linux-stable.git/arch/mips/kernel, branch v6.2 Linux kernel stable tree Merge tag 'mm-nonmm-stable-2022-12-12' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm 2022-12-13T01:28:58+00:00 Linus Torvalds torvalds@linux-foundation.org 2022-12-13T01:28:58+00:00 8702f2c611bf124c48b21b5c57bfc156cd11f4ca Pull non-MM updates from Andrew Morton: - A ptrace API cleanup series from Sergey Shtylyov - Fixes and cleanups for kexec from ye xingchen - nilfs2 updates from Ryusuke Konishi - squashfs feature work from Xiaoming Ni: permit configuration of the filesystem's compression concurrency from the mount command line - A series from Akinobu Mita which addresses bound checking errors when writing to debugfs files - A series from Yang Yingliang to address rapidio memory leaks - A series from Zheng Yejian to address possible overflow errors in encode_comp_t() - And a whole shower of singleton patches all over the place * tag 'mm-nonmm-stable-2022-12-12' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (79 commits) ipc: fix memory leak in init_mqueue_fs() hfsplus: fix bug causing custom uid and gid being unable to be assigned with mount rapidio: devices: fix missing put_device in mport_cdev_open kcov: fix spelling typos in comments hfs: Fix OOB Write in hfs_asc2mac hfs: fix OOB Read in __hfs_brec_find relay: fix type mismatch when allocating memory in relay_create_buf() ocfs2: always read both high and low parts of dinode link count io-mapping: move some code within the include guarded section kernel: kcsan: kcsan_test: build without structleak plugin mailmap: update email for Iskren Chernev eventfd: change int to __u64 in eventfd_signal() ifndef CONFIG_EVENTFD rapidio: fix possible UAF when kfifo_alloc() fails relay: use strscpy() is more robust and safer cpumask: limit visibility of FORCE_NR_CPUS acct: fix potential integer overflow in encode_comp_t() acct: fix accuracy loss for input value of encode_comp_t() linux/init.h: include <linux/build_bug.h> and <linux/stringify.h> rapidio: rio: fix possible name leak in rio_register_mport() rapidio: fix possible name leaks when rio_add_device() fails ... 
Pull non-MM updates from Andrew Morton:

 - A ptrace API cleanup series from Sergey Shtylyov

 - Fixes and cleanups for kexec from ye xingchen

 - nilfs2 updates from Ryusuke Konishi

 - squashfs feature work from Xiaoming Ni: permit configuration of the
   filesystem's compression concurrency from the mount command line

 - A series from Akinobu Mita which addresses bound checking errors when
   writing to debugfs files

 - A series from Yang Yingliang to address rapidio memory leaks

 - A series from Zheng Yejian to address possible overflow errors in
   encode_comp_t()

