From: Michael Ellerman <michael@ellerman.id.au>
To: <linuxppc-dev@ozlabs.org>
Cc: matt@ozlabs.org, amodra@gmail.com
Subject: [PATCH] powerpc: Fix BPF_JIT code to link with multiple TOCs
Date: Fri, 22 Jun 2012 13:50:27 +1000 [thread overview]
Message-ID: <1340337027-22110-1-git-send-email-michael@ellerman.id.au> (raw)
If the kernel is big enough (eg. allyesconfig), the linker may need to
switch TOCs when calling from the BPF JIT code out to the external
helpers (skb_copy_bits() & bpf_internal_load_pointer_neg_helper()).
In order to do that we need to leave space after the bl for the linker
to insert a reload of our TOC pointer.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
---
arch/powerpc/net/bpf_jit_64.S | 2 ++
1 file changed, 2 insertions(+)
diff --git a/arch/powerpc/net/bpf_jit_64.S b/arch/powerpc/net/bpf_jit_64.S
index 55ba385..7d3a3b5 100644
--- a/arch/powerpc/net/bpf_jit_64.S
+++ b/arch/powerpc/net/bpf_jit_64.S
@@ -105,6 +105,7 @@ sk_load_byte_msh_positive_offset:
mr r4, r_addr; \
li r6, SIZE; \
bl skb_copy_bits; \
+ nop; \
/* R3 = 0 on success */ \
addi r1, r1, BPF_PPC_SLOWPATH_FRAME; \
ld r0, 16(r1); \
@@ -156,6 +157,7 @@ bpf_slow_path_byte_msh:
mr r4, r_addr; \
li r5, SIZE; \
bl bpf_internal_load_pointer_neg_helper; \
+ nop; \
/* R3 != 0 on success */ \
addi r1, r1, BPF_PPC_SLOWPATH_FRAME; \
ld r0, 16(r1); \
--
1.7.9.5
next reply other threads:[~2012-06-22 3:50 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-22 3:50 Michael Ellerman [this message]
2012-06-22 8:58 ` [PATCH] powerpc: Fix BPF_JIT code to link with multiple TOCs matt
2012-06-22 9:01 ` matt
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