* [PATCH] ARC: Fix linking errors with CONFIG_MODULE + CONFIG_CC_OPTIMIZE_FOR_SIZE
@ 2015-12-21 7:24 ` Vineet Gupta
0 siblings, 0 replies; 2+ messages in thread
From: Vineet Gupta @ 2015-12-21 7:24 UTC (permalink / raw)
To: linux-snps-arc; +Cc: Vineet Gupta, Michal Marek, linux-kernel
At -Os, ARC gcc generates millicode thunk for function prologue/epilogue,
which are served by libgcc.
Modules historically are NOT linked with libgcc to avoid code bloat, reducing
runtime relocation fixups etc. I even once tried doign that but got lost
in makefile intricacies.
However CONFIG_MODULE + CONFIG_CC_OPTIMIZE_FOR_SIZE causes link errors
| MODPOST 5 modules
| ERROR: "__ld_r13_to_r18" [crypto/sha256_generic.ko] undefined!
| ERROR: "__ld_r13_to_r18_ret" [crypto/sha256_generic.ko] undefined!
| ERROR: "__st_r13_to_r18" [crypto/sha256_generic.ko] undefined!
| ERROR: "__ld_r13_to_r17_ret" [crypto/sha256_generic.ko] undefined!
| ERROR: "__st_r13_to_r17" [crypto/sha256_generic.ko] undefined!
| ERROR: "__ld_r13_to_r16_ret" [crypto/sha256_generic.ko] undefined!
| ERROR: "__st_r13_to_r16" [crypto/sha256_generic.ko] undefined!
|....
|....
Workaround that by inhibiting millicode thunks for loadable modules
Fixes STAR 9000641864:
("Linux built with optimizations for size emits errors for modules")
Reported-by: Anton Kolesov <akolesov@synosys.com>
Cc: Michal Marek <mmarek@suse.cz>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
---
arch/arc/Makefile | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arc/Makefile b/arch/arc/Makefile
index cf0cf34eeb24..aeb19021099e 100644
--- a/arch/arc/Makefile
+++ b/arch/arc/Makefile
@@ -81,7 +81,7 @@ endif
LIBGCC := $(shell $(CC) $(cflags-y) --print-libgcc-file-name)
# Modules with short calls might break for calls into builtin-kernel
-KBUILD_CFLAGS_MODULE += -mlong-calls
+KBUILD_CFLAGS_MODULE += -mlong-calls -mno-millicode
# Finally dump eveything into kernel build system
KBUILD_CFLAGS += $(cflags-y)
--
1.9.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* [PATCH] ARC: Fix linking errors with CONFIG_MODULE + CONFIG_CC_OPTIMIZE_FOR_SIZE
@ 2015-12-21 7:24 ` Vineet Gupta
0 siblings, 0 replies; 2+ messages in thread
From: Vineet Gupta @ 2015-12-21 7:24 UTC (permalink / raw)
To: linux-snps-arc
At -Os, ARC gcc generates millicode thunk for function prologue/epilogue,
which are served by libgcc.
Modules historically are NOT linked with libgcc to avoid code bloat, reducing
runtime relocation fixups etc. I even once tried doign that but got lost
in makefile intricacies.
However CONFIG_MODULE + CONFIG_CC_OPTIMIZE_FOR_SIZE causes link errors
| MODPOST 5 modules
| ERROR: "__ld_r13_to_r18" [crypto/sha256_generic.ko] undefined!
| ERROR: "__ld_r13_to_r18_ret" [crypto/sha256_generic.ko] undefined!
| ERROR: "__st_r13_to_r18" [crypto/sha256_generic.ko] undefined!
| ERROR: "__ld_r13_to_r17_ret" [crypto/sha256_generic.ko] undefined!
| ERROR: "__st_r13_to_r17" [crypto/sha256_generic.ko] undefined!
| ERROR: "__ld_r13_to_r16_ret" [crypto/sha256_generic.ko] undefined!
| ERROR: "__st_r13_to_r16" [crypto/sha256_generic.ko] undefined!
|....
|....
Workaround that by inhibiting millicode thunks for loadable modules
Fixes STAR 9000641864:
("Linux built with optimizations for size emits errors for modules")
Reported-by: Anton Kolesov <akolesov at synosys.com>
Cc: Michal Marek <mmarek at suse.cz>
Cc: linux-kernel at vger.kernel.org
Signed-off-by: Vineet Gupta <vgupta at synopsys.com>
---
arch/arc/Makefile | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arc/Makefile b/arch/arc/Makefile
index cf0cf34eeb24..aeb19021099e 100644
--- a/arch/arc/Makefile
+++ b/arch/arc/Makefile
@@ -81,7 +81,7 @@ endif
LIBGCC := $(shell $(CC) $(cflags-y) --print-libgcc-file-name)
# Modules with short calls might break for calls into builtin-kernel
-KBUILD_CFLAGS_MODULE += -mlong-calls
+KBUILD_CFLAGS_MODULE += -mlong-calls -mno-millicode
# Finally dump eveything into kernel build system
KBUILD_CFLAGS += $(cflags-y)
--
1.9.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
end of thread, other threads:[~2015-12-21 7:25 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2015-12-21 7:24 [PATCH] ARC: Fix linking errors with CONFIG_MODULE + CONFIG_CC_OPTIMIZE_FOR_SIZE Vineet Gupta
2015-12-21 7:24 ` Vineet Gupta
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.