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From: Andrii Nakryiko <andrii@kernel.org>
To: <dwarves@vger.kernel.org>, <acme@kernel.org>
Cc: <bpf@vger.kernel.org>, Andrii Nakryiko <andrii@kernel.org>
Subject: [PATCH dwarves] btf_encoder: ignore zero-sized ELF symbols
Date: Wed, 21 Oct 2020 08:52:20 -0700	[thread overview]
Message-ID: <20201021155220.1737964-1-andrii@kernel.org> (raw)

It's legal for ELF symbol to have size 0, if it's size is unknown or
unspecified. Instead of erroring out, just ignore such symbols, as they can't
be a valid per-CPU variable anyways.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
---
 btf_encoder.c | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/btf_encoder.c b/btf_encoder.c
index 2a6455be4c52..2af1fe447834 100644
--- a/btf_encoder.c
+++ b/btf_encoder.c
@@ -287,6 +287,10 @@ static int find_all_percpu_vars(struct btf_elf *btfe)
 		if (!addr)
 			continue;
 
+		size = elf_sym__size(&sym);
+		if (!size)
+			continue; /* ignore zero-sized symbols */
+
 		sym_name = elf_sym__name(&sym, btfe->symtab);
 		if (!btf_name_valid(sym_name)) {
 			dump_invalid_symbol("Found symbol of invalid name when encoding btf",
@@ -295,14 +299,6 @@ static int find_all_percpu_vars(struct btf_elf *btfe)
 				continue;
 			return -1;
 		}
-		size = elf_sym__size(&sym);
-		if (!size) {
-			dump_invalid_symbol("Found symbol of zero size when encoding btf",
-					    sym_name, btf_elf__verbose, btf_elf__force);
-			if (btf_elf__force)
-				continue;
-			return -1;
-		}
 
 		if (btf_elf__verbose)
 			printf("Found per-CPU symbol '%s' at address 0x%lx\n", sym_name, addr);
-- 
2.24.1


             reply	other threads:[~2020-10-21 15:52 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-21 15:52 Andrii Nakryiko [this message]
2020-10-22  5:19 ` [PATCH dwarves] btf_encoder: ignore zero-sized ELF symbols Jiri Slaby
2020-10-23 16:37   ` Arnaldo Carvalho de Melo

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