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OpenCloudOS-Kernel/arch/sparc/net/bpf_jit_asm.S

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net: filter: Just In Time compiler for sparc Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-16 11:06:27 +08:00
#include <asm/ptrace.h>
#include "bpf_jit.h"
#ifdef CONFIG_SPARC64
#define SAVE_SZ 176
#define SCRATCH_OFF STACK_BIAS + 128
#define BE_PTR(label) be,pn %xcc, label
sparc: bpf_jit: fix loads from negative offsets - fix BPF_LD|ABS|IND from negative offsets: make sure to sign extend lower 32 bits in 64-bit register before calling C helpers from JITed code, otherwise 'int k' argument of bpf_internal_load_pointer_neg_helper() function will be added as large unsigned integer, causing packet size check to trigger and abort the program. It's worth noting that JITed code for 'A = A op K' will affect upper 32 bits differently depending whether K is simm13 or not. Since small constants are sign extended, whereas large constants are stored in temp register and zero extended. That is ok and we don't have to pay a penalty of sign extension for every sethi, since all classic BPF instructions have 32-bit semantics and we only need to set correct upper bits when transitioning from JITed code into C. - though instructions 'A &= 0' and 'A *= 0' are odd, JIT compiler should not optimize them out Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-24 04:50:10 +08:00
#define SIGN_EXTEND(reg) sra reg, 0, reg
net: filter: Just In Time compiler for sparc Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-16 11:06:27 +08:00
#else
#define SAVE_SZ 96
#define SCRATCH_OFF 72
#define BE_PTR(label) be label
sparc: bpf_jit: fix loads from negative offsets - fix BPF_LD|ABS|IND from negative offsets: make sure to sign extend lower 32 bits in 64-bit register before calling C helpers from JITed code, otherwise 'int k' argument of bpf_internal_load_pointer_neg_helper() function will be added as large unsigned integer, causing packet size check to trigger and abort the program. It's worth noting that JITed code for 'A = A op K' will affect upper 32 bits differently depending whether K is simm13 or not. Since small constants are sign extended, whereas large constants are stored in temp register and zero extended. That is ok and we don't have to pay a penalty of sign extension for every sethi, since all classic BPF instructions have 32-bit semantics and we only need to set correct upper bits when transitioning from JITed code into C. - though instructions 'A &= 0' and 'A *= 0' are odd, JIT compiler should not optimize them out Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-24 04:50:10 +08:00
#define SIGN_EXTEND(reg)
net: filter: Just In Time compiler for sparc Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-16 11:06:27 +08:00
#endif
#define SKF_MAX_NEG_OFF (-0x200000) /* SKF_LL_OFF from filter.h */
.text
.globl bpf_jit_load_word
bpf_jit_load_word:
cmp r_OFF, 0
bl bpf_slow_path_word_neg
nop
.globl bpf_jit_load_word_positive_offset
bpf_jit_load_word_positive_offset:
sub r_HEADLEN, r_OFF, r_TMP
cmp r_TMP, 3
ble bpf_slow_path_word
add r_SKB_DATA, r_OFF, r_TMP
andcc r_TMP, 3, %g0
bne load_word_unaligned
nop
retl
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: David S. Miller <davem@davemloft.net>
2012-04-18 04:08:29 +08:00
ld [r_TMP], r_A
net: filter: Just In Time compiler for sparc Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-16 11:06:27 +08:00
load_word_unaligned:
ldub [r_TMP + 0x0], r_OFF
ldub [r_TMP + 0x1], r_TMP2
sll r_OFF, 8, r_OFF
or r_OFF, r_TMP2, r_OFF
ldub [r_TMP + 0x2], r_TMP2
sll r_OFF, 8, r_OFF
or r_OFF, r_TMP2, r_OFF
ldub [r_TMP + 0x3], r_TMP2
sll r_OFF, 8, r_OFF
retl
or r_OFF, r_TMP2, r_A
.globl bpf_jit_load_half
bpf_jit_load_half:
cmp r_OFF, 0
bl bpf_slow_path_half_neg
nop
.globl bpf_jit_load_half_positive_offset
bpf_jit_load_half_positive_offset:
sub r_HEADLEN, r_OFF, r_TMP
cmp r_TMP, 1
ble bpf_slow_path_half
add r_SKB_DATA, r_OFF, r_TMP
andcc r_TMP, 1, %g0
bne load_half_unaligned
nop
retl
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: David S. Miller <davem@davemloft.net>
2012-04-18 04:08:29 +08:00
lduh [r_TMP], r_A
net: filter: Just In Time compiler for sparc Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-16 11:06:27 +08:00
load_half_unaligned:
ldub [r_TMP + 0x0], r_OFF
ldub [r_TMP + 0x1], r_TMP2
sll r_OFF, 8, r_OFF
retl
or r_OFF, r_TMP2, r_A
.globl bpf_jit_load_byte
bpf_jit_load_byte:
