[PATCH 10/13] powerpc64/bpf: Use r12 for constant blinding
Naveen N. Rao
naveen.n.rao at linux.vnet.ibm.com
Thu Jan 6 22:45:14 AEDT 2022
In preparation for preserving kernel toc in r2, switch BPF_REG_AX from
r2 to r12. r12 is not used by bpf JIT except during external helper/bpf
calls, or with BPF_NOSPEC. These sequences aren't emitted when
BPF_REG_AX is used for constant blinding and other purposes.
Signed-off-by: Naveen N. Rao <naveen.n.rao at linux.vnet.ibm.com>
---
arch/powerpc/net/bpf_jit64.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/powerpc/net/bpf_jit64.h b/arch/powerpc/net/bpf_jit64.h
index b63b35e45e558c..82cdfee412784a 100644
--- a/arch/powerpc/net/bpf_jit64.h
+++ b/arch/powerpc/net/bpf_jit64.h
@@ -56,7 +56,7 @@ const int b2p[MAX_BPF_JIT_REG + 2] = {
/* frame pointer aka BPF_REG_10 */
[BPF_REG_FP] = 31,
/* eBPF jit internal registers */
- [BPF_REG_AX] = 2,
+ [BPF_REG_AX] = 12,
[TMP_REG_1] = 9,
[TMP_REG_2] = 10
};
--
2.34.1
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