6937487be7
Back in 2007, commit 0c97c9d43707 ("'simple' error message functions by Loic Grenie") introduced bb_simple_perror_msg() to allow for a lower overhead call to bb_perror_msg() when only a string was being printed with no parameters. This saves space for some CPU architectures because it avoids the overhead of a call to a variadic function. However there has never been a simple version of bb_error_msg(), and since 2007 many new calls to bb_perror_msg() have been added that only take a single parameter and so could have been using bb_simple_perror_message(). This changeset introduces 'simple' versions of bb_info_msg(), bb_error_msg(), bb_error_msg_and_die(), bb_herror_msg() and bb_herror_msg_and_die(), and replaces all calls that only take a single parameter, or use something like ("%s", arg), with calls to the corresponding 'simple' version. Since it is likely that single parameter calls to the variadic functions may be accidentally reintroduced in the future a new debugging config option WARN_SIMPLE_MSG has been introduced. This uses some macro magic which will cause any such calls to generate a warning, but this is turned off by default to avoid use of the unpleasant macros in normal circumstances. This is a large changeset due to the number of calls that have been replaced. The only files that contain changes other than simple substitution of function calls are libbb.h, libbb/herror_msg.c, libbb/verror_msg.c and libbb/xfuncs_printf.c. In miscutils/devfsd.c, networking/udhcp/common.h and util-linux/mdev.c additonal macros have been added for logging so that single parameter and multiple parameter logging variants exist. The amount of space saved varies considerably by architecture, and was found to be as follows (for 'defconfig' using GCC 7.4): Arm: -92 bytes MIPS: -52 bytes PPC: -1836 bytes x86_64: -938 bytes Note that for the MIPS architecture only an exception had to be made disabling the 'simple' calls for 'udhcp' (in networking/udhcp/common.h) because it made these files larger on MIPS. Signed-off-by: James Byrne <james.byrne@origamienergy.com> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
177 lines
5.0 KiB
C
177 lines
5.0 KiB
C
/* vi: set sw=4 ts=4: */
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/*
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* mkswap.c - format swap device (Linux v1 only)
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*
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* Copyright 2006 Rob Landley <rob@landley.net>
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*
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* Licensed under GPLv2, see file LICENSE in this source tree.
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*/
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//config:config MKSWAP
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//config: bool "mkswap (6.3 kb)"
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//config: default y
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//config: help
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//config: The mkswap utility is used to configure a file or disk partition as
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//config: Linux swap space. This allows Linux to use the entire file or
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//config: partition as if it were additional RAM, which can greatly increase
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//config: the capability of low-memory machines. This additional memory is
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//config: much slower than real RAM, but can be very helpful at preventing your
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//config: applications being killed by the Linux out of memory (OOM) killer.
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//config: Once you have created swap space using 'mkswap' you need to enable
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//config: the swap space using the 'swapon' utility.
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//config:
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//config:config FEATURE_MKSWAP_UUID
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//config: bool "UUID support"
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//config: default y
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//config: depends on MKSWAP
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//config: help
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//config: Generate swap spaces with universally unique identifiers.
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//applet:IF_MKSWAP(APPLET(mkswap, BB_DIR_SBIN, BB_SUID_DROP))
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//kbuild:lib-$(CONFIG_MKSWAP) += mkswap.o
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//usage:#define mkswap_trivial_usage
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//usage: "[-L LBL] BLOCKDEV [KBYTES]"
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//usage:#define mkswap_full_usage "\n\n"
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//usage: "Prepare BLOCKDEV to be used as swap partition\n"
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//usage: "\n -L LBL Label"
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#include "libbb.h"
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#include "common_bufsiz.h"
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#if ENABLE_SELINUX
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static void mkswap_selinux_setcontext(int fd, const char *path)
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{
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struct stat stbuf;
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if (!is_selinux_enabled())
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return;
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xfstat(fd, &stbuf, path);
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if (S_ISREG(stbuf.st_mode)) {
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security_context_t newcon;
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security_context_t oldcon = NULL;
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context_t context;
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if (fgetfilecon(fd, &oldcon) < 0) {
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if (errno != ENODATA)
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goto error;
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if (matchpathcon(path, stbuf.st_mode, &oldcon) < 0)
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goto error;
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}
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context = context_new(oldcon);
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if (!context || context_type_set(context, "swapfile_t"))
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goto error;
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newcon = context_str(context);
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if (!newcon)
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goto error;
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/* fsetfilecon_raw is hidden */
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if (strcmp(oldcon, newcon) != 0 && fsetfilecon(fd, newcon) < 0)
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goto error;
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if (ENABLE_FEATURE_CLEAN_UP) {
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context_free(context);
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freecon(oldcon);
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}
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}
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return;
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error:
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bb_simple_perror_msg_and_die("SELinux relabeling failed");
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}
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#else
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# define mkswap_selinux_setcontext(fd, path) ((void)0)
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#endif
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/* from Linux 2.6.23 */
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/*
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* Magic header for a swap area. ... Note that the first
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* kilobyte is reserved for boot loader or disk label stuff.
