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Commit 138d6153 authored by Naveen N. Rao's avatar Naveen N. Rao Committed by David S. Miller
Browse files

samples/bpf: Enable powerpc support 



Add the necessary definitions for building bpf samples on ppc.

Since ppc doesn't store function return address on the stack, modify how
PT_REGS_RET() and PT_REGS_FP() work.

Also, introduce PT_REGS_IP() to access the instruction pointer.

Cc: Alexei Starovoitov <ast@fb.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David S. Miller <davem@davemloft.net>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: default avatarNaveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: default avatarAlexei Starovoitov <ast@kernel.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 128d1514

samples/bpf/bpf_helpers.h

+26 −0
Original line number Diff line number Diff line
@@ -82,6 +82,7 @@ static int (*bpf_l4_csum_replace)(void *ctx, int off, int from, int to, int flag 
#define PT_REGS_FP(x) ((x)->bp)

#define PT_REGS_RC(x) ((x)->ax)

#define PT_REGS_SP(x) ((x)->sp)

#define PT_REGS_IP(x) ((x)->ip)



#elif defined(__s390x__)
@@ -94,6 +95,7 @@ static int (*bpf_l4_csum_replace)(void *ctx, int off, int from, int to, int flag 
#define PT_REGS_FP(x) ((x)->gprs[11]) /* Works only with CONFIG_FRAME_POINTER */

#define PT_REGS_RC(x) ((x)->gprs[2])

#define PT_REGS_SP(x) ((x)->gprs[15])

#define PT_REGS_IP(x) ((x)->ip)



#elif defined(__aarch64__)
@@ -106,6 +108,30 @@ static int (*bpf_l4_csum_replace)(void *ctx, int off, int from, int to, int flag 
#define PT_REGS_FP(x) ((x)->regs[29]) /* Works only with CONFIG_FRAME_POINTER */

#define PT_REGS_RC(x) ((x)->regs[0])

#define PT_REGS_SP(x) ((x)->sp)

#define PT_REGS_IP(x) ((x)->pc)



#elif defined(__powerpc__)



#define PT_REGS_PARM1(x) ((x)->gpr[3])

#define PT_REGS_PARM2(x) ((x)->gpr[4])

#define PT_REGS_PARM3(x) ((x)->gpr[5])

#define PT_REGS_PARM4(x) ((x)->gpr[6])

#define PT_REGS_PARM5(x) ((x)->gpr[7])

#define PT_REGS_RC(x) ((x)->gpr[3])

#define PT_REGS_SP(x) ((x)->sp)

#define PT_REGS_IP(x) ((x)->nip)



#endif



#ifdef __powerpc__

#define BPF_KPROBE_READ_RET_IP(ip, ctx)		({ (ip) = (ctx)->link; })

#define BPF_KRETPROBE_READ_RET_IP		BPF_KPROBE_READ_RET_IP

#else

#define BPF_KPROBE_READ_RET_IP(ip, ctx)		({				\

		bpf_probe_read(&(ip), sizeof(ip), (void *)PT_REGS_RET(ctx)); })

#define BPF_KRETPROBE_READ_RET_IP(ip, ctx)	({				\

		bpf_probe_read(&(ip), sizeof(ip),				\

				(void *)(PT_REGS_FP(ctx) + sizeof(ip))); })

#endif



#endif

samples/bpf/spintest_kern.c

+1 −1
Original line number Diff line number Diff line
@@ -34,7 +34,7 @@ struct bpf_map_def SEC("maps") stackmap = { 
#define PROG(foo) \

int foo(struct pt_regs *ctx) \

{ \

	long v = ctx->ip, *val; \

	long v = PT_REGS_IP(ctx), *val; \

\

	val = bpf_map_lookup_elem(&my_map, &v); \

	bpf_map_update_elem(&my_map, &v, &v, BPF_ANY); \

samples/bpf/tracex2_kern.c

+2 −2
Original line number Diff line number Diff line
@@ -27,10 +27,10 @@ int bpf_prog2(struct pt_regs *ctx) 
	long init_val = 1;

	long *value;



	/* x64/s390x specific: read ip of kfree_skb caller.

	/* read ip of kfree_skb caller.

	 * non-portable version of __builtin_return_address(0)

	 */

	bpf_probe_read(&loc, sizeof(loc), (void *)PT_REGS_RET(ctx));

	BPF_KPROBE_READ_RET_IP(loc, ctx);



	value = bpf_map_lookup_elem(&my_map, &loc);

	if (value)

samples/bpf/tracex4_kern.c

+1 −1
Original line number Diff line number Diff line
@@ -40,7 +40,7 @@ int bpf_prog2(struct pt_regs *ctx) 
	long ip = 0;



	/* get ip address of kmem_cache_alloc_node() caller */

	bpf_probe_read(&ip, sizeof(ip), (void *)(PT_REGS_FP(ctx) + sizeof(ip)));

	BPF_KRETPROBE_READ_RET_IP(ip, ctx);



	struct pair v = {

		.val = bpf_ktime_get_ns(),