From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1C2101C07 for ; Wed, 28 Dec 2022 16:29:46 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6D23DC433D2; Wed, 28 Dec 2022 16:29:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1672244985; bh=5YTnHYb44Tvh0ZcmQw5FvxR0neV5vVJwQSLYSKZWTEA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=0jerZaLN50QUZkyP6LpIqDcXK4WMfxNpNIeX0Y1ktZczlY0McS9nW8YqHSOCmHf/Y 5TnE9As+bbQcFD1O+bGIpaoY8wzwkz9hazvW6E90NMX2iyhZnaVzfMPbzSlIUg4Rb8 Y1szS1MD6tt6b6XxmMXVB0eY7vz0334qHG95bWss= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Ajay Kaher , Alexander Shishkin , Alexey Makhalov , Jiri Olsa , Leo Yan , Mark Rutland , Namhyung Kim , Peter Zijlstra , "Srivatsa S. Bhat" , "Steven Rostedt (VMware)" , Vasavi Sirnapalli , Arnaldo Carvalho de Melo , Sasha Levin Subject: [PATCH 6.1 0773/1146] perf symbol: correction while adjusting symbol Date: Wed, 28 Dec 2022 15:38:32 +0100 Message-Id: <20221228144351.145469659@linuxfoundation.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20221228144330.180012208@linuxfoundation.org> References: <20221228144330.180012208@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Ajay Kaher [ Upstream commit 6f520ce17920b3cdfbd2479b3ccf27f9706219d0 ] perf doesn't provide proper symbol information for specially crafted .debug files. Sometimes .debug file may not have similar program header as runtime ELF file. For example if we generate .debug file using objcopy --only-keep-debug resulting file will not contain .text, .data and other runtime sections. That means corresponding program headers will have zero FileSiz and modified Offset. Example: program header of text section of libxxx.so: Type Offset VirtAddr PhysAddr FileSiz MemSiz Flags Align LOAD 0x00000000003d3000 0x00000000003d3000 0x00000000003d3000 0x000000000055ae80 0x000000000055ae80 R E 0x1000 Same program header after executing: objcopy --only-keep-debug libxxx.so libxxx.so.debug LOAD 0x0000000000001000 0x00000000003d3000 0x00000000003d3000 0x0000000000000000 0x000000000055ae80 R E 0x1000 Offset and FileSiz have been changed. Following formula will not provide correct value, if program header taken from .debug file (syms_ss): sym.st_value -= phdr.p_vaddr - phdr.p_offset; Correct program header information is located inside runtime ELF file (runtime_ss). Fixes: 2d86612aacb7805f ("perf symbol: Correct address for bss symbols") Signed-off-by: Ajay Kaher Cc: Alexander Shishkin Cc: Alexey Makhalov Cc: Jiri Olsa Cc: Leo Yan Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Srivatsa S. Bhat Cc: Steven Rostedt (VMware) Cc: Vasavi Sirnapalli Link: http://lore.kernel.org/lkml/1669198696-50547-1-git-send-email-akaher@vmware.com Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin --- tools/perf/util/symbol-elf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c index 647b7dff8ef3..80345695b136 100644 --- a/tools/perf/util/symbol-elf.c +++ b/tools/perf/util/symbol-elf.c @@ -1303,7 +1303,7 @@ dso__load_sym_internal(struct dso *dso, struct map *map, struct symsrc *syms_ss, (!used_opd && syms_ss->adjust_symbols)) { GElf_Phdr phdr; - if (elf_read_program_header(syms_ss->elf, + if (elf_read_program_header(runtime_ss->elf, (u64)sym.st_value, &phdr)) { pr_debug4("%s: failed to find program header for " "symbol: %s st_value: %#" PRIx64 "\n", -- 2.35.1