Anton Blanchard <[email protected]> writes: > Module CRCs are implemented as absolute symbols that get resolved by > a linker script. We build an intermediate .o that contains an > unresolved symbol for each CRC. genksysms parses this .o, calculates > the CRCs and writes a linker script that "resolves" the symbols to > the calculated CRC. > > Unfortunately the ppc64 relocatable kernel sees these CRCs as symbols > that need relocating and relocates them at boot. Commit d4703aef > (module: handle ppc64 relocating kcrctabs when CONFIG_RELOCATABLE=y) > added a hook to reverse the bogus relocations. Part of this patch > created a symbol at 0x0: > > # head -2 /proc/kallsyms > 0000000000000000 T reloc_start > c000000000000000 T .__start > > This reloc_start symbol is causing lots of confusion to perf. It > thinks reloc_start is a massive function that stretches from 0x0 to > 0xc000000000000000 and we get various cryptic errors out of perf, > including: > > problem incrementing symbol count, skipping event > > This patch removes the reloc_start linker script label and instead > defines it as PHYSICAL_START. We also need to wrap it with > CONFIG_PPC64 because the ppc32 kernel can set a non zero > PHYSICAL_START at compile time and we wouldn't want to subtract > it from the CRCs in that case. > > Signed-off-by: Anton Blanchard <[email protected]> > Cc: <[email protected]>
Acked-by: Rusty Russell <[email protected]> Ben? Cheers, Rusty. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
