Re: [PATCH 1/2] Add %X to grub_vsnprintf_real and friends

[Steve McIntyre]

On Mon, Mar 11, 2019 at 03:05:19PM +0000, Colin Watson wrote:
>This is needed for UEFI Boot* variables, which the standard says are
>named using upper-case hexadecimal.
>---
> grub-core/kern/misc.c | 10 ++++++++--
> 1 file changed, 8 insertions(+), 2 deletions(-)
>
>diff --git a/grub-core/kern/misc.c b/grub-core/kern/misc.c
>index 3b633d51f..73f8e0e9e 100644
>--- a/grub-core/kern/misc.c
>+++ b/grub-core/kern/misc.c
>@@ -588,7 +588,7 @@ grub_divmod64 (grub_uint64_t n, grub_uint64_t d, 
>grub_uint64_t *r)
> static inline char *
> grub_lltoa (char *str, int c, unsigned long long n)
> {
>-  unsigned base = (c == 'x') ? 16 : 10;
>+  unsigned base = (c == 'x' || c == 'X') ? 16 : 10;
>   char *p;
> 
>   if ((long long) n < 0 && c == 'd')
>@@ -603,7 +603,10 @@ grub_lltoa (char *str, int c, unsigned long long n)
>     do
>       {
>       unsigned d = (unsigned) (n & 0xf);
>-      *p++ = (d > 9) ? d + 'a' - 10 : d + '0';
>+      *p = (d > 9) ? d + 'a' - 10 : d + '0';
>+      if (c == 'X')
>+        *p = grub_toupper (*p);
>+      p++;

I'd be more tempted to simply do the upper-case stuff using

        if (c == 'x')
          *p++ = (d > 9) ? d + 'a' - 10 : d + '0';
        else
          *p++ = (d > 9) ? d + 'A' - 10 : d + '0';
        fi

rather than the call out to grub_toupper(), but that's just minor
nit-picking on style.

>       }
>     while (n >>= 4);
>   else
>@@ -676,6 +679,7 @@ parse_printf_args (const char *fmt0, struct printf_args 
>*args,
>       {
>       case 'p':
>       case 'x':
>+      case 'X':
>       case 'u':
>       case 'd':
>       case 'c':
>@@ -762,6 +766,7 @@ parse_printf_args (const char *fmt0, struct printf_args 
>*args,
>       switch (c)
>       {
>       case 'x':
>+      case 'X':
>       case 'u':
>         args->ptr[curn].type = UNSIGNED_INT + longfmt;
>         break;
>@@ -900,6 +905,7 @@ grub_vsnprintf_real (char *str, grub_size_t max_len, const 
>char *fmt0,
>         c = 'x';
>         /* Fall through. */
>       case 'x':
>+      case 'X':
>       case 'u':
>       case 'd':
>         {
>-- 
>2.17.1

Reviewed-by: Steve McIntyre <address@hidden>

-- 
Steve McIntyre, Cambridge, UK.                                address@hidden
"Because heaters aren't purple!" -- Catherine Pitt