This is a note to let you know that I've just added the patch titled
libbpf: Initialize the bpf_seq_printf parameters array field by field
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
libbpf-initialize-the-bpf_seq_printf-parameters-arra.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit fec3dcda4f7187840ec156b0f920337c494da8c6
Author: Florent Revest <revest@xxxxxxxxxxxx>
Date: Mon Apr 19 17:52:41 2021 +0200
libbpf: Initialize the bpf_seq_printf parameters array field by field
[ Upstream commit 83cd92b46484aa8f64cdc0bff8ac6940d1f78519 ]
When initializing the __param array with a one liner, if all args are
const, the initial array value will be placed in the rodata section but
because libbpf does not support relocation in the rodata section, any
pointer in this array will stay NULL.
Fixes: c09add2fbc5a ("tools/libbpf: Add bpf_iter support")
Signed-off-by: Florent Revest <revest@xxxxxxxxxxxx>
Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx>
Acked-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
Link: https://lore.kernel.org/bpf/20210419155243.1632274-5-revest@xxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/tools/lib/bpf/bpf_tracing.h b/tools/lib/bpf/bpf_tracing.h
index f9ef37707888..1c2e91ee041d 100644
--- a/tools/lib/bpf/bpf_tracing.h
+++ b/tools/lib/bpf/bpf_tracing.h
@@ -413,20 +413,38 @@ typeof(name(0)) name(struct pt_regs *ctx) \
} \
static __always_inline typeof(name(0)) ____##name(struct pt_regs *ctx, ##args)
+#define ___bpf_fill0(arr, p, x) do {} while (0)
+#define ___bpf_fill1(arr, p, x) arr[p] = x
+#define ___bpf_fill2(arr, p, x, args...) arr[p] = x; ___bpf_fill1(arr, p + 1, args)
+#define ___bpf_fill3(arr, p, x, args...) arr[p] = x; ___bpf_fill2(arr, p + 1, args)
+#define ___bpf_fill4(arr, p, x, args...) arr[p] = x; ___bpf_fill3(arr, p + 1, args)
+#define ___bpf_fill5(arr, p, x, args...) arr[p] = x; ___bpf_fill4(arr, p + 1, args)
+#define ___bpf_fill6(arr, p, x, args...) arr[p] = x; ___bpf_fill5(arr, p + 1, args)
+#define ___bpf_fill7(arr, p, x, args...) arr[p] = x; ___bpf_fill6(arr, p + 1, args)
+#define ___bpf_fill8(arr, p, x, args...) arr[p] = x; ___bpf_fill7(arr, p + 1, args)
+#define ___bpf_fill9(arr, p, x, args...) arr[p] = x; ___bpf_fill8(arr, p + 1, args)
+#define ___bpf_fill10(arr, p, x, args...) arr[p] = x; ___bpf_fill9(arr, p + 1, args)
+#define ___bpf_fill11(arr, p, x, args...) arr[p] = x; ___bpf_fill10(arr, p + 1, args)
+#define ___bpf_fill12(arr, p, x, args...) arr[p] = x; ___bpf_fill11(arr, p + 1, args)
+#define ___bpf_fill(arr, args...) \
+ ___bpf_apply(___bpf_fill, ___bpf_narg(args))(arr, 0, args)
+
/*
* BPF_SEQ_PRINTF to wrap bpf_seq_printf to-be-printed values
* in a structure.
*/
-#define BPF_SEQ_PRINTF(seq, fmt, args...) \
- ({ \
- _Pragma("GCC diagnostic push") \
- _Pragma("GCC diagnostic ignored \"-Wint-conversion\"") \
- static const char ___fmt[] = fmt; \
- unsigned long long ___param[] = { args }; \
- _Pragma("GCC diagnostic pop") \
- int ___ret = bpf_seq_printf(seq, ___fmt, sizeof(___fmt), \
- ___param, sizeof(___param)); \
- ___ret; \
- })
+#define BPF_SEQ_PRINTF(seq, fmt, args...) \
+({ \
+ static const char ___fmt[] = fmt; \
+ unsigned long long ___param[___bpf_narg(args)]; \
+ \
+ _Pragma("GCC diagnostic push") \
+ _Pragma("GCC diagnostic ignored \"-Wint-conversion\"") \
+ ___bpf_fill(___param, args); \
+ _Pragma("GCC diagnostic pop") \
+ \
+ bpf_seq_printf(seq, ___fmt, sizeof(___fmt), \
+ ___param, sizeof(___param)); \
+})
#endif
