[PATCH] xen/common: Use const char * for string literals

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

For pre-ANSI-C compatibility reasons, string literals have a mutable type, but
it is undefined behaviour to mutate them.

Swap char *'s to const char *'s for variables which hold string literals.

This fixes several violations of MISRA Rule 7.4:

  A string literal shall not be assigned to an object unless the object's type
  is "pointer to const-qualified char".

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
CC: George Dunlap <George.Dunlap@xxxxxxxxxxxxx>
CC: Jan Beulich <JBeulich@xxxxxxxx>
CC: Stefano Stabellini <sstabellini@xxxxxxxxxx>
CC: Wei Liu <wl@xxxxxxx>
CC: Julien Grall <julien@xxxxxxx>
CC: Roberto Bagnara <roberto.bagnara@xxxxxxxxxxx>
CC: Nicola Vetrini <nicola.vetrini@xxxxxxxxxxx>
---
 xen/common/gunzip.c                | 2 +-
 xen/common/ioreq.c                 | 3 ++-
 xen/common/libelf/libelf-dominfo.c | 2 +-
 3 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/xen/common/gunzip.c b/xen/common/gunzip.c
index b810499be2b6..2c6eae167d54 100644
--- a/xen/common/gunzip.c
+++ b/xen/common/gunzip.c
@@ -52,7 +52,7 @@ typedef unsigned long   ulg;
 static long __initdata bytes_out;
 static void flush_window(void);
 
-static __init void error(char *x)
+static __init void error(const char *x)
 {
     panic("%s\n", x);
 }
diff --git a/xen/common/ioreq.c b/xen/common/ioreq.c
index ecb8f545e1c4..7cb717f7a2a4 100644
--- a/xen/common/ioreq.c
+++ b/xen/common/ioreq.c
@@ -501,7 +501,8 @@ static int ioreq_server_alloc_rangesets(struct ioreq_server 
*s,
 
     for ( i = 0; i < NR_IO_RANGE_TYPES; i++ )
     {
-        char *name, *type;
+        const char *type;
+        char *name;
 
         switch ( i )
         {
diff --git a/xen/common/libelf/libelf-dominfo.c 
b/xen/common/libelf/libelf-dominfo.c
index fcaee2f7bcff..a13a5e4db603 100644
--- a/xen/common/libelf/libelf-dominfo.c
+++ b/xen/common/libelf/libelf-dominfo.c
@@ -100,7 +100,7 @@ elf_errorstatus elf_xen_parse_note(struct elf_binary *elf,
 {
 /* *INDENT-OFF* */
     static const struct {
-        char *name;
+        const char *name;
         bool str;
     } note_desc[] = {
         [XEN_ELFNOTE_ENTRY] = { "ENTRY", 0},
-- 
2.30.2