Commit 7b56f76e authored by David S. Miller's avatar David S. Miller
Browse files

net: filter: Fix some minor issues in sparc JIT. 



Correct conventions comments.  %o4 and %o5 were swapped,
%g3 was not documented.

Use r_TMP instead of r_SKB_DATA + r_OFF where possible in
assembler stubs.

Correct discussion of %o4 and %o5 in one of bpf_jit_compile()'s
comments.

Based upon feedback from Richard Mortimer.

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent b3d7b2f2

arch/sparc/net/bpf_jit.h

+3 −2
Original line number Diff line number Diff line
@@ -4,13 +4,14 @@ 
/* Conventions:

 *  %g1 : temporary

 *  %g2 : Secondary temporary used by SKB data helper stubs.

 *  %g3 : packet offset passed into SKB data helper stubs.

 *  %o0 : pointer to skb (first argument given to JIT function)

 *  %o1 : BPF A accumulator

 *  %o2 : BPF X accumulator

 *  %o3 : Holds saved %o7 so we can call helper functions without needing

 *        to allocate a register window.

 *  %o4 : skb->data

 *  %o5 : skb->len - skb->data_len

 *  %o4 : skb->len - skb->data_len

 *  %o5 : skb->data

 */



#ifndef __ASSEMBLER__

arch/sparc/net/bpf_jit_asm.S

+2 −2
Original line number Diff line number Diff line
@@ -30,7 +30,7 @@ bpf_jit_load_word_positive_offset: 
	bne	load_word_unaligned

	 nop

	retl

	 ld	[r_SKB_DATA + r_OFF], r_A

	 ld	[r_TMP], r_A

load_word_unaligned:

	ldub	[r_TMP + 0x0], r_OFF

	ldub	[r_TMP + 0x1], r_TMP2
@@ -59,7 +59,7 @@ bpf_jit_load_half_positive_offset: 
	bne	load_half_unaligned

	 nop

	retl

	 lduh	[r_SKB_DATA + r_OFF], r_A

	 lduh	[r_TMP], r_A

load_half_unaligned:

	ldub	[r_TMP + 0x0], r_OFF

	ldub	[r_TMP + 0x1], r_TMP2

arch/sparc/net/bpf_jit_comp.c

+1 −1
Original line number Diff line number Diff line
@@ -378,7 +378,7 @@ void bpf_jit_compile(struct sk_filter *fp) 
				emit_clear(r_X);



			/* If this filter needs to access skb data,

			 * load %o4 and %o4 with:

			 * load %o4 and %o5 with:

			 *  %o4 = skb->len - skb->data_len

			 *  %o5 = skb->data

			 * And also back up %o7 into r_saved_O7 so we can

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