From f9733aa925d99268e3c1f284d3e62e6a643dcc1d Mon Sep 17 00:00:00 2001 From: Rolf Eike Beer Date: Tue, 14 Jan 2025 14:45:38 +0100 Subject: [PATCH 1/6] ARM: 9439/1: arm32: simplify ARM_MMU_KEEP usage 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) --- arch/arm/include/asm/vmlinux.lds.h | 2 +- arch/arm/kernel/vmlinux-xip.lds.S | 2 +- arch/arm/kernel/vmlinux.lds.S | 2 +- 3 files changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/arm/include/asm/vmlinux.lds.h b/arch/arm/include/asm/vmlinux.lds.h index d60f6e83a9f7..89697f204715 100644 --- a/arch/arm/include/asm/vmlinux.lds.h +++ b/arch/arm/include/asm/vmlinux.lds.h @@ -19,7 +19,7 @@ #endif #ifdef CONFIG_MMU -#define ARM_MMU_KEEP(x) x +#define ARM_MMU_KEEP(x) KEEP(x) #define ARM_MMU_DISCARD(x) #else #define ARM_MMU_KEEP(x) diff --git a/arch/arm/kernel/vmlinux-xip.lds.S b/arch/arm/kernel/vmlinux-xip.lds.S index 5eddb75a7174..f2e8d4fac068 100644 --- a/arch/arm/kernel/vmlinux-xip.lds.S +++ b/arch/arm/kernel/vmlinux-xip.lds.S @@ -63,7 +63,7 @@ SECTIONS . = ALIGN(4); __ex_table : AT(ADDR(__ex_table) - LOAD_OFFSET) { __start___ex_table = .; - ARM_MMU_KEEP(KEEP(*(__ex_table))) + ARM_MMU_KEEP(*(__ex_table)) __stop___ex_table = .; } diff --git a/arch/arm/kernel/vmlinux.lds.S b/arch/arm/kernel/vmlinux.lds.S index de373c6c2ae8..d592a203f9c6 100644 --- a/arch/arm/kernel/vmlinux.lds.S +++ b/arch/arm/kernel/vmlinux.lds.S @@ -74,7 +74,7 @@ SECTIONS . = ALIGN(4); __ex_table : AT(ADDR(__ex_table) - LOAD_OFFSET) { __start___ex_table = .; - ARM_MMU_KEEP(KEEP(*(__ex_table))) + ARM_MMU_KEEP(*(__ex_table)) __stop___ex_table = .; } From ccb8ce526807fcbd4578d6619100d8ec48769ea8 Mon Sep 17 00:00:00 2001 From: Christian Schrrefl Date: Fri, 31 Jan 2025 00:03:45 +0100 Subject: [PATCH 2/6] ARM: 9441/1: rust: Enable Rust support for ARMv7 This commit allows building ARMv7 kernels with Rust support. The rust core library expects some __eabi_... functions that are not implemented in the kernel. Those functions are some float operations and __aeabi_uldivmod. For now those are implemented with define_panicking_intrinsics!. This is based on the code by Sven Van Asbroeck from the original rust branch and inspired by the AArch version by Jamie Cunliffe. I have tested the rust samples and a custom simple MMIO module on hardware (De1SoC FPGA + Arm A9 CPU). Tested-by: Rudraksha Gupta Reviewed-by: Alice Ryhl Acked-by: Miguel Ojeda Tested-by: Miguel Ojeda Acked-by: Ard Biesheuvel Signed-off-by: Christian Schrefl Signed-off-by: Russell King (Oracle) --- Documentation/rust/arch-support.rst | 1 + arch/arm/Kconfig | 1 + arch/arm/Makefile | 1 + rust/Makefile | 8 ++++++++ rust/compiler_builtins.rs | 24 ++++++++++++++++++++++++ scripts/generate_rust_target.rs | 4 +++- 6 files changed, 38 insertions(+), 1 deletion(-) diff --git a/Documentation/rust/arch-support.rst b/Documentation/rust/arch-support.rst index 54be7ddf3e57..6e6a515d0899 100644 --- a/Documentation/rust/arch-support.rst +++ b/Documentation/rust/arch-support.rst @@ -15,6 +15,7 @@ support corresponds to ``S`` values in the ``MAINTAINERS`` file. ============= ================ ============================================== Architecture Level of support Constraints ============= ================ ============================================== +``arm`` Maintained