From: "Björn Töpel" <bjorn.topel@gmail.com>
To: daniel@iogearbox.net, ast@kernel.org, netdev@vger.kernel.org
Cc: "Björn Töpel" <bjorn.topel@gmail.com>,
linux-riscv@lists.infradead.org, bpf@vger.kernel.org
Subject: [PATCH bpf-next 5/8] riscv, bpf: provide RISC-V specific JIT image alloc/free
Date: Mon, 9 Dec 2019 18:31:33 +0100 [thread overview]
Message-ID: <20191209173136.29615-6-bjorn.topel@gmail.com> (raw)
In-Reply-To: <20191209173136.29615-1-bjorn.topel@gmail.com>
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>
---
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 cbcb33613d1d..f7b1ae3a968f 100644
--- a/arch/riscv/net/bpf_jit_comp.c
+++ b/arch/riscv/net/bpf_jit_comp.c
@@ -1672,3 +1672,16 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
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);
+}
--
2.20.1
next prev parent reply other threads:[~2019-12-09 17:32 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-09 17:31 [PATCH bpf-next 0/8] riscv: BPF JIT fix, optimizations and far jumps support Björn Töpel
2019-12-09 17:31 ` [PATCH bpf-next 1/8] riscv, bpf: fix broken BPF tail calls Björn Töpel
2019-12-09 17:31 ` [PATCH bpf-next 2/8] riscv, bpf: add support for far branching Björn Töpel
2019-12-09 21:08 ` Luke Nelson
2019-12-09 21:27 ` Daniel Borkmann
2019-12-10 7:02 ` Luke Nelson
2019-12-10 5:32 ` Björn Töpel
2019-12-10 5:31 ` Björn Töpel
2019-12-09 17:31 ` [PATCH bpf-next 3/8] riscv, bpf: add support for far jumps and exits Björn Töpel
2019-12-09 21:15 ` Luke Nelson
2019-12-09 17:31 ` [PATCH bpf-next 4/8] riscv, bpf: optimize BPF tail calls Björn Töpel
2019-12-09 17:31 ` Björn Töpel [this message]
2019-12-09 17:31 ` [PATCH bpf-next 6/8] riscv, bpf: optimize calls Björn Töpel
2019-12-09 17:31 ` [PATCH bpf-next 7/8] riscv, bpf: add missing uapi header for BPF_PROG_TYPE_PERF_EVENT programs Björn Töpel
2019-12-09 17:31 ` [PATCH bpf-next 8/8] riscv, perf: add arch specific perf_arch_bpf_user_pt_regs Björn Töpel
2019-12-19 21:59 ` [PATCH bpf-next 1/8] riscv, bpf: fix broken BPF tail calls Palmer Dabbelt
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