From f27c2f69cc8edc03ea8086f974811b9b45b2f3a5 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Wed, 7 Dec 2016 08:39:00 -0800 Subject: [PATCH] Revert "default exported asm symbols to zero" MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit This reverts commit 8ab2ae655bfe384335c5b6b0d6041e0ddce26b00. I loved that commit because of how it explained what the problem with newer versions of binutils were, but the actual patch itself turns out to not work very well. It has two problems: - a zero CRC value isn't actually right. It happens to work for the case where both sides of the equation fail at giving the symbol a crc, but there are cases where the users of the exported symbol get the right crc (due to seeing the C declarations), but the actual exporting itself does not (due to the whole weak asm symbol issue). So then the module load fails after all - we did have a crc for the symbol, but we couldn't match it with the loaded module. - it seems that the alpha assembler has special semantics for the '.set' directive, and on alpha it doesn't actually set the value of the specified symbol at all, it is instead used to set various assembly modes (eg ".set noat" and ".set noreorder"). So using ".set" to set the symbol value would just cause build failures on alpha. I'm sure we'll find some other workaround for these issues (hopefully that involves getting rid of modversions entirely some day, but people are also talking about just using smarter tools). But for now we'll just fall back on commit faaae2a58143 ("Re-enable CONFIG_MODVERSIONS in a slightly weaker form") that just let's a missing crc through. Reported-by: Jan Stancek Reported-by: Philip Müller Reported-by: Guenter Roeck Cc: Arnd Bergmann Signed-off-by: Linus Torvalds --- include/asm-generic/export.h | 1 - 1 file changed, 1 deletion(-) diff --git a/include/asm-generic/export.h b/include/asm-generic/export.h index 59a3b2f58c22..63554e9f6e0c 100644 --- a/include/asm-generic/export.h +++ b/include/asm-generic/export.h @@ -54,7 +54,6 @@ KSYM(__kstrtab_\name): KSYM(__kcrctab_\name): __put KSYM(__crc_\name) .weak KSYM(__crc_\name) - .set KSYM(__crc_\name), 0 .previous #endif #endif -- 2.20.1