linux-dev/arch/powerpc/kernel/vdso32/datapage.S, branch master

powerpc/vdso: Merge vdso64 and vdso32 into a single directory

2022-02-12T11:47:43Z

merge vdso64 into vdso32 and rename it vdso. Reported-by: kernel test robot Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/4dbe05cc130f6a0858d09ac72e436c373cb08b70.1642782130.git.christophe.leroy@csgroup.eu

powerpc/vdso: augment VDSO32 functions to support 64 bits build

2022-02-12T11:47:43Z

VDSO64 cacheflush.S datapage.S gettimeofday.S and vgettimeofday.c are very similar to their VDSO32 counterpart. VDSO32 counterpart is already more complete than the VDSO64 version as it supports both PPC32 vdso and 32 bits VDSO for PPC64. Use compat macros wherever necessary in PPC32 files so that they can also be used to build VDSO64. vdso64/note.S is already a link to vdso32/note.S so no change is required. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/c2cbb8f046b7efc251053521dc39b752795e26b7.1642782130.git.christophe.leroy@csgroup.eu

powerpc/vdso: Remove __kernel_datapage_offset

2020-12-03T14:01:18Z

__kernel_datapage_offset is not used anymore, remove it. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/ddb5c746bec4e1a026d7c85243213a1876ef844f.1601197618.git.christophe.leroy@csgroup.eu

powerpc/vdso: Remove unused \tmp param in __get_datapage()

2020-12-03T14:01:17Z

The \tmp param is not used anymore, remove it. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/4b13f897dcccce8ae03c031a4598cf26b32e2f1c.1601197618.git.christophe.leroy@csgroup.eu

powerpc: Remove support for PowerPC 601

2020-10-08T10:17:13Z

PowerPC 601 has been retired. Remove all associated specific code. CPU_FTRS_PPC601 has CPU_FTR_COHERENT_ICACHE and CPU_FTR_COMMON. CPU_FTR_COMMON is already present via other CPU_FTRS. None of the remaining CPU selects CPU_FTR_COHERENT_ICACHE. So CPU_FTRS_PPC601 can be removed from the possible features, hence can be removed completely. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/60b725d55e21beec3335175c20b77903ff98284f.1601362098.git.christophe.leroy@csgroup.eu

powerpc/vdso32: miscellaneous optimisations

2020-01-23T10:31:16Z

Various optimisations by inverting branches and removing redundant instructions. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/b4e79f963845545bcce1459cd6fcfe46bdde7863.1575273217.git.christophe.leroy@c-s.fr

powerpc/vdso32: inline __get_datapage()

2020-01-23T10:31:15Z

__get_datapage() is only a few instructions to retrieve the address of the page where the kernel stores data to the VDSO. By inlining this function into its users, a bl/blr pair and a mflr/mtlr pair is avoided, plus a few reg moves. The improvement is noticeable (about 55 nsec/call on an 8xx) vdsotest before the patch: gettimeofday: vdso: 731 nsec/call clock-gettime-realtime-coarse: vdso: 668 nsec/call clock-gettime-monotonic-coarse: vdso: 745 nsec/call vdsotest after the patch: gettimeofday: vdso: 677 nsec/call clock-gettime-realtime-coarse: vdso: 613 nsec/call clock-gettime-monotonic-coarse: vdso: 690 nsec/call Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/c39ef7f3dfa25356b01e211d539671f279086c09.1575273217.git.christophe.leroy@c-s.fr

powerpc/32s: drop CPU_FTR_USE_RTC feature

2019-08-28T13:19:33Z

CPU_FTR_USE_RTC feature only applies to powerpc601. Drop this feature and replace it with tests on CONFIG_PPC_BOOK3S_601. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/170411e2360861f4a95c21faad43519a08bc4040.1566834712.git.christophe.leroy@c-s.fr

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

2019-05-30T18:26:32Z

Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Allison Randal Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman

powerpc/vdso: Correct call frame information

2018-09-14T03:47:31Z

Call Frame Information is used by gdb for back-traces and inserting breakpoints on function return for the "finish" command. This failed when inside __kernel_clock_gettime. More concerning than difficulty debugging is that CFI is also used by stack frame unwinding code to implement exceptions. If you have an app that needs to handle asynchronous exceptions for some reason, and you are unlucky enough to get one inside the VDSO time functions, your app will crash. What's wrong: There is control flow in __kernel_clock_gettime that reaches label 99 without saving lr in r12. CFI info however is interpreted by the unwinder without reference to control flow: It's a simple matter of "Execute all the CFI opcodes up to the current address". That means the unwinder thinks r12 contains the return address at label 99. Disabuse it of that notion by resetting CFI for the return address at label 99. Note that the ".cfi_restore lr" could have gone anywhere from the "mtlr r12" a few instructions earlier to the instruction at label 99. I put the CFI as late as possible, because in general that's best practice (and if possible grouped with other CFI in order to reduce the number of CFI opcodes executed when unwinding). Using r12 as the return address is perfectly fine after the "mtlr r12" since r12 on that code path still contains the return address. __get_datapage also has a CFI error. That function temporarily saves lr in r0, and reflects that fact with ".cfi_register lr,r0". A later use of r0 means the CFI at that point isn't correct, as r0 no longer contains the return address. Fix that too. Signed-off-by: Alan Modra Tested-by: Reza Arbab Signed-off-by: Paul Mackerras