kernel/linux.git/arch/arm64/include/asm/sections.h, branch v6.19.11

KVM: arm64: Add .hyp.data section

2025-05-06T08:56:18+00:00

The hypervisor has not needed its own .data section because all globals were either .rodata or .bss. To avoid having to initialize future data-structures at run-time, let's introduce add a .data section to the hypervisor. Signed-off-by: David Brazdil Signed-off-by: Quentin Perret Link: https://lore.kernel.org/r/20250416160900.3078417-2-qperret@google.com Signed-off-by: Marc Zyngier

arm64: entry: Allow the trampoline text to occupy multiple pages

2022-02-15T17:40:28+00:00

Adding a second set of vectors to .entry.tramp.text will make it larger than a single 4K page. Allow the trampoline text to occupy up to three pages by adding two more fixmap slots. Previous changes to tramp_valias allowed it to reach beyond a single page. Reviewed-by: Catalin Marinas Signed-off-by: James Morse

arm64: kexec: use ld script for relocation function

2021-10-01T12:31:00+00:00

Currently, relocation code declares start and end variables which are used to compute its size. The better way to do this is to use ld script, and put relocation function in its own section. Signed-off-by: Pasha Tatashin Acked-by: Catalin Marinas Link: https://lore.kernel.org/r/20210930143113.1502553-11-pasha.tatashin@soleen.com Signed-off-by: Will Deacon

KVM: arm64: Introduce a BSS section for use at Hyp

2021-03-19T12:01:20+00:00

Currently, the hyp code cannot make full use of a bss, as the kernel section is mapped read-only. While this mapping could simply be changed to read-write, it would intermingle even more the hyp and kernel state than they currently are. Instead, introduce a __hyp_bss section, that uses reserved pages, and create the appropriate RW hyp mappings during KVM init. Acked-by: Will Deacon Signed-off-by: Quentin Perret Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20210319100146.1149909-8-qperret@google.com

KVM: arm64: Apply hyp relocations at runtime

2021-01-23T14:01:00+00:00

KVM nVHE code runs under a different VA mapping than the kernel, hence so far it avoided using absolute addressing because the VA in a constant pool is relocated by the linker to a kernel VA (see hyp_symbol_addr). Now the kernel has access to a list of positions that contain a kimg VA but will be accessed only in hyp execution context. These are generated by the gen-hyprel build-time tool and stored in .hyp.reloc. Add early boot pass over the entries and convert the kimg VAs to hyp VAs. Note that this requires for .hyp* ELF sections to be mapped read-write at that point. Signed-off-by: David Brazdil Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20210105180541.65031-6-dbrazdil@google.com

KVM: arm64: Set up .hyp.rodata ELF section

2021-01-23T13:58:49+00:00

We will need to recognize pointers in .rodata specific to hyp, so establish a .hyp.rodata ELF section. Merge it with the existing .hyp.data..ro_after_init as they are treated the same at runtime. Signed-off-by: David Brazdil Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20210105180541.65031-3-dbrazdil@google.com

KVM: arm64: Add .hyp.data..ro_after_init ELF section

2020-12-04T10:08:33+00:00

Add rules for renaming the .data..ro_after_init ELF section in KVM nVHE object files to .hyp.data..ro_after_init, linking it into the kernel and mapping it in hyp at runtime. The section is RW to the host, then mapped RO in hyp. The expectation is that the host populates the variables in the section and they are never changed by hyp afterwards. Signed-off-by: David Brazdil Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20201202184122.26046-13-dbrazdil@google.com

arm64: Remove __exception_text_start and __exception_text_end from asm/section.h

2020-01-08T17:30:19+00:00

Linux commit b6e43c0e3129 ("arm64: remove __exception annotations") has removed __exception_text_start and __exception_text_end sections. So removing reference of __exception_text_start and __exception_text_end from from asm/section.h. Cc: James Morse Reviewed-by: Anshuman Khandual Signed-off-by: Prabhakar Kushwaha Signed-off-by: Will Deacon

