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| author | Björn Töpel <bjorn.topel@gmail.com> | 2019-12-16 12:13:40 +0300 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2019-12-19 18:03:31 +0300 |
| commit | 7f3631e88ee6fb13beac333a0e9e605d2414d17f (patch) | |
| tree | 83de14e24c5f18b8d1197c815df60556471a37f6 /arch/riscv | |
| parent | fe8322b866d560a3b3535ed9aa49df59809decbe (diff) | |
| download | linux-7f3631e88ee6fb13beac333a0e9e605d2414d17f.tar.xz | |
riscv, bpf: Provide RISC-V specific JIT image alloc/free
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 <bjorn.topel@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20191216091343.23260-7-bjorn.topel@gmail.com
Diffstat (limited to 'arch/riscv')
| -rw-r--r-- | arch/riscv/include/asm/pgtable.h | 4 | ||||
| -rw-r--r-- | arch/riscv/net/bpf_jit_comp.c | 13 |
2 files changed, 17 insertions, 0 deletions
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); +} |