linux-kernel - [PATCH] __crc_... is intended to be absolute

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Message-Id: <E1HCcMR-0007OE-VW@ZenIV.linux.org.uk>
Date:	Thu, 01 Feb 2007 13:52:23 +0000
From:	Al Viro <viro@....linux.org.uk>
To:	torvalds@...ux-foundation.org
Cc:	linux-kernel@...r.kernel.org, vgoyal@...ibm.com
Subject: [PATCH] __crc_... is intended to be absolute

i386 boot/compressed/relocs checks for absolute symbols and warns about
unexpected ones.  If you build with modversions, you get ~2500 warnings
about __crc_<symbol>.  These suckers are really absolute symbols - we
do _not_ want to modify them on relocation.

They are generated by genksyms - EXPORT_... generates a weak alias, then
genksyms produces an ld script with __crc_<symbol> = <checksum> and it's
fed to ld to produce the final object file.  Their only use is to match
kernel and module at modprobe time; they _must_ be absolute.

boot/compressed/relocs has a whitelist of known absolute symbols, but
it doesn't know about __crc_... stuff.  As the result, we get shitloads
of false positives on any ld(1) version.

Signed-off-by: Al Viro <viro@...iv.linux.org.uk>
---
 arch/i386/boot/compressed/relocs.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/arch/i386/boot/compressed/relocs.c b/arch/i386/boot/compressed/relocs.c
index 468da89..881951c 100644
--- a/arch/i386/boot/compressed/relocs.c
+++ b/arch/i386/boot/compressed/relocs.c
@@ -43,6 +43,8 @@ static int is_safe_abs_reloc(const char* sym_name)
 			/* Match found */
 			return 1;
 	}
+	if (strncmp(sym_name, "__crc_", 6) == 0)
+		return 1;
 	return 0;
 }

-- 
1.5.0-rc2.GIT

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