kernel/linux.git/arch/arm/include/asm/vmlinux.lds.h, branch v6.19.11

ARM: 9444/1: add KEEP() keyword to ARM_VECTORS

2025-03-26T13:31:48+00:00

Without this, the vectors are removed if LD_DEAD_CODE_DATA_ELIMINATION is enabled. At startup, the CPU (silently) hangs in the undefined instruction exception as soon as the first timer interrupt arrives. On my setup, the system also boots fine without the 2nd and 3rd KEEP() statements, so I cannot tell whether these are actually required. [nathan: Use OVERLAY_KEEP() to avoid breaking old ld.lld versions] Cc: stable@vger.kernel.org Fixes: ed0f94102251 ("ARM: 9404/1: arm32: enable HAVE_LD_DEAD_CODE_DATA_ELIMINATION") Signed-off-by: Christian Eggers Reviewed-by: Linus Walleij Signed-off-by: Nathan Chancellor Signed-off-by: Russell King (Oracle)

ARM: 9443/1: Require linker to support KEEP within OVERLAY for DCE

2025-03-26T13:31:47+00:00

ld.lld prior to 21.0.0 does not support using the KEEP keyword within an overlay description, which may be needed to avoid discarding necessary sections within an overlay with '--gc-sections', which can be enabled for the kernel via CONFIG_LD_DEAD_CODE_DATA_ELIMINATION. Disallow CONFIG_LD_DEAD_CODE_DATA_ELIMINATION without support for KEEP within OVERLAY and introduce a macro, OVERLAY_KEEP, that can be used to conditionally add KEEP when it is properly supported to avoid breaking old versions of ld.lld. Cc: stable@vger.kernel.org Link: https://github.com/llvm/llvm-project/commit/381599f1fe973afad3094e55ec99b1620dba7d8c Reviewed-by: Linus Walleij Signed-off-by: Nathan Chancellor Signed-off-by: Russell King (Oracle)

ARM: 9439/1: arm32: simplify ARM_MMU_KEEP usage

2025-03-26T13:31:13+00:00

All current users need to add a KEEP() around the argument so the value is actually kept, which doesn't feel very natural and is prone to upcoming bugs as the name suggests that this macro alone already keeps things. Move that directly into the definition. Signed-off-by: Rolf Eike Beer Reviewed-by: Linus Walleij Signed-off-by: Russell King (Oracle)

ARM: 9404/1: arm32: enable HAVE_LD_DEAD_CODE_DATA_ELIMINATION

2024-06-10T11:01:33+00:00

The current arm32 architecture does not yet support the HAVE_LD_DEAD_CODE_DATA_ELIMINATION feature. arm32 is widely used in embedded scenarios, and enabling this feature would be beneficial for reducing the size of the kernel image. In order to make this work, we keep the necessary tables by annotating them with KEEP, also it requires further changes to linker script to KEEP some tables and wildcard compiler generated sections into the right place. When using ld.lld for linking, KEEP is not recognized within the OVERLAY command, and Ard proposed a concise method to solve this problem. It boots normally with defconfig, vexpress_defconfig and tinyconfig. The size comparison of zImage is as follows: defconfig vexpress_defconfig tinyconfig 5137712 5138024 424192 no dce 5032560 4997824 298384 dce 2.0% 2.7% 29.7% shrink When using smaller config file, there is a significant reduction in the size of the zImage. We also tested this patch on a commercially available single-board computer, and the comparison is as follows: a15eb_config 2161384 no dce 2092240 dce 3.2% shrink The zImage size has been reduced by approximately 3.2%, which is 70KB on 2.1M. Signed-off-by: Yuntao Liu Tested-by: Arnd Bergmann Reviewed-by: Arnd Bergmann Reviewed-by: Linus Walleij Signed-off-by: Russell King (Oracle)

objtool/idle: Validate __cpuidle code as noinstr

2023-01-13T10:48:15+00:00

Idle code is very like entry code in that RCU isn't available. As such, add a little validation. Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Tested-by: Tony Lindgren Tested-by: Ulf Hansson Acked-by: Geert Uytterhoeven Acked-by: Rafael J. Wysocki Acked-by: Frederic Weisbecker Link: https://lore.kernel.org/r/20230112195540.373461409@infradead.org

ARM: Do not use NOCROSSREFS directive with ld.lld

2022-03-09T22:14:16+00:00

ld.lld does not support the NOCROSSREFS directive at the moment, which breaks the build after commit b9baf5c8c5c3 ("ARM: Spectre-BHB workaround"): ld.lld: error: ./arch/arm/kernel/vmlinux.lds:34: AT expected, but got NOCROSSREFS Support for this directive will eventually be implemented, at which point a version check can be added. To avoid breaking the build in the meantime, just define NOCROSSREFS to nothing when using ld.lld, with a link to the issue for tracking. Cc: stable@vger.kernel.org Fixes: b9baf5c8c5c3 ("ARM: Spectre-BHB workaround") Link: https://github.com/ClangBuiltLinux/linux/issues/1609 Signed-off-by: Nathan Chancellor Signed-off-by: Linus Torvalds

ARM: Spectre-BHB workaround

2022-03-05T10:42:07+00:00

Workaround the Spectre BHB issues for Cortex-A15, Cortex-A57, Cortex-A72, Cortex-A73 and Cortex-A75. We also include Brahma B15 as well to be safe, which is affected by Spectre V2 in the same ways as Cortex-A15. Reviewed-by: Catalin Marinas Signed-off-by: Russell King (Oracle)

ARM: use LOADADDR() to get load address of sections

2022-03-05T10:41:58+00:00

Use the linker's LOADADDR() macro to get the load address of the sections, and provide a macro to set the start and end symbols. Acked-by: Catalin Marinas Signed-off-by: Russell King (Oracle)

arm/build: Assert for unwanted sections

2020-09-01T08:03:18+00:00

In preparation for warning on orphan sections, enforce expected-to-be-zero-sized sections (since discarding them might hide problems with them suddenly gaining unexpected entries). Signed-off-by: Kees Cook Signed-off-by: Ingo Molnar Cc: Russell King Link: https://lore.kernel.org/r/20200821194310.3089815-19-keescook@chromium.org

arm/build: Add missing sections

2020-09-01T08:03:18+00:00

Add missing text stub sections .vfp11_veneer and .v4_bx, as well as missing DWARF sections, when present in the build. Signed-off-by: Kees Cook Signed-off-by: Ingo Molnar Reviewed-by: Nick Desaulniers Cc: Russell King Link: https://lore.kernel.org/r/20200821194310.3089815-18-keescook@chromium.org