]> asedeno.scripts.mit.edu Git - linux.git/blobdiff - scripts/recordmcount.c
Merge branch 'hugepage-fallbacks' (hugepatch patches from David Rientjes)
[linux.git] / scripts / recordmcount.c
index 1fe5fba999599a05258224e11a3f6caeddbfb5d0..612268eabef463e783a75bd61252ef6c6e122496 100644 (file)
@@ -27,7 +27,6 @@
 #include <getopt.h>
 #include <elf.h>
 #include <fcntl.h>
-#include <setjmp.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -43,56 +42,37 @@ static int fd_map;  /* File descriptor for file being modified. */
 static int mmap_failed; /* Boolean flag. */
 static char gpfx;      /* prefix for global symbol name (sometimes '_') */
 static struct stat sb; /* Remember .st_size, etc. */
-static jmp_buf jmpenv; /* setjmp/longjmp per-file error escape */
 static const char *altmcount;  /* alternate mcount symbol name */
 static int warn_on_notrace_sect; /* warn when section has mcount not being recorded */
 static void *file_map; /* pointer of the mapped file */
 static void *file_end; /* pointer to the end of the mapped file */
 static int file_updated; /* flag to state file was changed */
 static void *file_ptr; /* current file pointer location */
+
 static void *file_append; /* added to the end of the file */
 static size_t file_append_size; /* how much is added to end of file */
 
-/* setjmp() return values */
-enum {
-       SJ_SETJMP = 0,  /* hardwired first return */
-       SJ_FAIL,
-       SJ_SUCCEED
-};
-
 /* Per-file resource cleanup when multiple files. */
-static void
-cleanup(void)
+static void file_append_cleanup(void)
 {
-       if (!mmap_failed)
-               munmap(file_map, sb.st_size);
-       else
-               free(file_map);
-       file_map = NULL;
        free(file_append);
        file_append = NULL;
        file_append_size = 0;
        file_updated = 0;
 }
 
-static void __attribute__((noreturn))
-fail_file(void)
+static void mmap_cleanup(void)
 {
-       cleanup();
-       longjmp(jmpenv, SJ_FAIL);
-}
-
-static void __attribute__((noreturn))
-succeed_file(void)
-{
-       cleanup();
-       longjmp(jmpenv, SJ_SUCCEED);
+       if (!mmap_failed)
+               munmap(file_map, sb.st_size);
+       else
+               free(file_map);
+       file_map = NULL;
 }
 
 /* ulseek, uwrite, ...:  Check return value for errors. */
 
-static off_t
-ulseek(off_t const offset, int const whence)
+static off_t ulseek(off_t const offset, int const whence)
 {
        switch (whence) {
        case SEEK_SET:
@@ -107,13 +87,12 @@ ulseek(off_t const offset, int const whence)
        }
        if (file_ptr < file_map) {
                fprintf(stderr, "lseek: seek before file\n");
-               fail_file();
+               return -1;
        }
        return file_ptr - file_map;
 }
 
-static size_t
-uwrite(void const *const buf, size_t const count)
+static ssize_t uwrite(void const *const buf, size_t const count)
 {
        size_t cnt = count;
        off_t idx = 0;
@@ -129,7 +108,9 @@ uwrite(void const *const buf, size_t const count)
                }
                if (!file_append) {
                        perror("write");
-                       fail_file();
+                       file_append_cleanup();
+                       mmap_cleanup();
+                       return -1;
                }
                if (file_ptr < file_end) {
                        cnt = file_end - file_ptr;
@@ -149,17 +130,81 @@ uwrite(void const *const buf, size_t const count)
        return count;
 }
 
-static void *
-umalloc(size_t size)
+static void * umalloc(size_t size)
 {
        void *const addr = malloc(size);
        if (addr == 0) {
                fprintf(stderr, "malloc failed: %zu bytes\n", size);
-               fail_file();
+               file_append_cleanup();
+               mmap_cleanup();
+               return NULL;
        }
        return addr;
 }
 
