clang compilation fails with
lib/x86/fwcfg.c:32:3: error: array index 17 is past the end of the array (which contains 16 elements) [-Werror,-Warray-bounds]
fw_override[FW_CFG_MAX_RAM] = atol(str) * 1024 * 1024;
The reason is that FW_CFG_MAX_RAM does not exist in the fw-cfg spec and was
added for bare metal support. Fix the size of the array and rename FW_CFG_MAX_ENTRY
to FW_CFG_NUM_ENTRIES, so that it is clear that it must be one plus the
highest valid entry.
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
lib/x86/fwcfg.c | 6 +++---
lib/x86/fwcfg.h | 5 ++++-
2 files changed, 7 insertions(+), 4 deletions(-)
diff --git a/lib/x86/fwcfg.c b/lib/x86/fwcfg.c
index c2aaf5a..1734afb 100644
--- a/lib/x86/fwcfg.c
+++ b/lib/x86/fwcfg.c
@@ -4,7 +4,7 @@
static struct spinlock lock;
-static long fw_override[FW_CFG_MAX_ENTRY];
+static long fw_override[FW_CFG_NUM_ENTRIES];
static bool fw_override_done;
bool no_test_device;
@@ -15,7 +15,7 @@ static void read_cfg_override(void)
int i;
/* Initialize to negative value that would be considered as invalid */
- for (i = 0; i < FW_CFG_MAX_ENTRY; i++)
+ for (i = 0; i < FW_CFG_NUM_ENTRIES; i++)
fw_override[i] = -1;
if ((str = getenv("NR_CPUS")))
@@ -44,7 +44,7 @@ static uint64_t fwcfg_get_u(uint16_t index, int bytes)
if (!fw_override_done)
read_cfg_override();
- if (index < FW_CFG_MAX_ENTRY && fw_override[index] >= 0)
+ if (index < FW_CFG_NUM_ENTRIES && fw_override[index] >= 0)
return fw_override[index];
spin_lock(&lock);
diff --git a/lib/x86/fwcfg.h b/lib/x86/fwcfg.h
index 64d4c6e..ac4257e 100644
--- a/lib/x86/fwcfg.h
+++ b/lib/x86/fwcfg.h
@@ -20,9 +20,12 @@
#define FW_CFG_NUMA 0x0d
#define FW_CFG_BOOT_MENU 0x0e
#define FW_CFG_MAX_CPUS 0x0f
-#define FW_CFG_MAX_ENTRY 0x10
+
+/* Dummy entries used when running on bare metal */
#define FW_CFG_MAX_RAM 0x11
+#define FW_CFG_NUM_ENTRIES (FW_CFG_MAX_RAM + 1)
+
#define FW_CFG_WRITE_CHANNEL 0x4000
#define FW_CFG_ARCH_LOCAL 0x8000
#define FW_CFG_ENTRY_MASK ~(FW_CFG_WRITE_CHANNEL | FW_CFG_ARCH_LOCAL)
--
2.26.2
