samples/bpf, selftests/bpf: Use bpf_probe_read_kernel

A handful of samples and selftests fail to build on s390, because
after commit 0ebeea8ca8 ("bpf: Restrict bpf_probe_read{, str}()
only to archs where they work") bpf_probe_read is not available
anymore.

Fix by using bpf_probe_read_kernel.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200720114806.88823-1-iii@linux.ibm.com
This commit is contained in:
Ilya Leoshkevich 2020-07-20 13:48:06 +02:00 committed by Alexei Starovoitov
parent 6bd557275a
commit e4d9c23207
10 changed files with 33 additions and 16 deletions

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@ -12,7 +12,12 @@
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>
#define _(P) ({typeof(P) val; bpf_probe_read(&val, sizeof(val), &P); val;})
#define _(P) \
({ \
typeof(P) val; \
bpf_probe_read_kernel(&val, sizeof(val), &(P)); \
val; \
})
#define MINBLOCK_US 1

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@ -10,7 +10,12 @@
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>
#define _(P) ({typeof(P) val = 0; bpf_probe_read(&val, sizeof(val), &P); val;})
#define _(P) \
({ \
typeof(P) val = 0; \
bpf_probe_read_kernel(&val, sizeof(val), &(P)); \
val; \
})
SEC("kprobe/__set_task_comm")
int prog(struct pt_regs *ctx)
@ -25,8 +30,9 @@ int prog(struct pt_regs *ctx)
tsk = (void *)PT_REGS_PARM1(ctx);
pid = _(tsk->pid);
bpf_probe_read(oldcomm, sizeof(oldcomm), &tsk->comm);
bpf_probe_read(newcomm, sizeof(newcomm), (void *)PT_REGS_PARM2(ctx));
bpf_probe_read_kernel(oldcomm, sizeof(oldcomm), &tsk->comm);
bpf_probe_read_kernel(newcomm, sizeof(newcomm),
(void *)PT_REGS_PARM2(ctx));
signal = _(tsk->signal);
oom_score_adj = _(signal->oom_score_adj);
return 0;

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@ -11,7 +11,12 @@
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>
#define _(P) ({typeof(P) val = 0; bpf_probe_read(&val, sizeof(val), &P); val;})
#define _(P) \
({ \
typeof(P) val = 0; \
bpf_probe_read_kernel(&val, sizeof(val), &(P)); \
val; \
})
/* kprobe is NOT a stable ABI
* kernel functions can be removed, renamed or completely change semantics.
@ -34,7 +39,7 @@ int bpf_prog1(struct pt_regs *ctx)
dev = _(skb->dev);
len = _(skb->len);
bpf_probe_read(devname, sizeof(devname), dev->name);
bpf_probe_read_kernel(devname, sizeof(devname), dev->name);
if (devname[0] == 'l' && devname[1] == 'o') {
char fmt[] = "skb %p len %d\n";

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@ -47,7 +47,7 @@ PROG(SYS__NR_write)(struct pt_regs *ctx)
{
struct seccomp_data sd;
bpf_probe_read(&sd, sizeof(sd), (void *)PT_REGS_PARM2(ctx));
bpf_probe_read_kernel(&sd, sizeof(sd), (void *)PT_REGS_PARM2(ctx));
if (sd.args[2] == 512) {
char fmt[] = "write(fd=%d, buf=%p, size=%d)\n";
bpf_trace_printk(fmt, sizeof(fmt),
@ -60,7 +60,7 @@ PROG(SYS__NR_read)(struct pt_regs *ctx)
{
struct seccomp_data sd;
bpf_probe_read(&sd, sizeof(sd), (void *)PT_REGS_PARM2(ctx));
bpf_probe_read_kernel(&sd, sizeof(sd), (void *)PT_REGS_PARM2(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),

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@ -71,7 +71,8 @@ int iter(struct bpf_iter__task_file *ctx)
e.pid = task->tgid;
e.id = get_obj_id(file->private_data, obj_type);
bpf_probe_read(&e.comm, sizeof(e.comm), task->group_leader->comm);
bpf_probe_read_kernel(&e.comm, sizeof(e.comm),
task->group_leader->comm);
bpf_seq_write(ctx->meta->seq, &e, sizeof(e));
return 0;

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@ -36,10 +36,10 @@ int dump_netlink(struct bpf_iter__netlink *ctx)
if (!nlk->groups) {
group = 0;
} else {
/* FIXME: temporary use bpf_probe_read here, needs
/* FIXME: temporary use bpf_probe_read_kernel here, needs
* verifier support to do direct access.
*/
bpf_probe_read(&group, sizeof(group), &nlk->groups[0]);
bpf_probe_read_kernel(&group, sizeof(group), &nlk->groups[0]);
}
BPF_SEQ_PRINTF(seq, "%-10u %08x %-8d %-8d %-5d %-8d ",
nlk->portid, (u32)group,
@ -56,7 +56,7 @@ int dump_netlink(struct bpf_iter__netlink *ctx)
* with current verifier.
*/
inode = SOCK_INODE(sk);
bpf_probe_read(&ino, sizeof(ino), &inode->i_ino);
bpf_probe_read_kernel(&ino, sizeof(ino), &inode->i_ino);
}
BPF_SEQ_PRINTF(seq, "%-8u %-8lu\n", s->sk_drops.counter, ino);

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@ -57,7 +57,7 @@ static long sock_i_ino(const struct sock *sk)
return 0;
inode = &container_of(sk_socket, struct socket_alloc, socket)->vfs_inode;
bpf_probe_read(&ino, sizeof(ino), &inode->i_ino);
bpf_probe_read_kernel(&ino, sizeof(ino), &inode->i_ino);
return ino;
}

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@ -57,7 +57,7 @@ static long sock_i_ino(const struct sock *sk)
return 0;
inode = &container_of(sk_socket, struct socket_alloc, socket)->vfs_inode;
bpf_probe_read(&ino, sizeof(ino), &inode->i_ino);
bpf_probe_read_kernel(&ino, sizeof(ino), &inode->i_ino);
return ino;
}

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@ -18,7 +18,7 @@ static long sock_i_ino(const struct sock *sk)
return 0;
inode = &container_of(sk_socket, struct socket_alloc, socket)->vfs_inode;
bpf_probe_read(&ino, sizeof(ino), &inode->i_ino);
bpf_probe_read_kernel(&ino, sizeof(ino), &inode->i_ino);
return ino;
}

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@ -25,7 +25,7 @@ static long sock_i_ino(const struct sock *sk)
return 0;
inode = &container_of(sk_socket, struct socket_alloc, socket)->vfs_inode;
bpf_probe_read(&ino, sizeof(ino), &inode->i_ino);
bpf_probe_read_kernel(&ino, sizeof(ino), &inode->i_ino);
return ino;
}