[U-Boot] [PATCH v3] board_r - fixup functions table after relocation
This is only required for "PIC" relocation and doesn't apply to modern "PIE" relocation which does data relocation as well as code.
"init_sequence_r" is just an array that consists of compile-time adresses of init functions. Since this is basically an array of integers (pointers to "void" to be more precise) it won't be modified during relocation - it will be just copied to new location as it is.
As a consequence on execution after relocation "initcall_run_list" will be jumping to pre-relocation addresses. As long as we don't overwrite pre-relocation memory area init calls are executed correctly. But still it is dangerous because after relocation we don't expect initially used memory to stay untouched.
Signed-off-by: Alexey Brodkin abrodkin@synopsys.com
Cc: Tom Rini trini@ti.com Cc: Simon Glass sjg@chromium.org Cc: Masahiro Yamada yamada.m@jp.panasonic.com Cc: Doug Anderson dianders@chromium.org Cc: Thomas Langer thomas.langer@lantiq.com Cc: Albert ARIBAUD albert.u.boot@aribaud.net
Changes to v2: * Use ARRAY_SIZE as suggested by Simon Glass * Added CONFIG_NEEDS_MANUAL_RELOC wrapper for temporary index variable "i" to fix compile-time warning for boards without CONFIG_NEEDS_MANUAL_RELOC --- common/board_r.c | 10 ++++++++++ 1 file changed, 10 insertions(+)
diff --git a/common/board_r.c b/common/board_r.c index 86ca1cb..c2d0763 100644 --- a/common/board_r.c +++ b/common/board_r.c @@ -903,9 +903,19 @@ init_fnc_t init_sequence_r[] = {
void board_init_r(gd_t *new_gd, ulong dest_addr) { +#ifdef CONFIG_NEEDS_MANUAL_RELOC + int i; +#endif + #ifndef CONFIG_X86 gd = new_gd; #endif + +#ifdef CONFIG_NEEDS_MANUAL_RELOC + for (i = 0; i < ARRAY_SIZE(init_sequence_r); i++) + init_sequence_r[i] += gd->reloc_off; +#endif + if (initcall_run_list(init_sequence_r)) hang();
Hi,
On 20 January 2014 03:30, Alexey Brodkin abrodkin@synopsys.com wrote:
This is only required for "PIC" relocation and doesn't apply to modern "PIE" relocation which does data relocation as well as code.
"init_sequence_r" is just an array that consists of compile-time adresses of init functions. Since this is basically an array of integers (pointers to "void" to be more precise) it won't be modified during relocation - it will be just copied to new location as it is.
As a consequence on execution after relocation "initcall_run_list" will be jumping to pre-relocation addresses. As long as we don't overwrite pre-relocation memory area init calls are executed correctly. But still it is dangerous because after relocation we don't expect initially used memory to stay untouched.
Signed-off-by: Alexey Brodkin abrodkin@synopsys.com
It's unfortunate that we need to carry over CONFIG_NEEDS_MANUAL_RELOC to the new common board init code. But if we do, this patch looks reasonable, so:
Acked-by: Simon Glass sjg@chromium.org
Cc: Tom Rini trini@ti.com Cc: Simon Glass sjg@chromium.org Cc: Masahiro Yamada yamada.m@jp.panasonic.com Cc: Doug Anderson dianders@chromium.org Cc: Thomas Langer thomas.langer@lantiq.com Cc: Albert ARIBAUD albert.u.boot@aribaud.net
Changes to v2:
- Use ARRAY_SIZE as suggested by Simon Glass
- Added CONFIG_NEEDS_MANUAL_RELOC wrapper for temporary index variable
"i" to fix compile-time warning for boards without CONFIG_NEEDS_MANUAL_RELOC
common/board_r.c | 10 ++++++++++ 1 file changed, 10 insertions(+)
diff --git a/common/board_r.c b/common/board_r.c index 86ca1cb..c2d0763 100644 --- a/common/board_r.c +++ b/common/board_r.c @@ -903,9 +903,19 @@ init_fnc_t init_sequence_r[] = {
void board_init_r(gd_t *new_gd, ulong dest_addr) { +#ifdef CONFIG_NEEDS_MANUAL_RELOC
int i;+#endif
#ifndef CONFIG_X86 gd = new_gd; #endif
+#ifdef CONFIG_NEEDS_MANUAL_RELOC
for (i = 0; i < ARRAY_SIZE(init_sequence_r); i++)init_sequence_r[i] += gd->reloc_off;+#endif
if (initcall_run_list(init_sequence_r)) hang();-- 1.8.4.2
Hi Simon,
On Tue, 2014-01-21 at 09:13 -0700, Simon Glass wrote:
Hi,
It's unfortunate that we need to carry over CONFIG_NEEDS_MANUAL_RELOC to the new common board init code. But if we do, this patch looks reasonable, so:
I think as long as PIC relocation is supported in U-Boot (for some architectures) it's good to accept fixes for it. And I have to confess that this kind of fixes are missing in many other places.
That's why I switched to PIE as well so this particular patch doesn't change anything for me now. But for those who still use PIC it might be helpful - that's why I did another re-spin.
-Alexey
On Mon, Jan 20, 2014 at 02:30:39PM +0400, Alexey Brodkin wrote:
This is only required for "PIC" relocation and doesn't apply to modern "PIE" relocation which does data relocation as well as code.
"init_sequence_r" is just an array that consists of compile-time adresses of init functions. Since this is basically an array of integers (pointers to "void" to be more precise) it won't be modified during relocation - it will be just copied to new location as it is.
As a consequence on execution after relocation "initcall_run_list" will be jumping to pre-relocation addresses. As long as we don't overwrite pre-relocation memory area init calls are executed correctly. But still it is dangerous because after relocation we don't expect initially used memory to stay untouched.
Signed-off-by: Alexey Brodkin abrodkin@synopsys.com
Cc: Tom Rini trini@ti.com Cc: Simon Glass sjg@chromium.org Cc: Masahiro Yamada yamada.m@jp.panasonic.com Cc: Doug Anderson dianders@chromium.org Cc: Thomas Langer thomas.langer@lantiq.com Cc: Albert ARIBAUD albert.u.boot@aribaud.net
Applied to u-boot/master, thanks!
participants (3)
-
Alexey Brodkin -
Simon Glass -
Tom Rini