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2023-07-13sparc: mark __arch_xchg() as __always_inlineArnd Bergmann1-1/+1
An otherwise correct change to the atomic operations uncovered an existing bug in the sparc __arch_xchg() function, which is calls __xchg_called_with_bad_pointer() when its arguments are unknown at compile time: ERROR: modpost: "__xchg_called_with_bad_pointer" [lib/atomic64_test.ko] undefined! This now happens because gcc determines that it's better to not inline the function. Avoid this by just marking the function as __always_inline to force the compiler to do the right thing here. Reported-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/all/c525adc9-6623-4660-8718-e0c9311563b8@roeck-us.net/ Fixes: d12157efc8e08 ("locking/atomic: make atomic*_{cmp,}xchg optional") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Palmer Dabbelt <palmer@rivosinc.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Sam Ravnborg <sam@ravnborg.org> Acked-by: Guenter Roeck <linux@roeck-us.net> Acked-by: Andi Shyti <andi.shyti@linux.intel.com> Link: https://lore.kernel.org/r/20230628094938.2318171-1-arnd@kernel.org Signed-off-by: Kees Cook <keescook@chromium.org>
2023-04-29locking/arch: Rename all internal __xchg() names to __arch_xchg()Andrzej Hajda1-3/+3
Decrease the probability of this internal facility to be used by driver code. Signed-off-by: Andrzej Hajda <andrzej.hajda@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> [m68k] Acked-by: Palmer Dabbelt <palmer@rivosinc.com> [riscv] Link: https://lore.kernel.org/r/20230118154450.73842-1-andrzej.hajda@intel.com Cc: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-07locking/atomic: sparc: Fix arch_cmpxchg64_local()Mark Rutland1-1/+1
Anatoly reports that since commit: ff5b4f1ed580c59d ("locking/atomic: sparc: move to ARCH_ATOMIC") ... it's possible to reliably trigger an oops by running: stress-ng -v --mmap 1 -t 30s ... which results in a NULL pointer dereference in __split_huge_pmd_locked(). The underlying problem is that commit ff5b4f1ed580c59d left arch_cmpxchg64_local() defined in terms of cmpxchg_local() rather than arch_cmpxchg_local(). In <asm-generic/atomic-instrumented.h> we wrap these with macros which use identically-named variables. When cmpxchg_local() nests inside cmpxchg64_local(), this casues it to use an unitialized variable as the pointer, which can be NULL. This can also be seen in pmdp_establish(), where the compiler can generate the pointer with a `clr` instruction: 0000000000000360 <pmdp_establish>: 360: 9d e3 bf 50 save %sp, -176, %sp 364: fa 5e 80 00 ldx [ %i2 ], %i5 368: 82 10 00 1b mov %i3, %g1 36c: 84 10 20 00 clr %g2 370: c3 f0 90 1d casx [ %g2 ], %i5, %g1 374: 80 a7 40 01 cmp %i5, %g1 378: 32 6f ff fc bne,a %xcc, 368 <pmdp_establish+0x8> 37c: fa 5e 80 00 ldx [ %i2 ], %i5 380: d0 5e 20 40 ldx [ %i0 + 0x40 ], %o0 384: 96 10 00 1b mov %i3, %o3 388: 94 10 00 1d mov %i5, %o2 38c: 92 10 00 19 mov %i1, %o1 390: 7f ff ff 84 call 1a0 <__set_pmd_acct> 394: b0 10 00 1d mov %i5, %i0 398: 81 cf e0 08 return %i7 + 8 39c: 01 00 00 00 nop This patch fixes the problem by defining arch_cmpxchg64_local() in terms of arch_cmpxchg_local(), avoiding potential shadowing, and resulting in working cmpxchg64_local() and variants, e.g. 0000000000000360 <pmdp_establish>: 360: 9d e3 bf 50 save %sp, -176, %sp 364: fa 5e 80 00 ldx [ %i2 ], %i5 368: 82 10 00 1b mov %i3, %g1 36c: c3 f6 90 1d casx [ %i2 ], %i5, %g1 370: 80 a7 40 01 cmp %i5, %g1 374: 32 6f ff fd bne,a %xcc, 368 <pmdp_establish+0x8> 378: fa 5e 80 00 ldx [ %i2 ], %i5 37c: d0 5e 20 40 ldx [ %i0 + 0x40 ], %o0 380: 96 10 00 1b mov %i3, %o3 384: 94 10 00 1d mov %i5, %o2 388: 92 10 00 19 mov %i1, %o1 38c: 7f ff ff 85 call 1a0 <__set_pmd_acct> 390: b0 10 00 1d mov %i5, %i0 394: 81 cf e0 08 return %i7 + 8 398: 01 00 00 00 nop 39c: 01 00 00 00 nop Fixes: ff5b4f1ed580c59d ("locking/atomic: sparc: move to ARCH_ATOMIC") Reported-by: Anatoly Pugachev <matorola@gmail.com> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Tested-by: Anatoly Pugachev <matorola@gmail.com> Link: https://lore.kernel.org/r/20210707083032.567-1-mark.rutland@arm.com
2021-05-26locking/atomic: sparc: move to ARCH_ATOMICMark Rutland1-5/+5
