From 7f3631e88ee6fb13beac333a0e9e605d2414d17f Mon Sep 17 00:00:00 2001 From: =?utf8?q?Bj=C3=B6rn=20T=C3=B6pel?= Date: Mon, 16 Dec 2019 10:13:40 +0100 Subject: [PATCH] riscv, bpf: Provide RISC-V specific JIT image alloc/free MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit This commit makes sure that the JIT images is kept close to the kernel text, so BPF calls can use relative calling with auipc/jalr or jal instead of loading the full 64-bit address and jalr. The BPF JIT image region is 128 MB before the kernel text. Signed-off-by: Björn Töpel Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20191216091343.23260-7-bjorn.topel@gmail.com --- arch/riscv/include/asm/pgtable.h | 4 ++++ arch/riscv/net/bpf_jit_comp.c | 13 +++++++++++++ 2 files changed, 17 insertions(+) diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h index 7ff0ed4f292e..cc3f49415620 100644 --- a/arch/riscv/include/asm/pgtable.h +++ b/arch/riscv/include/asm/pgtable.h @@ -404,6 +404,10 @@ static inline int ptep_clear_flush_young(struct vm_area_struct *vma, #define VMALLOC_END (PAGE_OFFSET - 1) #define VMALLOC_START (PAGE_OFFSET - VMALLOC_SIZE) +#define BPF_JIT_REGION_SIZE (SZ_128M) +#define BPF_JIT_REGION_START (PAGE_OFFSET - BPF_JIT_REGION_SIZE) +#define BPF_JIT_REGION_END (VMALLOC_END) + /* * Roughly size the vmemmap space to be large enough to fit enough * struct pages to map half the virtual address space. Then diff --git a/arch/riscv/net/bpf_jit_comp.c b/arch/riscv/net/bpf_jit_comp.c index 8aa19c846881..46cff093f526 100644 --- a/arch/riscv/net/bpf_jit_comp.c +++ b/arch/riscv/net/bpf_jit_comp.c @@ -1656,3 +1656,16 @@ out: tmp : orig_prog); return prog; } + +void *bpf_jit_alloc_exec(unsigned long size) +{ + return __vmalloc_node_range(size, PAGE_SIZE, BPF_JIT_REGION_START, + BPF_JIT_REGION_END, GFP_KERNEL, + PAGE_KERNEL_EXEC, 0, NUMA_NO_NODE, + __builtin_return_address(0)); +} + +void bpf_jit_free_exec(void *addr) +{ + return vfree(addr); +} -- 2.30.2