linux-stable.git/lib/vsprintf.c, branch v5.15.151

lib/vsprintf: Fix %pfwf when current node refcount == 0

2024-01-05T14:13:35+00:00

commit 5c47251e8c4903111608ddcba2a77c0c425c247c upstream.

A refcount issue can appeared in __fwnode_link_del() due to the
pr_debug() call:
  WARNING: CPU: 0 PID: 901 at lib/refcount.c:25 refcount_warn_saturate+0xe5/0x110
  Call Trace:
  
  ...
  of_node_get+0x1e/0x30
  of_fwnode_get+0x28/0x40
  fwnode_full_name_string+0x34/0x90
  fwnode_string+0xdb/0x140
  ...
  vsnprintf+0x17b/0x630
  ...
  __fwnode_link_del+0x25/0xa0
  fwnode_links_purge+0x39/0xb0
  of_node_release+0xd9/0x180
  ...

Indeed, an fwnode (of_node) is being destroyed and so, of_node_release()
is called because the of_node refcount reached 0.
From of_node_release() several function calls are done and lead to
a pr_debug() calls with %pfwf to print the fwnode full name.
The issue is not present if we change %pfwf to %pfwP.

To print the full name, %pfwf iterates over the current node and its
parents and obtain/drop a reference to all nodes involved.

In order to allow to print the full name (%pfwf) of a node while it is
being destroyed, do not obtain/drop a reference to this current node.

Fixes: a92eb7621b9f ("lib/vsprintf: Make use of fwnode API to obtain node names and separators")
Cc: stable@vger.kernel.org
Signed-off-by: Herve Codina 
Reviewed-by: Sakari Ailus 
Reviewed-by: Andy Shevchenko 
Signed-off-by: Petr Mladek 
Link: https://lore.kernel.org/r/20231114152655.409331-1-herve.codina@bootlin.com
Signed-off-by: Greg Kroah-Hartman

random: replace custom notifier chain with standard one

2022-05-30T07:29:10+00:00

commit 5acd35487dc911541672b3ffc322851769c32a56 upstream.

We previously rolled our own randomness readiness notifier, which only
has two users in the whole kernel. Replace this with a more standard
atomic notifier block that serves the same purpose with less code. Also
unexport the symbols, because no modules use it, only unconditional
builtins. The only drawback is that it's possible for a notification
handler returning the "stop" code to prevent further processing, but
given that there are only two users, and that we're unexporting this
anyway, that doesn't seem like a significant drawback for the
simplification we receive here.

Cc: Greg Kroah-Hartman 
Cc: Theodore Ts'o 
Reviewed-by: Dominik Brodowski 
[Jason: for stable, also backported to crypto/drbg.c, not unexporting.]
Signed-off-by: Jason A. Donenfeld 
Signed-off-by: Greg Kroah-Hartman

vsprintf: Fix %pK with kptr_restrict == 0

2022-04-08T12:23:18+00:00

[ Upstream commit 84842911322fc6a02a03ab9e728a48c691fe3efd ]

Although kptr_restrict is set to 0 and the kernel is booted with
no_hash_pointers parameter, the content of /proc/vmallocinfo is
lacking the real addresses.

  / # cat /proc/vmallocinfo
  0x(ptrval)-0x(ptrval)    8192 load_module+0xc0c/0x2c0c pages=1 vmalloc
  0x(ptrval)-0x(ptrval)   12288 start_kernel+0x4e0/0x690 pages=2 vmalloc
  0x(ptrval)-0x(ptrval)   12288 start_kernel+0x4e0/0x690 pages=2 vmalloc
  0x(ptrval)-0x(ptrval)    8192 _mpic_map_mmio.constprop.0+0x20/0x44 phys=0x80041000 ioremap
  0x(ptrval)-0x(ptrval)   12288 _mpic_map_mmio.constprop.0+0x20/0x44 phys=0x80041000 ioremap
    ...

According to the documentation for /proc/sys/kernel/, %pK is
equivalent to %p when kptr_restrict is set to 0.

Fixes: 5ead723a20e0 ("lib/vsprintf: no_hash_pointers prints all addresses as unhashed")
Signed-off-by: Christophe Leroy 
Reviewed-by: Petr Mladek 
Signed-off-by: Petr Mladek 
Link: https://lore.kernel.org/r/107476128e59bff11a309b5bf7579a1753a41aca.1645087605.git.christophe.leroy@csgroup.eu
Signed-off-by: Sasha Levin

lib: uninline simple_strntoull() as well

2022-04-08T12:23:18+00:00

[ Upstream commit 839b395eb9c13ae56ea5fc3ca9802734a72293f0 ]

