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ARM: fixup SMP alternatives in modules

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With certain configurations, we inline the unlock functions in modules,
which results in SMP alternatives being created in modules.  We need to
fix those up when loading a module to prevent undefined instruction
faults.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Russell King 2011-02-10 15:25:18 +00:00
parent 0193c00e85
commit 4a9cb36019
2 changed files with 48 additions and 14 deletions
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40
arch/arm/kernel/head.S
View File

@ -391,6 +391,7 @@ ENDPROC(__turn_mmu_on)
#ifdef CONFIG_SMP_ON_UP
__INIT
__fixup_smp:
and r3, r9, #0x000f0000 @ architecture version
teq r3, #0x000f0000 @ CPU ID supported?
@ -415,18 +416,7 @@ __fixup_smp_on_up:
sub r3, r0, r3
add r4, r4, r3
add r5, r5, r3
2: cmp r4, r5
movhs pc, lr
ldmia r4!, {r0, r6}
ARM( str r6, [r0, r3] )
THUMB( add r0, r0, r3 )
#ifdef __ARMEB__
THUMB( mov r6, r6, ror #16 ) @ Convert word order for big-endian.
#endif
THUMB( strh r6, [r0], #2 ) @ For Thumb-2, store as two halfwords
THUMB( mov r6, r6, lsr #16 ) @ to be robust against misaligned r3.
THUMB( strh r6, [r0] )
b 2b
b __do_fixup_smp_on_up
ENDPROC(__fixup_smp)
.align
@ -440,7 +430,31 @@ smp_on_up:
ALT_SMP(.long 1)
ALT_UP(.long 0)
.popsection
#endif
.text
__do_fixup_smp_on_up:
cmp r4, r5
movhs pc, lr
ldmia r4!, {r0, r6}
ARM( str r6, [r0, r3] )
THUMB( add r0, r0, r3 )
#ifdef __ARMEB__
THUMB( mov r6, r6, ror #16 ) @ Convert word order for big-endian.
#endif
THUMB( strh r6, [r0], #2 ) @ For Thumb-2, store as two halfwords
THUMB( mov r6, r6, lsr #16 ) @ to be robust against misaligned r3.
THUMB( strh r6, [r0] )
b __do_fixup_smp_on_up
ENDPROC(__do_fixup_smp_on_up)
ENTRY(fixup_smp)
stmfd sp!, {r4 - r6, lr}
mov r4, r0
add r5, r0, r1
mov r3, #0
bl __do_fixup_smp_on_up
ldmfd sp!, {r4 - r6, pc}
ENDPROC(fixup_smp)
#include "head-common.S"

22
arch/arm/kernel/module.c
View File

@ -22,6 +22,7 @@
#include <asm/pgtable.h>
#include <asm/sections.h>
#include <asm/smp_plat.h>
#include <asm/unwind.h>
#ifdef CONFIG_XIP_KERNEL
@ -268,12 +269,28 @@ struct mod_unwind_map {
const Elf_Shdr *txt_sec;
};
static const Elf_Shdr *find_mod_section(const Elf32_Ehdr *hdr,
const Elf_Shdr *sechdrs, const char *name)
{
const Elf_Shdr *s, *se;
const char *secstrs = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
for (s = sechdrs, se = sechdrs + hdr->e_shnum; s < se; s++)
if (strcmp(name, secstrs + s->sh_name) == 0)
return s;
return NULL;
}
extern void fixup_smp(const void *, unsigned long);
int module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs,
struct module *mod)
{
const Elf_Shdr * __maybe_unused s = NULL;
#ifdef CONFIG_ARM_UNWIND
const char *secstrs = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
const Elf_Shdr *s, *sechdrs_end = sechdrs + hdr->e_shnum;
const Elf_Shdr *sechdrs_end = sechdrs + hdr->e_shnum;
struct mod_unwind_map maps[ARM_SEC_MAX];
int i;
@ -315,6 +332,9 @@ int module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs,
maps[i].txt_sec->sh_addr,
maps[i].txt_sec->sh_size);
#endif
s = find_mod_section(hdr, sechdrs, ".alt.smp.init");
if (s && !is_smp())
fixup_smp((void *)s->sh_addr, s->sh_size);
return 0;
}