On 3/31/16 4:25 AM, Naveen N. Rao wrote:
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. I have
fixed this to work with x86_64 and arm64, but not s390.
Cc: Alexei Starovoitov <a...@fb.com>
Cc: David S. Miller <da...@davemloft.net>
Cc: Ananth N Mavinakayanahalli <ana...@in.ibm.com>
Cc: Michael Ellerman <m...@ellerman.id.au>
Signed-off-by: Naveen N. Rao <naveen.n....@linux.vnet.ibm.com>
---
...
+
+#ifdef __powerpc__
+#define BPF_KPROBE_READ_RET_IP(ip, ctx) { (ip) = (ctx)->link; }
+#define BPF_KRETPROBE_READ_RET_IP(ip, ctx) BPF_KPROBE_READ_RET_IP(ip, ctx)
+#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)))
makes sense, but please use ({ }) gcc extension instead of {} and
open call to make sure that macro body is scoped.