 - And a whole shower of singleton patches all over the place

* tag 'mm-nonmm-stable-2022-12-12' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (79 commits)
  ipc: fix memory leak in init_mqueue_fs()
  hfsplus: fix bug causing custom uid and gid being unable to be assigned with mount
  rapidio: devices: fix missing put_device in mport_cdev_open
  kcov: fix spelling typos in comments
  hfs: Fix OOB Write in hfs_asc2mac
  hfs: fix OOB Read in __hfs_brec_find
  relay: fix type mismatch when allocating memory in relay_create_buf()
  ocfs2: always read both high and low parts of dinode link count
  io-mapping: move some code within the include guarded section
  kernel: kcsan: kcsan_test: build without structleak plugin
  mailmap: update email for Iskren Chernev
  eventfd: change int to __u64 in eventfd_signal() ifndef CONFIG_EVENTFD
  rapidio: fix possible UAF when kfifo_alloc() fails
  relay: use strscpy() is more robust and safer
  cpumask: limit visibility of FORCE_NR_CPUS
  acct: fix potential integer overflow in encode_comp_t()
  acct: fix accuracy loss for input value of encode_comp_t()
  linux/init.h: include <linux/build_bug.h> and <linux/stringify.h>
  rapidio: rio: fix possible name leak in rio_register_mport()
  rapidio: fix possible name leaks when rio_add_device() fails
  ...
Merge tag 'random-6.2-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random 2022-12-13T00:22:22+00:00 Linus Torvalds torvalds@linux-foundation.org 2022-12-13T00:22:22+00:00 268325bda5299836a6ad4c3952474a2be125da5f Pull random number generator updates from Jason Donenfeld: - Replace prandom_u32_max() and various open-coded variants of it, there is now a new family of functions that uses fast rejection sampling to choose properly uniformly random numbers within an interval: get_random_u32_below(ceil) - [0, ceil) get_random_u32_above(floor) - (floor, U32_MAX] get_random_u32_inclusive(floor, ceil) - [floor, ceil] Coccinelle was used to convert all current users of prandom_u32_max(), as well as many open-coded patterns, resulting in improvements throughout the tree. I'll have a "late" 6.1-rc1 pull for you that removes the now unused prandom_u32_max() function, just in case any other trees add a new use case of it that needs to converted. According to linux-next, there may be two trivial cases of prandom_u32_max() reintroductions that are fixable with a 's/.../.../'. So I'll have for you a final conversion patch doing that alongside the removal patch during the second week. This is a treewide change that touches many files throughout. - More consistent use of get_random_canary(). - Updates to comments, documentation, tests, headers, and simplification in configuration. - The arch_get_random*_early() abstraction was only used by arm64 and wasn't entirely useful, so this has been replaced by code that works in all relevant contexts. - The kernel will use and manage random seeds in non-volatile EFI variables, refreshing a variable with a fresh seed when the RNG is initialized. The RNG GUID namespace is then hidden from efivarfs to prevent accidental leakage. These changes are split into random.c infrastructure code used in the EFI subsystem, in this pull request, and related support inside of EFISTUB, in Ard's EFI tree. These are co-dependent for full functionality, but the order of merging doesn't matter. - Part of the infrastructure added for the EFI support is also used for an improvement to the way vsprintf initializes its siphash key, replacing an sleep loop wart. - The hardware RNG framework now always calls its correct random.c input function, add_hwgenerator_randomness(), rather than sometimes going through helpers better suited for other cases. - The add_latent_entropy() function has long been called from the fork handler, but is a no-op when the latent entropy gcc plugin isn't used, which is fine for the purposes of latent entropy. But it was missing out on the cycle counter that was also being mixed in beside the latent entropy variable. So now, if the latent entropy gcc plugin isn't enabled, add_latent_entropy() will expand to a call to add_device_randomness(NULL, 0), which adds a cycle counter, without the absent latent entropy variable. - The RNG is now reseeded from a delayed worker, rather than on demand when used. Always running from a worker allows it to make use of the CPU RNG on platforms like S390x, whose instructions are too slow to do so from interrupts. It also has the effect of adding in new inputs more frequently with more regularity, amounting to a long term transcript of random values. Plus, it helps a bit with the upcoming vDSO implementation (which isn't yet ready for 6.2). - The jitter entropy algorithm now tries to execute on many different CPUs, round-robining, in hopes of hitting even more memory latencies and other unpredictable effects. It also will mix in a cycle counter when the entropy timer fires, in addition to being mixed in from the main loop, to account more explicitly for fluctuations in that timer firing. And the state it touches is now kept within the same cache line, so that it's assured that the different execution contexts will cause latencies. * tag 'random-6.2-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random: (23 commits) random: include <linux/once.h> in the right header random: align entropy_timer_state to cache line random: mix in cycle counter when jitter timer fires random: spread out jitter callback to different CPUs random: remove extraneous period and add a missing one in comments efi: random: refresh non-volatile random seed when RNG is initialized vsprintf: initialize siphash key using notifier random: add back async readiness notifier random: reseed in delayed work rather than on-demand random: always mix cycle counter in add_latent_entropy() hw_random: use add_hwgenerator_randomness() for early entropy random: modernize documentation comment on get_random_bytes() random: adjust comment to account for removed function random: remove early archrandom abstraction random: use random.trust_{bootloader,cpu} command line option only stackprotector: actually use get_random_canary() stackprotector: move get_random_canary() into stackprotector.h treewide: use get_random_u32_inclusive() when possible treewide: use get_random_u32_{above,below}() instead of manual loop treewide: use get_random_u32_below() instead of deprecated function ... 
Pull random number generator updates from Jason Donenfeld:

