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authorCatalin Marinas <catalin.marinas@arm.com>2009-02-11 13:09:54 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2009-02-19 11:27:19 +0000
commit2e1926e7b5d39eb31880152d636e8d8d011888cb (patch)
tree3d871e05d14db1358f065cd87e310c6f59430cb8 /arch/arm/kernel
parentbff595c15c92b9c5c8f3d32edefcef6c3cbdd59f (diff)
[ARM] 5384/1: unwind: Add stack unwinding support for loadable modules
This patch adds ELF section parsing for the unwinding tables in loadable modules together with the PREL31 relocation symbol resolving. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/kernel')
-rw-r--r--arch/arm/kernel/module.c64
1 files changed, 64 insertions, 0 deletions
diff --git a/arch/arm/kernel/module.c b/arch/arm/kernel/module.c
index dab48f27263..13dbd5bf5cc 100644
--- a/arch/arm/kernel/module.c
+++ b/arch/arm/kernel/module.c
@@ -22,6 +22,7 @@
#include <asm/pgtable.h>
#include <asm/sections.h>
+#include <asm/unwind.h>
#ifdef CONFIG_XIP_KERNEL
/*
@@ -66,6 +67,24 @@ int module_frob_arch_sections(Elf_Ehdr *hdr,
char *secstrings,
struct module *mod)
{
+#ifdef CONFIG_ARM_UNWIND
+ Elf_Shdr *s, *sechdrs_end = sechdrs + hdr->e_shnum;
+
+ for (s = sechdrs; s < sechdrs_end; s++) {
+ if (strcmp(".ARM.exidx.init.text", secstrings + s->sh_name) == 0)
+ mod->arch.unw_sec_init = s;
+ else if (strcmp(".ARM.exidx.devinit.text", secstrings + s->sh_name) == 0)
+ mod->arch.unw_sec_devinit = s;
+ else if (strcmp(".ARM.exidx", secstrings + s->sh_name) == 0)
+ mod->arch.unw_sec_core = s;
+ else if (strcmp(".init.text", secstrings + s->sh_name) == 0)
+ mod->arch.sec_init_text = s;
+ else if (strcmp(".devinit.text", secstrings + s->sh_name) == 0)
+ mod->arch.sec_devinit_text = s;
+ else if (strcmp(".text", secstrings + s->sh_name) == 0)
+ mod->arch.sec_core_text = s;
+ }
+#endif
return 0;
}
@@ -104,6 +123,10 @@ apply_relocate(Elf32_Shdr *sechdrs, const char *strtab, unsigned int symindex,
loc = dstsec->sh_addr + rel->r_offset;
switch (ELF32_R_TYPE(rel->r_info)) {
+ case R_ARM_NONE:
+ /* ignore */
+ break;
+
case R_ARM_ABS32:
*(u32 *)loc += sym->st_value;
break;
@@ -132,6 +155,11 @@ apply_relocate(Elf32_Shdr *sechdrs, const char *strtab, unsigned int symindex,
*(u32 *)loc |= offset & 0x00ffffff;
break;
+ case R_ARM_PREL31:
+ offset = *(u32 *)loc + sym->st_value - loc;
+ *(u32 *)loc = offset & 0x7fffffff;
+ break;
+
default:
printk(KERN_ERR "%s: unknown relocation: %u\n",
module->name, ELF32_R_TYPE(rel->r_info));
@@ -150,14 +178,50 @@ apply_relocate_add(Elf32_Shdr *sechdrs, const char *strtab,
return -ENOEXEC;
}
+#ifdef CONFIG_ARM_UNWIND
+static void register_unwind_tables(struct module *mod)
+{
+ if (mod->arch.unw_sec_init && mod->arch.sec_init_text)
+ mod->arch.unwind_init =
+ unwind_table_add(mod->arch.unw_sec_init->sh_addr,
+ mod->arch.unw_sec_init->sh_size,
+ mod->arch.sec_init_text->sh_addr,
+ mod->arch.sec_init_text->sh_size);
+ if (mod->arch.unw_sec_devinit && mod->arch.sec_devinit_text)
+ mod->arch.unwind_devinit =
+ unwind_table_add(mod->arch.unw_sec_devinit->sh_addr,
+ mod->arch.unw_sec_devinit->sh_size,
+ mod->arch.sec_devinit_text->sh_addr,
+ mod->arch.sec_devinit_text->sh_size);
+ if (mod->arch.unw_sec_core && mod->arch.sec_core_text)
+ mod->arch.unwind_core =
+ unwind_table_add(mod->arch.unw_sec_core->sh_addr,
+ mod->arch.unw_sec_core->sh_size,
+ mod->arch.sec_core_text->sh_addr,
+ mod->arch.sec_core_text->sh_size);
+}
+
+static void unregister_unwind_tables(struct module *mod)
+{
+ unwind_table_del(mod->arch.unwind_init);
+ unwind_table_del(mod->arch.unwind_devinit);
+ unwind_table_del(mod->arch.unwind_core);
+}
+#else
+static inline void register_unwind_tables(struct module *mod) { }
+static inline void unregister_unwind_tables(struct module *mod) { }
+#endif
+
int
module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs,
struct module *module)
{
+ register_unwind_tables(module);
return 0;
}
void
module_arch_cleanup(struct module *mod)
{
+ unregister_unwind_tables(mod);
}