Codegen become bloated again after simple_strntoull() introduction

	add/remove: 0/0 grow/shrink: 0/4 up/down: 0/-224 (-224)
	Function                                     old     new   delta
	simple_strtoul                                 5       2      -3
	simple_strtol                                 23      20      -3
	simple_strtoull                              119      15    -104
	simple_strtoll                               155      41    -114

Link: https://lkml.kernel.org/r/YVmlB9yY4lvbNKYt@localhost.localdomain
Signed-off-by: Alexey Dobriyan 
Cc: Richard Fitzgerald 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Sasha Levin

vsprintf: Fix potential unaligned access

2022-04-08T12:23:16+00:00

[ Upstream commit d75b26f880f60ead301e79ba0f4a635c5a60767f ]

The %p4cc specifier in some cases might get an unaligned pointer.
Due to this we need to make copy to local variable once to avoid
potential crashes on some architectures due to improper access.

Fixes: af612e43de6d ("lib/vsprintf: Add support for printing V4L2 and DRM fourccs")
Cc: Sakari Ailus 
Signed-off-by: Andy Shevchenko 
Reviewed-by: Petr Mladek 
Signed-off-by: Petr Mladek 
Link: https://lore.kernel.org/r/20220127181233.72910-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Sasha Levin

Merge branch 'akpm' (patches from Andrew)

2021-09-08T19:55:35+00:00

Merge more updates from Andrew Morton:
 "147 patches, based on 7d2a07b769330c34b4deabeed939325c77a7ec2f.

  Subsystems affected by this patch series: mm (memory-hotplug, rmap,
  ioremap, highmem, cleanups, secretmem, kfence, damon, and vmscan),
  alpha, percpu, procfs, misc, core-kernel, MAINTAINERS, lib,
  checkpatch, epoll, init, nilfs2, coredump, fork, pids, criu, kconfig,
  selftests, ipc, and scripts"

* emailed patches from Andrew Morton : (94 commits)
  scripts: check_extable: fix typo in user error message
  mm/workingset: correct kernel-doc notations
  ipc: replace costly bailout check in sysvipc_find_ipc()
  selftests/memfd: remove unused variable
  Kconfig.debug: drop selecting non-existing HARDLOCKUP_DETECTOR_ARCH
  configs: remove the obsolete CONFIG_INPUT_POLLDEV
  prctl: allow to setup brk for et_dyn executables
  pid: cleanup the stale comment mentioning pidmap_init().
  kernel/fork.c: unexport get_{mm,task}_exe_file
  coredump: fix memleak in dump_vma_snapshot()
  fs/coredump.c: log if a core dump is aborted due to changed file permissions
  nilfs2: use refcount_dec_and_lock() to fix potential UAF
  nilfs2: fix memory leak in nilfs_sysfs_delete_snapshot_group
  nilfs2: fix memory leak in nilfs_sysfs_create_snapshot_group
  nilfs2: fix memory leak in nilfs_sysfs_delete_##name##_group
  nilfs2: fix memory leak in nilfs_sysfs_create_##name##_group
  nilfs2: fix NULL pointer in nilfs_##name##_attr_release
  nilfs2: fix memory leak in nilfs_sysfs_create_device_group
  trap: cleanup trap_init()
  init: move usermodehelper_enable() to populate_rootfs()
  ...

mm: introduce PAGEFLAGS_MASK to replace ((1UL << NR_PAGEFLAGS) - 1)

2021-09-08T18:50:24+00:00

Instead of hard-coding ((1UL << NR_PAGEFLAGS) - 1) everywhere, introducing
PAGEFLAGS_MASK to make the code clear to get the page flags.

Link: https://lkml.kernel.org/r/20210819150712.59948-1-songmuchun@bytedance.com
Signed-off-by: Muchun Song 
Reviewed-by: Roman Gushchin 
Acked-by: Johannes Weiner 
Reviewed-by: Shakeel Butt 
Cc: Michal Hocko 
Cc: Vladimir Davydov 
Cc: Matthew Wilcox (Oracle) 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

isystem: ship and use stdarg.h

2021-08-19T00:02:55+00:00

Ship minimal stdarg.h (1 type, 4 macros) as .
stdarg.h is the only userspace header commonly used in the kernel.

GPL 2 version of  can be extracted from
http://archive.debian.org/debian/pool/main/g/gcc-4.2/gcc-4.2_4.2.4.orig.tar.gz

Signed-off-by: Alexey Dobriyan 
Acked-by: Rafael J. Wysocki 
Acked-by: Ard Biesheuvel 
Signed-off-by: Masahiro Yamada

module: add printk formats to add module build ID to stacktraces

2021-07-08T18:48:22+00:00

Let's make kernel stacktraces easier to identify by including the build
ID[1] of a module if the stacktrace is printing a symbol from a module.
This makes it simpler for developers to locate a kernel module's full
debuginfo for a particular stacktrace.  Combined with
scripts/decode_stracktrace.sh, a developer can download the matching
debuginfo from a debuginfod[2] server and find the exact file and line
number for the functions plus offsets in a stacktrace that match the
module.  This is especially useful for pstore crash debugging where the
kernel crashes are recorded in something like console-ramoops and the
recovery kernel/modules are different or the debuginfo doesn't exist on
the device due to space concerns (the debuginfo can be too large for space
limited devices).

