From 7ac3b5b8e3ec944e7cd3bcc6d992882c4d443414 Mon Sep 17 00:00:00 2001 From: Karel Zak Date: Tue, 6 Feb 2007 11:35:15 +0100 Subject: Clean up pagesize/PAGE_SIZE usage. Now all code in util-linux uses sysconf(_SC_PAGESIZE) that is standardized and preferred way of querying page size. The asm/page.h file is not included to the code anymore. (This patch doesn't change mount's FS detection code which will be removed later). Signed-off-by: Karel Zak --- disk-utils/mkswap.c | 56 +++++++++++++++++++---------------------------------- 1 file changed, 20 insertions(+), 36 deletions(-) (limited to 'disk-utils/mkswap.c') diff --git a/disk-utils/mkswap.c b/disk-utils/mkswap.c index 861290fed..cbf898c13 100644 --- a/disk-utils/mkswap.c +++ b/disk-utils/mkswap.c @@ -47,17 +47,6 @@ #include #endif -/* Try to get PAGE_SIZE from libc or kernel includes */ -#ifdef HAVE_SYS_USER_H - /* Note: says: for gdb only */ -#include /* for PAGE_SIZE and PAGE_SHIFT */ -#else -#ifdef HAVE_ASM_PAGE_H -#include /* for PAGE_SIZE and PAGE_SHIFT */ - /* we also get PAGE_SIZE via getpagesize() */ -#endif -#endif - #ifndef _IO /* pre-1.3.45 */ #define BLKGETSIZE 0x1260 @@ -142,22 +131,25 @@ is_sparc64(void) { #endif /* - * The definition of the union swap_header uses the constant PAGE_SIZE. - * Unfortunately, on some architectures this depends on the hardware model, - * and can only be found at run time -- we use getpagesize(), so that - * we do not need separate binaries e.g. for sun4, sun4c/d/m and sun4u. + * The definition of the union swap_header uses the kernel constant PAGE_SIZE. + * Unfortunately, on some architectures this depends on the hardware model, and + * can only be found at run time -- we use getpagesize(), so that we do not + * need separate binaries e.g. for sun4, sun4c/d/m and sun4u. + * + * Even more unfortunately, getpagesize() does not always return the right + * information. For example, libc4, libc5 and glibc 2.0 do not use the system + * call but invent a value themselves (EXEC_PAGESIZE or NBPG * CLSIZE or NBPC), + * and thus it may happen that e.g. on a sparc kernel PAGE_SIZE=4096 and + * getpagesize() returns 8192. * - * Even more unfortunately, getpagesize() does not always return - * the right information. For example, libc4 and libc5 do not use - * the system call but invent a value themselves - * (EXEC_PAGESIZE or NBPG * CLSIZE or NBPC), and thus it may happen - * that e.g. on a sparc PAGE_SIZE=4096 and getpagesize() returns 8192. * What to do? Let us allow the user to specify the pagesize explicitly. + * + * Update 05-Feb-2007 (kzak): + * - use sysconf(_SC_PAGESIZE) to be consistent with the rest of + * util-linux code. It is the standardized and preferred way of + * querying page size. */ - -static int user_pagesize = 0; -static int kernel_pagesize; /* obtained via getpagesize(); */ -static int defined_pagesize = 0; /* PAGE_SIZE, when that exists */ +static int user_pagesize; static int pagesize; static long *signature_page; struct swap_header_v1 *p; @@ -165,11 +157,7 @@ struct swap_header_v1 *p; static void init_signature_page(void) { -#ifdef PAGE_SIZE - defined_pagesize = PAGE_SIZE; -#endif - kernel_pagesize = getpagesize(); - pagesize = kernel_pagesize; + int kernel_pagesize = pagesize = (int) sysconf(_SC_PAGESIZE); if (user_pagesize) { if ((user_pagesize & (user_pagesize-1)) || @@ -181,14 +169,10 @@ init_signature_page(void) { pagesize = user_pagesize; } - if (user_pagesize && user_pagesize != kernel_pagesize && - user_pagesize != defined_pagesize) + if (user_pagesize && user_pagesize != kernel_pagesize) fprintf(stderr, _("Using user-specified page size %d, " - "instead of the system values %d/%d\n"), - pagesize, kernel_pagesize, defined_pagesize); - else if (defined_pagesize && pagesize != defined_pagesize) - fprintf(stderr, _("Assuming pages of size %d (not %d)\n"), - pagesize, defined_pagesize); + "instead of the system value %d\n"), + pagesize, kernel_pagesize); signature_page = (long *) malloc(pagesize); memset(signature_page, 0, pagesize); -- cgit v1.2.3-55-g7522