ARMv7 Little Endian only. ``arm64`` Maintained Little Endian only. ``loongarch`` Maintained \- ``riscv`` Maintained ``riscv64`` and LLVM/Clang only. diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 835b5f100e92..202dbd17ad2f 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -133,6 +133,7 @@ config ARM select MMU_GATHER_RCU_TABLE_FREE if SMP && ARM_LPAE select HAVE_REGS_AND_STACK_ACCESS_API select HAVE_RSEQ + select HAVE_RUST if CPU_LITTLE_ENDIAN && CPU_32v7 select HAVE_STACKPROTECTOR select HAVE_SYSCALL_TRACEPOINTS select HAVE_UID16 diff --git a/arch/arm/Makefile b/arch/arm/Makefile index 00ca7886b18e..4808d3ed98e4 100644 --- a/arch/arm/Makefile +++ b/arch/arm/Makefile @@ -150,6 +150,7 @@ endif KBUILD_CPPFLAGS +=$(cpp-y) KBUILD_CFLAGS +=$(CFLAGS_ABI) $(CFLAGS_ISA) $(arch-y) $(tune-y) $(call cc-option,-mshort-load-bytes,$(call cc-option,-malignment-traps,)) -msoft-float -Uarm KBUILD_AFLAGS +=$(CFLAGS_ABI) $(AFLAGS_ISA) -Wa,$(arch-y) $(tune-y) -include asm/unified.h -msoft-float +KBUILD_RUSTFLAGS += --target=arm-unknown-linux-gnueabi CHECKFLAGS += -D__arm__ diff --git a/rust/Makefile b/rust/Makefile index 8fcfd60447bc..5b45f760f462 100644 --- a/rust/Makefile +++ b/rust/Makefile @@ -245,6 +245,7 @@ bindgen_skip_c_flags := -mno-fp-ret-in-387 -mpreferred-stack-boundary=% \ # Derived from `scripts/Makefile.clang`. BINDGEN_TARGET_x86 := x86_64-linux-gnu BINDGEN_TARGET_arm64 := aarch64-linux-gnu +BINDGEN_TARGET_arm := arm-linux-gnueabi BINDGEN_TARGET := $(BINDGEN_TARGET_$(SRCARCH)) # All warnings are inhibited since GCC builds are very experimental, @@ -397,6 +398,13 @@ redirect-intrinsics = \ __muloti4 __multi3 \ __udivmodti4 __udivti3 __umodti3 +ifdef CONFIG_ARM + # Add eabi initrinsics for ARM 32-bit + redirect-intrinsics += \ + __aeabi_fadd __aeabi_fmul __aeabi_fcmpeq __aeabi_fcmple __aeabi_fcmplt __aeabi_fcmpun \ + __aeabi_dadd __aeabi_dmul __aeabi_dcmple __aeabi_dcmplt __aeabi_dcmpun \ + __aeabi_uldivmod +endif ifneq ($(or $(CONFIG_ARM64),$(and $(CONFIG_RISCV),$(CONFIG_64BIT))),) # These intrinsics are defined for ARM64 and RISCV64 redirect-intrinsics += \ diff --git a/rust/compiler_builtins.rs b/rust/compiler_builtins.rs index f14b8d7caf89..dd16c1dc899c 100644 --- a/rust/compiler_builtins.rs +++ b/rust/compiler_builtins.rs @@ -73,5 +73,29 @@ pub extern "C" fn $ident() { __umodti3, }); +#[cfg(target_arch = "arm")] +define_panicking_intrinsics!("`f32` should not be used", { + __aeabi_fadd, + __aeabi_fmul, + __aeabi_fcmpeq, + __aeabi_fcmple, + __aeabi_fcmplt, + __aeabi_fcmpun, +}); + +#[cfg(target_arch = "arm")] +define_panicking_intrinsics!("`f64` should not be used", { + __aeabi_dadd, + __aeabi_dmul, + __aeabi_dcmple, + __aeabi_dcmplt, + __aeabi_dcmpun, +}); + +#[cfg(target_arch = "arm")] +define_panicking_intrinsics!("`u64` division/modulo should not be used", { + __aeabi_uldivmod, +}); + // NOTE: if you are adding a new intrinsic here, you should also add it to // `redirect-intrinsics` in `rust/Makefile`. diff --git a/scripts/generate_rust_target.rs b/scripts/generate_rust_target.rs index 0d00ac3723b5..f8e7fb38bf16 100644 --- a/scripts/generate_rust_target.rs +++ b/scripts/generate_rust_target.rs @@ -172,7 +172,9 @@ fn main() { let mut ts = TargetSpec::new(); // `llvm-target`s are taken from `scripts/Makefile.clang`. - if cfg.has("ARM64") { + if cfg.has("ARM") { + panic!