[PATCH] avoid signed vs unsigned comparison in efi_range_is_wc()
This little function in include/linux/efi.h : static inline int efi_range_is_wc(unsigned long start, unsigned long len) { int i; for (i = 0; i < len; i += (1UL << EFI_PAGE_SHIFT)) { unsigned long paddr = __pa(start + i); if (!(efi_mem_attributes(paddr) & EFI_MEMORY_WC)) return 0; } /* The range checked out */ return 1; } generates this warning when building with gcc -W : include/linux/efi.h: In function `efi_range_is_wc': include/linux/efi.h:320: warning: comparison between signed and unsigned It looks to me like a significantly large 'len' passed in could cause the loop to never end. Isn't it safer to make 'i' an unsigned long as well? Like this little patch below (which of course also kills the warning) : Signed-off-by: Jesper Juhl <[EMAIL PROTECTED]> diff -up linux-2.6.11-mm4-orig/include/linux/efi.h linux-2.6.11-mm4/include/linux/efi.h --- linux-2.6.11-mm4-orig/include/linux/efi.h 2005-03-16 15:45:35.0 +0100 +++ linux-2.6.11-mm4/include/linux/efi.h2005-03-18 00:34:36.0 +0100 @@ -315,7 +315,7 @@ extern struct efi_memory_map memmap; */ static inline int efi_range_is_wc(unsigned long start, unsigned long len) { - int i; + unsigned long i; for (i = 0; i < len; i += (1UL << EFI_PAGE_SHIFT)) { unsigned long paddr = __pa(start + i); - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH] avoid signed vs unsigned comparison in efi_range_is_wc()
This little function in include/linux/efi.h : static inline int efi_range_is_wc(unsigned long start, unsigned long len) { int i; for (i = 0; i len; i += (1UL EFI_PAGE_SHIFT)) { unsigned long paddr = __pa(start + i); if (!(efi_mem_attributes(paddr) EFI_MEMORY_WC)) return 0; } /* The range checked out */ return 1; } generates this warning when building with gcc -W : include/linux/efi.h: In function `efi_range_is_wc': include/linux/efi.h:320: warning: comparison between signed and unsigned It looks to me like a significantly large 'len' passed in could cause the loop to never end. Isn't it safer to make 'i' an unsigned long as well? Like this little patch below (which of course also kills the warning) : Signed-off-by: Jesper Juhl [EMAIL PROTECTED] diff -up linux-2.6.11-mm4-orig/include/linux/efi.h linux-2.6.11-mm4/include/linux/efi.h --- linux-2.6.11-mm4-orig/include/linux/efi.h 2005-03-16 15:45:35.0 +0100 +++ linux-2.6.11-mm4/include/linux/efi.h2005-03-18 00:34:36.0 +0100 @@ -315,7 +315,7 @@ extern struct efi_memory_map memmap; */ static inline int efi_range_is_wc(unsigned long start, unsigned long len) { - int i; + unsigned long i; for (i = 0; i len; i += (1UL EFI_PAGE_SHIFT)) { unsigned long paddr = __pa(start + i); - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/