Fix array-bound compilation warnings

Resolves : the warray bounds warning during compilation

/build/libc/include/string.h:34:16: warning: '__builtin_memset' offset [0, 2097151] is out of the bounds [0, 0] [-Warray-bounds]
34 | #define memset __builtin_memset
hw/fsp/fsp.c:1855:9: note: in expansion of macro 'memset'
1855 | memset(fsp_tce_table, 0, PSI_TCE_TABLE_SIZE);

use volatile pointer to avoid optimization introduced with gcc-11 on constant
address assignment to pointer.

Signed-off-by: Abhishek Singh Tomar <abhishek@linux.ibm.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>

8 files changed, 29 insertions, 10 deletions

diff --git a/core/console.c b/core/console.c
index 2a15090..374ee03 100644
--- a/core/console.c
+++ b/core/console.c
@@ -15,7 +15,7 @@
 #include <processor.h>
 #include <cpu.h>
 
-static char *con_buf = (char *)INMEM_CON_START;
+static char *skiboot_constant_addr con_buf = (char *)INMEM_CON_START;
 static size_t con_in;
 static size_t con_out;
 static bool con_wrapped;
diff --git a/core/fast-reboot.c b/core/fast-reboot.c
index fedfa88..6f6ef3a 100644
--- a/core/fast-reboot.c
+++ b/core/fast-reboot.c
@@ -307,6 +307,8 @@ void __noreturn fast_reboot_entry(void);
 void __noreturn fast_reboot_entry(void)
 {
 	struct cpu_thread *cpu = this_cpu();
+	void *skiboot_constant_addr kerneal_load_base_addr = KERNEL_LOAD_BASE;
+	void *skiboot_constant_addr initramfs_load_base_addr = INITRAMFS_LOAD_BASE;
 
 	if (proc_gen == proc_gen_p8) {
 		/* We reset our ICP first ! Otherwise we might get stray
@@ -425,8 +427,8 @@ void __noreturn fast_reboot_entry(void)
 		 * Mambo may have embedded payload here, so don't clear
 		 * it at all.
 		 */
-		memset(KERNEL_LOAD_BASE, 0, KERNEL_LOAD_SIZE);
-		memset(INITRAMFS_LOAD_BASE, 0, INITRAMFS_LOAD_SIZE);
+		memset(kerneal_load_base_addr, 0, KERNEL_LOAD_SIZE);
+		memset(initramfs_load_base_addr, 0, INITRAMFS_LOAD_SIZE);
 	}
 
 	/* Start preloading kernel and ramdisk */
diff --git a/core/init.c b/core/init.c
index b4d3351..a1fd5f2 100644
--- a/core/init.c
+++ b/core/init.c
@@ -869,7 +869,11 @@ void copy_exception_vectors(void)
 	 * this is the boot flag used by CPUs still potentially entering
 	 * skiboot.
 	 */
-	memcpy((void *)0x100, (void *)(SKIBOOT_BASE + 0x100),
+	void *skiboot_constant_addr exception_vectors_start_addr = (void *)(SKIBOOT_BASE + 0x100);
+	void *skiboot_constant_addr dst = (void *)0x100;
+
+
+	memcpy(dst, exception_vectors_start_addr,
 			EXCEPTION_VECTORS_END - 0x100);
 	sync_icache();
 }
diff --git a/core/opal-dump.c b/core/opal-dump.c
index 4f54a3e..577a906 100644
--- a/core/opal-dump.c
+++ b/core/opal-dump.c
@@ -301,6 +301,7 @@ static int64_t opal_mpipl_update(enum opal_mpipl_ops ops,
 				 u64 src, u64 dest, u64 size)
 {
 	int rc;
+	void *skiboot_constant_addr mdrt_table_base_addr = (void *) MDRT_TABLE_BASE;
 
 	switch (ops) {
 	case OPAL_MPIPL_ADD_RANGE:
@@ -330,7 +331,7 @@ static int64_t opal_mpipl_update(enum opal_mpipl_ops ops,
 		free(opal_mpipl_cpu_data);
 		opal_mpipl_cpu_data = NULL;
 		/* Clear MDRT table */
-		memset((void *)MDRT_TABLE_BASE, 0, MDRT_TABLE_SIZE);
+		memset(mdrt_table_base_addr, 0, MDRT_TABLE_SIZE);
 		/* Set MDRT count to max allocated count */
 		ntuple_mdrt->act_cnt = cpu_to_be16(MDRT_TABLE_SIZE / sizeof(struct mdrt_table));
 		rc = OPAL_SUCCESS;
@@ -529,8 +530,8 @@ bool is_mpipl_enabled(void)
 
 void opal_mpipl_init(void)
 {
-	void *mdst_base = (void *)MDST_TABLE_BASE;
-	void *mddt_base = (void *)MDDT_TABLE_BASE;
+	void *skiboot_constant_addr mdst_base = (void *)MDST_TABLE_BASE;
+	void *skiboot_constant_addr mddt_base = (void *)MDDT_TABLE_BASE;
 	struct dt_node *dump_node;
 
 	dump_node = dt_find_by_path(opal_node, "dump");
diff --git a/hdata/spira.c b/hdata/spira.c
index 1a35146..fbb14b0 100644
--- a/hdata/spira.c
+++ b/hdata/spira.c
@@ -236,7 +236,7 @@ __section(".spirah.data") struct spirah spirah = {
 };
 
 /* The service processor SPIRA-S structure */
-struct spiras *spiras;
+struct spiras *skiboot_constant_addr spiras;
 
 /* Overridden for testing. */
 #ifndef spira_check_ptr
diff --git a/hdata/spira.h b/hdata/spira.h
index 8def23b..c0eb2a0 100644
--- a/hdata/spira.h
+++ b/hdata/spira.h
@@ -150,7 +150,7 @@ struct spiras {
 	u8			reserved[0x180];
 } __packed __align(0x100);
 
-extern struct spiras *spiras;
+extern struct spiras *skiboot_constant_addr spiras;
 
 
 /* This macro can be used to check the validity of a pointer returned
diff --git a/hw/fsp/fsp.c b/hw/fsp/fsp.c
index 2c5f9d7..2fd9e5f 100644
--- a/hw/fsp/fsp.c
+++ b/hw/fsp/fsp.c
@@ -91,7 +91,7 @@ static enum ipl_state ipl_state = ipl_initial;
 static struct fsp *first_fsp;
 static struct fsp *active_fsp;
 static u16 fsp_curseq = 0x8000;
-static __be64 *fsp_tce_table;
+static __be64 *skiboot_constant_addr fsp_tce_table;
 
 #define FSP_INBOUND_SIZE	0x00100000UL
 static void *fsp_inbound_buf = NULL;
diff --git a/include/compiler.h b/include/compiler.h
index a9ccfae..77821ec 100644
--- a/include/compiler.h
+++ b/include/compiler.h
@@ -38,4 +38,16 @@ static inline void barrier(void)
 #define __tostr(x)	#x
 #define tostr(x)	__tostr(x)
 
+
+#if __GNUC__ >= 11
+/* Compiler workaround to avoid compiler optimization warnings
+ * when assigning constant address to pointer and using memory
+ * functions such as memcpy and  memset
+ */
+#define skiboot_constant_addr          volatile
+#else
+#define skiboot_constant_addr
+#endif
+
+
 #endif /* __COMPILER_H */