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*/
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struct swap_header_v1 {
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/* char bootbits[1024]; Space for disklabel etc. */
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uint32_t version; /* second kbyte, word 0 */
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uint32_t last_page; /* 1 */
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uint32_t nr_badpages; /* 2 */
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char sws_uuid[16]; /* 3,4,5,6 */
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char sws_volume[16]; /* 7,8,9,10 */
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uint32_t padding[117]; /* 11..127 */
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uint32_t badpages[1]; /* 128 */
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/* total 129 32-bit words in 2nd kilobyte */
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} FIX_ALIASING;
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#define NWORDS 129
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#define hdr ((struct swap_header_v1*)bb_common_bufsiz1)
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#define INIT_G() do { setup_common_bufsiz(); } while (0)
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struct BUG_sizes {
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char swap_header_v1_wrong[sizeof(*hdr) != (NWORDS * 4) ? -1 : 1];
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char bufsiz1_is_too_small[COMMON_BUFSIZE < (NWORDS * 4) ? -1 : 1];
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};
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/* Stored without terminating NUL */
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static const char SWAPSPACE2[sizeof("SWAPSPACE2")-1] ALIGN1 = "SWAPSPACE2";
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int mkswap_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
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int mkswap_main(int argc UNUSED_PARAM, char **argv)
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{
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int fd;
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unsigned pagesize;
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off_t len;
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const char *label = "";
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INIT_G();
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/* TODO: -p PAGESZ, -U UUID */
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getopt32(argv, "^" "L:" "\0" "-1"/*at least one arg*/, &label);
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argv += optind;
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fd = xopen(argv[0], O_WRONLY);
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/* Figure out how big the device is */
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len = get_volume_size_in_bytes(fd, argv[1], 1024, /*extend:*/ 1);
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pagesize = getpagesize();
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len -= pagesize;
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/* Announce our intentions */
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printf("Setting up swapspace version 1, size = %"OFF_FMT"u bytes\n", len);
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mkswap_selinux_setcontext(fd, argv[0]);
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/* hdr is zero-filled so far. Clear the first kbyte, or else
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* mkswap-ing former FAT partition does NOT erase its signature.
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*
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* util-linux-ng 2.17.2 claims to erase it only if it does not see
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* a partition table and is not run on whole disk. -f forces it.
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*/
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xwrite(fd, hdr, 1024);
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/* Fill the header. */
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hdr->version = 1;
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hdr->last_page = (uoff_t)len / pagesize;
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if (ENABLE_FEATURE_MKSWAP_UUID) {
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char uuid_string[32];
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generate_uuid((void*)hdr->sws_uuid);
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bin2hex(uuid_string, hdr->sws_uuid, 16);
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/* f.e. UUID=dfd9c173-be52-4d27-99a5-c34c6c2ff55f */
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printf("UUID=%.8s" "-%.4s-%.4s-%.4s-%.12s\n",
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uuid_string,
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uuid_string+8,
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uuid_string+8+4,
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uuid_string+8+4+4,
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uuid_string+8+4+4+4
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);
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}
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safe_strncpy(hdr->sws_volume, label, 16);
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/* Write the header. Sync to disk because some kernel versions check
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* signature on disk (not in cache) during swapon. */
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xwrite(fd, hdr, NWORDS * 4);
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xlseek(fd, pagesize - 10, SEEK_SET);
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xwrite(fd, SWAPSPACE2, 10);
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fsync(fd);
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if (ENABLE_FEATURE_CLEAN_UP)
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close(fd);
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return 0;
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}
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