 - Replace prandom_u32_max() and various open-coded variants of it,
   there is now a new family of functions that uses fast rejection
   sampling to choose properly uniformly random numbers within an
   interval:

       get_random_u32_below(ceil) - [0, ceil)
       get_random_u32_above(floor) - (floor, U32_MAX]
       get_random_u32_inclusive(floor, ceil) - [floor, ceil]

   Coccinelle was used to convert all current users of
   prandom_u32_max(), as well as many open-coded patterns, resulting in
   improvements throughout the tree.

   I'll have a "late" 6.1-rc1 pull for you that removes the now unused
   prandom_u32_max() function, just in case any other trees add a new
   use case of it that needs to converted. According to linux-next,
   there may be two trivial cases of prandom_u32_max() reintroductions
   that are fixable with a 's/.../.../'. So I'll have for you a final
   conversion patch doing that alongside the removal patch during the
   second week.

   This is a treewide change that touches many files throughout.

 - More consistent use of get_random_canary().

 - Updates to comments, documentation, tests, headers, and
   simplification in configuration.

 - The arch_get_random*_early() abstraction was only used by arm64 and
   wasn't entirely useful, so this has been replaced by code that works
   in all relevant contexts.

 - The kernel will use and manage random seeds in non-volatile EFI
   variables, refreshing a variable with a fresh seed when the RNG is
   initialized. The RNG GUID namespace is then hidden from efivarfs to
   prevent accidental leakage.

   These changes are split into random.c infrastructure code used in the
   EFI subsystem, in this pull request, and related support inside of
   EFISTUB, in Ard's EFI tree. These are co-dependent for full
   functionality, but the order of merging doesn't matter.

 - Part of the infrastructure added for the EFI support is also used for
   an improvement to the way vsprintf initializes its siphash key,
   replacing an sleep loop wart.

 - The hardware RNG framework now always calls its correct random.c
   input function, add_hwgenerator_randomness(), rather than sometimes
   going through helpers better suited for other cases.

 - The add_latent_entropy() function has long been called from the fork
   handler, but is a no-op when the latent entropy gcc plugin isn't
   used, which is fine for the purposes of latent entropy.

   But it was missing out on the cycle counter that was also being mixed
   in beside the latent entropy variable. So now, if the latent entropy
   gcc plugin isn't enabled, add_latent_entropy() will expand to a call
   to add_device_randomness(NULL, 0), which adds a cycle counter,
   without the absent latent entropy variable.

 - The RNG is now reseeded from a delayed worker, rather than on demand
   when used. Always running from a worker allows it to make use of the
   CPU RNG on platforms like S390x, whose instructions are too slow to
   do so from interrupts. It also has the effect of adding in new inputs
   more frequently with more regularity, amounting to a long term
   transcript of random values. Plus, it helps a bit with the upcoming
   vDSO implementation (which isn't yet ready for 6.2).

 - The jitter entropy algorithm now tries to execute on many different
   CPUs, round-robining, in hopes of hitting even more memory latencies
   and other unpredictable effects. It also will mix in a cycle counter
   when the entropy timer fires, in addition to being mixed in from the
   main loop, to account more explicitly for fluctuations in that timer
   firing. And the state it touches is now kept within the same cache
   line, so that it's assured that the different execution contexts will
   cause latencies.

