390: define get_cycles macro for arch-override
parisc: define get_cycles macro for arch-override
alpha: define get_cycles macro for arch-override
powerpc: define get_cycles macro for arch-override
timekeeping: Add raw clock fallback for random_get_entropy()
m68k: use fallback for random_get_entropy() instead of zero
mips: use fallback for random_get_entropy() instead of just c0 random
arm: use fallback for random_get_entropy() instead of zero
nios2: use fallback for random_get_entropy() instead of zero
x86/tsc: Use fallback for random_get_entropy() instead of zero
um: use fallback for random_get_entropy() instead of zero
sparc: use fallback for random_get_entropy() instead of zero
xtensa: use fallback for random_get_entropy() instead of zero
uapi: rename ext2_swab() to swab() and share globally in swab.h
random: insist on random_get_entropy() existing in order to simplify
random: do not use batches when !crng_ready()
random: do not pretend to handle premature next security model
random: order timer entropy functions below interrupt functions
random: do not use input pool from hard IRQs
random: help compiler out with fast_mix() by using simpler arguments
siphash: use one source of truth for siphash permutations
random: use symbolic constants for crng_init states
random: avoid initializing twice in credit race
random: remove ratelimiting for in-kernel unseeded randomness
random: use proper jiffies comparison macro
random: handle latent entropy and command line from random_init()
random: credit architectural init the exact amount
random: use static branch for crng_ready()
random: remove extern from functions in header
random: use proper return types on get_random_{int,long}_wait()
random: move initialization functions out of hot pages
random: move randomize_page() into mm where it belongs
random: convert to using fops->write_iter()
random: wire up fops->splice_{read,write}_iter()
random: check for signals after page of pool writes
Revert "random: use static branch for crng_ready()"
crypto: drbg - add FIPS 140-2 CTRNG for noise source
crypto: drbg - always seeded with SP800-90B compliant noise source
crypto: drbg - prepare for more fine-grained tracking of seeding state
crypto: drbg - track whether DRBG was seeded with !rng_is_initialized()
crypto: drbg - move dynamic ->reseed_threshold adjustments to __drbg_seed()
crypto: drbg - always try to free Jitter RNG instance
crypto: drbg - make reseeding from get_random_bytes() synchronous
random: avoid checking crng_ready() twice in random_init()
random: mark bootloader randomness code as __init
random: account for arch randomness in bits
ASoC: cs42l52: Fix TLV scales for mixer controls
ASoC: cs53l30: Correct number of volume levels on SX controls
ASoC: cs42l52: Correct TLV for Bypass Volume
ASoC: cs42l56: Correct typo in minimum level for SX volume controls
ata: libata-core: fix NULL pointer deref in ata_host_alloc_pinfo()
ASoC: wm8962: Fix suspend while playing music
scsi: vmw_pvscsi: Expand vcpuHint to 16 bits
scsi: lpfc: Fix port stuck in bypassed state after LIP in PT2PT topology
virtio-mmio: fix missing put_device() when vm_cmdline_parent registration failed
nfc: nfcmrvl: Fix memory leak in nfcmrvl_play_deferred
ipv6: Fix signed integer overflow in l2tp_ip6_sendmsg
net: ethernet: mtk_eth_soc: fix misuse of mem alloc interface netdev[napi]_alloc_frag
random: credit cpu and bootloader seeds by default
pNFS: Don't keep retrying if the server replied NFS4ERR_LAYOUTUNAVAILABLE
misc: atmel-ssc: Fix IRQ check in ssc_probe
irqchip/gic/realview: Fix refcount leak in realview_gic_of_init
irqchip/gic-v3: Iterate over possible CPUs by for_each_possible_cpu()
comedi: vmk80xx: fix expression for tx buffer size
USB: serial: option: add support for Cinterion MV31 with new baseline
USB: serial: io_ti: add Agilent E5805A support
usb: gadget: lpc32xx_udc: Fix refcount leak in lpc32xx_udc_probe
serial: 8250: Store to lsr_save_flags after lsr read
ext4: fix bug_on ext4_mb_use_inode_pa
ext4: make variable "count" signed
ext4: add reserved GDT blocks check
l2tp: don't use inet_shutdown on ppp session destroy
l2tp: fix race in pppol2tp_release with session object destroy
s390/mm: use non-quiescing sske for KVM switch to keyed guest
xprtrdma: fix incorrect header size calculations
swiotlb: fix info leak with DMA_FROM_DEVICE
Reinstate some of "swiotlb: rework "fix info leak with DMA_FROM_DEVICE""
fuse: fix pipe buffer lifetime for direct_io
tcp: change source port randomizarion at connect() time
tcp: add some entropy in __inet_hash_connect()
secure_seq: use the 64 bits of the siphash for port offset calculation
tcp: use different parts of the port_offset for index and offset
tcp: add small random increments to the source port
tcp: dynamically allocate the perturb table used by source ports
tcp: increase source port perturb table to 2^16
tcp: drop the hash_32() part from the index calculation
Linux 4.9.320
Conflicts:
crypto/chacha20_generic.c
drivers/char/random.c
drivers/of/fdt.c
include/crypto/chacha20.h
lib/chacha20.c
Merge resolution notes:
- Added CHACHA20_KEY_SIZE and CHACHA20_BLOCK_SIZE constants to
chacha.h, to minimize changes from the 4.9.320 version of random.c
- Updated lib/vsprintf.c for
"random: replace custom notifier chain with standard one".