+/*
+ * Get the whole file as a programming convenience in order to avoid
+ * malloc+lseek+read+free of many pieces.  If successful, then mmap
+ * avoids copying unused pieces; else just read the whole file.
+ * Open for both read and write; new info will be appended to the file.
+ * Use MAP_PRIVATE so that a few changes to the in-memory ElfXX_Ehdr
+ * do not propagate to the file until an explicit overwrite at the last.
+ * This preserves most aspects of consistency (all except .st_size)
+ * for simultaneous readers of the file while we are appending to it.
+ * However, multiple writers still are bad.  We choose not to use
+ * locking because it is expensive and the use case of kernel build
+ * makes multiple writers unlikely.
+ */
+static void *mmap_file(char const *fname)
+{
+       /* Avoid problems if early cleanup() */
+       fd_map = -1;
+       mmap_failed = 1;
+       file_map = NULL;
+       file_ptr = NULL;
+       file_updated = 0;
+       sb.st_size = 0;
+
+       fd_map = open(fname, O_RDONLY);
+       if (fd_map < 0) {
+               perror(fname);
+               return NULL;
+       }
+       if (fstat(fd_map, &sb) < 0) {
+               perror(fname);
+               goto out;
+       }
+       if (!S_ISREG(sb.st_mode)) {
+               fprintf(stderr, "not a regular file: %s\n", fname);
+               goto out;
+       }
+       file_map = mmap(0, sb.st_size, PROT_READ|PROT_WRITE, MAP_PRIVATE,
+                       fd_map, 0);
+       if (file_map == MAP_FAILED) {
+               mmap_failed = 1;
+               file_map = umalloc(sb.st_size);
+               if (!file_map) {
+                       perror(fname);
+                       goto out;
+               }
+               if (read(fd_map, file_map, sb.st_size) != sb.st_size) {
+                       perror(fname);
+                       free(file_map);
+                       file_map = NULL;
+                       goto out;
+               }
+       } else
+               mmap_failed = 0;
+out:
+       close(fd_map);
+       fd_map = -1;
+
+       file_end = file_map + sb.st_size;
+
+       return file_map;
+}
+
+
 static unsigned char ideal_nop5_x86_64[5] = { 0x0f, 0x1f, 0x44, 0x00, 0x00 };
 static unsigned char ideal_nop5_x86_32[5] = { 0x3e, 0x8d, 0x74, 0x26, 0x00 };
 static unsigned char *ideal_nop;
@@ -183,8 +228,10 @@ static int make_nop_x86(void *map, size_t const offset)
                return -1;
 
        /* convert to nop */
-       ulseek(offset - 1, SEEK_SET);
-       uwrite(ideal_nop, 5);
+       if (ulseek(offset - 1, SEEK_SET) < 0)
+               return -1;
+       if (uwrite(ideal_nop, 5) < 0)
+               return -1;
        return 0;
 }
 
@@ -232,10 +279,12 @@ static int make_nop_arm(void *map, size_t const offset)
                return -1;
 
        /* Convert to nop */
-       ulseek(off, SEEK_SET);
+       if (ulseek(off, SEEK_SET) < 0)
+               return -1;
 
        do {
-               uwrite(ideal_nop, nop_size);
+               if (uwrite(ideal_nop, nop_size) < 0)
+                       return -1;
        } while (--cnt > 0);
 
        return 0;
@@ -252,60 +301,20 @@ static int make_nop_arm64(void *map, size_t const offset)
                return -1;
 
        /* Convert to nop */
-       ulseek(offset, SEEK_SET);
-       uwrite(ideal_nop, 4);
+       if (ulseek(offset, SEEK_SET) < 0)
+               return -1;
+       if (uwrite(ideal_nop, 4) < 0)
+               return -1;
        return 0;
 }
 