("arm uses the builtin rustc target"); + } else if cfg.has("ARM64") { panic!("arm64 uses the builtin rustc aarch64-unknown-none target"); } else if cfg.has("RISCV") { if cfg.has("64BIT") { From 9cac324d6f4900f92d41db5fd6b73b6feb0bfb68 Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Wed, 5 Feb 2025 14:24:15 +0100 Subject: [PATCH 3/6] ARM: 9442/1: smp: Fix IPI alignment in /proc/interrupts On a system with less than 1000 interrupts, prec = 3, causing a misalignment for the IPI interrupts. E.g. on Koelsch (R-Car M2-W): 200: 0 0 gpio-rcar 6 Edge SW36 IPI0: 0 0 CPU wakeup interrupts IPI1: 0 0 Timer broadcast interrupts IPI2: 1701 2844 Rescheduling interrupts IPI3: 10338 21181 Function call interrupts IPI4: 0 0 CPU stop interrupts IPI5: 651 825 IRQ work interrupts IPI6: 0 0 completion interrupts Err: 0 Fix this by adopting the same solution as used on arm64. Signed-off-by: Geert Uytterhoeven Reviewed-by: Anshuman Khandual Signed-off-by: Russell King (Oracle) --- arch/arm/kernel/smp.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index 3431c0553f45..50999886a8b5 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -551,7 +551,8 @@ void show_ipi_list(struct seq_file *p, int prec) if (!ipi_desc[i]) continue; - seq_printf(p, "%*s%u: ", prec - 1, "IPI", i); + seq_printf(p, "%*s%u:%s", prec - 1, "IPI", i, + prec >= 4 ? " " : ""); for_each_online_cpu(cpu) seq_printf(p, "%10u ", irq_desc_kstat_cpu(ipi_desc[i], cpu)); From e7607f7d6d81af71dcc5171278aadccc94d277cd Mon Sep 17 00:00:00 2001 From: Nathan Chancellor Date: Thu, 20 Mar 2025 22:33:49 +0100 Subject: [PATCH 4/6] ARM: 9443/1: Require linker to support KEEP within OVERLAY for DCE 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) --- arch/arm/Kconfig | 2 +- arch/arm/include/asm/vmlinux.lds.h | 6 ++++++ init/Kconfig | 5 +++++ 3 files changed, 12 insertions(+), 1 deletion(-) diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 202dbd17ad2f..25ed6f1a7c7a 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -121,7 +121,7 @@ config ARM select HAVE_KERNEL_XZ select HAVE_KPROBES if !XIP_KERNEL && !CPU_ENDIAN_BE32 && !CPU_V7M select HAVE_KRETPROBES if HAVE_KPROBES - select HAVE_LD_DEAD_CODE_DATA_ELIMINATION if (LD_VERSION >= 23600 || LD_IS_LLD) + select HAVE_LD_DEAD_CODE_DATA_ELIMINATION if (LD_VERSION >= 23600 || LD_CAN_USE_KEEP_IN_OVERLAY) select HAVE_MOD_ARCH_SPECIFIC select HAVE_NMI select HAVE_OPTPROBES if !THUMB2_KERNEL diff --git a/arch/arm/include/asm/vmlinux.lds.h b/arch/arm/include/asm/vmlinux.lds.h index 89697f204715..a54db342653a 100644 --- a/arch/arm/include/asm/vmlinux.lds.h +++ b/arch/arm/include/asm/vmlinux.lds.h @@ -34,6 +34,12 @@ #define NOCROSSREFS #endif +#ifdef CONFIG_LD_CAN_USE_KEEP_IN_OVERLAY +#define OVERLAY_KEEP(x) KEEP(x) +#else +#define OVERLAY_KEEP(x) x +#endif + /* Set start/end symbol names to the LMA for the section */ #define ARM_LMA(sym, section) \ sym##_start = LOADADDR(section); \ diff --git a/init/Kconfig b/init/Kconfig index d0d021b3fa3b..fc994f5cd5db 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -129,6 +129,11 @@ config CC_HAS_COUNTED_BY # https://github.com/llvm/llvm-project/pull/112636 depends on !