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ARM: net: bpf: always use odd/even register pair

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Always use an odd/even register pair for our 64-bit registers, so that
we're able to use the double-word load/store instructions in the future.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This commit is contained in:
Russell King 2018-07-11 10:32:33 +01:00 committed by Daniel Borkmann
parent b504522998
commit bef8968df8
1 changed files with 14 additions and 14 deletions
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28
arch/arm/net/bpf_jit_32.c
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@ -47,27 +47,27 @@
* The callee saved registers depends on whether frame pointers are enabled.
* With frame pointers (to be compliant with the ABI):
*
* high
* original ARM_SP => +------------------+ \
* | pc | |
* current ARM_FP => +------------------+ } callee saved registers
* |r4-r8,r10,fp,ip,lr| |
* +------------------+ /
* low
* high
* original ARM_SP => +--------------+ \
* | pc | |
* current ARM_FP => +--------------+ } callee saved registers
* |r4-r9,fp,ip,lr| |
* +--------------+ /
* low
*
* Without frame pointers:
*
* high
* original ARM_SP => +------------------+
* | r4-r8,r10,fp,lr | callee saved registers
* current ARM_FP => +------------------+
* low
* high
* original ARM_SP => +--------------+
* | r4-r9,fp,lr | callee saved registers
* current ARM_FP => +--------------+
* low
*
* When popping registers off the stack at the end of a BPF function, we
* reference them via the current ARM_FP register.
*/
#define CALLEE_MASK (1 << ARM_R4 | 1 << ARM_R5 | 1 << ARM_R6 | \
1 << ARM_R7 | 1 << ARM_R8 | 1 << ARM_R10 | \
1 << ARM_R7 | 1 << ARM_R8 | 1 << ARM_R9 | \
1 << ARM_FP)
#define CALLEE_PUSH_MASK (CALLEE_MASK | 1 << ARM_LR)
#define CALLEE_POP_MASK (CALLEE_MASK | 1 << ARM_PC)
@ -157,7 +157,7 @@ static const s8 bpf2a32[][2] = {
* for constant blindings and others.
*/
[TMP_REG_1] = {ARM_R7, ARM_R6},
[TMP_REG_2] = {ARM_R10, ARM_R8},
[TMP_REG_2] = {ARM_R9, ARM_R8},
/* Tail call count. Stored on stack scratch space. */
[TCALL_CNT] = {STACK_OFFSET(BPF_TC_HI), STACK_OFFSET(BPF_TC_LO)},
/* temporary register for blinding constants.