bpf: avoid warning for wrong pointer cast
Two new functions in bpf contain a cast from a 'u64' to a
pointer. This works on 64-bit architectures but causes a warning
on all 32-bit architectures:
kernel/trace/bpf_trace.c: In function 'bpf_perf_event_output_tp':
kernel/trace/bpf_trace.c:350:13: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast]
u64 ctx = *(long *)r1;
This changes the cast to first convert the u64 argument into a uintptr_t,
which is guaranteed to be the same size as a pointer.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 9940d67c93b5 ("bpf: support bpf_get_stackid() and bpf_perf_event_output() in tracepoint programs")
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 6855878..f389629 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -351,7 +351,7 @@
* from bpf program and contain a pointer to 'struct pt_regs'. Fetch it
* from there and call the same bpf_perf_event_output() helper
*/
- u64 ctx = *(long *)r1;
+ u64 ctx = *(long *)(uintptr_t)r1;
return bpf_perf_event_output(ctx, r2, index, r4, size);
}
@@ -369,7 +369,7 @@
static u64 bpf_get_stackid_tp(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
{
- u64 ctx = *(long *)r1;
+ u64 ctx = *(long *)(uintptr_t)r1;
return bpf_get_stackid(ctx, r2, r3, r4, r5);
}