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| author | Will Deacon <will@kernel.org> | 2020-05-28 18:00:51 +0100 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2020-05-28 18:00:51 +0100 |
| commit | d27865279f12035c730818aa1a0280fada866a37 (patch) | |
| tree | 5c4462885c2a6d7453b34ceb51d39b390030a2a6 /arch/arm64/net | |
| parent | 342403bcb4dfe41324a0f6f4cb5a8d324f31c725 (diff) | |
| parent | a4eb355a3fdad85d16e4b098e8d56bb28b812ce0 (diff) | |
Merge branch 'for-next/bti' into for-next/core
Support for Branch Target Identification (BTI) in user and kernel
(Mark Brown and others)
* for-next/bti: (39 commits)
arm64: vdso: Fix CFI directives in sigreturn trampoline
arm64: vdso: Don't prefix sigreturn trampoline with a BTI C instruction
arm64: bti: Fix support for userspace only BTI
arm64: kconfig: Update and comment GCC version check for kernel BTI
arm64: vdso: Map the vDSO text with guarded pages when built for BTI
arm64: vdso: Force the vDSO to be linked as BTI when built for BTI
arm64: vdso: Annotate for BTI
arm64: asm: Provide a mechanism for generating ELF note for BTI
arm64: bti: Provide Kconfig for kernel mode BTI
arm64: mm: Mark executable text as guarded pages
arm64: bpf: Annotate JITed code for BTI
arm64: Set GP bit in kernel page tables to enable BTI for the kernel
arm64: asm: Override SYM_FUNC_START when building the kernel with BTI
arm64: bti: Support building kernel C code using BTI
arm64: Document why we enable PAC support for leaf functions
arm64: insn: Report PAC and BTI instructions as skippable
arm64: insn: Don't assume unrecognized HINTs are skippable
arm64: insn: Provide a better name for aarch64_insn_is_nop()
arm64: insn: Add constants for new HINT instruction decode
arm64: Disable old style assembly annotations
...
Diffstat (limited to 'arch/arm64/net')
| -rw-r--r-- | arch/arm64/net/bpf_jit.h | 8 | ||||
| -rw-r--r-- | arch/arm64/net/bpf_jit_comp.c | 12 |
2 files changed, 20 insertions, 0 deletions
diff --git a/arch/arm64/net/bpf_jit.h b/arch/arm64/net/bpf_jit.h index 923ae7ff68c8..cc0cf0f5c7c3 100644 --- a/arch/arm64/net/bpf_jit.h +++ b/arch/arm64/net/bpf_jit.h @@ -211,4 +211,12 @@ /* Rn & imm; set condition flags */ #define A64_TST_I(sf, Rn, imm) A64_ANDS_I(sf, A64_ZR, Rn, imm) +/* HINTs */ +#define A64_HINT(x) aarch64_insn_gen_hint(x) + +/* BTI */ +#define A64_BTI_C A64_HINT(AARCH64_INSN_HINT_BTIC) +#define A64_BTI_J A64_HINT(AARCH64_INSN_HINT_BTIJ) +#define A64_BTI_JC A64_HINT(AARCH64_INSN_HINT_BTIJC) + #endif /* _BPF_JIT_H */ diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c index 561a2fea9cdd..3cb25b43b368 100644 --- a/arch/arm64/net/bpf_jit_comp.c +++ b/arch/arm64/net/bpf_jit_comp.c @@ -177,7 +177,11 @@ static bool is_addsub_imm(u32 imm) #define STACK_ALIGN(sz) (((sz) + 15) & ~15) /* Tail call offset to jump into */ +#if IS_ENABLED(CONFIG_ARM64_BTI_KERNEL) +#define PROLOGUE_OFFSET 8 +#else #define PROLOGUE_OFFSET 7 +#endif static int build_prologue(struct jit_ctx *ctx, bool ebpf_from_cbpf) { @@ -214,6 +218,10 @@ static int build_prologue(struct jit_ctx *ctx, bool ebpf_from_cbpf) * */ + /* BTI landing pad */ + if (IS_ENABLED(CONFIG_ARM64_BTI_KERNEL)) + emit(A64_BTI_C, ctx); + /* Save FP and LR registers to stay align with ARM64 AAPCS */ emit(A64_PUSH(A64_FP, A64_LR, A64_SP), ctx); emit(A64_MOV(1, A64_FP, A64_SP), ctx); @@ -236,6 +244,10 @@ static int build_prologue(struct jit_ctx *ctx, bool ebpf_from_cbpf) cur_offset, PROLOGUE_OFFSET); return -1; } + + /* BTI landing pad for the tail call, done with a BR */ + if (IS_ENABLED(CONFIG_ARM64_BTI_KERNEL)) + emit(A64_BTI_J, ctx); } ctx->stack_size = STACK_ALIGN(prog->aux->stack_depth); |