mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
* [PATCH] kbuild: make better section mismatch reports on i386 and mips
@ 2007-05-14 15:40 Atsushi Nemoto
  2007-05-15 20:47 ` Sam Ravnborg
  0 siblings, 1 reply; 4+ messages in thread
From: Atsushi Nemoto @ 2007-05-14 15:40 UTC (permalink / raw)
  To: linux-kernel; +Cc: sam, ralf

On i386 and MIPS, warn_sec_mismatch() sometimes fails to show usefull
symbol name.  This is because empty 'refsym' due to 0 r_addend value.
This patch is to adjust r_addend value, consulting with
apply_relocate() routine in kernel code.

Without this patch:
  MODPOST vmlinux
WARNING: init/built-in.o - Section mismatch: reference to .init.text: from .text between 'rest_init' (at offset 0xf4) and 'try_name'
WARNING: mm/built-in.o - Section mismatch: reference to .init.text: from .text between 'kmem_cache_create' (at offset 0x18a39) and 'cache_reap'
WARNING: mm/built-in.o - Section mismatch: reference to .init.text: from .text between 'kmem_cache_create' (at offset 0x18a6b) and 'cache_reap'

With this patch:
  MODPOST vmlinux
WARNING: mm/built-in.o - Section mismatch: reference to .init.text:set_up_list3s from .text between 'kmem_cache_create' (at offset 0x18a39) and 'cache_reap'
WARNING: mm/built-in.o - Section mismatch: reference to .init.text:set_up_list3s from .text between 'kmem_cache_create' (at offset 0x18a6b) and 'cache_reap'

Now modpost can detect "kernel_init" name (and whitelist it) and show
"set_up_list3s" name.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
---
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 113dc77..459ac2e 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -384,6 +384,7 @@ static int parse_elf(struct elf_info *info, const char *filename)
 		sechdrs[i].sh_size   = TO_NATIVE(sechdrs[i].sh_size);
 		sechdrs[i].sh_link   = TO_NATIVE(sechdrs[i].sh_link);
 		sechdrs[i].sh_name   = TO_NATIVE(sechdrs[i].sh_name);
+		sechdrs[i].sh_info   = TO_NATIVE(sechdrs[i].sh_info);
 	}
 	/* Find symbol table. */
 	for (i = 1; i < hdr->e_shnum; i++) {
@@ -911,6 +912,51 @@ static void warn_sec_mismatch(const char *modname, const char *fromsec,
 	}
 }
 
+static void addend_386_rel(struct elf_info *elf,
+			   int section, Elf_Rela *r)
+{
+	Elf_Shdr *sechdrs = elf->sechdrs;
+	unsigned int r_typ;
+	unsigned int *location;
+
+	r_typ = ELF_R_TYPE(r->r_info);
+	location = (void *)elf->hdr +
+		sechdrs[sechdrs[section].sh_info].sh_offset + r->r_offset;
+	switch (r_typ) {
+	case R_386_32:
+		r->r_addend = TO_NATIVE(*location);
+		break;
+	case R_386_PC32:
+		r->r_addend = TO_NATIVE(*location) + 4;
+		break;
+	}
+}
+
+static int addend_mips_rel(struct elf_info *elf,
+			   int section, Elf_Rela *r)
+{
+	Elf_Shdr *sechdrs = elf->sechdrs;
+	unsigned int r_typ;
+	unsigned int *location;
+	unsigned int inst;
+
+	r_typ = ELF_R_TYPE(r->r_info);
+	if (r_typ == R_MIPS_HI16)
+		return 1;	/* skip this */
+	location = (void *)elf->hdr +
+		sechdrs[sechdrs[section].sh_info].sh_offset + r->r_offset;
+	inst = TO_NATIVE(*location);
+	switch (r_typ) {
+	case R_MIPS_LO16:
+		r->r_addend = ((inst & 0xffff) ^ 0x8000) - 0x8000;
+		break;
+	case R_MIPS_26:
+		r->r_addend = (inst & 0x03ffffff) << 2;
+		break;
+	}
+	return 0;
+}
+
 /**
  * A module includes a number of sections that are discarded
  * either when loaded or when used as built-in.
@@ -954,8 +1000,11 @@ static void check_sec_ref(struct module *mod, const char *modname,
 				r.r_offset = TO_NATIVE(rela->r_offset);
 #if KERNEL_ELFCLASS == ELFCLASS64
 				if (hdr->e_machine == EM_MIPS) {
+					unsigned int r_typ;
 					r_sym = ELF64_MIPS_R_SYM(rela->r_info);
 					r_sym = TO_NATIVE(r_sym);
+					r_typ = ELF64_MIPS_R_TYPE(rela->r_info);
+					r.r_info = ELF64_R_INFO(r_sym, r_typ);
 				} else {
 					r.r_info = TO_NATIVE(rela->r_info);
 					r_sym = ELF_R_SYM(r.r_info);
@@ -988,8 +1037,11 @@ static void check_sec_ref(struct module *mod, const char *modname,
 				r.r_offset = TO_NATIVE(rel->r_offset);
 #if KERNEL_ELFCLASS == ELFCLASS64
 				if (hdr->e_machine == EM_MIPS) {
+					unsigned int r_typ;
 					r_sym = ELF64_MIPS_R_SYM(rel->r_info);
 					r_sym = TO_NATIVE(r_sym);
+					r_typ = ELF64_MIPS_R_TYPE(rel->r_info);
+					r.r_info = ELF64_R_INFO(r_sym, r_typ);
 				} else {
 					r.r_info = TO_NATIVE(rel->r_info);
 					r_sym = ELF_R_SYM(r.r_info);
@@ -999,6 +1051,12 @@ static void check_sec_ref(struct module *mod, const char *modname,
 				r_sym = ELF_R_SYM(r.r_info);
 #endif
 				r.r_addend = 0;
+				if (hdr->e_machine == EM_386)
+					addend_386_rel(elf, i, &r);
+				else if (hdr->e_machine == EM_MIPS) {
+					if (addend_mips_rel(elf, i, &r))
+						continue;
+				}
 				sym = elf->symtab_start + r_sym;
 				/* Skip special sections */
 				if (sym->st_shndx >= SHN_LORESERVE)
diff --git a/scripts/mod/modpost.h b/scripts/mod/modpost.h
index 0858caa..4156dd3 100644
--- a/scripts/mod/modpost.h
+++ b/scripts/mod/modpost.h
@@ -60,6 +60,9 @@ typedef union
 #define ELF64_MIPS_R_SYM(i) \
   ((__extension__ (_Elf64_Mips_R_Info_union)(i)).r_info_fields.r_sym)
 