Change-Id: Ia7a12d8883b808f88bbe807d6150552bb084f6b3
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewing Tobin's patches for getting pointers out early before
entropy has been established, I noticed that there's a lone smp_mb() in
the code. As with most lone memory barriers, this one appears to be
incorrectly used.
We currently basically have this:
get_random_bytes(&ptr_key, sizeof(ptr_key));
/*
* have_filled_random_ptr_key==true is dependent on get_random_bytes().
* ptr_to_id() needs to see have_filled_random_ptr_key==true
* after get_random_bytes() returns.
*/
smp_mb();
WRITE_ONCE(have_filled_random_ptr_key, true);
And later we have:
if (unlikely(!have_filled_random_ptr_key))
return string(buf, end, "(ptrval)", spec);
/* Missing memory barrier here. */
hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key);
As the CPU can perform speculative loads, we could have a situation
with the following:
CPU0 CPU1
---- ----
load ptr_key = 0
store ptr_key = random
smp_mb()
store have_filled_random_ptr_key
load have_filled_random_ptr_key = true
BAD BAD BAD! (you're so bad!)
Because nothing prevents CPU1 from loading ptr_key before loading
have_filled_random_ptr_key.
But this race is very unlikely, but we can't keep an incorrect smp_mb() in
place. Instead, replace the have_filled_random_ptr_key with a static_branch
not_filled_random_ptr_key, that is initialized to true and changed to false
when we get enough entropy. If the update happens in early boot, the
static_key is updated immediately, otherwise it will have to wait till
entropy is filled and this happens in an interrupt handler which can't
enable a static_key, as that requires a preemptible context. In that case, a
work_queue is used to enable it, as entropy already took too long to
establish in the first place waiting a little more shouldn't hurt anything.
The benefit of using the static key is that the unlikely branch in
vsprintf() now becomes a nop.
Link: http://lkml.kernel.org/r/20180515100558.21df515e@gandalf.local.home
Cc: stable@vger.kernel.org
Fixes: ad67b74d2469d ("printk: hash addresses printed with %p")
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
(cherry picked from commit 85f4f12d51397f1648e1f4350f77e24039b82d61)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I1cff63252bc4ac40795bf852c0f469ba37f4231f
Steven Rostedt (VMware)authored and Greg Kroah-Hartmancommited 2022-02-21 16:20:29 +01:00
printk specifier %p now hashes all addresses before printing. Sometimes
we need to see the actual unmodified address. This can be achieved using
%lx but then we face the risk that if in future we want to change the
way the Kernel handles printing of pointers we will have to grep through
the already existent 50 000 %lx call sites. Let's add specifier %px as a
clear, opt-in, way to print a pointer and maintain some level of
isolation from all the other hex integer output within the Kernel.
Add printk specifier %px to print the actual unmodified address.
Signed-off-by: Tobin C. Harding <me@tobin.cc>
(cherry picked from commit 7b1924a1d930eb27fc79c4e4e2a6c1c970623e68)
Signed-off-by: Sandeep Patil <sspatil@android.com>
Bug: 78533979
Test: Build and boot cuttlefish
Change-Id: I735db3b72abb318f535d55122f1745d0ead0dbe7
Tobin C. Hardingauthored and Alistair Strachancommited 2019-03-28 21:13:04 -07:00
Currently there exist approximately 14 000 places in the kernel where
addresses are being printed using an unadorned %p. This potentially
leaks sensitive information regarding the Kernel layout in memory. Many
of these calls are stale, instead of fixing every call lets hash the
address by default before printing. This will of course break some
users, forcing code printing needed addresses to be updated.
Code that _really_ needs the address will soon be able to use the new
printk specifier %px to print the address.
For what it's worth, usage of unadorned %p can be broken down as
follows (thanks to Joe Perches).
$ git grep -E '%p[^A-Za-z0-9]' | cut -f1 -d"/" | sort | uniq -c
1084 arch
20 block
10 crypto
32 Documentation
8121 drivers
1221 fs
143 include
101 kernel
69 lib
100 mm
1510 net
40 samples
7 scripts
11 security
166 sound
152 tools
2 virt
Add function ptr_to_id() to map an address to a 32 bit unique
identifier. Hash any unadorned usage of specifier %p and any malformed
specifiers.
