[Qemu-devel] [PATCH] multiboot: copy the cmdline verbatim, unescape module strings

[Qemu-devel] [PATCH] multiboot: copy the cmdline verbatim, unescape module strings

[Vlad Lungu]

get_opt_value() truncates the value at the first comma
Rename mb_add_cmdline() to mb_add_modstring()
Unescape filename too
Add new mb_add_cmdline() using  memcpy()

Signed-off-by: Vlad Lungu <vlad.lungu@windriver.com>
---
 hw/i386/multiboot.c | 23 +++++++++++++++++------
 1 file changed, 17 insertions(+), 6 deletions(-)

diff --git a/hw/i386/multiboot.c b/hw/i386/multiboot.c
index 387caa6..bfb52fc 100644
--- a/hw/i386/multiboot.c
+++ b/hw/i386/multiboot.c
@@ -109,6 +109,16 @@ static uint32_t mb_add_cmdline(MultibootState *s, const char *cmdline)
     hwaddr p = s->offset_cmdlines;
     char *b = (char *)s->mb_buf + p;
 
+    memcpy(b, cmdline, strlen(cmdline) + 1);
+    s->offset_cmdlines += strlen(b) + 1;
+    return s->mb_buf_phys + p;
+}
+
+static uint32_t mb_add_modstring(MultibootState *s, const char *cmdline)
+{
+    hwaddr p = s->offset_cmdlines;
+    char *b = (char *)s->mb_buf + p;
+
     get_opt_value(b, strlen(cmdline) + 1, cmdline);
     s->offset_cmdlines += strlen(b) + 1;
     return s->mb_buf_phys + p;
@@ -287,7 +297,7 @@ int load_multiboot(FWCfgState *fw_cfg,
     mbs.offset_bootloader = mbs.offset_cmdlines + cmdline_len;
 
     if (initrd_filename) {
-        char *next_initrd, not_last;
+        char *next_initrd, not_last, tmpbuf[strlen(initrd_filename) + 1];
 
         mbs.offset_mods = mbs.mb_buf_size;
 
@@ -301,20 +311,21 @@ int load_multiboot(FWCfgState *fw_cfg,
             *next_initrd = '\0';
             /* if a space comes after the module filename, treat everything
                after that as parameters */
-            hwaddr c = mb_add_cmdline(&mbs, initrd_filename);
+            hwaddr c = mb_add_modstring(&mbs, initrd_filename);
             if ((next_space = strchr(initrd_filename, ' ')))
                 *next_space = '\0';
-            mb_debug("multiboot loading module: %s\n", initrd_filename);
-            mb_mod_length = get_image_size(initrd_filename);
+            get_opt_value(tmpbuf, strlen(initrd_filename) + 1, initrd_filename);
+            mb_debug("multiboot loading module: %s\n", tmpbuf);
+            mb_mod_length = get_image_size(tmpbuf);
             if (mb_mod_length < 0) {
-                fprintf(stderr, "Failed to open file '%s'\n", initrd_filename);
+                fprintf(stderr, "Failed to open file '%s'\n", tmpbuf);
                 exit(1);
             }
 
             mbs.mb_buf_size = TARGET_PAGE_ALIGN(mb_mod_length + mbs.mb_buf_size);
             mbs.mb_buf = g_realloc(mbs.mb_buf, mbs.mb_buf_size);
 
-            load_image(initrd_filename, (unsigned char *)mbs.mb_buf + offs);
+            load_image(tmpbuf, (unsigned char *)mbs.mb_buf + offs);
             mb_add_mod(&mbs, mbs.mb_buf_phys + offs,
                        mbs.mb_buf_phys + offs + mb_mod_length, c);
 
-- 
1.9.1

Re: [Qemu-devel] [PATCH] multiboot: copy the cmdline verbatim, unescape module strings

[Vlad Lungu]

Sorry about replying to myself, I only had one coffee today.

