From 2efac77e82a36bf616d474f2eb721d95543cfae9 Mon Sep 17 00:00:00 2001 From: Ralf Baechle Date: Mon, 11 Dec 2006 11:54:52 +0000 Subject: [PATCH] [MIPS] Discard .exit.text and .exit.data at runtime. While the recent cset 86384d544157db23879064cde36061cdcafc6794 did improve things it didn't resolve all the problems. So bite the bullet and discard .exit.text and .exit.data at runtime. Which of course sucks because it bloats binaries with code that will never ever be used but it's the only thing that will work reliable as demonstrated by the function sd_major() in drivers/scsi/sd.c. Gcc may compile sd_major() using a jump table which it will put into .rodata. If it also inlines sd_major's function body into exit_sd() which gcc > 3.4.x does. If CONFIG_BLK_DEV_SD has been set to y we would like ld to discard exit_sd's code at link time. However sd_major happens to contain a switch statement which gcc will compile using a jump table in .rodata on the architectures I checked. So, when ld later discards .exit.text only the jump table in .rodata with its stale references to the discard .exit.text will be left which any no antique ld will honor with a link error. Signed-off-by: Ralf Baechle --- arch/mips/kernel/vmlinux.lds.S | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/arch/mips/kernel/vmlinux.lds.S b/arch/mips/kernel/vmlinux.lds.S index 2f4508f55fca..cecff24cc972 100644 --- a/arch/mips/kernel/vmlinux.lds.S +++ b/arch/mips/kernel/vmlinux.lds.S @@ -109,6 +109,10 @@ SECTIONS .con_initcall.init : { *(.con_initcall.init) } __con_initcall_end = .; SECURITY_INIT + /* .exit.text is discarded at runtime, not link time, to deal with + references from .rodata */ + .exit.text : { *(.exit.text) } + .exit.data : { *(.exit.data) } . = ALIGN(_PAGE_SIZE); __initramfs_start = .; .init.ramfs : { *(.init.ramfs) } @@ -136,8 +140,6 @@ SECTIONS /* Sections to be discarded */ /DISCARD/ : { - *(.exit.text) - *(.exit.data) *(.exitcall.exit) /* ABI crap starts here */ -- 2.20.1