powerpc allows using up to 8 registers to pass arguments between function calls. This value is hardcoded in multiple places, use a define for this value.
Signed-off-by: Alexis Lothoré (eBPF Foundation) alexis.lothore@bootlin.com --- arch/powerpc/net/bpf_jit_comp.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/net/bpf_jit_comp.c b/arch/powerpc/net/bpf_jit_comp.c index c0684733e9d6ac79b4cf653bf1b9ad40eb3e1aca..d313920a42c2310c6b5deab6d82e13af49c8ecb1 100644 --- a/arch/powerpc/net/bpf_jit_comp.c +++ b/arch/powerpc/net/bpf_jit_comp.c @@ -22,6 +22,8 @@
#include "bpf_jit.h"
+#define MAX_REGS_FOR_ARGS 8 + /* These offsets are from bpf prog end and stay the same across progs */ static int bpf_jit_ool_stub, bpf_jit_long_branch_stub;
@@ -613,7 +615,7 @@ static void bpf_trampoline_save_args(u32 *image, struct codegen_context *ctx, in param_save_area_offset += STACK_FRAME_MIN_SIZE; /* param save area is past frame header */
for (int i = 0; i < nr_regs; i++) { - if (i < 8) { + if (i < MAX_REGS_FOR_ARGS) { EMIT(PPC_RAW_STL(_R3 + i, _R1, regs_off + i * SZL)); } else { EMIT(PPC_RAW_LL(_R3, _R1, param_save_area_offset + i * SZL)); @@ -626,7 +628,7 @@ static void bpf_trampoline_save_args(u32 *image, struct codegen_context *ctx, in static void bpf_trampoline_restore_args_regs(u32 *image, struct codegen_context *ctx, int nr_regs, int regs_off) { - for (int i = 0; i < nr_regs && i < 8; i++) + for (int i = 0; i < nr_regs && i < MAX_REGS_FOR_ARGS; i++) EMIT(PPC_RAW_LL(_R3 + i, _R1, regs_off + i * SZL)); }
@@ -725,7 +727,9 @@ static int __arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *rw_im * * Reserve space for at least 8 registers for now. This can be optimized later. */ - bpf_frame_size += (nr_regs > 8 ? nr_regs : 8) * SZL; + bpf_frame_size += + (nr_regs > MAX_REGS_FOR_ARGS ? nr_regs : MAX_REGS_FOR_ARGS) * + SZL;
/* Room for struct bpf_tramp_run_ctx */ run_ctx_off = bpf_frame_size;