Signed-off-by: Tobin C. Harding <me@tobin.cc>
(cherry picked from commit ad67b74d2469d9b82aaa572d76474c95bc484d57)
Signed-off-by: Sandeep Patil <sspatil@android.com>
Bug: 78533979
Test: Build and boot cuttlefish
Test: Runtime tests by enabling CONFIG_TEST_PRINTF
Change-Id: I4a12d890d7b22caa502280d78cb4f6a09c866471
Tobin C. Hardingauthored and Alistair Strachancommited 2019-03-28 21:13:04 -07:00
Currently code to handle %pK is all within the switch statement in
pointer(). This is the wrong level of abstraction. Each of the other switch
clauses call a helper function, pK should do the same.
Refactor code out of pointer() to new function restricted_pointer().
Signed-off-by: Tobin C. Harding <me@tobin.cc>
(cherry picked from commit 57e734423adda83f3b05505875343284efe3b39c)
Signed-off-by: Sandeep Patil <sspatil@android.com>
Bug: 78533979
Test: Build and boot cuttlefish
Change-Id: Ib08350851ab0e99a3569c2c2e12aa421fb6bc622
Tobin C. Hardingauthored and Alistair Strachancommited 2019-03-28 21:13:03 -07:00
commit 666902e42fd8344b923c02dc5b0f37948ff4f225 upstream.
"%pCr" formats the current rate of a clock, and calls clk_get_rate().
The latter obtains a mutex, hence it must not be called from atomic
context.
Remove support for this rarely-used format, as vsprintf() (and e.g.
printk()) must be callable from any context.
Any remaining out-of-tree users will start seeing the clock's name
printed instead of its rate.
Reported-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Fixes: 900cca2944 ("lib/vsprintf: add %pC{,n,r} format specifiers for clocks")
Link: http://lkml.kernel.org/r/1527845302-12159-5-git-send-email-geert+renesas@glider.be
To: Jia-Ju Bai <baijiaju1990@gmail.com>
To: Jonathan Corbet <corbet@lwn.net>
To: Michael Turquette <mturquette@baylibre.com>
To: Stephen Boyd <sboyd@kernel.org>
To: Zhang Rui <rui.zhang@intel.com>
To: Eduardo Valentin <edubezval@gmail.com>
To: Eric Anholt <eric@anholt.net>
To: Stefan Wahren <stefan.wahren@i2se.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-doc@vger.kernel.org
Cc: linux-clk@vger.kernel.org
Cc: linux-pm@vger.kernel.org
Cc: linux-serial@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-renesas-soc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: stable@vger.kernel.org # 4.1+
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Geert Uytterhoevenauthored and Greg Kroah-Hartmancommited 2018-07-03 11:23:06 +02:00
There are new helpers in this patch:
uuid_is_valid checks if a UUID is valid
uuid_be_to_bin converts from string to binary (big endian)
uuid_le_to_bin converts from string to binary (little endian)
They will be used in future, i.e. in the following patches in the series.
This also moves the indices arrays to lib/uuid.c to be shared accross
modules.
[andriy.shevchenko@linux.intel.com: fix typo]
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Dmitry Kasatkin <dmitry.kasatkin@gmail.com>
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andy Shevchenkoauthored and Linus Torvaldscommited 2016-05-20 17:58:30 -07:00
There are few functions here and there along with type definitions that
provide UUID API. This series consolidates everything under one hood
and converts current users.
This has been tested for a while internally, however it doesn't mean we
covered all possible cases (especially accuracy of UUID constants after
conversion). So, please test this as much as you can and provide your
tag. We appreciate the effort.
The ACPI conversion is postponed for now to sort more generic things out
first.
This patch (of 9):
Since we have hex_byte_pack_upper() we may use it directly and avoid
second loop.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Dmitry Kasatkin <dmitry.kasatkin@gmail.com>
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andy Shevchenkoauthored and Linus Torvaldscommited 2016-05-20 17:58:30 -07:00
Implement basic character sets for the '%[' conversion specifier.
The '%[' conversion specifier matches a nonempty sequence of characters
from the specified set of accepted (or with '^', rejected) characters
between the brackets. The substring matched is to be made up of
characters in (or not in) the set. This is useful for matching
substrings that are delimited by something other than spaces.
This implementation differs from its glibc counterpart in the following ways:
(1) No support for character ranges (e.g., 'a-z' or '0-9')
(2) The hyphen '-' is not a special character
(3) The closing bracket ']' cannot be matched
(4) No support (yet) for discarding matching input ('%*[')
The bitmap code is largely based upon sample code which was provided by
Rasmus.
The motivation for adding character set support to sscanf originally
stemmed from the kernel livepatching project. An ongoing patchset
utilizes new livepatch Elf symbol and section names to store important
metadata livepatch needs to properly apply its patches. Such metadata
is stored in these section and symbol names as substrings delimited by
periods '.' and commas ','. For example, a livepatch symbol name might
look like this:
.klp.sym.vmlinux.printk,0
However, sscanf currently can only extract "substrings" delimited by
whitespace using the "%s" specifier. Thus for the above symbol name,
one cannot not use sscanf() to extract substrings "vmlinux" or
"printk", for example. A number of discussions on the livepatch
mailing list dealing with string parsing code for extracting these '.'
and ',' delimited substrings eventually led to the conclusion that such
code would be completely unnecessary if the kernel sscanf() supported
character sets. Thus only a single sscanf() call would be necessary to
extract these substrings. In addition, such an addition to sscanf()
could benefit other areas of the kernel that might have a similar need
in the future.
