From c97fea26254b284c93a67b788968622f9cc03b30 Mon Sep 17 00:00:00 2001 From: Matt Helsley Date: Wed, 31 Jul 2019 11:24:15 -0700 Subject: [PATCH] recordmcount: Remove redundant cleanup() calls Redundant cleanup calls were introduced when transitioning from the old error/success handling via setjmp/longjmp -- the longjmp ensured the cleanup() call only happened once but replacing the success_file()/fail_file() calls with cleanup() meant that multiple cleanup() calls can happen as we return from function calls. In do_file(), looking just before and after the "goto out" jumps we can see that multiple cleanups() are being performed. We remove cleanup() calls from the nested functions because it makes the code easier to review -- the resources being cleaned up are generally allocated and initialized in the callers so freeing them there makes more sense. Other redundant cleanup() calls: mmap_file() is only called from do_file() and, if mmap_file() fails, then we goto out and do cleanup() there too. write_file() is only called from do_file() and do_file() calls cleanup() unconditionally after returning from write_file() therefore the cleanup() calls in write_file() are not necessary. find_secsym_ndx(), called from do_func()'s for-loop, when we are cleaning up here it's obvious that we break out of the loop and do another cleanup(). __has_rel_mcount() is called from two parts of do_func() and calls cleanup(). In theory we move them into do_func(), however these in turn prove redundant so another simplification step removes them as well. Link: http://lkml.kernel.org/r/de197e17fc5426623a847ea7cf3a1560a7402a4b.1564596289.git.mhelsley@vmware.com Signed-off-by: Matt Helsley Signed-off-by: Steven Rostedt (VMware) --- scripts/recordmcount.c | 13 ------------- scripts/recordmcount.h | 2 -- 2 files changed, 15 deletions(-) diff --git a/scripts/recordmcount.c b/scripts/recordmcount.c index 273ca8b42b20..5677fcc88a72 100644 --- a/scripts/recordmcount.c +++ b/scripts/recordmcount.c @@ -258,17 +258,14 @@ static void *mmap_file(char const *fname) fd_map = open(fname, O_RDONLY); if (fd_map < 0) { perror(fname); - cleanup(); return NULL; } if (fstat(fd_map, &sb) < 0) { perror(fname); - cleanup(); goto out; } if (!S_ISREG(sb.st_mode)) { fprintf(stderr, "not a regular file: %s\n", fname); - cleanup(); goto out; } file_map = mmap(0, sb.st_size, PROT_READ|PROT_WRITE, MAP_PRIVATE, @@ -314,13 +311,11 @@ static int write_file(const char *fname) fd_map = open(tmp_file, O_WRONLY | O_TRUNC | O_CREAT, sb.st_mode); if (fd_map < 0) { perror(fname); - cleanup(); return -1; } n = write(fd_map, file_map, sb.st_size); if (n != sb.st_size) { perror("write"); - cleanup(); close(fd_map); return -1; } @@ -328,7 +323,6 @@ static int write_file(const char *fname) n = write(fd_map, file_append, file_append_size); if (n != file_append_size) { perror("write"); - cleanup(); close(fd_map); return -1; } @@ -336,7 +330,6 @@ static int write_file(const char *fname) close(fd_map); if (rename(tmp_file, fname) < 0) { perror(fname); - cleanup(); return -1; } return 0; @@ -460,7 +453,6 @@ static int do_file(char const *const fname) default: fprintf(stderr, "unrecognized ELF data encoding %d: %s\n", ehdr->e_ident[EI_DATA], fname); - cleanup(); goto out; case ELFDATA2LSB: if (*(unsigned char const *)&endian != 1) { @@ -493,7 +485,6 @@ static int do_file(char const *const fname) w2(ehdr->e_type) != ET_REL || ehdr->e_ident[EI_VERSION] != EV_CURRENT) { fprintf(stderr, "unrecognized ET_REL file %s\n", fname); - cleanup(); goto out; } @@ -502,7 +493,6 @@ static int do_file(char const *const fname) default: fprintf(stderr, "unrecognized e_machine %u %s\n", w2(ehdr->e_machine), fname); - cleanup(); goto out; case EM_386: reltype = R_386_32; @@ -546,14 +536,12 @@ static int do_file(char const *const fname) default: fprintf(stderr, "unrecognized ELF class %d %s\n", ehdr->e_ident[EI_CLASS], fname); - cleanup(); goto out; case ELFCLASS32: if (w2(ehdr->e_ehsize) != sizeof(Elf32_Ehdr) || w2(ehdr->e_shentsize) != sizeof(Elf32_Shdr)) { fprintf(stderr, "unrecognized ET_REL file: %s\n", fname); - cleanup(); goto out; } if (w2(ehdr->e_machine) == EM_MIPS) { @@ -569,7 +557,6 @@ static int do_file(char const *const fname) || w2(ghdr->e_shentsize) != sizeof(Elf64_Shdr)) { fprintf(stderr, "unrecognized ET_REL file: %s\n", fname); - cleanup(); goto out; } if (w2(ghdr->e_machine) == EM_S390) { diff --git a/scripts/recordmcount.h b/scripts/recordmcount.h index ca9aaac89bfb..8f0a278ce0af 100644 --- a/scripts/recordmcount.h +++ b/scripts/recordmcount.h @@ -463,7 +463,6 @@ static int find_secsym_ndx(unsigned const txtndx, } fprintf(stderr, "Cannot find symbol for section %u: %s.\n", txtndx, txtname); - cleanup(); return -1; } @@ -480,7 +479,6 @@ static char const * __has_rel_mcount(Elf_Shdr const *const relhdr, /* reltype */ if (strcmp("__mcount_loc", txtname) == 0) { fprintf(stderr, "warning: __mcount_loc already exists: %s\n", fname); - cleanup(); return already_has_rel_mcount; } if (w(txthdr->sh_type) != SHT_PROGBITS || -- 2.30.2