* [PATCH] powerpc: Fix BPF_JIT code to link with multiple TOCs
@ 2012-06-22 3:50 Michael Ellerman
2012-06-22 8:58 ` matt
2012-06-22 9:01 ` matt
0 siblings, 2 replies; 3+ messages in thread
From: Michael Ellerman @ 2012-06-22 3:50 UTC (permalink / raw)
To: linuxppc-dev; +Cc: matt, amodra
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
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] powerpc: Fix BPF_JIT code to link with multiple TOCs
2012-06-22 3:50 [PATCH] powerpc: Fix BPF_JIT code to link with multiple TOCs Michael Ellerman
@ 2012-06-22 8:58 ` matt
2012-06-22 9:01 ` matt
1 sibling, 0 replies; 3+ messages in thread
From: matt @ 2012-06-22 8:58 UTC (permalink / raw)
To: Michael Ellerman; +Cc: linuxppc-dev, matt, amodra
On 2012-06-22 04:50, Michael Ellerman wrote:
> 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>
Oops..!
Acked-by: Matt Evans <matt@ozlabs.org>
> ---
> 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); \
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] powerpc: Fix BPF_JIT code to link with multiple TOCs
2012-06-22 3:50 [PATCH] powerpc: Fix BPF_JIT code to link with multiple TOCs Michael Ellerman
2012-06-22 8:58 ` matt
@ 2012-06-22 9:01 ` matt
1 sibling, 0 replies; 3+ messages in thread
From: matt @ 2012-06-22 9:01 UTC (permalink / raw)
To: Michael Ellerman; +Cc: linuxppc-dev, amodra
Whee! Let's try that again with MUA configured better...
On 2012-06-22 04:50, Michael Ellerman wrote:
> 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>
Oops, x2, and
Acked-by: Matt Evans <matt@ozlabs.org>
:-)
> ---
> 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); \
^ permalink raw reply [flat|nested] 3+ messages in thread
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2012-06-22 8:58 ` matt
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