[akpm@linux-foundation.org: 80-col tweaks]
Signed-off-by: Jessica Yu <jeyu@redhat.com>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jessica Yuauthored and Linus Torvaldscommited 2016-03-17 15:09:34 -07:00
In mm we use several kinds of flags bitfields that are sometimes printed
for debugging purposes, or exported to userspace via sysfs. To make
them easier to interpret independently on kernel version and config, we
want to dump also the symbolic flag names. So far this has been done
with repeated calls to pr_cont(), which is unreliable on SMP, and not
usable for e.g. sysfs export.
To get a more reliable and universal solution, this patch extends
printk() format string for pointers to handle the page flags (%pGp),
gfp_flags (%pGg) and vma flags (%pGv). Existing users of
dump_flag_names() are converted and simplified.
It would be possible to pass flags by value instead of pointer, but the
%p format string for pointers already has extensions for various kernel
structures, so it's a good fit, and the extra indirection in a
non-critical path is negligible.
[linux@rasmusvillemoes.dk: lots of good implementation suggestions]
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Vlastimil Babkaauthored and Linus Torvaldscommited 2016-03-15 16:55:16 -07:00
The kptr_restrict flag, when set to 1, only prints the kernel address
when the user has CAP_SYSLOG. When it is set to 2, the kernel address
is always printed as zero. When set to 1, this needs to check whether
or not we're in IRQ.
However, when set to 2, this check is unneccessary, and produces
confusing results in dmesg. Thus, only make sure we're not in IRQ when
mode 1 is used, but not mode 2.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jason A. Donenfeldauthored and Linus Torvaldscommited 2016-02-11 18:35:48 -08:00
Move switch case to the netdev_features_string() and rename it to
netdev_bits(). In the future we can extend it as needed.
Here we replace the fallback of %pN from '%p' with possible flags to
sticter '0x%p' without any flags variation.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andy Shevchenkoauthored and Linus Torvaldscommited 2016-01-16 11:17:30 -08:00
special_hex_number() is a helper to print a fixed size type in a hex
format with '0x' prefix, zero padding, and small letters. In the module
we have already several copies of such code. Consolidate them under
special_hex_number() helper.
There are couple of differences though.
It seems nobody cared about the output in case of CONFIG_KALLSYMS=n,
when printing symbol address, because the asked field width is not
enough to care last 2 characters in the string represantation of the
pointer. Fixed here.
The %pNF specifier used to be allowed with a specific field width,
though there is neither any user of it nor mention the possibility in
the documentation.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andy Shevchenkoauthored and Linus Torvaldscommited 2016-01-16 11:17:30 -08:00
The field width is overloaded to pass some extra information for some %p
extensions (e.g. #bits for %pb). But we might silently truncate the
passed value when we stash it in struct printf_spec (see e.g.
"lib/vsprintf.c: expand field_width to 24 bits"). Hopefully 23 value
bits should now be enough for everybody, but if not, let's make some
noise.
Do the same for the precision. In both cases, clamping seems more
sensible than truncating. While, according to POSIX, "A negative
precision is taken as if the precision were omitted.", the kernel's
printf has always treated that case as if the precision was 0, so we use
that as lower bound. For the field width, the smallest representable
value is actually -(1<<23), but a negative field width means 'set the
LEFT flag and use the absolute value', so we want the absolute value to
fit.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Joe Perches <joe@perches.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Maurizio Lombardi <mlombard@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rasmus Villemoesauthored and Linus Torvaldscommited 2016-01-16 11:17:27 -08:00
One consequence of the reorganization of struct printf_spec to make
field_width 24 bits was that number() gained about 180 bytes. Since
spec is never passed to other functions, we can help gcc make number()
lose most of that extra weight by using local variables for the field
width and precision.
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Joe Perches <joe@perches.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Maurizio Lombardi <mlombard@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rasmus Villemoesauthored and Linus Torvaldscommited 2016-01-16 11:17:26 -08:00
Maurizio Lombardi reported a problem [1] with the %pb extension: It
doesn't work for sufficiently large bitmaps, since the size is stashed
in the field_width field of the struct printf_spec, which is currently
an s16. Concretely, this manifested itself in
/sys/bus/pseudo/drivers/scsi_debug/map being empty, since the bitmap
printer got a size of 0, which is the 16 bit truncation of the actual
bitmap size.
We do want to keep struct printf_spec at 8 bytes so that it can cheaply
be passed by value. The qualifier field is only used for internal
bookkeeping in format_decode, so we might as well use a local variable
for that. This gives us an additional 8 bits, which we can then use for
the field width.
To stay in 8 bytes, we need to do a little rearranging and make the type
member a bitfield as well. For consistency, change all the members to
bit fields. gcc doesn't generate much worse code with these changes (in
fact, bloat-o-meter says we save 300 bytes - which I think is a little
surprising).
