[PATCH] s390/kdump: Use "LINUX" ELF note name instead of "CORE" (v4.4)

[PATCH] s390/kdump: Use "LINUX" ELF note name instead of "CORE" (v4.4)

[Michael Holzheu]

Commit a4a81d8eebdc1d209d034f62a082a5131e4242b5 upstream

In binutils/libbfd (bfd/elf.c) it is enforced that all s390 specific ELF
notes like e.g. NT_S390_PREFIX or NT_S390_CTRS have "LINUX" specified
as note name. Otherwise the notes are ignored.

For /proc/vmcore we currently use "CORE" for these notes.

Up to now this has not been a real problem because the dump analysis tool
"crash" does not check the note name. But it will break all programs that
use libbfd for processing ELF notes.

So fix this and use "LINUX" for all s390 specific notes to comply with
libbfd.

Cc: stable@vger.kernel.org # v4.4
Reported-by: Philipp Rudo <prudo@linux.vnet.ibm.com>
Reviewed-by: Philipp Rudo <prudo@linux.vnet.ibm.com>
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
---
* Requested versions for stable: v4.4
* Justification: Bug breaks all programs using libbfd
---
 arch/s390/kernel/crash_dump.c | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/arch/s390/kernel/crash_dump.c b/arch/s390/kernel/crash_dump.c
index 171e09b..f7c3a61 100644
--- a/arch/s390/kernel/crash_dump.c
+++ b/arch/s390/kernel/crash_dump.c
@@ -23,6 +23,8 @@
 #define PTR_SUB(x, y) (((char *) (x)) - ((unsigned long) (y)))
 #define PTR_DIFF(x, y) ((unsigned long)(((char *) (x)) - ((unsigned long) (y))))
 
+#define LINUX_NOTE_NAME "LINUX"
+
 static struct memblock_region oldmem_region;
 
 static struct memblock_type oldmem_type = {
@@ -312,7 +314,7 @@ static void *nt_fpregset(void *ptr, struct save_area *sa)
 static void *nt_s390_timer(void *ptr, struct save_area *sa)
 {
 	return nt_init(ptr, NT_S390_TIMER, &sa->timer, sizeof(sa->timer),
-			 KEXEC_CORE_NOTE_NAME);
+			 LINUX_NOTE_NAME);
 }
 
 /*
@@ -321,7 +323,7 @@ static void *nt_s390_timer(void *ptr, struct save_area *sa)
 static void *nt_s390_tod_cmp(void *ptr, struct save_area *sa)
 {
 	return nt_init(ptr, NT_S390_TODCMP, &sa->clk_cmp,
-		       sizeof(sa->clk_cmp), KEXEC_CORE_NOTE_NAME);
+		       sizeof(sa->clk_cmp), LINUX_NOTE_NAME);
 }
 
 /*
@@ -330,7 +332,7 @@ static void *nt_s390_tod_cmp(void *ptr, struct save_area *sa)
 static void *nt_s390_tod_preg(void *ptr, struct save_area *sa)
 {
 	return nt_init(ptr, NT_S390_TODPREG, &sa->tod_reg,
-		       sizeof(sa->tod_reg), KEXEC_CORE_NOTE_NAME);
+		       sizeof(sa->tod_reg), LINUX_NOTE_NAME);
 }
 
 /*
@@ -339,7 +341,7 @@ static void *nt_s390_tod_preg(void *ptr, struct save_area *sa)
 static void *nt_s390_ctrs(void *ptr, struct save_area *sa)
 {
 	return nt_init(ptr, NT_S390_CTRS, &sa->ctrl_regs,
-		       sizeof(sa->ctrl_regs), KEXEC_CORE_NOTE_NAME);
+		       sizeof(sa->ctrl_regs), LINUX_NOTE_NAME);
 }
 
 /*
@@ -348,7 +350,7 @@ static void *nt_s390_ctrs(void *ptr, struct save_area *sa)
 static void *nt_s390_prefix(void *ptr, struct save_area *sa)
 {
 	return nt_init(ptr, NT_S390_PREFIX, &sa->pref_reg,
-			 sizeof(sa->pref_reg), KEXEC_CORE_NOTE_NAME);
+			 sizeof(sa->pref_reg), LINUX_NOTE_NAME);
 }
 
 /*
@@ -357,7 +359,7 @@ static void *nt_s390_prefix(void *ptr, struct save_area *sa)
 static void *nt_s390_vx_high(void *ptr, __vector128 *vx_regs)
 {
 	return nt_init(ptr, NT_S390_VXRS_HIGH, &vx_regs[16],
-		       16 * sizeof(__vector128), KEXEC_CORE_NOTE_NAME);
+		       16 * sizeof(__vector128), LINUX_NOTE_NAME);
 }
 
 /*
@@ -370,12 +372,12 @@ static void *nt_s390_vx_low(void *ptr, __vector128 *vx_regs)
 	int i;
 
 	note = (Elf64_Nhdr *)ptr;
-	note->n_namesz = strlen(KEXEC_CORE_NOTE_NAME) + 1;
+	note->n_namesz = strlen(LINUX_NOTE_NAME) + 1;
 	note->n_descsz = 16 * 8;
 	note->n_type = NT_S390_VXRS_LOW;
 	len = sizeof(Elf64_Nhdr);
 
-	memcpy(ptr + len, KEXEC_CORE_NOTE_NAME, note->n_namesz);
+	memcpy(ptr + len, LINUX_NOTE_NAME, note->n_namesz);
 	len = roundup(len + note->n_namesz, 4);
 
 	ptr += len;
-- 
2.8.4