arm64: insn: consistently handle exit text

2019-12-04T11:32:20+00:00

A kernel built with KASAN && FTRACE_WITH_REGS && !MODULES, produces a boot-time splat in the bowels of ftrace: | [ 0.000000] ftrace: allocating 32281 entries in 127 pages | [ 0.000000] ------------[ cut here ]------------ | [ 0.000000] WARNING: CPU: 0 PID: 0 at kernel/trace/ftrace.c:2019 ftrace_bug+0x27c/0x328 | [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 5.4.0-rc3-00008-g7f08ae53a7e3 #13 | [ 0.000000] Hardware name: linux,dummy-virt (DT) | [ 0.000000] pstate: 60000085 (nZCv daIf -PAN -UAO) | [ 0.000000] pc : ftrace_bug+0x27c/0x328 | [ 0.000000] lr : ftrace_init+0x640/0x6cc | [ 0.000000] sp : ffffa000120e7e00 | [ 0.000000] x29: ffffa000120e7e00 x28: ffff00006ac01b10 | [ 0.000000] x27: ffff00006ac898c0 x26: dfffa00000000000 | [ 0.000000] x25: ffffa000120ef290 x24: ffffa0001216df40 | [ 0.000000] x23: 000000000000018d x22: ffffa0001244c700 | [ 0.000000] x21: ffffa00011bf393c x20: ffff00006ac898c0 | [ 0.000000] x19: 00000000ffffffff x18: 0000000000001584 | [ 0.000000] x17: 0000000000001540 x16: 0000000000000007 | [ 0.000000] x15: 0000000000000000 x14: ffffa00010432770 | [ 0.000000] x13: ffff940002483519 x12: 1ffff40002483518 | [ 0.000000] x11: 1ffff40002483518 x10: ffff940002483518 | [ 0.000000] x9 : dfffa00000000000 x8 : 0000000000000001 | [ 0.000000] x7 : ffff940002483519 x6 : ffffa0001241a8c0 | [ 0.000000] x5 : ffff940002483519 x4 : ffff940002483519 | [ 0.000000] x3 : ffffa00011780870 x2 : 0000000000000001 | [ 0.000000] x1 : 1fffe0000d591318 x0 : 0000000000000000 | [ 0.000000] Call trace: | [ 0.000000] ftrace_bug+0x27c/0x328 | [ 0.000000] ftrace_init+0x640/0x6cc | [ 0.000000] start_kernel+0x27c/0x654 | [ 0.000000] random: get_random_bytes called from print_oops_end_marker+0x30/0x60 with crng_init=0 | [ 0.000000] ---[ end trace 0000000000000000 ]--- | [ 0.000000] ftrace faulted on writing | [ 0.000000] [] _GLOBAL__sub_D_65535_0___tracepoint_initcall_level+0x4/0x28 | [ 0.000000] Initializing ftrace call sites | [ 0.000000] ftrace record flags: 0 | [ 0.000000] (0) | [ 0.000000] expected tramp: ffffa000100b3344 This is due to an unfortunate combination of several factors. Building with KASAN results in the compiler generating anonymous functions to register/unregister global variables against the shadow memory. These functions are placed in .text.startup/.text.exit, and given mangled names like _GLOBAL__sub_{I,D}_65535_0_$OTHER_SYMBOL. The kernel linker script places these in .init.text and .exit.text respectively, which are both discarded at runtime as part of initmem. Building with FTRACE_WITH_REGS uses -fpatchable-function-entry=2, which also instruments KASAN's anonymous functions. When these are discarded with the rest of initmem, ftrace removes dangling references to these call sites. Building without MODULES implicitly disables STRICT_MODULE_RWX, and causes arm64's patch_map() function to treat any !core_kernel_text() symbol as something that can be modified in-place. As core_kernel_text() is only true for .text and .init.text, with the latter depending on system_state < SYSTEM_RUNNING, we'll treat .exit.text as something that can be patched in-place. However, .exit.text is mapped read-only. Hence in this configuration the ftrace init code blows up while trying to patch one of the functions generated by KASAN. We could try to filter out the call sites in .exit.text rather than initializing them, but this would be inconsistent with how we handle .init.text, and requires hooking into core bits of ftrace. The behaviour of patch_map() is also inconsistent today, so instead let's clean that up and have it consistently handle .exit.text. This patch teaches patch_map() to handle .exit.text at init time, preventing the boot-time splat above. The flow of patch_map() is reworked to make the logic clearer and minimize redundant conditionality. Fixes: 3b23e4991fb66f6d ("arm64: implement ftrace with regs") Signed-off-by: Mark Rutland Cc: Amit Daniel Kachhap Cc: Ard Biesheuvel Cc: Torsten Duwe Cc: Will Deacon Signed-off-by: Catalin Marinas

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234

2019-06-19T15:09:07+00:00

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 version 2 as published by the free software foundation this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not see http www gnu org licenses extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 503 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Alexios Zavras Reviewed-by: Allison Randal Reviewed-by: Enrico Weigelt Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190602204653.811534538@linutronix.de Signed-off-by: Greg Kroah-Hartman