I didn't find a BUILD_BUG/compiletime_assertion/... which would work
outside function context, so for now I just open-coded it.
[1] http://thread.gmane.org/gmane.linux.kernel/2034835
[akpm@linux-foundation.org: avoid open-coded BUILD_BUG_ON]
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Reported-by: Maurizio Lombardi <mlombard@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Joe Perches <joe@perches.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rasmus Villemoesauthored and Linus Torvaldscommited 2016-01-16 11:17:26 -08:00
If the string corresponding to a %s specifier can change under us, we
might end up copying a \0 byte to the output buffer. There might be
callers who expect the output buffer to contain a genuine C string whose
length is exactly the snprintf return value (assuming truncation hasn't
happened or has been checked for).
We can avoid this by only passing over the source string once, stopping
the first time we meet a nul byte (or when we reach the given
precision), and then letting widen_string() handle left/right space
padding. As a small bonus, this code reuse also makes the generated
code slightly smaller.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Joe Perches <joe@perches.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Maurizio Lombardi <mlombard@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rasmus Villemoesauthored and Linus Torvaldscommited 2016-01-16 11:17:26 -08:00
This is pure code movement, making sure the widen_string() helper is
defined before the string() function.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Joe Perches <joe@perches.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Maurizio Lombardi <mlombard@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rasmus Villemoesauthored and Linus Torvaldscommited 2016-01-16 11:17:26 -08:00
Pull out the logic in dentry_name() which handles field width space
padding, in preparation for reusing it from string(). Rename the
widen() helper to move_right(), since it is used for handling the
!(flags & LEFT) case.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Joe Perches <joe@perches.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Maurizio Lombardi <mlombard@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rasmus Villemoesauthored and Linus Torvaldscommited 2016-01-16 11:17:25 -08:00
This allow to directly print block_device name.
Currently one should use bdevname() with temporal char buffer.
This is very ineffective because bloat stack usage for deep IO call-traces
Example:
%pg -> sda, sda1 or loop0p1
[AV: fixed a minor braino - position updates should not be dependent
upon having reached the of buffer]
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Dmitry Monakhovauthored and Al Virocommited 2016-01-06 12:55:29 -05:00
%n is no longer just ignored; it results in early return from vsnprintf.
Also add a request to add test cases for future %p extensions.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Reviewed-by: Martin Kletzander <mkletzan@redhat.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rasmus Villemoesauthored and Linus Torvaldscommited 2015-11-06 17:50:42 -08:00
As a quick
git grep -E '%[ +0#-]*#[ +0#-]*(\*|[0-9]+)?(\.(\*|[0-9]+)?)?p'
shows, nobody uses the # flag with %p. Should one try to do so, one
will be met with
warning: `#' flag used with `%p' gnu_printf format [-Wformat]
(POSIX and C99 both say "... For other conversion specifiers, the
behavior is undefined.". Obviously, the kernel can choose to define
the behaviour however it wants, but as long as gcc issues that
warning, users are unlikely to show up.)
Since default_width is effectively always 2*sizeof(void*), we can
simplify the prologue of pointer() and save a few instructions.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Martin Kletzander <mkletzan@redhat.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rasmus Villemoesauthored and Linus Torvaldscommited 2015-11-06 17:50:42 -08:00
Quoting from 2aa2f9e21e ("lib/vsprintf.c: improve sanity check in
vsnprintf()"):
On 64 bit, size may very well be huge even if bit 31 happens to be 0.
Somehow it doesn't feel right that one can pass a 5 GiB buffer but not a
3 GiB one. So cap at INT_MAX as was probably the intention all along.
This is also the made-up value passed by sprintf and vsprintf.
I should have seen this copy-pasted instance back then, but let's just
do it now.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Martin Kletzander <mkletzan@redhat.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rasmus Villemoesauthored and Linus Torvaldscommited 2015-11-06 17:50:42 -08:00
If we meet any invalid or unsupported format specifier, 'handling' it by
just printing it as a literal string is not safe: Presumably the format
string and the arguments passed gcc's type checking, but that means
something like sprintf(buf, "%n %pd", &intvar, dentry) would end up
interpreting &intvar as a struct dentry*.
When the offending specifier was %n it used to be at the end of the format
string, but we can't rely on that always being the case. Also, gcc
doesn't complain about some more or less exotic qualifiers (or 'length
modifiers' in posix-speak) such as 'j' or 'q', but being unrecognized by
the kernel's printf implementation, they'd be interpreted as unknown
specifiers, and the rest of arguments would be interpreted wrongly.
So let's complain about anything we don't understand, not just %n, and
stop pretending that we'd be able to make sense of the rest of the
format/arguments. If the offending specifier is in a printk() call we
unfortunately only get a "BUG: recent printk recursion!", but at least
direct users of the sprintf family will be caught.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Martin Kletzander <mkletzan@redhat.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rasmus Villemoesauthored and Linus Torvaldscommited 2015-11-06 17:50:42 -08:00
Move all pointer-formatting documentation to one place in the code and one
place in the documentation instead of keeping it in three places with
different level of completeness. Documentation/printk-formats.txt has
detailed information about each modifier, docstring above pointer() has
short descriptions of them (as that is the function dealing with %p) and
docstring above vsprintf() is removed as redundant. Both docstrings in
the code that were modified are updated with a reminder of updating the
documentation upon any further change.
