kernel/linux.git/lib/test_printf.c, branch v6.6.132

lib/vsprintf: declare no_hash_pointers in sprintf.h

2023-08-21T20:46:24+00:00

Sparse is not happy to see non-static variable without declaration: lib/vsprintf.c:61:6: warning: symbol 'no_hash_pointers' was not declared. Should it be static? Declare respective variable in the sprintf.h. With this, add a comment to discourage its use if no real need. Link: https://lkml.kernel.org/r/20230814163344.17429-3-andriy.shevchenko@linux.intel.com Signed-off-by: Andy Shevchenko Acked-by: Marco Elver Reviewed-by: Petr Mladek Cc: Alexander Potapenko Cc: Dmitry Vyukov Cc: Rasmus Villemoes Cc: Sergey Senozhatsky Cc: Steven Rostedt (Google) Signed-off-by: Andrew Morton

lib/vsprintf: split out sprintf() and friends

2023-08-21T20:46:24+00:00

Patch series "lib/vsprintf: Rework header inclusions", v3. Some patches that reduce the mess with the header inclusions related to vsprintf.c module. Each patch has its own description, and has no dependencies to each other, except the collisions over modifications of the same places. Hence the series. This patch (of 2): kernel.h is being used as a dump for all kinds of stuff for a long time. sprintf() and friends are used in many drivers without need of the full kernel.h dependency train with it. Here is the attempt on cleaning it up by splitting out sprintf() and friends. Link: https://lkml.kernel.org/r/20230814163344.17429-1-andriy.shevchenko@linux.intel.com Link: https://lkml.kernel.org/r/20230814163344.17429-2-andriy.shevchenko@linux.intel.com Signed-off-by: Andy Shevchenko Reviewed-by: Petr Mladek Cc: Alexander Potapenko Cc: Dmitry Vyukov Cc: Marco Elver Cc: Rasmus Villemoes Cc: Sergey Senozhatsky Cc: Steven Rostedt (Google) Signed-off-by: Andrew Morton

mm, printk: introduce new format %pGt for page_type

2023-03-28T23:20:09+00:00

%pGp format is used to display 'flags' field of a struct page. However, some page flags (i.e. PG_buddy, see page-flags.h for more details) are stored in page_type field. To display human-readable output of page_type, introduce %pGt format. It is important to note the meaning of bits are different in page_type. if page_type is 0xffffffff, no flags are set. Setting PG_buddy (0x00000080) flag results in a page_type of 0xffffff7f. Clearing a bit actually means setting a flag. Bits in page_type are inverted when displaying type names. Only values for which page_type_has_type() returns true are considered as page_type, to avoid confusion with mapcount values. if it returns false, only raw values are displayed and not page type names. Link: https://lkml.kernel.org/r/20230130042514.2418-3-42.hyeyoo@gmail.com Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Reviewed-by: Petr Mladek [vsprintf part] Cc: Andy Shevchenko Cc: David Hildenbrand Cc: Joe Perches Cc: John Ogness Cc: Matthew Wilcox Cc: Sergey Senozhatsky Cc: Steven Rostedt (Google) Cc: Vlastimil Babka Signed-off-by: Andrew Morton

mm: discard __GFP_ATOMIC

2023-02-03T06:33:13+00:00

__GFP_ATOMIC serves little purpose. Its main effect is to set ALLOC_HARDER which adds a few little boosts to increase the chance of an allocation succeeding, one of which is to lower the water-mark at which it will succeed. It is *always* paired with __GFP_HIGH which sets ALLOC_HIGH which also adjusts this watermark. It is probable that other users of __GFP_HIGH should benefit from the other little bonuses that __GFP_ATOMIC gets. __GFP_ATOMIC also gives a warning if used with __GFP_DIRECT_RECLAIM. There is little point to this. We already get a might_sleep() warning if __GFP_DIRECT_RECLAIM is set. __GFP_ATOMIC allows the "watermark_boost" to be side-stepped. It is probable that testing ALLOC_HARDER is a better fit here. __GFP_ATOMIC is used by tegra-smmu.c to check if the allocation might sleep. This should test __GFP_DIRECT_RECLAIM instead. This patch: - removes __GFP_ATOMIC - allows __GFP_HIGH allocations to ignore watermark boosting as well as GFP_ATOMIC requests. - makes other adjustments as suggested by the above. The net result is not change to GFP_ATOMIC allocations. Other allocations that use __GFP_HIGH will benefit from a few different extra privileges. This affects: xen, dm, md, ntfs3 the vermillion frame buffer hibernation ksm swap all of which likely produce more benefit than cost if these selected allocation are more likely to succeed quickly. [mgorman: Minor adjustments to rework on top of a series] Link: https://lkml.kernel.org/r/163712397076.13692.4727608274002939094@noble.neil.brown.name Link: https://lkml.kernel.org/r/20230113111217.14134-7-mgorman@techsingularity.net Signed-off-by: NeilBrown Signed-off-by: Mel Gorman Acked-by: Vlastimil Babka Acked-by: Michal Hocko Cc: Matthew Wilcox Cc: Thierry Reding Signed-off-by: Andrew Morton

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

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 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 ...

