Re: [PATCH v2 04/12] mm/execmem, arch: convert remaining overrides of module_alloc to execmem
From: Song Liu <song@kernel.org>
Date: 2023-06-16 18:54:34
Also in:
bpf, linux-arm-kernel, linux-mips, linux-mm, linux-riscv, linux-s390, linux-trace-kernel, linuxppc-dev, lkml, loongarch, netdev, sparclinux
On Fri, Jun 16, 2023 at 1:51 AM Mike Rapoport [off-list ref] wrote: [...]
quoted hunk ↗ jump to hunk
diff --git a/arch/arm64/kernel/module.c b/arch/arm64/kernel/module.c index 5af4975caeb5..c3d999f3a3dd 100644 --- a/arch/arm64/kernel/module.c +++ b/arch/arm64/kernel/module.c@@ -17,56 +17,50 @@ #include <linux/moduleloader.h> #include <linux/scs.h> #include <linux/vmalloc.h> +#include <linux/execmem.h> #include <asm/alternative.h> #include <asm/insn.h> #include <asm/scs.h> #include <asm/sections.h> -void *module_alloc(unsigned long size) +static struct execmem_params execmem_params = { + .modules = { + .flags = EXECMEM_KASAN_SHADOW, + .text = { + .alignment = MODULE_ALIGN, + }, + }, +}; + +struct execmem_params __init *execmem_arch_params(void) { u64 module_alloc_end = module_alloc_base + MODULES_VSIZE; - gfp_t gfp_mask = GFP_KERNEL; - void *p; - - /* Silence the initial allocation */ - if (IS_ENABLED(CONFIG_ARM64_MODULE_PLTS)) - gfp_mask |= __GFP_NOWARN; - if (IS_ENABLED(CONFIG_KASAN_GENERIC) || - IS_ENABLED(CONFIG_KASAN_SW_TAGS)) - /* don't exceed the static module region - see below */ - module_alloc_end = MODULES_END; + execmem_params.modules.text.pgprot = PAGE_KERNEL; + execmem_params.modules.text.start = module_alloc_base;
I think I mentioned this earlier. For arm64 with CONFIG_RANDOMIZE_BASE, module_alloc_base is not yet set when execmem_arch_params() is called. So we will need some extra logic for this. Thanks, Song
+ execmem_params.modules.text.end = module_alloc_end;
- p = __vmalloc_node_range(size, MODULE_ALIGN, module_alloc_base,
- module_alloc_end, gfp_mask, PAGE_KERNEL, VM_DEFER_KMEMLEAK,
- NUMA_NO_NODE, __builtin_return_address(0));
-
- if (!p && IS_ENABLED(CONFIG_ARM64_MODULE_PLTS) &&
+ /*
+ * KASAN without KASAN_VMALLOC can only deal with module
+ * allocations being served from the reserved module region,
+ * since the remainder of the vmalloc region is already
+ * backed by zero shadow pages, and punching holes into it
+ * is non-trivial. Since the module region is not randomized
+ * when KASAN is enabled without KASAN_VMALLOC, it is even
+ * less likely that the module region gets exhausted, so we
+ * can simply omit this fallback in that case.
+ */
+ if (IS_ENABLED(CONFIG_ARM64_MODULE_PLTS) &&
(IS_ENABLED(CONFIG_KASAN_VMALLOC) ||
(!IS_ENABLED(CONFIG_KASAN_GENERIC) &&
- !IS_ENABLED(CONFIG_KASAN_SW_TAGS))))
- /*
- * KASAN without KASAN_VMALLOC can only deal with module
- * allocations being served from the reserved module region,
- * since the remainder of the vmalloc region is already
- * backed by zero shadow pages, and punching holes into it
- * is non-trivial. Since the module region is not randomized
- * when KASAN is enabled without KASAN_VMALLOC, it is even
- * less likely that the module region gets exhausted, so we
- * can simply omit this fallback in that case.
- */
- p = __vmalloc_node_range(size, MODULE_ALIGN, module_alloc_base,
- module_alloc_base + SZ_2G, GFP_KERNEL,
- PAGE_KERNEL, 0, NUMA_NO_NODE,
- __builtin_return_address(0));
-
- if (p && (kasan_alloc_module_shadow(p, size, gfp_mask) < 0)) {
- vfree(p);
- return NULL;
+ !IS_ENABLED(CONFIG_KASAN_SW_TAGS)))) {
+ unsigned long end = module_alloc_base + SZ_2G;
+
+ execmem_params.modules.text.fallback_start = module_alloc_base;
+ execmem_params.modules.text.fallback_end = end;
}
- /* Memory is intended to be executable, reset the pointer tag. */
- return kasan_reset_tag(p);
+ return &execmem_params;
}
enum aarch64_reloc_op {