Re: [RFC PATCH] ARM: Use generic BUG() handler

From: Russell King - ARM Linux
Date: Thu Mar 03 2011 - 09:11:55 EST


On Wed, Mar 02, 2011 at 10:59:50AM +0000, Dave Martin wrote:
> + asm volatile("1:\t" __bug_instr "\n" q \
> + ".pushsection .rodata.str, \"a\"\n" \
> + "2:\t.asciz \"" #__file "\"\n" \
> + ".popsection\n" \

Doesn't this mean we end up with multiple file names?

> + ".pushsection __bug_table,\"a\"\n" \
> + "3:\t.word 1b, 2b\n" \
> + "\t.hword " #__line ", 0\n" \
> + ".popsection" \
> + unreachable(); \
> +} while (0)

Second problem is that the above produces this:

1: .word 0xec000000
.pushsection .rodata.str, "a"
2: .asciz "__FILE__"
.popsection
.pushsection __bug_table,"a"
3: .word 1b, 2b
.hword __LINE__, 0
.popsection

which is clearly not what we want. Adding another level of indirection
starts to get closer to what we desire:

1: .word 0xec000000
.pushsection .rodata.str, "a"
2: .asciz ""t.c""
.popsection
.pushsection __bug_table,"a"
3: .word 1b, 2b
.hword 19, 0
.popsection

but we're still ending up with multiple strings containing the filename,
which is going to excessively bloat the kernel no end.
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