Merge tag 'printk-for-6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux

2022-12-12T17:01:36+00:00

Pull printk updates from Petr Mladek: - Add NMI-safe SRCU reader API. It uses atomic_inc() instead of this_cpu_inc() on strong load-store architectures. - Introduce new console_list_lock to synchronize a manipulation of the list of registered consoles and their flags. This is a first step in removing the big-kernel-lock-like behavior of console_lock(). This semaphore still serializes console->write() calbacks against: - each other. It primary prevents potential races between early and proper console drivers using the same device. - suspend()/resume() callbacks and init() operations in some drivers. - various other operations in the tty/vt and framebufer susbsystems. It is likely that console_lock() serializes even operations that are not directly conflicting with the console->write() callbacks here. This is the most complicated big-kernel-lock aspect of the console_lock() that will be hard to untangle. - Introduce new console_srcu lock that is used to safely iterate and access the registered console drivers under SRCU read lock. This is a prerequisite for introducing atomic console drivers and console kthreads. It will reduce the complexity of serialization against normal consoles and console_lock(). Also it should remove the risk of deadlock during critical situations, like Oops or panic, when only atomic consoles are registered. - Check whether the console is registered instead of enabled on many locations. It was a historical leftover. - Cleanly force a preferred console in xenfb code instead of a dirty hack. - A lot of code and comment clean ups and improvements. * tag 'printk-for-6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux: (47 commits) printk: htmldocs: add missing description tty: serial: sh-sci: use setup() callback for early console printk: relieve console_lock of list synchronization duties tty: serial: kgdboc: use console_list_lock to trap exit tty: serial: kgdboc: synchronize tty_find_polling_driver() and register_console() tty: serial: kgdboc: use console_list_lock for list traversal tty: serial: kgdboc: use srcu console list iterator proc: consoles: use console_list_lock for list iteration tty: tty_io: use console_list_lock for list synchronization printk, xen: fbfront: create/use safe function for forcing preferred netconsole: avoid CON_ENABLED misuse to track registration usb: early: xhci-dbc: use console_is_registered() tty: serial: xilinx_uartps: use console_is_registered() tty: serial: samsung_tty: use console_is_registered() tty: serial: pic32_uart: use console_is_registered() tty: serial: earlycon: use console_is_registered() tty: hvc: use console_is_registered() efi: earlycon: use console_is_registered() tty: nfcon: use console_is_registered() serial_core: replace uart_console_enabled() with uart_console_registered() ...

lib: assume char is unsigned

2022-11-18T23:56:15+00:00

Now that we use -funsigned-char, there's no need for this kind of ifdef. Signed-off-by: Jason A. Donenfeld

treewide: use get_random_u32_inclusive() when possible

2022-11-18T01:18:02+00:00

These cases were done with this Coccinelle: @@ expression H; expression L; @@ - (get_random_u32_below(H) + L) + get_random_u32_inclusive(L, H + L - 1) @@ expression H; expression L; expression E; @@ get_random_u32_inclusive(L, H - + E - - E ) @@ expression H; expression L; expression E; @@ get_random_u32_inclusive(L, H - - E - + E ) @@ expression H; expression L; expression E; expression F; @@ get_random_u32_inclusive(L, H - - E + F - + E ) @@ expression H; expression L; expression E; expression F; @@ get_random_u32_inclusive(L, H - + E + F - - E ) And then subsequently cleaned up by hand, with several automatic cases rejected if it didn't make sense contextually. Reviewed-by: Kees Cook Reviewed-by: Greg Kroah-Hartman Reviewed-by: Jason Gunthorpe # for infiniband Signed-off-by: Jason A. Donenfeld

treewide: use get_random_u32_below() instead of deprecated function

2022-11-18T01:15:15+00:00

This is a simple mechanical transformation done by: @@ expression E; @@ - prandom_u32_max + get_random_u32_below (E) Reviewed-by: Kees Cook Reviewed-by: Greg Kroah-Hartman Acked-by: Darrick J. Wong # for xfs Reviewed-by: SeongJae Park # for damon Reviewed-by: Jason Gunthorpe # for infiniband Reviewed-by: Russell King (Oracle) # for arm Acked-by: Ulf Hansson # for mmc Signed-off-by: Jason A. Donenfeld

test_printf: Refactor fwnode_pointer() to make it more readable

2022-11-01T12:41:22+00:00

Converting fwnode_pointer() to use better swnode API allows to make code more readable. While at it, rename full_name to full_name_third to show exact relation in the hierarchy. Signed-off-by: Andy Shevchenko Signed-off-by: Petr Mladek Link: https://lore.kernel.org/r/20220824170542.18263-1-andriy.shevchenko@linux.intel.com