[ Sasha's backport helper bot ]
Hi,
✅ All tests passed successfully. No issues detected. No action required from the submitter.
The upstream commit SHA1 provided is correct: 0dfefc2ea2f29ced2416017d7e5b1253a54c2735
WARNING: Author mismatch between patch and upstream commit: Backport author: Pu Lehuipulehui@huaweicloud.com Commit author: James Morsejames.morse@arm.com
Status in newer kernel trees: 6.15.y | Present (exact SHA1) 6.14.y | Present (different SHA1: 852b8ae934b5) 6.12.y | Present (different SHA1: 38c345fd54af) 6.6.y | Present (different SHA1: 42a20cf51011) 6.1.y | Present (different SHA1: 8fe5c37b0e08)
Note: The patch differs from the upstream commit: --- 1: 0dfefc2ea2f29 ! 1: f697b935a7719 arm64: bpf: Add BHB mitigation to the epilogue for cBPF programs @@ Metadata ## Commit message ## arm64: bpf: Add BHB mitigation to the epilogue for cBPF programs
+ [ Upstream commit 0dfefc2ea2f29ced2416017d7e5b1253a54c2735 ] + A malicious BPF program may manipulate the branch history to influence what the hardware speculates will happen next.
@@ Commit message Signed-off-by: James Morse james.morse@arm.com Reviewed-by: Catalin Marinas catalin.marinas@arm.com Acked-by: Daniel Borkmann daniel@iogearbox.net + Signed-off-by: Pu Lehui pulehui@huawei.com
## arch/arm64/include/asm/spectre.h ## @@ arch/arm64/include/asm/spectre.h: enum mitigation_state arm64_get_meltdown_state(void); @@ arch/arm64/net/bpf_jit_comp.c +#include <linux/arm-smccc.h> #include <linux/bitfield.h> #include <linux/bpf.h> ++#include <linux/cpu.h> #include <linux/filter.h> -@@ - #include <asm/asm-extable.h> + #include <linux/printk.h> + #include <linux/slab.h> + #include <asm/byteorder.h> #include <asm/cacheflush.h> +#include <asm/cpufeature.h> #include <asm/debug-monitors.h> #include <asm/insn.h> - #include <asm/text-patching.h> -@@ arch/arm64/net/bpf_jit_comp.c: static void build_plt(struct jit_ctx *ctx) - plt->target = (u64)&dummy_tramp; + #include <asm/set_memory.h> +@@ arch/arm64/net/bpf_jit_comp.c: static int emit_bpf_tail_call(struct jit_ctx *ctx) + #undef jmp_offset }
-static void build_epilogue(struct jit_ctx *ctx) @@ arch/arm64/net/bpf_jit_comp.c: static void build_plt(struct jit_ctx *ctx) +static void build_epilogue(struct jit_ctx *ctx, bool was_classic) { const u8 r0 = bpf2a64[BPF_REG_0]; - const u8 ptr = bpf2a64[TCCNT_PTR]; + const u8 r6 = bpf2a64[BPF_REG_6]; @@ arch/arm64/net/bpf_jit_comp.c: static void build_epilogue(struct jit_ctx *ctx) - - emit(A64_POP(A64_ZR, ptr, A64_SP), ctx); + emit(A64_POP(r8, r9, A64_SP), ctx); + emit(A64_POP(r6, r7, A64_SP), ctx);
+ if (was_classic) + build_bhb_mitigation(ctx); @@ arch/arm64/net/bpf_jit_comp.c: static void build_epilogue(struct jit_ctx *ctx) + /* Move the return value from bpf:r0 (aka x7) to x0 */ emit(A64_MOV(1, A64_R(0), r0), ctx);
- /* Authenticate lr */ + emit(A64_RET(A64_LR), ctx); @@ arch/arm64/net/bpf_jit_comp.c: struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) }
ctx.epilogue_offset = ctx.idx; - build_epilogue(&ctx); + build_epilogue(&ctx, was_classic); - build_plt(&ctx);
- extable_align = __alignof__(struct exception_table_entry); + extable_size = prog->aux->num_exentries * + sizeof(struct exception_table_entry); @@ arch/arm64/net/bpf_jit_comp.c: struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) - goto out_free_hdr; + goto out_off; }
- build_epilogue(&ctx); + build_epilogue(&ctx, was_classic); - build_plt(&ctx);
- /* Extra pass to validate JITed code. */ + /* 3. Extra pass to validate JITed code. */ + if (validate_code(&ctx)) { ---
Results of testing on various branches:
| Branch | Patch Apply | Build Test | |---------------------------|-------------|------------| | stable/linux-6.1.y | Success | Success |