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authorPhilipp Rudo <prudo@linux.ibm.com>2018-06-27 12:03:43 +0200
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2018-07-06 08:47:51 +0200
commit287d6070acbb2529e24462faffca46663885dddc (patch)
tree25a34c095e4d1983926043f92bf4ca5fb86e3141 /arch
parentc315e69308c739a43c4ebc539bedbc1ac8d79854 (diff)
s390/purgatory: Remove duplicate variable definitions
Currently there are some variables in the purgatory (e.g. kernel_entry) which are defined twice, once in assembler- and once in c-code. The reason for this is that these variables are set during purgatory load, where sanity checks on the corresponding Elf_Sym's are made, while they are used in assembler-code. Thus adding a second definition in c-code is a handy workaround to guarantee correct Elf_Sym's are created. When the purgatory is compiled with -fcommon (default for gcc on s390) this is no problem because both symbols are merged by the linker. However this is not required by ISO C and when the purgatory is built with -fno-common the linker fails with errors like arch/s390/purgatory/purgatory.o:(.bss+0x18): multiple definition of `kernel_entry' arch/s390/purgatory/head.o:/.../arch/s390/purgatory/head.S:230: first defined here Thus remove the duplicate definitions and add the required size and type information to the assembler definition. Also add -fno-common to the command line options to prevent similar hacks in the future. Signed-off-by: Philipp Rudo <prudo@linux.ibm.com> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/s390/include/asm/purgatory.h6
-rw-r--r--arch/s390/purgatory/Makefile2
-rw-r--r--arch/s390/purgatory/head.S45
-rw-r--r--arch/s390/purgatory/purgatory.c9
4 files changed, 20 insertions, 42 deletions
diff --git a/arch/s390/include/asm/purgatory.h b/arch/s390/include/asm/purgatory.h
index 6090670df51f..e297bcfc476f 100644
--- a/arch/s390/include/asm/purgatory.h
+++ b/arch/s390/include/asm/purgatory.h
@@ -13,11 +13,5 @@
int verify_sha256_digest(void);
-extern u64 kernel_entry;
-extern u64 kernel_type;
-
-extern u64 crash_start;
-extern u64 crash_size;
-
#endif /* __ASSEMBLY__ */
#endif /* _S390_PURGATORY_H_ */
diff --git a/arch/s390/purgatory/Makefile b/arch/s390/purgatory/Makefile
index abfa8c7a6d9a..8d61218a71aa 100644
--- a/arch/s390/purgatory/Makefile
+++ b/arch/s390/purgatory/Makefile
@@ -21,7 +21,7 @@ LDFLAGS_purgatory.ro += -z nodefaultlib
KBUILD_CFLAGS := -fno-strict-aliasing -Wall -Wstrict-prototypes
KBUILD_CFLAGS += -Wno-pointer-sign -Wno-sign-compare
KBUILD_CFLAGS += -fno-zero-initialized-in-bss -fno-builtin -ffreestanding
-KBUILD_CFLAGS += -c -MD -Os -m64 -msoft-float
+KBUILD_CFLAGS += -c -MD -Os -m64 -msoft-float -fno-common
KBUILD_CFLAGS += $(call cc-option,-fno-PIE)
KBUILD_AFLAGS := $(filter-out -DCC_USING_EXPOLINE,$(KBUILD_AFLAGS))
diff --git a/arch/s390/purgatory/head.S b/arch/s390/purgatory/head.S
index 660c96a05a9b..2e3707b12edd 100644
--- a/arch/s390/purgatory/head.S
+++ b/arch/s390/purgatory/head.S
@@ -243,33 +243,26 @@ gprregs:
.quad 0
.endr
-purgatory_sha256_digest:
- .global purgatory_sha256_digest
- .rept 32 /* SHA256_DIGEST_SIZE */
- .byte 0
- .endr
-
-purgatory_sha_regions:
- .global purgatory_sha_regions
- .rept 16 * __KEXEC_SHA_REGION_SIZE /* KEXEC_SEGMENTS_MAX */
- .byte 0
- .endr
-
-kernel_entry:
- .global kernel_entry
- .quad 0
-
-kernel_type:
- .global kernel_type
- .quad 0
-
-crash_start:
- .global crash_start
- .quad 0
+/* Macro to define a global variable with name and size (in bytes) to be
+ * shared with C code.
+ *
+ * Add the .size and .type attribute to satisfy checks on the Elf_Sym during
+ * purgatory load.
+ */
+.macro GLOBAL_VARIABLE name,size
+\name:
+ .global \name
+ .size \name,\size
+ .type \name,object
+ .skip \size,0
+.endm
-crash_size:
- .global crash_size
- .quad 0
+GLOBAL_VARIABLE purgatory_sha256_digest,32
+GLOBAL_VARIABLE purgatory_sha_regions,16*__KEXEC_SHA_REGION_SIZE
+GLOBAL_VARIABLE kernel_entry,8
+GLOBAL_VARIABLE kernel_type,8
+GLOBAL_VARIABLE crash_start,8
+GLOBAL_VARIABLE crash_size,8
.align PAGE_SIZE
stack:
diff --git a/arch/s390/purgatory/purgatory.c b/arch/s390/purgatory/purgatory.c
index 4e2beb3c29b7..3528e6da4e87 100644
--- a/arch/s390/purgatory/purgatory.c
+++ b/arch/s390/purgatory/purgatory.c
@@ -12,15 +12,6 @@
#include <linux/string.h>
#include <asm/purgatory.h>
-struct kexec_sha_region purgatory_sha_regions[KEXEC_SEGMENT_MAX];
-u8 purgatory_sha256_digest[SHA256_DIGEST_SIZE];
-
-u64 kernel_entry;
-u64 kernel_type;
-
-u64 crash_start;
-u64 crash_size;
-
int verify_sha256_digest(void)
{
struct kexec_sha_region *ptr, *end;

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