+#define ELF64_MIPS_R_TYPE(i) \
+  ((__extension__ (_Elf64_Mips_R_Info_union)(i)).r_info_fields.r_type1)
+
 #if KERNEL_ELFDATA != HOST_ELFDATA
 
 static inline void __endian(const void *src, void *dest, unsigned int size)

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH] kbuild: make better section mismatch reports on i386 and mips
  2007-05-14 15:40 [PATCH] kbuild: make better section mismatch reports on i386 and mips Atsushi Nemoto
@ 2007-05-15 20:47 ` Sam Ravnborg
  2007-05-16 16:14   ` Atsushi Nemoto
  0 siblings, 1 reply; 4+ messages in thread
From: Sam Ravnborg @ 2007-05-15 20:47 UTC (permalink / raw)
  To: Atsushi Nemoto; +Cc: linux-kernel, ralf

On Tue, May 15, 2007 at 12:40:35AM +0900, Atsushi Nemoto wrote:
> On i386 and MIPS, warn_sec_mismatch() sometimes fails to show usefull
> symbol name.  This is because empty 'refsym' due to 0 r_addend value.
> This patch is to adjust r_addend value, consulting with
> apply_relocate() routine in kernel code.
> 
> Without this patch:
>   MODPOST vmlinux
> WARNING: init/built-in.o - Section mismatch: reference to .init.text: from .text between 'rest_init' (at offset 0xf4) and 'try_name'
> WARNING: mm/built-in.o - Section mismatch: reference to .init.text: from .text between 'kmem_cache_create' (at offset 0x18a39) and 'cache_reap'
> WARNING: mm/built-in.o - Section mismatch: reference to .init.text: from .text between 'kmem_cache_create' (at offset 0x18a6b) and 'cache_reap'
> 
> With this patch:
>   MODPOST vmlinux
> WARNING: mm/built-in.o - Section mismatch: reference to .init.text:set_up_list3s from .text between 'kmem_cache_create' (at offset 0x18a39) and 'cache_reap'
> WARNING: mm/built-in.o - Section mismatch: reference to .init.text:set_up_list3s from .text between 'kmem_cache_create' (at offset 0x18a6b) and 'cache_reap'
> 
> Now modpost can detect "kernel_init" name (and whitelist it) and show
> "set_up_list3s" name.

Applied.
It seems arm is impacted by the same.
Can you add arm support for the same?

	Sam


^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH] kbuild: make better section mismatch reports on i386 and mips
  2007-05-15 20:47 ` Sam Ravnborg
@ 2007-05-16 16:14   ` Atsushi Nemoto
  2007-05-17  7:07     ` Sam Ravnborg
  0 siblings, 1 reply; 4+ messages in thread
From: Atsushi Nemoto @ 2007-05-16 16:14 UTC (permalink / raw)
  To: sam; +Cc: linux-kernel, ralf, rmk

On Tue, 15 May 2007 22:47:54 +0200, Sam Ravnborg <sam@ravnborg.org> wrote:
> > Now modpost can detect "kernel_init" name (and whitelist it) and show
> > "set_up_list3s" name.
> 
> Applied.
> It seems arm is impacted by the same.
> Can you add arm support for the same?