* tag 'random-6.2-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random: (23 commits)
  random: include <linux/once.h> in the right header
  random: align entropy_timer_state to cache line
  random: mix in cycle counter when jitter timer fires
  random: spread out jitter callback to different CPUs
  random: remove extraneous period and add a missing one in comments
  efi: random: refresh non-volatile random seed when RNG is initialized
  vsprintf: initialize siphash key using notifier
  random: add back async readiness notifier
  random: reseed in delayed work rather than on-demand
  random: always mix cycle counter in add_latent_entropy()
  hw_random: use add_hwgenerator_randomness() for early entropy
  random: modernize documentation comment on get_random_bytes()
  random: adjust comment to account for removed function
  random: remove early archrandom abstraction
  random: use random.trust_{bootloader,cpu} command line option only
  stackprotector: actually use get_random_canary()
  stackprotector: move get_random_canary() into stackprotector.h
  treewide: use get_random_u32_inclusive() when possible
  treewide: use get_random_u32_{above,below}() instead of manual loop
  treewide: use get_random_u32_below() instead of deprecated function
  ...
MIPS: vpe-cmp: fix possible memory leak while module exiting 2022-11-22T12:09:36+00:00 Yang Yingliang yangyingliang@huawei.com 2022-11-04T03:39:45+00:00 c5ed1fe0801f0c66b0fbce2785239a5664629057 dev_set_name() allocates memory for name, it need be freed when module exiting, call put_device() to give up reference, so that it can be freed in kobject_cleanup() when the refcount hit to 0. The vpe_device is static, so remove kfree() from vpe_device_release(). Fixes: 17a1d523aa58 ("MIPS: APRP: Add VPE loader support for CMP platforms.") Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> 
dev_set_name() allocates memory for name, it need be freed
when module exiting, call put_device() to give up reference,
so that it can be freed in kobject_cleanup() when the refcount
hit to 0. The vpe_device is static, so remove kfree() from
vpe_device_release().

Fixes: 17a1d523aa58 ("MIPS: APRP: Add VPE loader support for CMP platforms.")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
MIPS: vpe-mt: fix possible memory leak while module exiting 2022-11-22T12:09:04+00:00 Yang Yingliang yangyingliang@huawei.com 2022-11-04T03:39:44+00:00 5822e8cc84ee37338ab0bdc3124f6eec04dc232d Afer commit 1fa5ae857bb1 ("driver core: get rid of struct device's bus_id string array"), the name of device is allocated dynamically, it need be freed when module exiting, call put_device() to give up reference, so that it can be freed in kobject_cleanup() when the refcount hit to 0. The vpe_device is static, so remove kfree() from vpe_device_release(). Fixes: 1fa5ae857bb1 ("driver core: get rid of struct device's bus_id string array") Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> 
Afer commit 1fa5ae857bb1 ("driver core: get rid of struct device's
bus_id string array"), the name of device is allocated dynamically,
it need be freed when module exiting, call put_device() to give up
reference, so that it can be freed in kobject_cleanup() when the
refcount hit to 0. The vpe_device is static, so remove kfree() from
vpe_device_release().

Fixes: 1fa5ae857bb1 ("driver core: get rid of struct device's bus_id string array")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
treewide: use get_random_u32_below() instead of deprecated function 2022-11-18T01:15:15+00:00 Jason A. Donenfeld Jason@zx2c4.com 2022-10-10T02:44:02+00:00 8032bf1233a74627ce69b803608e650f3f35971c This is a simple mechanical transformation done by: @@ expression E; @@ - prandom_u32_max + get_random_u32_below (E) Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs Reviewed-by: SeongJae Park <sj@kernel.org> # for damon Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> # for infiniband Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> # for arm Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # for mmc Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> 
This is a simple mechanical transformation done by:

@@
expression E;
@@
- prandom_u32_max
+ get_random_u32_below
  (E)

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs
Reviewed-by: SeongJae Park <sj@kernel.org> # for damon
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> # for infiniband
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> # for arm
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # for mmc
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
mips: ptrace: user_regset_copyin_ignore() always returns 0 2022-11-15T22:30:40+00:00 Sergey Shtylyov s.shtylyov@omp.ru 2022-10-14T21:22:28+00:00 540e58d200e32141d3c280bd8c90b9932e3c7afb user_regset_copyin_ignore() always returns 0, so checking its result seems pointless -- don't do this anymore... Link: https://lkml.kernel.org/r/20221014212235.10770-7-s.shtylyov@omp.ru Signed-off-by: Sergey Shtylyov <s.shtylyov@omp.ru> Cc: Brian Cain <bcain@quicinc.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: David S. Miller <davem@davemloft.net> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Cc: Jonas Bonn <jonas@southpole.se> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Will Deacon <will@kernel.org> Cc: Yoshinori Sato <ysato@users.osdn.me> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> 
user_regset_copyin_ignore() always returns 0, so checking its result seems
pointless -- don't do this anymore...

Link: https://lkml.kernel.org/r/20221014212235.10770-7-s.shtylyov@omp.ru
Signed-off-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Cc: Brian Cain <bcain@quicinc.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: David S. Miller <davem@davemloft.net>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Helge Deller <deller@gmx.de>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.osdn.me>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
MIPS: jump_label: Fix compat branch range check 2022-11-11T14:46:03+00:00 Jiaxun Yang jiaxun.yang@flygoat.com 2022-11-03T15:10:53+00:00 64ac0befe75bdfaffc396c2b4a0ed5ae6920eeee Cast upper bound of branch range to long to do signed compare, avoid negative offset trigger this warning. Fixes: 9b6584e35f40 ("MIPS: jump_label: Use compact branches for >= r6") Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: stable@vger.kernel.org Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> 
Cast upper bound of branch range to long to do signed compare,
avoid negative offset trigger this warning.

Fixes: 9b6584e35f40 ("MIPS: jump_label: Use compact branches for >= r6")
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: stable@vger.kernel.org
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
MIPS: fix duplicate definitions for exported symbols 2022-11-11T14:44:44+00:00 Rongwei Zhang pudh4418@gmail.com 2022-11-02T12:27:39+00:00 612d80784fdc0c2e2ee2e2d901a55ef2f72ebf4b Building with clang-14 fails with: AS arch/mips/kernel/relocate_kernel.o <unknown>:0: error: symbol 'kexec_args' is already defined <unknown>:0: error: symbol 'secondary_kexec_args' is already defined <unknown>:0: error: symbol 'kexec_start_address' is already defined <unknown>:0: error: symbol 'kexec_indirection_page' is already defined <unknown>:0: error: symbol 'relocate_new_kernel_size' is already defined It turns out EXPORT defined in asm/asm.h expands to a symbol definition, so there is no need to define these symbols again. Remove duplicated symbol definitions. Fixes: 7aa1c8f47e7e ("MIPS: kdump: Add support") Signed-off-by: Rongwei Zhang <pudh4418@gmail.com> Reviewed-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> 
Building with clang-14 fails with:

AS      arch/mips/kernel/relocate_kernel.o
<unknown>:0: error: symbol 'kexec_args' is already defined
<unknown>:0: error: symbol 'secondary_kexec_args' is already defined
<unknown>:0: error: symbol 'kexec_start_address' is already defined
<unknown>:0: error: symbol 'kexec_indirection_page' is already defined
<unknown>:0: error: symbol 'relocate_new_kernel_size' is already defined

It turns out EXPORT defined in asm/asm.h expands to a symbol definition,
so there is no need to define these symbols again. Remove duplicated
symbol definitions.

