diff mbox series

[powerpc/next,05/17] powerpc64/bpf: Use r12 for constant blinding

Message ID e109f98617eacb4512c17a48525e94eda42889e6.1644834730.git.naveen.n.rao@linux.vnet.ibm.com (mailing list archive)
State Not Applicable
Delegated to: BPF
Headers show
Series powerpc/bpf: Some updates and cleanups | expand

Checks

Context Check Description
bpf/vmtest-bpf-next success VM_Test
bpf/vmtest-bpf-next-PR success PR summary
netdev/tree_selection success Not a local patch, async

Commit Message

Naveen N. Rao Feb. 14, 2022, 10:41 a.m. UTC 
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@linux.vnet.ibm.com>
---
 arch/powerpc/net/bpf_jit64.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox series

Patch

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
 };