[akpm@linux-foundation.org: fix comment]
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Martin Kletzanderauthored and Linus Torvaldscommited 2015-11-06 17:50:42 -08:00
This file uses the clk API so it should include clk.h directly
instead of indirectly including it through clk-provider.h.
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
I hadn't had enough coffee when I wrote this. Currently, the final
increment of buf depends on the value loaded from the table, and
causes gcc to emit a cmov immediately before the return. It is smarter
to let it depend on r, since the increment can then be computed in
parallel with the final load/store pair. It also shaves 16 bytes of
.text.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Tejun Heo <tj@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rasmus Villemoesauthored and Linus Torvaldscommited 2015-04-17 09:03:55 -04:00
The most expensive part of decimal conversion is the divisions by 10
(albeit done using reciprocal multiplication with appropriately chosen
constants). I decided to see if one could eliminate around half of
these multiplications by emitting two digits at a time, at the cost of a
200 byte lookup table, and it does indeed seem like there is something
to be gained, especially on 64 bits. Microbenchmarking shows
improvements ranging from -50% (for numbers uniformly distributed in [0,
2^64-1]) to -25% (for numbers heavily biased toward the smaller end, a
more realistic distribution).
On a larger scale, perf shows that top, one of the big consumers of /proc
data, uses 0.5-1.0% fewer cpu cycles.
I had to jump through some hoops to get the 32 bit code to compile and run
on my 64 bit machine, so I'm not sure how relevant these numbers are, but
just for comparison the microbenchmark showed improvements between -30%
and -10%.
The bloat-o-meter costs are around 150 bytes (the generated code is a
little smaller, so it's not the full 200 bytes) on both 32 and 64 bit.
I'm aware that extra cache misses won't show up in a microbenchmark as
used above, but on the other hand decimal conversions often happen in bulk
(for example in the case of top).
I have of course tested that the new code generates the same output as the
old, for both the first and last 1e10 numbers in [0,2^64-1] and 4e9
'random' numbers in-between.
Test and verification code on github: https://github.com/Villemoes/dec.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Tested-by: Jeff Epler <jepler@unpythonic.net>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rasmus Villemoesauthored and Linus Torvaldscommited 2015-04-17 09:03:54 -04:00
The current semantics of string_escape_mem are inadequate for one of its
current users, vsnprintf(). If that is to honour its contract, it must
know how much space would be needed for the entire escaped buffer, and
string_escape_mem provides no way of obtaining that (short of allocating a
large enough buffer (~4 times input string) to let it play with, and
that's definitely a big no-no inside vsnprintf).
So change the semantics for string_escape_mem to be more snprintf-like:
Return the size of the output that would be generated if the destination
buffer was big enough, but of course still only write to the part of dst
it is allowed to, and (contrary to snprintf) don't do '\0'-termination.
It is then up to the caller to detect whether output was truncated and to
append a '\0' if desired. Also, we must output partial escape sequences,
otherwise a call such as snprintf(buf, 3, "%1pE", "\123") would cause
printf to write a \0 to buf[2] but leaving buf[0] and buf[1] with whatever
they previously contained.
This also fixes a bug in the escaped_string() helper function, which used
to unconditionally pass a length of "end-buf" to string_escape_mem();
since the latter doesn't check osz for being insanely large, it would
happily write to dst. For example, kasprintf(GFP_KERNEL, "something and
then %pE", ...); is an easy way to trigger an oops.
In test-string_helpers.c, the -ENOMEM test is replaced with testing for
getting the expected return value even if the buffer is too small. We
also ensure that nothing is written (by relying on a NULL pointer deref)
if the output size is 0 by passing NULL - this has to work for
kasprintf("%pE") to work.
In net/sunrpc/cache.c, I think qword_add still has the same semantics.
Someone should definitely double-check this.
In fs/proc/array.c, I made the minimum possible change, but longer-term it
should stop poking around in seq_file internals.
[andriy.shevchenko@linux.intel.com: simplify qword_add]
[andriy.shevchenko@linux.intel.com: add missed curly braces]
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-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>
Rasmus Villemoesauthored and Linus Torvaldscommited 2015-04-15 16:35:24 -07:00
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: 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>
Rasmus Villemoesauthored and Linus Torvaldscommited 2015-04-15 16:35:23 -07:00
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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Geert Uytterhoevenauthored and Linus Torvaldscommited 2015-04-15 16:35:23 -07:00
Making ZEROPAD == '0'-' ', we can eliminate a few more instructions.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rasmus Villemoesauthored and Linus Torvaldscommited 2015-04-15 16:35:23 -07:00
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: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rasmus Villemoesauthored and Linus Torvaldscommited 2015-04-15 16:35:23 -07:00
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: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rasmus Villemoesauthored and Linus Torvaldscommited 2015-04-15 16:35:23 -07:00
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: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rasmus Villemoesauthored and Linus Torvaldscommited 2015-04-15 16:35:23 -07:00
bitmap and its derivatives such as cpumask and nodemask currently only
provide formatting functions which put the output string into the
provided buffer; however, how long this buffer should be isn't defined
anywhere and given that some of these bitmaps can be too large to be
formatted into an on-stack buffer it users sometimes are unnecessarily
forced to come up with creative solutions and compromises for the
buffer just to printk these bitmaps.