We'd like all architectures to convert to ARCH_ATOMIC, as once all architectures are converted it will be possible to make significant cleanups to the atomics headers, and this will make it much easier to generically enable atomic functionality (e.g. debug logic in the instrumented wrappers). As a step towards that, this patch migrates sparc to ARCH_ATOMIC. The arch code provides arch_{atomic,atomic64,xchg,cmpxchg}*(), and common code wraps these with optional instrumentation to provide the regular functions. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Will Deacon <will@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20210525140232.53872-31-mark.rutland@arm.com
2021-05-26locking/atomic: cmpxchg: make `generic` a prefixMark Rutland1-1/+1
The asm-generic implementations of cmpxchg_local() and cmpxchg64_local() use a `_generic` suffix to distinguish themselves from arch code or wrappers used elsewhere. Subsequent patches will add ARCH_ATOMIC support to these implementations, and will distinguish more functions with a `generic` portion. To align with how ARCH_ATOMIC uses an `arch_` prefix, it would be helpful to use a `generic_` prefix rather than a `_generic` suffix. In preparation for this, this patch renames the existing functions to make `generic` a prefix rather than a suffix. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Will Deacon <will@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20210525140232.53872-12-mark.rutland@arm.com
2018-10-27sparc64: Rework xchg() definition to avoid warnings.David S. Miller1-1/+6
Such as: fs/ocfs2/file.c: In function ‘ocfs2_file_write_iter’: ./arch/sparc/include/asm/cmpxchg_64.h:55:22: warning: value computed is not used [-Wunused-value] #define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr)))) and drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c: In function ‘ixgbevf_xdp_setup’: ./arch/sparc/include/asm/cmpxchg_64.h:55:22: warning: value computed is not used [-Wunused-value] #define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr)))) Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman1-0/+1
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-25arch/sparc: Introduce xchg16 for SPARCBabu Moger1-10/+39
SPARC supports 32 bit and 64 bit xchg right now. Add the support for 16 bit (2 byte) xchg. This is required to support queued spinlock feature which uses 2 byte xchg. This is achieved using 4 byte cas instructions with byte manipulations. Also re-arranged the code to call __cmpxchg_u32 inside xchg16. Signed-off-by: Babu Moger <babu.moger@oracle.com> Reviewed-by: Håkon Bugge <haakon.bugge@oracle.com> Reviewed-by: Steven Sistare <steven.sistare@oracle.com> Reviewed-by: Shannon Nelson <shannon.nelson@oracle.com> Reviewed-by: Jane Chu <jane.chu@oracle.com> Reviewed-by: Vijay Kumar <vijay.ac.kumar@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-25arch/sparc: Introduce cmpxchg_u8 SPARCBabu Moger1-0/+29
SPARC supports 32 bit and 64 bit cmpxchg right now. Add support for 8 bit (1 byte) cmpxchg. This is required to support queued rwlocks feature which uses 1 byte cmpxchg. The function __cmpxchg_u8 here uses the 4 byte cas instruction with a byte manipulation to achieve 1 byte cmpxchg. Signed-off-by: Babu Moger <babu.moger@oracle.com> Reviewed-by: Håkon Bugge <haakon.bugge@oracle.com> Reviewed-by: Steve Sistare <steven.sistare@oracle.com> Reviewed-by: Shannon Nelson <shannon.nelson@oracle.com> Reviewed-by: Jane Chu <jane.chu@oracle.com> Reviewed-by: Vijay Kumar <vijay.ac.kumar@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-13arch: Remove __ARCH_HAVE_CMPXCHGThomas Gleixner1-2/+0
We removed the only user of this define in the rtmutex code. Get rid of it. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
2014-05-19sparc: drop use of extern for prototypes in arch/sparc/include/asmSam Ravnborg1-2/+2
Drop extern for all prototypes and adjust alignment of parameters as required after the removal. In a few rare cases adjust linelength to conform to maximum 80 chars, and likewise in a few rare cases adjust alignment of parameters to static functions. Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-03-20sparc64: Provide cmpxchg64()Geert Uytterhoeven1-0/+1
sparc64 allmodconfig: drivers/block/blockconsole.c: In function ‘bcon_advance_console_bytes’: drivers/block/blockconsole.c:164: error: implicit declaration of function ‘cmpxchg64’ Map cmpxchg64() to cmpxchg64_local() (which eventually calls __cmpxchg_u64()) to fix this. Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-03-28Disintegrate asm/system.h for SparcDavid Howells1-0/+145
Disintegrate asm/system.h for Sparc. Signed-off-by: David Howells <dhowells@redhat.com> cc: sparclinux@vger.kernel.org