OK, revised with ARM support (and minor cleanups).


Subject: [PATCH] kbuild: make better section mismatch reports on i386, arm and mips

On i386, ARM and MIPS, warn_sec_mismatch() sometimes fails to show
usefull symbol name.  This is because empty 'refsym' due to 0 r_addend
value.  This patch is to adjust r_addend value, consulting with
apply_relocate() routine in kernel code.

Without this patch:
  MODPOST vmlinux
WARNING: init/built-in.o - Section mismatch: reference to .init.text: from .text between 'rest_init' (at offset 0xf4) and 'try_name'
WARNING: mm/built-in.o - Section mismatch: reference to .init.text: from .text between 'kmem_cache_create' (at offset 0x18a39) and 'cache_reap'
WARNING: mm/built-in.o - Section mismatch: reference to .init.text: from .text between 'kmem_cache_create' (at offset 0x18a6b) and 'cache_reap'

With this patch:
  MODPOST vmlinux
WARNING: mm/built-in.o - Section mismatch: reference to .init.text:set_up_list3s from .text between 'kmem_cache_create' (at offset 0x18a39) and 'cache_reap'
WARNING: mm/built-in.o - Section mismatch: reference to .init.text:set_up_list3s from .text between 'kmem_cache_create' (at offset 0x18a6b) and 'cache_reap'

Now modpost can detect "kernel_init" name (and whitelist it) and show
"set_up_list3s" name.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
---
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 113dc77..4a67652 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -384,6 +384,7 @@ static int parse_elf(struct elf_info *info, const char *filename)
 		sechdrs[i].sh_size   = TO_NATIVE(sechdrs[i].sh_size);
 		sechdrs[i].sh_link   = TO_NATIVE(sechdrs[i].sh_link);
 		sechdrs[i].sh_name   = TO_NATIVE(sechdrs[i].sh_name);
+		sechdrs[i].sh_info   = TO_NATIVE(sechdrs[i].sh_info);
 	}
 	/* Find symbol table. */
 	for (i = 1; i < hdr->e_shnum; i++) {
@@ -773,6 +774,8 @@ static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf_Addr addr,
 	for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
 		if (sym->st_shndx != relsym->st_shndx)
 			continue;
+		if (ELF_ST_TYPE(sym->st_info) == STT_SECTION)
+			continue;
 		if (sym->st_value == addr)
 			return sym;
 	}
@@ -911,6 +914,68 @@ static void warn_sec_mismatch(const char *modname, const char *fromsec,
 	}
 }
 
