[PATCH v6 8/8] x86/module: enable ROX caches for module text on 64 bit
Mike Rapoport <[email protected]>
| Newsgroups | gmane.linux.ports.ppc.embedded,gmane.linux.kernel.bpf,gmane.linux.ports.alpha,gmane.linux.kernel.cross-arch,gmane.linux.ports.arm.kernel,gmane.linux.ports.hexagon,gmane.linux.kernel,gmane.linux.ports.mips,gmane.linux.kernel.mm,gmane.linux.kernel.modules,gmane.linux.ports.parisc,gmane.linux.ports.riscv,gmane.linux.ports.sh.devel,gmane.linux.kernel.arc,gmane.linux.uml.devel,gmane.linux.ports.sparc |
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From: "Mike Rapoport (Microsoft)" <[email protected]> Enable execmem's cache of PMD_SIZE'ed pages mapped as ROX for module text allocations on 64 bit. Signed-off-by: Mike Rapoport (Microsoft) <[email protected]> --- arch/x86/Kconfig | 1 + arch/x86/mm/init.c | 37 ++++++++++++++++++++++++++++++++++++- 2 files changed, 37 insertions(+), 1 deletion(-) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 2852fcd82cbd..ff71d18253ba 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -83,6 +83,7 @@ config X86 select ARCH_HAS_DMA_OPS if GART_IOMMU || XEN select ARCH_HAS_EARLY_DEBUG if KGDB select ARCH_HAS_ELF_RANDOMIZE + select ARCH_HAS_EXECMEM_ROX if X86_64 select ARCH_HAS_FAST_MULTIPLIER select ARCH_HAS_FORTIFY_SOURCE select ARCH_HAS_GCOV_PROFILE_ALL diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c index eb503f53c319..c2e4f389f47f 100644 --- a/arch/x86/mm/init.c +++ b/arch/x86/mm/init.c @@ -1053,18 +1053,53 @@ unsigned long arch_max_swapfile_size(void) #ifdef CONFIG_EXECMEM static struct execmem_info execmem_info __ro_after_init; +#ifdef CONFIG_ARCH_HAS_EXECMEM_ROX +void execmem_fill_trapping_insns(void *ptr, size_t size, bool writeable) +{ + /* fill memory with INT3 instructions */ + if (writeable) + memset(ptr, INT3_INSN_OPCODE, size); + else + text_poke_set(ptr, INT3_INSN_OPCODE, size); +} +#endif + struct execmem_info __init *execmem_arch_setup(void) { unsigned long start, offset = 0; + enum execmem_range_flags flags; + pgprot_t pgprot; if (kaslr_enabled()) offset = get_random_u32_inclusive(1, 1024) * PAGE_SIZE; start = MODULES_VADDR + offset; + if (IS_ENABLED(CONFIG_ARCH_HAS_EXECMEM_ROX)) { + pgprot = PAGE_KERNEL_ROX; + flags = EXECMEM_KASAN_SHADOW | EXECMEM_ROX_CACHE; + } else { + pgprot = PAGE_KERNEL; + flags = EXECMEM_KASAN_SHADOW; + } + execmem_info = (struct execmem_info){ .ranges = { - [EXECMEM_DEFAULT] = { + [EXECMEM_MODULE_TEXT] = { + .flags = flags, + .start = start, + .end = MODULES_END, + .pgprot = pgprot, + .alignment = MODULE_ALIGN, + }, + [EXECMEM_KPROBES ... EXECMEM_BPF] = { + .flags = EXECMEM_KASAN_SHADOW, + .start = start, + .end = MODULES_END, + .pgprot = PAGE_KERNEL, + .alignment = MODULE_ALIGN, + }, + [EXECMEM_MODULE_DATA] = { .flags = EXECMEM_KASAN_SHADOW, .start = start, .end = MODULES_END, -- 2.43.0