There have been a couple different attempts at making this easier.
1. Way back, PeterZ tried printk '%pb' extension with the precision
for bit width - '%.*pb'. This was intuitive and made sense but
unfortunately triggered a compile warning about using precision
for a pointer.
http://lkml.kernel.org/g/1336577562.2527.58.camel@twins
2. I implemented bitmap_pr_cont[_list]() and its wrappers for cpumask
and nodemask. This works but PeterZ pointed out that pr_cont's
tendency to produce broken lines when multiple CPUs are printing is
bothering considering the usages.
http://lkml.kernel.org/g/1418226774-30215-3-git-send-email-tj@kernel.org
So, this patch is another attempt at teaching printk and friends how
to print bitmaps. It's almost identical to what PeterZ tried with
precision but it uses the field width for the number of bits instead
of precision. The format used is '%*pb[l]', with the optional
trailing 'l' specifying list format instead of hex masks.
This is a valid format string and doesn't trigger compiler warnings;
however, it does make it impossible to specify output field width when
printing bitmaps. I think this is an acceptable trade-off given how
much easier it makes printing bitmaps and that we don't have any
in-kernel user which is using the field width specification. If any
future user wants to use field width with a bitmap, it'd have to
format the bitmap into a string buffer and then print that buffer with
width spec, which isn't different from how it should be done now.
This patch implements bitmap[_list]_string() which are called from the
vsprintf pointer() formatting function. The implementation is mostly
identical to bitmap_scn[list]printf() except that the output is
performed in the vsprintf way. These functions handle formatting into
too small buffers and sprintf() family of functions report the correct
overrun output length.
bitmap_scn[list]printf() are now thin wrappers around scnprintf().
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: "John W. Linville" <linville@tuxdriver.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Mike Travis <travis@sgi.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Tejun Heoauthored and Linus Torvaldscommited 2015-02-13 21:21:36 -08:00
All callers of skip_atoi have already checked for the first character
being a digit. In this case, gcc generates simpler code for a do
while-loop.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rasmus Villemoesauthored and Linus Torvaldscommited 2015-02-12 18:54:13 -08:00
On 64 bit, size may very well be huge even if bit 31 happens to be 0.
Somehow it doesn't feel right that one can pass a 5 GiB buffer but not a
3 GiB one. So cap at INT_MAX as was probably the intention all along.
This is also the made-up value passed by sprintf and vsprintf.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rasmus Villemoesauthored and Linus Torvaldscommited 2015-02-12 18:54:13 -08:00
It seems a little simpler to consume the p from a %p specifier in
format_decode, just as it is done for the surrounding %c, %s and %% cases.
While there, delete a redundant and misplaced comment.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rasmus Villemoesauthored and Linus Torvaldscommited 2015-02-12 18:54:13 -08:00
This allows user to print a given buffer as an escaped string. The
rules are applied according to an optional mix of flags provided by
additional format letters.
For example, if the given buffer is:
1b 62 20 5c 43 07 22 90 0d 5d
The result strings would be:
%*pE "\eb \C\a"\220\r]"
%*pEhp "\x1bb \C\x07"\x90\x0d]"
%*pEa "\e\142\040\\\103\a\042\220\r\135"
Please, read Documentation/printk-formats.txt and lib/string_helpers.c
kernel documentation to get further information.
[akpm@linux-foundation.org: tidy up comment layout, per Joe]
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Suggested-by: Joe Perches <joe@perches.com>
Cc: "John W . Linville" <linville@tuxdriver.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andy Shevchenkoauthored and Linus Torvaldscommited 2014-10-14 02:18:26 +02:00
This patch fix spelling typo found in DocBook/kernel-api.xml.
It is because the file is generated from the source comments,
I have to fix the comments in source codes.
Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Masanari Iidaauthored and Jiri Kosinacommited 2014-09-09 10:34:56 +02:00
Fixing 2 coccinelle warnings:
lib/vsprintf.c:2350:2-9: WARNING: Assignment of bool to 0/1
lib/vsprintf.c:2389:3-10: WARNING: Assignment of bool to 0/1
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fabian Frederickauthored and Linus Torvaldscommited 2014-06-04 16:54:18 -07:00
All in-kernel users of %n in format strings have now been removed and
the %n directive is ignored. Remove the handling of %n so that it is
treated the same as any other invalid format string directive. Keep a
warning in place to deter new instances of %n in format strings.
