From 6937487be73cd4563b876413277a295a5fe2f32c Mon Sep 17 00:00:00 2001 From: James Byrne Date: Tue, 2 Jul 2019 11:35:03 +0200 Subject: libbb: reduce the overhead of single parameter bb_error_msg() calls 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 Signed-off-by: Denys Vlasenko --- modutils/modutils-24.c | 26 +++++++++++++------------- modutils/rmmod.c | 2 +- 2 files changed, 14 insertions(+), 14 deletions(-) (limited to 'modutils') diff --git a/modutils/modutils-24.c b/modutils/modutils-24.c index 1a30dd8..ac86324 100644 --- a/modutils/modutils-24.c +++ b/modutils/modutils-24.c @@ -2600,7 +2600,7 @@ static void new_get_kernel_symbols(void) module_names = xrealloc(module_names, bufsize); goto retry_modules_load; } - bb_perror_msg_and_die("QM_MODULES"); + bb_simple_perror_msg_and_die("QM_MODULES"); } n_ext_modules = nmod = ret; @@ -2661,7 +2661,7 @@ static void new_get_kernel_symbols(void) syms = xrealloc(syms, bufsize); goto retry_kern_sym_load; } - bb_perror_msg_and_die("kernel: QM_SYMBOLS"); + bb_simple_perror_msg_and_die("kernel: QM_SYMBOLS"); } nksyms = nsyms = ret; ksyms = syms; @@ -3247,21 +3247,21 @@ static struct obj_file *obj_load(char *image, size_t image_size, int loadprogbit f->load_order_search_start = &f->load_order; if (image_size < sizeof(f->header)) - bb_error_msg_and_die("error while loading ELF header"); + bb_simple_error_msg_and_die("error while loading ELF header"); memcpy(&f->header, image, sizeof(f->header)); if (*(aliased_uint32_t*)(&f->header.e_ident) != ELFMAG_U32) { - bb_error_msg_and_die("not an ELF file"); + bb_simple_error_msg_and_die("not an ELF file"); } if (f->header.e_ident[EI_CLASS] != ELFCLASSM || f->header.e_ident[EI_DATA] != (BB_BIG_ENDIAN ? ELFDATA2MSB : ELFDATA2LSB) || f->header.e_ident[EI_VERSION] != EV_CURRENT || !MATCH_MACHINE(f->header.e_machine) ) { - bb_error_msg_and_die("ELF file not for this architecture"); + bb_simple_error_msg_and_die("ELF file not for this architecture"); } if (f->header.e_type != ET_REL) { - bb_error_msg_and_die("ELF file not a relocatable object"); + bb_simple_error_msg_and_die("ELF file not a relocatable object"); } /* Read the section headers. */ @@ -3280,7 +3280,7 @@ static struct obj_file *obj_load(char *image, size_t image_size, int loadprogbit section_headers = alloca(sizeof(ElfW(Shdr)) * shnum); if (image_size < f->header.e_shoff + sizeof(ElfW(Shdr)) * shnum) - bb_error_msg_and_die("error while loading section headers"); + bb_simple_error_msg_and_die("error while loading section headers"); memcpy(section_headers, image + f->header.e_shoff, sizeof(ElfW(Shdr)) * shnum); /* Read the section data. */ @@ -3317,16 +3317,16 @@ static struct obj_file *obj_load(char *image, size_t image_size, int loadprogbit if (sec->header.sh_size > 0) { sec->contents = xmalloc(sec->header.sh_size); if (image_size < (sec->header.sh_offset + sec->header.sh_size)) - bb_error_msg_and_die("error while loading section data"); + bb_simple_error_msg_and_die("error while loading section data"); memcpy(sec->contents, image + sec->header.sh_offset, sec->header.sh_size); } break; #if SHT_RELM == SHT_REL case SHT_RELA: - bb_error_msg_and_die("RELA relocations not supported on this architecture"); + bb_simple_error_msg_and_die("RELA relocations not supported on this architecture"); #else case SHT_REL: - bb_error_msg_and_die("REL relocations not supported on this architecture"); + bb_simple_error_msg_and_die("REL relocations not supported on this architecture"); #endif default: if (sec->header.sh_type >= SHT_LOPROC) { @@ -3447,7 +3447,7 @@ static int obj_load_progbits(char *image, size_t image_size, struct obj_file *f, continue; sec->contents = imagebase + (sec->header.sh_addr - base); if (image_size < (sec->header.sh_offset + sec->header.sh_size)) { - bb_error_msg("error reading ELF section data"); + bb_simple_error_msg("error reading ELF section data"); return 0; /* need to delete half-loaded module! */ } memcpy(sec->contents, image + sec->header.sh_offset, sec->header.sh_size); @@ -3845,7 +3845,7 @@ int FAST_FUNC bb_init_module_24(const char *m_filename, const char *options) if (m_has_modinfo) { int m_version = new_get_module_version(f, m_strversion); if (m_version == -1) { - bb_error_msg_and_die("can't find the kernel version " + bb_simple_error_msg_and_die("can't find the kernel version " "the module was compiled for"); } } @@ -3864,7 +3864,7 @@ int FAST_FUNC bb_init_module_24(const char *m_filename, const char *options) #endif if (query_module(NULL, 0, NULL, 0, NULL)) - bb_error_msg_and_die("old (unsupported) kernel"); + bb_simple_error_msg_and_die("old (unsupported) kernel"); new_get_kernel_symbols(); k_crcs = new_is_kernel_checksummed(); diff --git a/modutils/rmmod.c b/modutils/rmmod.c index a354887..8d4639f 100644 --- a/modutils/rmmod.c +++ b/modutils/rmmod.c @@ -52,7 +52,7 @@ int rmmod_main(int argc UNUSED_PARAM, char **argv) /* Unload _all_ unused modules via NULL delete_module() call */ err = bb_delete_module(NULL, flags); if (err && err != EFAULT) - bb_perror_msg_and_die("rmmod"); + bb_simple_perror_msg_and_die("rmmod"); return EXIT_SUCCESS; } -- cgit v1.1