[xen master] cmdline: parse multiple instances of the vga option

[patchbot@xxxxxxx]

commit 9473d9a241827b90b7f6db32b93e12bc77e2e44f
Author:     Roger Pau Monné <roger.pau@xxxxxxxxxx>
AuthorDate: Mon Jul 10 12:19:03 2023 +0200
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Mon Jul 10 12:19:03 2023 +0200

    cmdline: parse multiple instances of the vga option
    
    Parse all instances of the vga= option on the command line, in order
    to always enforce the last selection on the command line.
    
    Note that it's not safe to parse just the last occurrence of the vga=
    option, as then a command line with `vga=current vga=keep` would
    result in current being ignored.
    
    Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
    Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
---
 xen/arch/x86/boot/cmdline.c | 83 +++++++++++++++++++++++----------------------
 1 file changed, 42 insertions(+), 41 deletions(-)

diff --git a/xen/arch/x86/boot/cmdline.c b/xen/arch/x86/boot/cmdline.c
index fc11c6d3c5..10dcc6142c 100644
--- a/xen/arch/x86/boot/cmdline.c
+++ b/xen/arch/x86/boot/cmdline.c
@@ -277,59 +277,60 @@ static u16 rows2vmode(unsigned int rows)
 
 static void vga_parse(const char *cmdline, early_boot_opts_t *ebo)
 {
-    const char *c;
-    unsigned int tmp, vesa_depth, vesa_height, vesa_width;
-
-    c = find_opt(cmdline, "vga=", true);
-
-    if ( !c )
-        return;
+    const char *c = cmdline;
 
     ebo->boot_vid_mode = ASK_VGA;
 
-    if ( !strmaxcmp(c, "current", delim_chars_comma) )
-        ebo->boot_vid_mode = VIDEO_CURRENT_MODE;
-    else if ( !strsubcmp(c, "text-80x") )
-    {
-        c += strlen("text-80x");
-        ebo->boot_vid_mode = rows2vmode(strtoui(c, delim_chars_comma, NULL));
-    }
-    else if ( !strsubcmp(c, "gfx-") )
+    while ( (c = find_opt(c, "vga=", true)) != NULL )
     {
-        vesa_width = strtoui(c + strlen("gfx-"), "x", &c);
+        unsigned int tmp, vesa_depth, vesa_height, vesa_width;
+
+        if ( !strmaxcmp(c, "current", delim_chars_comma) )
+            ebo->boot_vid_mode = VIDEO_CURRENT_MODE;
+        else if ( !strsubcmp(c, "text-80x") )
+        {
+            c += strlen("text-80x");
+            ebo->boot_vid_mode = rows2vmode(strtoui(c, delim_chars_comma, 
NULL));
+        }
+        else if ( !strsubcmp(c, "gfx-") )
+        {
+            vesa_width = strtoui(c + strlen("gfx-"), "x", &c);
 
-        if ( vesa_width > U16_MAX )
-            return;
+            if ( vesa_width > U16_MAX )
+                return;
 
-        /*
-         * Increment c outside of strtoui() because otherwise some
-         * compiler may complain with following message:
-         * warning: operation on 'c' may be undefined.
-         */
-        ++c;
-        vesa_height = strtoui(c, "x", &c);
+            /*
+             * Increment c outside of strtoui() because otherwise some
+             * compiler may complain with following message:
+             * warning: operation on 'c' may be undefined.
+             */
+            ++c;
+            vesa_height = strtoui(c, "x", &c);
 
-        if ( vesa_height > U16_MAX )
-            return;
+            if ( vesa_height > U16_MAX )
+                return;
 
-        vesa_depth = strtoui(++c, delim_chars_comma, NULL);
+            vesa_depth = strtoui(++c, delim_chars_comma, NULL);
 
-        if ( vesa_depth > U16_MAX )
-            return;
+            if ( vesa_depth > U16_MAX )
+                return;
 
-        ebo->vesa_width = vesa_width;
-        ebo->vesa_height = vesa_height;
-        ebo->vesa_depth = vesa_depth;
-        ebo->boot_vid_mode = VIDEO_VESA_BY_SIZE;
-    }
-    else if ( !strsubcmp(c, "mode-") )
-    {
-        tmp = strtoui(c + strlen("mode-"), delim_chars_comma, NULL);
+            ebo->vesa_width = vesa_width;
+            ebo->vesa_height = vesa_height;
+            ebo->vesa_depth = vesa_depth;
+            ebo->boot_vid_mode = VIDEO_VESA_BY_SIZE;
+        }
+        else if ( !strsubcmp(c, "mode-") )
+        {
+            tmp = strtoui(c + strlen("mode-"), delim_chars_comma, NULL);
 
-        if ( tmp > U16_MAX )
-            return;
+            if ( tmp > U16_MAX )
+                return;
 
-        ebo->boot_vid_mode = tmp;
+            ebo->boot_vid_mode = tmp;
+        }
+        else if ( !strmaxcmp(c, "ask", delim_chars_comma) )
+            ebo->boot_vid_mode = ASK_VGA;
     }
 }
 #endif
--
generated by git-patchbot for /home/xen/git/xen.git#master