There is no need for mb_add_modstring(), we can simply  do
get_opt_value(tmpbuf,..) then mb_add_cmdline(&mbs, tmpbuf)

Regards,
Vlad

On 12/15/2016 11:45 AM, Vlad Lungu wrote:
> get_opt_value() truncates the value at the first comma
> Rename mb_add_cmdline() to mb_add_modstring()
> Unescape filename too
> Add new mb_add_cmdline() using  memcpy()
>
> Signed-off-by: Vlad Lungu <vlad.lungu@windriver.com>
> ---
>  hw/i386/multiboot.c | 23 +++++++++++++++++------
>  1 file changed, 17 insertions(+), 6 deletions(-)
>
> diff --git a/hw/i386/multiboot.c b/hw/i386/multiboot.c
> index 387caa6..bfb52fc 100644
> --- a/hw/i386/multiboot.c
> +++ b/hw/i386/multiboot.c
> @@ -109,6 +109,16 @@ static uint32_t mb_add_cmdline(MultibootState *s, const char *cmdline)
>      hwaddr p = s->offset_cmdlines;
>      char *b = (char *)s->mb_buf + p;
>  
> +    memcpy(b, cmdline, strlen(cmdline) + 1);
> +    s->offset_cmdlines += strlen(b) + 1;
> +    return s->mb_buf_phys + p;
> +}
> +
> +static uint32_t mb_add_modstring(MultibootState *s, const char *cmdline)
> +{
> +    hwaddr p = s->offset_cmdlines;
> +    char *b = (char *)s->mb_buf + p;
> +
>      get_opt_value(b, strlen(cmdline) + 1, cmdline);
>      s->offset_cmdlines += strlen(b) + 1;
>      return s->mb_buf_phys + p;
> @@ -287,7 +297,7 @@ int load_multiboot(FWCfgState *fw_cfg,
>      mbs.offset_bootloader = mbs.offset_cmdlines + cmdline_len;
>  
>      if (initrd_filename) {
> -        char *next_initrd, not_last;
> +        char *next_initrd, not_last, tmpbuf[strlen(initrd_filename) + 1];
>  
>          mbs.offset_mods = mbs.mb_buf_size;
>  
> @@ -301,20 +311,21 @@ int load_multiboot(FWCfgState *fw_cfg,
>              *next_initrd = '\0';
>              /* if a space comes after the module filename, treat everything
>                 after that as parameters */
> -            hwaddr c = mb_add_cmdline(&mbs, initrd_filename);
> +            hwaddr c = mb_add_modstring(&mbs, initrd_filename);
>              if ((next_space = strchr(initrd_filename, ' ')))
>                  *next_space = '\0';
> -            mb_debug("multiboot loading module: %s\n", initrd_filename);
> -            mb_mod_length = get_image_size(initrd_filename);
> +            get_opt_value(tmpbuf, strlen(initrd_filename) + 1, initrd_filename);
> +            mb_debug("multiboot loading module: %s\n", tmpbuf);
> +            mb_mod_length = get_image_size(tmpbuf);
>              if (mb_mod_length < 0) {
> -                fprintf(stderr, "Failed to open file '%s'\n", initrd_filename);
> +                fprintf(stderr, "Failed to open file '%s'\n", tmpbuf);
>                  exit(1);
>              }
>  
>              mbs.mb_buf_size = TARGET_PAGE_ALIGN(mb_mod_length + mbs.mb_buf_size);
>              mbs.mb_buf = g_realloc(mbs.mb_buf, mbs.mb_buf_size);
>  
> -            load_image(initrd_filename, (unsigned char *)mbs.mb_buf + offs);
> +            load_image(tmpbuf, (unsigned char *)mbs.mb_buf + offs);
>              mb_add_mod(&mbs, mbs.mb_buf_phys + offs,
>                         mbs.mb_buf_phys + offs + mb_mod_length, c);
>