Fixes: 7aa1c8f47e7e ("MIPS: kdump: Add support")
Signed-off-by: Rongwei Zhang <pudh4418@gmail.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
treewide: use prandom_u32_max() when possible, part 1 2022-10-11T23:42:55+00:00 Jason A. Donenfeld Jason@zx2c4.com 2022-10-05T14:43:38+00:00 81895a65ec63ee1daec3255dc1a06675d2fbe915 Rather than incurring a division or requesting too many random bytes for the given range, use the prandom_u32_max() function, which only takes the minimum required bytes from the RNG and avoids divisions. This was done mechanically with this coccinelle script: @basic@ expression E; type T; identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32"; typedef u64; @@ ( - ((T)get_random_u32() % (E)) + prandom_u32_max(E) | - ((T)get_random_u32() & ((E) - 1)) + prandom_u32_max(E * XXX_MAKE_SURE_E_IS_POW2) | - ((u64)(E) * get_random_u32() >> 32) + prandom_u32_max(E) | - ((T)get_random_u32() & ~PAGE_MASK) + prandom_u32_max(PAGE_SIZE) ) @multi_line@ identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32"; identifier RAND; expression E; @@ - RAND = get_random_u32(); ... when != RAND - RAND %= (E); + RAND = prandom_u32_max(E); // Find a potential literal @literal_mask@ expression LITERAL; type T; identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32"; position p; @@ ((T)get_random_u32()@p & (LITERAL)) // Add one to the literal. @script:python add_one@ literal << literal_mask.LITERAL; RESULT; @@ value = None if literal.startswith('0x'): value = int(literal, 16) elif literal[0] in '123456789': value = int(literal, 10) if value is None: print("I don't know how to handle %s" % (literal)) cocci.include_match(False) elif value == 2**32 - 1 or value == 2**31 - 1 or value == 2**24 - 1 or value == 2**16 - 1 or value == 2**8 - 1: print("Skipping 0x%x for cleanup elsewhere" % (value)) cocci.include_match(False) elif value & (value + 1) != 0: print("Skipping 0x%x because it's not a power of two minus one" % (value)) cocci.include_match(False) elif literal.startswith('0x'): coccinelle.RESULT = cocci.make_expr("0x%x" % (value + 1)) else: coccinelle.RESULT = cocci.make_expr("%d" % (value + 1)) // Replace the literal mask with the calculated result. @plus_one@ expression literal_mask.LITERAL; position literal_mask.p; expression add_one.RESULT; identifier FUNC; @@ - (FUNC()@p & (LITERAL)) + prandom_u32_max(RESULT) @collapse_ret@ type T; identifier VAR; expression E; @@ { - T VAR; - VAR = (E); - return VAR; + return E; } @drop_var@ type T; identifier VAR; @@ { - T VAR; ... when != VAR } Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Yury Norov <yury.norov@gmail.com> Reviewed-by: KP Singh <kpsingh@kernel.org> Reviewed-by: Jan Kara <jack@suse.cz> # for ext4 and sbitmap Reviewed-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com> # for drbd Acked-by: Jakub Kicinski <kuba@kernel.org> Acked-by: Heiko Carstens <hca@linux.ibm.com> # for s390 Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # for mmc Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> 
Rather than incurring a division or requesting too many random bytes for
the given range, use the prandom_u32_max() function, which only takes
the minimum required bytes from the RNG and avoids divisions. This was
done mechanically with this coccinelle script:

@basic@
expression E;
type T;
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
typedef u64;
@@
(
- ((T)get_random_u32() % (E))
+ prandom_u32_max(E)
|
- ((T)get_random_u32() & ((E) - 1))
+ prandom_u32_max(E * XXX_MAKE_SURE_E_IS_POW2)
|
- ((u64)(E) * get_random_u32() >> 32)
+ prandom_u32_max(E)
|
- ((T)get_random_u32() & ~PAGE_MASK)
+ prandom_u32_max(PAGE_SIZE)
)