Signed-off-by: Ryan Mallon <rmallon@gmail.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Ryan Mallonauthored and Linus Torvaldscommited 2014-04-03 16:21:07 -07:00
Sometimes we have a struct resource where we know the type (MEM/IO/etc.)
and the size, but we haven't assigned address space for it. The
IORESOURCE_UNSET flag is a way to indicate this situation. For these
"unset" resources, the start address is meaningless, so print only the
size, e.g.,
- pci 0000:0c:00.0: reg 184: [mem 0x00000000-0x00001fff 64bit]
+ pci 0000:0c:00.0: reg 184: [mem size 0x2000 64bit]
For %pr (printing with raw flags), we still print the address range,
because %pr is mostly used for debugging anyway.
Thanks to Fengguang Wu <fengguang.wu@intel.com> for suggesting
resource_size().
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
dma_addr_t's can be either u32 or u64 depending on a CONFIG option.
There are a few hundred dma_addr_t's printed via either cast to unsigned
long long, unsigned long or no cast at all.
Add %pad to be able to emit them without the cast.
Update Documentation/printk-formats.txt too.
Signed-off-by: Joe Perches <joe@perches.com>
Cc: "Shevchenko, Andriy" <andriy.shevchenko@intel.com>
Cc: Rob Landley <rob@landley.net>
Cc: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Cc: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Joe Perchesauthored and Linus Torvaldscommited 2014-01-23 16:36:56 -08:00
This ignores %n in printf again, as was originally documented.
Implementing %n poses a greater security risk than utility, so it should
stay ignored. To help anyone attempting to use %n, a warning will be
emitted if it is encountered.
Based on an earlier patch by Joe Perches.
Because %n was designed to write to pointers on the stack, it has been
frequently used as an attack vector when bugs are found that leak
user-controlled strings into functions that ultimately process format
strings. While this class of bug can still be turned into an
information leak, removing %n eliminates the common method of elevating
such a bug into an arbitrary kernel memory writing primitive,
significantly reducing the danger of this class of bug.
For seq_file users that need to know the length of a written string for
padding, please see seq_setwidth() and seq_pad() instead.
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Joe Perches <joe@perches.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Kees Cookauthored and Linus Torvaldscommited 2013-11-15 09:32:20 +09:00
Looks like these were added to Documentation/printk-formats.txt but
not the in-file table.
Signed-off-by: Olof Johansson <olof@lixom.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Olof Johanssonauthored and Linus Torvaldscommited 2013-11-13 12:09:22 +09:00
Some setuid binaries will allow reading of files which have read
permission by the real user id. This is problematic with files which
use %pK because the file access permission is checked at open() time,
but the kptr_restrict setting is checked at read() time. If a setuid
binary opens a %pK file as an unprivileged user, and then elevates
permissions before reading the file, then kernel pointer values may be
leaked.
This happens for example with the setuid pppd application on Ubuntu 12.04:
$ head -1 /proc/kallsyms
00000000 T startup_32
$ pppd file /proc/kallsyms
pppd: In file /proc/kallsyms: unrecognized option 'c1000000'
This will only leak the pointer value from the first line, but other
setuid binaries may leak more information.
Fix this by adding a check that in addition to the current process having
CAP_SYSLOG, that effective user and group ids are equal to the real ids.
If a setuid binary reads the contents of a file which uses %pK then the
pointer values will be printed as NULL if the real user is unprivileged.
Update the sysctl documentation to reflect the changes, and also correct
the documentation to state the kptr_restrict=0 is the default.
This is a only temporary solution to the issue. The correct solution is
to do the permission check at open() time on files, and to replace %pK
with a function which checks the open() time permission. %pK uses in
printk should be removed since no sane permission check can be done, and
instead protected by using dmesg_restrict.
Signed-off-by: Ryan Mallon <rmallon@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Joe Perches <joe@perches.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Ryan Mallonauthored and Linus Torvaldscommited 2013-11-13 12:09:14 +09:00
New formats: %p[dD][234]?. The next pointer is interpreted as struct dentry *
or struct file * resp. ('d' => dentry, 'D' => file) and the last component(s)
of pathname are printed (%pd => just the last one, %pd2 => the last two, etc.)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Sergey Senozhatsky
authored and
Sorayukii
commited 
Eric Biggers
commited 
Steven Rostedt (VMware)
authored and
Greg Kroah-Hartman
commited 
Tobin C. Harding
authored and
Alistair Strachan
commited 
Geert Uytterhoeven
authored and
Greg Kroah-Hartman
commited 
Andy Shevchenko
authored and
Linus Torvalds
commited 
Jessica Yu
authored and
Vlastimil Babka
authored and
Jason A. Donenfeld
authored and
Rasmus Villemoes
authored and
Dmitry Monakhov
authored and
Al Viro
commited 
Martin Kletzander
authored and
Stephen Boyd
commited 
Tejun Heo
authored and
Masanari Iida
authored and
Jiri Kosina
commited 
Fabian Frederick
authored and
Ryan Mallon
authored and
Bjorn Helgaas
commited 
Joe Perches
authored and
Kees Cook
authored and
Olof Johansson
authored and