Originally, I put this on the %pS format, but that was quickly rejected
given that %pS is used in other places such as ftrace where build IDs
aren't meaningful.  There was some discussions on the list to put every
module build ID into the "Modules linked in:" section of the stacktrace
message but that quickly becomes very hard to read once you have more than
three or four modules linked in.  It also provides too much information
when we don't expect each module to be traversed in a stacktrace.  Having
the build ID for modules that aren't important just makes things messy.
Splitting it to multiple lines for each module quickly explodes the number
of lines printed in an oops too, possibly wrapping the warning off the
console.  And finally, trying to stash away each module used in a
callstack to provide the ID of each symbol printed is cumbersome and would
require changes to each architecture to stash away modules and return
their build IDs once unwinding has completed.

Instead, we opt for the simpler approach of introducing new printk formats
'%pS[R]b' for "pointer symbolic backtrace with module build ID" and '%pBb'
for "pointer backtrace with module build ID" and then updating the few
places in the architecture layer where the stacktrace is printed to use
this new format.

Before:

 Call trace:
  lkdtm_WARNING+0x28/0x30 [lkdtm]
  direct_entry+0x16c/0x1b4 [lkdtm]
  full_proxy_write+0x74/0xa4
  vfs_write+0xec/0x2e8

After:

 Call trace:
  lkdtm_WARNING+0x28/0x30 [lkdtm 6c2215028606bda50de823490723dc4bc5bf46f9]
  direct_entry+0x16c/0x1b4 [lkdtm 6c2215028606bda50de823490723dc4bc5bf46f9]
  full_proxy_write+0x74/0xa4
  vfs_write+0xec/0x2e8

[akpm@linux-foundation.org: fix build with CONFIG_MODULES=n, tweak code layout]
[rdunlap@infradead.org: fix build when CONFIG_MODULES is not set]
  Link: https://lkml.kernel.org/r/20210513171510.20328-1-rdunlap@infradead.org
[akpm@linux-foundation.org: make kallsyms_lookup_buildid() static]
[cuibixuan@huawei.com: fix build error when CONFIG_SYSFS is disabled]
  Link: https://lkml.kernel.org/r/20210525105049.34804-1-cuibixuan@huawei.com

Link: https://lkml.kernel.org/r/20210511003845.2429846-6-swboyd@chromium.org
Link: https://fedoraproject.org/wiki/Releases/FeatureBuildId [1]
Link: https://sourceware.org/elfutils/Debuginfod.html [2]
Signed-off-by: Stephen Boyd 
Signed-off-by: Bixuan Cui 
Signed-off-by: Randy Dunlap 
Cc: Jiri Olsa 
Cc: Alexei Starovoitov 
Cc: Jessica Yu 
Cc: Evan Green 
Cc: Hsin-Yi Wang 
Cc: Petr Mladek 
Cc: Steven Rostedt 
Cc: Sergey Senozhatsky 
Cc: Andy Shevchenko 
Cc: Rasmus Villemoes 
Cc: Matthew Wilcox 
Cc: Baoquan He 
Cc: Borislav Petkov 
Cc: Catalin Marinas 
Cc: Dave Young 
Cc: Ingo Molnar 
Cc: Konstantin Khlebnikov 
Cc: Sasha Levin 
Cc: Thomas Gleixner 
Cc: Vivek Goyal 
Cc: Will Deacon 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

lib: fix spelling mistakes

2021-07-08T18:48:20+00:00

Fix some spelling mistakes in comments:
permanentely ==> permanently
wont ==> won't
remaning ==> remaining
succed ==> succeed
shouldnt ==> shouldn't
alpha-numeric ==> alphanumeric
storeing ==> storing
funtion ==> function
documenation ==> documentation
Determin ==> Determine
intepreted ==> interpreted
ammount ==> amount
obious ==> obvious
interupts ==> interrupts
occured ==> occurred
asssociated ==> associated
taking into acount ==> taking into account
squence ==> sequence
stil ==> still
contiguos ==> contiguous
matchs ==> matches

Link: https://lkml.kernel.org/r/20210607072555.12416-1-thunder.leizhen@huawei.com
Signed-off-by: Zhen Lei 
Reviewed-by: Jacob Keller 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds