From: Alexander Gordeev <agordeev@linux.ibm.com>
Date: Sat, 29 Jan 2022 07:38:56 +0000 (+0100)
Subject: s390/dump: fix old lowcore virtual vs physical address confusion
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=dc306186a130c6d9feb0aabc1c71b8ed1674a3bf;p=linux.git

s390/dump: fix old lowcore virtual vs physical address confusion

Virtual addresses of vmcore_info and os_info members are
wrongly passed to copy_oldmem_kernel(), while the function
expects physical address of the source. Instead, __pa()
macro should have been applied.

Yet, use of __pa() macro could be somehow confusing, since
copy_oldmem_kernel() may treat the source as an offset, not
as a direct physical address (that depens from the oldmem
availability and location).

Fix the virtual vs physical address confusion and make the
way the old lowcore is read consistent across all sources.

Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
---

diff --git a/arch/s390/kernel/asm-offsets.c b/arch/s390/kernel/asm-offsets.c
index 8e00bb2286623..a496b08ea5d14 100644
--- a/arch/s390/kernel/asm-offsets.c
+++ b/arch/s390/kernel/asm-offsets.c
@@ -131,6 +131,8 @@ int main(void)
 	OFFSET(__LC_LAST_BREAK, lowcore, last_break);
 	/* software defined ABI-relevant lowcore locations 0xe00 - 0xe20 */
 	OFFSET(__LC_DUMP_REIPL, lowcore, ipib);
+	OFFSET(__LC_VMCORE_INFO, lowcore, vmcore_info);
+	OFFSET(__LC_OS_INFO, lowcore, os_info);
 	/* hardware defined lowcore locations 0x1000 - 0x18ff */
 	OFFSET(__LC_MCESAD, lowcore, mcesad);
 	OFFSET(__LC_EXT_PARAMS2, lowcore, ext_params2);
diff --git a/arch/s390/kernel/crash_dump.c b/arch/s390/kernel/crash_dump.c
index af82021216423..a62bee83a88bb 100644
--- a/arch/s390/kernel/crash_dump.c
+++ b/arch/s390/kernel/crash_dump.c
@@ -432,7 +432,7 @@ static void *get_vmcoreinfo_old(unsigned long *size)
 	Elf64_Nhdr note;
 	void *addr;
 
-	if (copy_oldmem_kernel(&addr, &S390_lowcore.vmcore_info, sizeof(addr)))
+	if (copy_oldmem_kernel(&addr, (void *)__LC_VMCORE_INFO, sizeof(addr)))
 		return NULL;
 	memset(nt_name, 0, sizeof(nt_name));
 	if (copy_oldmem_kernel(&note, addr, sizeof(note)))
diff --git a/arch/s390/kernel/os_info.c b/arch/s390/kernel/os_info.c
index fa2be71b2c6bb..a2b08d3f53ec8 100644
--- a/arch/s390/kernel/os_info.c
+++ b/arch/s390/kernel/os_info.c
@@ -15,6 +15,7 @@
 #include <asm/checksum.h>
 #include <asm/lowcore.h>
 #include <asm/os_info.h>
+#include <asm/asm-offsets.h>
 
 /*
  * OS info structure has to be page aligned
@@ -123,7 +124,7 @@ static void os_info_old_init(void)
 		return;
 	if (!oldmem_data.start)
 		goto fail;
-	if (copy_oldmem_kernel(&addr, &S390_lowcore.os_info, sizeof(addr)))
+	if (copy_oldmem_kernel(&addr, (void *)__LC_OS_INFO, sizeof(addr)))
 		goto fail;
 	if (addr == 0 || addr % PAGE_SIZE)
 		goto fail;