cmp r_OFF, 0
bl bpf_slow_path_byte_neg
nop
.globl bpf_jit_load_byte_positive_offset
bpf_jit_load_byte_positive_offset:
cmp r_OFF, r_HEADLEN
bge bpf_slow_path_byte
nop
retl
ldub [r_SKB_DATA + r_OFF], r_A
.globl bpf_jit_load_byte_msh
bpf_jit_load_byte_msh:
cmp r_OFF, 0
bl bpf_slow_path_byte_msh_neg
nop
.globl bpf_jit_load_byte_msh_positive_offset
bpf_jit_load_byte_msh_positive_offset:
cmp r_OFF, r_HEADLEN
bge bpf_slow_path_byte_msh
nop
ldub [r_SKB_DATA + r_OFF], r_OFF
and r_OFF, 0xf, r_OFF
retl
sll r_OFF, 2, r_X
#define bpf_slow_path_common(LEN) \
save %sp, -SAVE_SZ, %sp; \
mov %i0, %o0; \
mov r_OFF, %o1; \
add %fp, SCRATCH_OFF, %o2; \
call skb_copy_bits; \
mov (LEN), %o3; \
cmp %o0, 0; \
restore;
bpf_slow_path_word:
bpf_slow_path_common(4)
bl bpf_error
ld [%sp + SCRATCH_OFF], r_A
retl
nop
bpf_slow_path_half:
bpf_slow_path_common(2)
bl bpf_error
lduh [%sp + SCRATCH_OFF], r_A
retl
nop
bpf_slow_path_byte:
bpf_slow_path_common(1)
bl bpf_error
ldub [%sp + SCRATCH_OFF], r_A
retl
nop
bpf_slow_path_byte_msh:
bpf_slow_path_common(1)
bl bpf_error
ldub [%sp + SCRATCH_OFF], r_A
and r_OFF, 0xf, r_OFF
retl
sll r_OFF, 2, r_X
#define bpf_negative_common(LEN) \
save %sp, -SAVE_SZ, %sp; \
mov %i0, %o0; \
mov r_OFF, %o1; \
sparc: bpf_jit: fix loads from negative offsets - fix BPF_LD|ABS|IND from negative offsets: make sure to sign extend lower 32 bits in 64-bit register before calling C helpers from JITed code, otherwise 'int k' argument of bpf_internal_load_pointer_neg_helper() function will be added as large unsigned integer, causing packet size check to trigger and abort the program. It's worth noting that JITed code for 'A = A op K' will affect upper 32 bits differently depending whether K is simm13 or not. Since small constants are sign extended, whereas large constants are stored in temp register and zero extended. That is ok and we don't have to pay a penalty of sign extension for every sethi, since all classic BPF instructions have 32-bit semantics and we only need to set correct upper bits when transitioning from JITed code into C. - though instructions 'A &= 0' and 'A *= 0' are odd, JIT compiler should not optimize them out Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-24 04:50:10 +08:00
SIGN_EXTEND(%o1); \
net: filter: Just In Time compiler for sparc Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-16 11:06:27 +08:00
call bpf_internal_load_pointer_neg_helper; \
mov (LEN), %o2; \
mov %o0, r_TMP; \
cmp %o0, 0; \
BE_PTR(bpf_error); \
restore;
bpf_slow_path_word_neg:
sethi %hi(SKF_MAX_NEG_OFF), r_TMP
cmp r_OFF, r_TMP
bl bpf_error
nop
.globl bpf_jit_load_word_negative_offset
bpf_jit_load_word_negative_offset:
bpf_negative_common(4)
andcc r_TMP, 3, %g0
bne load_word_unaligned
nop
retl
ld [r_TMP], r_A
bpf_slow_path_half_neg:
sethi %hi(SKF_MAX_NEG_OFF), r_TMP
cmp r_OFF, r_TMP
bl bpf_error
nop
.globl bpf_jit_load_half_negative_offset
bpf_jit_load_half_negative_offset:
bpf_negative_common(2)
andcc r_TMP, 1, %g0
bne load_half_unaligned
nop
retl
lduh [r_TMP], r_A
bpf_slow_path_byte_neg:
sethi %hi(SKF_MAX_NEG_OFF), r_TMP
cmp r_OFF, r_TMP
bl bpf_error
nop
.globl bpf_jit_load_byte_negative_offset
bpf_jit_load_byte_negative_offset:
bpf_negative_common(1)
retl
ldub [r_TMP], r_A
bpf_slow_path_byte_msh_neg:
sethi %hi(SKF_MAX_NEG_OFF), r_TMP
cmp r_OFF, r_TMP
bl bpf_error
nop
.globl bpf_jit_load_byte_msh_negative_offset
bpf_jit_load_byte_msh_negative_offset:
bpf_negative_common(1)
ldub [r_TMP], r_OFF
and r_OFF, 0xf, r_OFF
retl
sll r_OFF, 2, r_X
bpf_error:
net: filter: Fix some more small issues in sparc JIT. Fix mixed space and tabs. Put bpf_jit_load_*[] externs into bpf_jit.h "while(0)" --> "while (0)" "COND (X)" --> "COND(X)" Document branch offset calculations, and bpf_error's return sequence. Document the reason we need to emit three nops between the %y register write and the divide instruction. Remove erroneous trailing semicolons from emit_read_y() and emit_write_y(). Based upon feedback from Sam Ravnborg. Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-18 04:38:16 +08:00
/* Make the JIT program return zero. The JIT epilogue
* stores away the original %o7 into r_saved_O7. The
* normal leaf function return is to use "retl" which
* would evalute to "jmpl %o7 + 8, %g0" but we want to
* use the saved value thus the sequence you see here.
*/
net: filter: Just In Time compiler for sparc Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-16 11:06:27 +08:00
jmpl r_saved_O7 + 8, %g0
clr %o0