[PATCH] lib: fwts_smbios: use fwts_safe_memcpy to read SMBIOS entry

[Colin King]

From: Colin Ian King <colin.king at canonical.com>

Use fwts_safe_memcpy rather than a fwts_safe_memread and then an
un-safe copy as a micro optimisation.  Also throw an error and
return a NULL address if the memcpy failed because the memory is
unreadable.  Fixes a bug on aarch64 systems where this entry is
non-readable and causes a BUS error.

Signed-off-by: Colin Ian King <colin.king at canonical.com>
---
 src/lib/src/fwts_smbios.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/src/lib/src/fwts_smbios.c b/src/lib/src/fwts_smbios.c
index b3773aa2..abef4eb6 100644
--- a/src/lib/src/fwts_smbios.c
+++ b/src/lib/src/fwts_smbios.c
@@ -56,13 +56,14 @@ static void *fwts_smbios_find_entry_uefi(fwts_framework *fw, fwts_smbios_entry *
 		const size_t size = sizeof(fwts_smbios_entry);
 
 		if ((mapped_entry = fwts_mmap((off_t)addr, size)) != FWTS_MAP_FAILED) {
-			if (fwts_safe_memread(mapped_entry, size) == FWTS_OK) {
-				*entry = *mapped_entry;
+			if (fwts_safe_memcpy(entry, mapped_entry, size) == FWTS_OK) {
 				(void)fwts_munmap(mapped_entry, size);
 				*type  = FWTS_SMBIOS;
 				return addr;
 			} else {
+				fwts_log_error(fw, "Cannot read mmap'd SMBIOS entry at 0x%p\n", addr);
 				(void)fwts_munmap(mapped_entry, size);
+				addr = NULL;
 			}
 		}
 
@@ -73,7 +74,7 @@ static void *fwts_smbios_find_entry_uefi(fwts_framework *fw, fwts_smbios_entry *
 			return addr;
 		}
 
-		fwts_log_error(fw, "Cannot mmap SMBIOS entry at %p\n", addr);
+		fwts_log_error(fw, "Cannot mmap SMBIOS entry at 0x%p\n", addr);
 	}
 	return NULL;
 }
-- 
2.11.0