diff options
| author | Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> | 2022-02-14 16:11:42 +0530 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2022-03-08 00:04:58 +1100 |
| commit | 43d636f8b4fd2ee668e75e835fae2fcf4bc0f699 (patch) | |
| tree | 0e06d57c3ca44ef6f79c57a9c5ca877ef352b74a /arch/powerpc/net/bpf_jit_comp32.c | |
| parent | b10cb163c4b31b03ac5014abbfd0b868913fd8e3 (diff) | |
| download | lwn-43d636f8b4fd2ee668e75e835fae2fcf4bc0f699.tar.gz lwn-43d636f8b4fd2ee668e75e835fae2fcf4bc0f699.zip | |
powerpc64/bpf elfv1: Do not load TOC before calling functions
BPF helpers always reside in core kernel and all BPF programs use the
kernel TOC. As such, there is no need to load the TOC before calling
helpers or other BPF functions. Drop code to do the same.
Add a check to ensure we don't proceed if this assumption ever changes
in future.
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/a3cd3da4d24d95d845cd10382b1af083600c9074.1644834730.git.naveen.n.rao@linux.vnet.ibm.com
Diffstat (limited to 'arch/powerpc/net/bpf_jit_comp32.c')
| -rw-r--r-- | arch/powerpc/net/bpf_jit_comp32.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/arch/powerpc/net/bpf_jit_comp32.c b/arch/powerpc/net/bpf_jit_comp32.c index 8e743b7bf8f5..511d2a203e7d 100644 --- a/arch/powerpc/net/bpf_jit_comp32.c +++ b/arch/powerpc/net/bpf_jit_comp32.c @@ -193,7 +193,7 @@ void bpf_jit_build_epilogue(u32 *image, struct codegen_context *ctx) EMIT(PPC_RAW_BLR()); } -void bpf_jit_emit_func_call_rel(u32 *image, struct codegen_context *ctx, u64 func) +int bpf_jit_emit_func_call_rel(u32 *image, struct codegen_context *ctx, u64 func) { s32 rel = (s32)func - (s32)(image + ctx->idx); @@ -209,6 +209,8 @@ void bpf_jit_emit_func_call_rel(u32 *image, struct codegen_context *ctx, u64 fun EMIT(PPC_RAW_MTCTR(_R0)); EMIT(PPC_RAW_BCTRL()); } + + return 0; } static int bpf_jit_emit_tail_call(u32 *image, struct codegen_context *ctx, u32 out) @@ -961,7 +963,9 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context * EMIT(PPC_RAW_STW(bpf_to_ppc(ctx, BPF_REG_5), _R1, 12)); } - bpf_jit_emit_func_call_rel(image, ctx, func_addr); + ret = bpf_jit_emit_func_call_rel(image, ctx, func_addr); + if (ret) + return ret; EMIT(PPC_RAW_MR(bpf_to_ppc(ctx, BPF_REG_0) - 1, _R3)); EMIT(PPC_RAW_MR(bpf_to_ppc(ctx, BPF_REG_0), _R4)); |