@multi_line@
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
identifier RAND;
expression E;
@@

-       RAND = get_random_u32();
        ... when != RAND
-       RAND %= (E);
+       RAND = prandom_u32_max(E);

// Find a potential literal
@literal_mask@
expression LITERAL;
type T;
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
position p;
@@

        ((T)get_random_u32()@p & (LITERAL))

// Add one to the literal.
@script:python add_one@
literal << literal_mask.LITERAL;
RESULT;
@@

value = None
if literal.startswith('0x'):
        value = int(literal, 16)
elif literal[0] in '123456789':
        value = int(literal, 10)
if value is None:
        print("I don't know how to handle %s" % (literal))
        cocci.include_match(False)
elif value == 2**32 - 1 or value == 2**31 - 1 or value == 2**24 - 1 or value == 2**16 - 1 or value == 2**8 - 1:
        print("Skipping 0x%x for cleanup elsewhere" % (value))
        cocci.include_match(False)
elif value & (value + 1) != 0:
        print("Skipping 0x%x because it's not a power of two minus one" % (value))
        cocci.include_match(False)
elif literal.startswith('0x'):
        coccinelle.RESULT = cocci.make_expr("0x%x" % (value + 1))
else:
        coccinelle.RESULT = cocci.make_expr("%d" % (value + 1))

// Replace the literal mask with the calculated result.
@plus_one@
expression literal_mask.LITERAL;
position literal_mask.p;
expression add_one.RESULT;
identifier FUNC;
@@

-       (FUNC()@p & (LITERAL))
+       prandom_u32_max(RESULT)

@collapse_ret@
type T;
identifier VAR;
expression E;
@@

 {
-       T VAR;
-       VAR = (E);
-       return VAR;
+       return E;
 }

@drop_var@
type T;
identifier VAR;
@@

 {
-       T VAR;
        ... when != VAR
 }

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Yury Norov <yury.norov@gmail.com>
Reviewed-by: KP Singh <kpsingh@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz> # for ext4 and sbitmap
Reviewed-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com> # for drbd
Acked-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Heiko Carstens <hca@linux.ibm.com> # for s390
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # for mmc
Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Merge tag 'bitmap-6.1-rc1' of https://github.com/norov/linux 2022-10-10T19:49:34+00:00 Linus Torvalds torvalds@linux-foundation.org 2022-10-10T19:49:34+00:00 d4013bc4d49f6da8178a340348369bb9920225c9 Pull bitmap updates from Yury Norov: - Fix unsigned comparison to -1 in CPUMAP_FILE_MAX_BYTES (Phil Auld) - cleanup nr_cpu_ids vs nr_cpumask_bits mess (me) This series cleans that mess and adds new config FORCE_NR_CPUS that allows to optimize cpumask subsystem if the number of CPUs is known at compile-time. - optimize find_bit() functions (me) Reworks find_bit() functions based on new FIND_{FIRST,NEXT}_BIT() macros. - add find_nth_bit() (me) Adds find_nth_bit(), which is ~70 times faster than bitcounting with for_each() loop: for_each_set_bit(bit, mask, size) if (n-- == 0) return bit; Also adds bitmap_weight_and() to let people replace this pattern: tmp = bitmap_alloc(nbits); bitmap_and(tmp, map1, map2, nbits); weight = bitmap_weight(tmp, nbits); bitmap_free(tmp); with a single bitmap_weight_and() call. - repair cpumask_check() (me) After switching cpumask to use nr_cpu_ids, cpumask_check() started generating many false-positive warnings. This series fixes it. - Add for_each_cpu_andnot() and for_each_cpu_andnot() (Valentin Schneider) Extends the API with one more function and applies it in sched/core. * tag 'bitmap-6.1-rc1' of https://github.com/norov/linux: (28 commits) sched/core: Merge cpumask_andnot()+for_each_cpu() into for_each_cpu_andnot() lib/test_cpumask: Add for_each_cpu_and(not) tests cpumask: Introduce for_each_cpu_andnot() lib/find_bit: Introduce find_next_andnot_bit() cpumask: fix checking valid cpu range lib/bitmap: add tests for for_each() loops lib/find: optimize for_each() macros lib/bitmap: introduce for_each_set_bit_wrap() macro lib/find_bit: add find_next{,_and}_bit_wrap cpumask: switch for_each_cpu{,_not} to use for_each_bit() net: fix cpu_max_bits_warn() usage in netif_attrmask_next{,_and} cpumask: add cpumask_nth_{,and,andnot} lib/bitmap: remove bitmap_ord_to_pos lib/bitmap: add tests for find_nth_bit() lib: add find_nth{,_and,_andnot}_bit() lib/bitmap: add bitmap_weight_and() lib/bitmap: don't call __bitmap_weight() in kernel code tools: sync find_bit() implementation lib/find_bit: optimize find_next_bit() functions lib/find_bit: create find_first_zero_bit_le() ... 
Pull bitmap updates from Yury Norov:

 - Fix unsigned comparison to -1 in CPUMAP_FILE_MAX_BYTES (Phil Auld)

 - cleanup nr_cpu_ids vs nr_cpumask_bits mess (me)

   This series cleans that mess and adds new config FORCE_NR_CPUS that
   allows to optimize cpumask subsystem if the number of CPUs is known
   at compile-time.

 - optimize find_bit() functions (me)

   Reworks find_bit() functions based on new FIND_{FIRST,NEXT}_BIT()
   macros.

 - add find_nth_bit() (me)

   Adds find_nth_bit(), which is ~70 times faster than bitcounting with
   for_each() loop:

	for_each_set_bit(bit, mask, size)
		if (n-- == 0)
			return bit;

   Also adds bitmap_weight_and() to let people replace this pattern:

	tmp = bitmap_alloc(nbits);
	bitmap_and(tmp, map1, map2, nbits);
	weight = bitmap_weight(tmp, nbits);
	bitmap_free(tmp);

   with a single bitmap_weight_and() call.

 - repair cpumask_check() (me)

   After switching cpumask to use nr_cpu_ids, cpumask_check() started
   generating many false-positive warnings. This series fixes it.

 - Add for_each_cpu_andnot() and for_each_cpu_andnot() (Valentin
   Schneider)

   Extends the API with one more function and applies it in sched/core.

* tag 'bitmap-6.1-rc1' of https://github.com/norov/linux: (28 commits)
  sched/core: Merge cpumask_andnot()+for_each_cpu() into for_each_cpu_andnot()
  lib/test_cpumask: Add for_each_cpu_and(not) tests
  cpumask: Introduce for_each_cpu_andnot()
  lib/find_bit: Introduce find_next_andnot_bit()
  cpumask: fix checking valid cpu range
  lib/bitmap: add tests for for_each() loops
  lib/find: optimize for_each() macros
  lib/bitmap: introduce for_each_set_bit_wrap() macro
  lib/find_bit: add find_next{,_and}_bit_wrap
  cpumask: switch for_each_cpu{,_not} to use for_each_bit()
  net: fix cpu_max_bits_warn() usage in netif_attrmask_next{,_and}
  cpumask: add cpumask_nth_{,and,andnot}
  lib/bitmap: remove bitmap_ord_to_pos
  lib/bitmap: add tests for find_nth_bit()
  lib: add find_nth{,_and,_andnot}_bit()
  lib/bitmap: add bitmap_weight_and()
  lib/bitmap: don't call __bitmap_weight() in kernel code
  tools: sync find_bit() implementation
  lib/find_bit: optimize find_next_bit() functions
  lib/find_bit: create find_first_zero_bit_le()
  ...