(CC_IS_CLANG && CLANG_VERSION < 190103) +config LD_CAN_USE_KEEP_IN_OVERLAY + # ld.lld prior to 21.0.0 did not support KEEP within an overlay description + # https://github.com/llvm/llvm-project/pull/130661 + def_bool LD_IS_BFD || LLD_VERSION >= 210000 + config RUSTC_HAS_COERCE_POINTEE def_bool RUSTC_VERSION >= 108400 From c3d944a367c0d9e4e125c7006e52f352e75776dc Mon Sep 17 00:00:00 2001 From: Christian Eggers Date: Thu, 20 Mar 2025 22:33:51 +0100 Subject: [PATCH 5/6] ARM: 9444/1: add KEEP() keyword to ARM_VECTORS 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) --- arch/arm/include/asm/vmlinux.lds.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/arm/include/asm/vmlinux.lds.h b/arch/arm/include/asm/vmlinux.lds.h index a54db342653a..0341973e30e1 100644 --- a/arch/arm/include/asm/vmlinux.lds.h +++ b/arch/arm/include/asm/vmlinux.lds.h @@ -131,13 +131,13 @@ __vectors_lma = .; \ OVERLAY 0xffff0000 : NOCROSSREFS AT(__vectors_lma) { \ .vectors { \ - *(.vectors) \ + OVERLAY_KEEP(*(.vectors)) \ } \ .vectors.bhb.loop8 { \ - *(.vectors.bhb.loop8) \ + OVERLAY_KEEP(*(.vectors.bhb.loop8)) \ } \ .vectors.bhb.bpiall { \ - *(.vectors.bhb.bpiall) \ + OVERLAY_KEEP(*(.vectors.bhb.bpiall)) \ } \ } \ ARM_LMA(__vectors, .vectors); \ From 623c3015d8c9b7d7c6b9796f6e3667428ab6327a Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Mon, 24 Mar 2025 20:46:51 +0100 Subject: [PATCH 6/6] ARM: 9445/1: clkdev: Mark some functions with __printf() attribute MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Some of the functions are using printf() type of format, and compiler is not happy about them as is: clkdev.c:185:17: error: function ‘vclkdev_alloc’ might be a candidate for gnu_printf’ format attribute [-Werror=suggest-attribute=format] clkdev.c:224:9: error: function ‘vclkdev_create’ might be a candidate for gnu_printf’ format attribute [-Werror=suggest-attribute=format] clkdev.c:314:9: error: function ‘__clk_register_clkdev’ might be a candidate for ‘gnu_printf’ format attribute [-Werror=suggest-attribute=format] Fix the compilation errors by adding __printf() attributes. Signed-off-by: Andy Shevchenko Signed-off-by: Russell King (Oracle) --- drivers/clk/clkdev.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/drivers/clk/clkdev.c b/drivers/clk/clkdev.c index 2f83fb97c6fb..e0bede6350e1 100644 --- a/drivers/clk/clkdev.c +++ b/drivers/clk/clkdev.c @@ -153,7 +153,7 @@ struct clk_lookup_alloc { char con_id[MAX_CON_ID]; }; -static struct clk_lookup * __ref +static __printf(3, 0) struct clk_lookup * __ref vclkdev_alloc(struct clk_hw *hw, const char *con_id, const char *dev_fmt, va_list ap) { @@ -215,7 +215,7 @@ vclkdev_alloc(struct clk_hw *hw, const char *con_id, const char *dev_fmt, return &cla->cl; } -static struct clk_lookup * +static __printf(3, 0) struct clk_lookup * vclkdev_create(struct clk_hw *hw, const char *con_id, const char *dev_fmt, va_list ap) { @@ -303,9 +303,8 @@ void clkdev_drop(struct clk_lookup *cl) } EXPORT_SYMBOL(clkdev_drop); -static struct clk_lookup *__clk_register_clkdev(struct clk_hw *hw, - const char *con_id, - const char *dev_id, ...) +static __printf(3, 4) struct clk_lookup * +__clk_register_clkdev(struct clk_hw *hw, const char *con_id, const char *dev_id, ...) { struct clk_lookup *cl; va_list ap;