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samples: bpf: enable trace samples for s390x 

The trace bpf samples do not compile on s390x because they use x86
specific fields from the "pt_regs" structure.

Fix this and access the fields via new PT_REGS macros.

Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Michael Holzheu 2015-07-06 16:20:07 +02:00 committed by David S. Miller
parent 7baaa9092d
commit d912557b34
6 changed files with 37 additions and 12 deletions
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25
samples/bpf/bpf_helpers.h
View File

@ -60,4 +60,29 @@ static int (*bpf_l3_csum_replace)(void *ctx, int off, int from, int to, int flag
static int (*bpf_l4_csum_replace)(void *ctx, int off, int from, int to, int flags) =
(void *) BPF_FUNC_l4_csum_replace;
#if defined(__x86_64__)
#define PT_REGS_PARM1(x) ((x)->di)
#define PT_REGS_PARM2(x) ((x)->si)
#define PT_REGS_PARM3(x) ((x)->dx)
#define PT_REGS_PARM4(x) ((x)->cx)
#define PT_REGS_PARM5(x) ((x)->r8)
#define PT_REGS_RET(x) ((x)->sp)
#define PT_REGS_FP(x) ((x)->bp)
#define PT_REGS_RC(x) ((x)->ax)
#define PT_REGS_SP(x) ((x)->sp)
#elif defined(__s390x__)
#define PT_REGS_PARM1(x) ((x)->gprs[2])
#define PT_REGS_PARM2(x) ((x)->gprs[3])
#define PT_REGS_PARM3(x) ((x)->gprs[4])
#define PT_REGS_PARM4(x) ((x)->gprs[5])
#define PT_REGS_PARM5(x) ((x)->gprs[6])
#define PT_REGS_RET(x) ((x)->gprs[14])
#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])
#endif
#endif

2
samples/bpf/tracex1_kern.c
View File

@ -29,7 +29,7 @@ int bpf_prog1(struct pt_regs *ctx)
int len;
/* non-portable! works for the given kernel only */
skb = (struct sk_buff *) ctx->di;
skb = (struct sk_buff *) PT_REGS_PARM1(ctx);
dev = _(skb->dev);

6
samples/bpf/tracex2_kern.c
View File

@ -27,10 +27,10 @@ int bpf_prog2(struct pt_regs *ctx)
long init_val = 1;
long *value;
/* x64 specific: read ip of kfree_skb caller.
/* x64/s390x specific: read ip of kfree_skb caller.
* non-portable version of __builtin_return_address(0)
*/
bpf_probe_read(&loc, sizeof(loc), (void *)ctx->sp);
bpf_probe_read(&loc, sizeof(loc), (void *)PT_REGS_RET(ctx));
value = bpf_map_lookup_elem(&my_map, &loc);
if (value)
@ -79,7 +79,7 @@ struct bpf_map_def SEC("maps") my_hist_map = {
SEC("kprobe/sys_write")
int bpf_prog3(struct pt_regs *ctx)
{
long write_size = ctx->dx; /* arg3 */
long write_size = PT_REGS_PARM3(ctx);
long init_val = 1;
long *value;
struct hist_key key = {};

4
samples/bpf/tracex3_kern.c
View File

@ -23,7 +23,7 @@ struct bpf_map_def SEC("maps") my_map = {
SEC("kprobe/blk_mq_start_request")
int bpf_prog1(struct pt_regs *ctx)
{
long rq = ctx->di;
long rq = PT_REGS_PARM1(ctx);
u64 val = bpf_ktime_get_ns();
bpf_map_update_elem(&my_map, &rq, &val, BPF_ANY);
@ -51,7 +51,7 @@ struct bpf_map_def SEC("maps") lat_map = {
SEC("kprobe/blk_update_request")
int bpf_prog2(struct pt_regs *ctx)
{
long rq = ctx->di;
long rq = PT_REGS_PARM1(ctx);
u64 *value, l, base;
u32 index;

6
samples/bpf/tracex4_kern.c
View File

@ -27,7 +27,7 @@ struct bpf_map_def SEC("maps") my_map = {
SEC("kprobe/kmem_cache_free")
int bpf_prog1(struct pt_regs *ctx)
{
long ptr = ctx->si;
long ptr = PT_REGS_PARM2(ctx);
bpf_map_delete_elem(&my_map, &ptr);
return 0;
@ -36,11 +36,11 @@ int bpf_prog1(struct pt_regs *ctx)
SEC("kretprobe/kmem_cache_alloc_node")
int bpf_prog2(struct pt_regs *ctx)
{
long ptr = ctx->ax;
long ptr = PT_REGS_RC(ctx);
long ip = 0;
/* get ip address of kmem_cache_alloc_node() caller */
bpf_probe_read(&ip, sizeof(ip), (void *)(ctx->bp + sizeof(ip)));
bpf_probe_read(&ip, sizeof(ip), (void *)(PT_REGS_FP(ctx) + sizeof(ip)));
struct pair v = {
.val = bpf_ktime_get_ns(),

6
samples/bpf/tracex5_kern.c
View File

@ -24,7 +24,7 @@ int bpf_prog1(struct pt_regs *ctx)
{
struct seccomp_data sd = {};
bpf_probe_read(&sd, sizeof(sd), (void *)ctx->di);
bpf_probe_read(&sd, sizeof(sd), (void *)PT_REGS_PARM1(ctx));
/* dispatch into next BPF program depending on syscall number */
bpf_tail_call(ctx, &progs, sd.nr);
@ -42,7 +42,7 @@ PROG(__NR_write)(struct pt_regs *ctx)
{
struct seccomp_data sd = {};
bpf_probe_read(&sd, sizeof(sd), (void *)ctx->di);
bpf_probe_read(&sd, sizeof(sd), (void *)PT_REGS_PARM1(ctx));
if (sd.args[2] == 512) {
char fmt[] = "write(fd=%d, buf=%p, size=%d)\n";
bpf_trace_printk(fmt, sizeof(fmt),
@ -55,7 +55,7 @@ PROG(__NR_read)(struct pt_regs *ctx)
{
struct seccomp_data sd = {};
bpf_probe_read(&sd, sizeof(sd), (void *)ctx->di);
bpf_probe_read(&sd, sizeof(sd), (void *)PT_REGS_PARM1(ctx));
if (sd.args[2] > 128 && sd.args[2] <= 1024) {
char fmt[] = "read(fd=%d, buf=%p, size=%d)\n";
bpf_trace_printk(fmt, sizeof(fmt),