+static void addend_386_rel(struct elf_info *elf, int section, Elf_Rela *r)
+{
+	Elf_Shdr *sechdrs = elf->sechdrs;
+	unsigned int r_typ;
+	unsigned int *location;
+
+	r_typ = ELF_R_TYPE(r->r_info);
+	location = (void *)elf->hdr +
+		sechdrs[sechdrs[section].sh_info].sh_offset + r->r_offset;
+	switch (r_typ) {
+	case R_386_32:
+		r->r_addend = TO_NATIVE(*location);
+		break;
+	case R_386_PC32:
+		r->r_addend = TO_NATIVE(*location) + 4;
+		break;
+	}
+}
+
+static void addend_arm_rel(struct elf_info *elf, int section, Elf_Rela *r)
+{
+	Elf_Shdr *sechdrs = elf->sechdrs;
+	unsigned int r_typ;
+	unsigned int *location;
+
+	r_typ = ELF_R_TYPE(r->r_info);
+	location = (void *)elf->hdr +
+		sechdrs[sechdrs[section].sh_info].sh_offset + r->r_offset;
+	switch (r_typ) {
+	case R_ARM_ABS32:
+		r->r_addend = TO_NATIVE(*location);
+		break;
+	case R_ARM_PC24:
+		r->r_addend = ((TO_NATIVE(*location) & 0x00ffffff) << 2) + 8;
+		break;
+	}
+}
+
+static int addend_mips_rel(struct elf_info *elf, int section, Elf_Rela *r)
+{
+	Elf_Shdr *sechdrs = elf->sechdrs;
+	unsigned int r_typ;
+	unsigned int *location;
+	unsigned int inst;
+
+	r_typ = ELF_R_TYPE(r->r_info);
+	if (r_typ == R_MIPS_HI16)
+		return 1;	/* skip this */
+	location = (void *)elf->hdr +
+		sechdrs[sechdrs[section].sh_info].sh_offset + r->r_offset;
+	inst = TO_NATIVE(*location);
+	switch (r_typ) {
+	case R_MIPS_LO16:
+		r->r_addend = ((inst & 0xffff) ^ 0x8000) - 0x8000;
+		break;
+	case R_MIPS_26:
+		r->r_addend = (inst & 0x03ffffff) << 2;
+		break;
+	}
+	return 0;
+}
+
 /**
  * A module includes a number of sections that are discarded
  * either when loaded or when used as built-in.
@@ -954,8 +1019,11 @@ static void check_sec_ref(struct module *mod, const char *modname,
 				r.r_offset = TO_NATIVE(rela->r_offset);
 #if KERNEL_ELFCLASS == ELFCLASS64
 				if (hdr->e_machine == EM_MIPS) {
+					unsigned int r_typ;
 					r_sym = ELF64_MIPS_R_SYM(rela->r_info);
 					r_sym = TO_NATIVE(r_sym);
+					r_typ = ELF64_MIPS_R_TYPE(rela->r_info);
+					r.r_info = ELF64_R_INFO(r_sym, r_typ);
 				} else {
 					r.r_info = TO_NATIVE(rela->r_info);
 					r_sym = ELF_R_SYM(r.r_info);
@@ -988,8 +1056,11 @@ static void check_sec_ref(struct module *mod, const char *modname,
 				r.r_offset = TO_NATIVE(rel->r_offset);
 #if KERNEL_ELFCLASS == ELFCLASS64
 				if (hdr->e_machine == EM_MIPS) {
+					unsigned int r_typ;
 					r_sym = ELF64_MIPS_R_SYM(rel->r_info);
 					r_sym = TO_NATIVE(r_sym);
+					r_typ = ELF64_MIPS_R_TYPE(rel->r_info);
+					r.r_info = ELF64_R_INFO(r_sym, r_typ);
 				} else {
 					r.r_info = TO_NATIVE(rel->r_info);
 					r_sym = ELF_R_SYM(r.r_info);
@@ -999,6 +1070,14 @@ static void check_sec_ref(struct module *mod, const char *modname,
 				r_sym = ELF_R_SYM(r.r_info);
 #endif
 				r.r_addend = 0;
+				if (hdr->e_machine == EM_386)
+					addend_386_rel(elf, i, &r);
+				else if (hdr->e_machine == EM_ARM)
+					addend_arm_rel(elf, i, &r);
+				else if (hdr->e_machine == EM_MIPS) {
+					if (addend_mips_rel(elf, i, &r))
+						continue;
+				}
 				sym = elf->symtab_start + r_sym;
 				/* Skip special sections */
 				if (sym->st_shndx >= SHN_LORESERVE)
diff --git a/scripts/mod/modpost.h b/scripts/mod/modpost.h
index 0858caa..4156dd3 100644
--- a/scripts/mod/modpost.h
+++ b/scripts/mod/modpost.h
@@ -60,6 +60,9 @@ typedef union
 #define ELF64_MIPS_R_SYM(i) \
   ((__extension__ (_Elf64_Mips_R_Info_union)(i)).r_info_fields.r_sym)
 
+#define ELF64_MIPS_R_TYPE(i) \
+  ((__extension__ (_Elf64_Mips_R_Info_union)(i)).r_info_fields.r_type1)
+
 #if KERNEL_ELFDATA != HOST_ELFDATA
 
 static inline void __endian(const void *src, void *dest, unsigned int size)

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH] kbuild: make better section mismatch reports on i386 and mips
  2007-05-16 16:14   ` Atsushi Nemoto
@ 2007-05-17  7:07     ` Sam Ravnborg
  0 siblings, 0 replies; 4+ messages in thread
From: Sam Ravnborg @ 2007-05-17  7:07 UTC (permalink / raw)
  To: Atsushi Nemoto; +Cc: linux-kernel, ralf, rmk

On Thu, May 17, 2007 at 01:14:38AM +0900, Atsushi Nemoto wrote:
> On Tue, 15 May 2007 22:47:54 +0200, Sam Ravnborg <sam@ravnborg.org> wrote:
> > > Now modpost can detect "kernel_init" name (and whitelist it) and show
> > > "set_up_list3s" name.
> > 
> > Applied.
> > It seems arm is impacted by the same.
> > Can you add arm support for the same?
> 
> OK, revised with ARM support (and minor cleanups).

Thanks, I added this patch instead.
Tested on arm and it works.

	Sam

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2007-05-17  7:06 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2007-05-14 15:40 [PATCH] kbuild: make better section mismatch reports on i386 and mips Atsushi Nemoto
2007-05-15 20:47 ` Sam Ravnborg
2007-05-16 16:14   ` Atsushi Nemoto
2007-05-17  7:07     ` Sam Ravnborg

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox

Powered by JetHome