-/*
- * Get the whole file as a programming convenience in order to avoid
- * malloc+lseek+read+free of many pieces.  If successful, then mmap
- * avoids copying unused pieces; else just read the whole file.
- * Open for both read and write; new info will be appended to the file.
- * Use MAP_PRIVATE so that a few changes to the in-memory ElfXX_Ehdr
- * do not propagate to the file until an explicit overwrite at the last.
- * This preserves most aspects of consistency (all except .st_size)
- * for simultaneous readers of the file while we are appending to it.
- * However, multiple writers still are bad.  We choose not to use
- * locking because it is expensive and the use case of kernel build
- * makes multiple writers unlikely.
- */
-static void *mmap_file(char const *fname)
-{
-       fd_map = open(fname, O_RDONLY);
-       if (fd_map < 0 || fstat(fd_map, &sb) < 0) {
-               perror(fname);
-               fail_file();
-       }
-       if (!S_ISREG(sb.st_mode)) {
-               fprintf(stderr, "not a regular file: %s\n", fname);
-               fail_file();
-       }
-       file_map = mmap(0, sb.st_size, PROT_READ|PROT_WRITE, MAP_PRIVATE,
-                       fd_map, 0);
-       mmap_failed = 0;
-       if (file_map == MAP_FAILED) {
-               mmap_failed = 1;
-               file_map = umalloc(sb.st_size);
-               if (read(fd_map, file_map, sb.st_size) != sb.st_size) {
-                       perror(fname);
-                       fail_file();
-               }
-       }
-       close(fd_map);
-
-       file_end = file_map + sb.st_size;
-
-       return file_map;
-}
-
-static void write_file(const char *fname)
+static int write_file(const char *fname)
 {
        char tmp_file[strlen(fname) + 4];
        size_t n;
 
        if (!file_updated)
-               return;
+               return 0;
 
        sprintf(tmp_file, "%s.rc", fname);
 
@@ -317,25 +326,28 @@ static void 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);
-               fail_file();
+               return -1;
        }
        n = write(fd_map, file_map, sb.st_size);
        if (n != sb.st_size) {
                perror("write");
-               fail_file();
+               close(fd_map);
+               return -1;
        }
        if (file_append_size) {
                n = write(fd_map, file_append, file_append_size);
                if (n != file_append_size) {
                        perror("write");
-                       fail_file();
+                       close(fd_map);
+                       return -1;
                }
        }
        close(fd_map);
        if (rename(tmp_file, fname) < 0) {
                perror(fname);
-               fail_file();
+               return -1;
        }
+       return 0;
 }
 
 /* w8rev, w8nat, ...: Handle endianness. */
@@ -386,8 +398,7 @@ static uint32_t (*w)(uint32_t);
 static uint32_t (*w2)(uint16_t);
 
 /* Names of the sections that could contain calls to mcount. */
-static int
-is_mcounted_section_name(char const *const txtname)
+static int is_mcounted_section_name(char const *const txtname)
 {
        return strncmp(".text",          txtname, 5) == 0 ||
                strcmp(".init.text",     txtname) == 0 ||
@@ -400,6 +411,8 @@ is_mcounted_section_name(char const *const txtname)
                strcmp(".cpuidle.text", txtname) == 0;
 }
 
+static char const *already_has_rel_mcount = "success"; /* our work here is done! */
+
 /* 32 bit and 64 bit are very similar */
 #include "recordmcount.h"
 #define RECORD_MCOUNT_64
@@ -438,11 +451,15 @@ static void MIPS64_r_info(Elf64_Rel *const rp, unsigned sym, unsigned type)
        }).r_info;
 }
 
-static void
-do_file(char const *const fname)
+static int do_file(char const *const fname)
 {
-       Elf32_Ehdr *const ehdr = mmap_file(fname);
        unsigned int reltype = 0;
+       Elf32_Ehdr *ehdr;
+       int rc = -1;
+
+       ehdr = mmap_file(fname);
+       if (!ehdr)
+               goto out;
 
        w = w4nat;
        w2 = w2nat;
@@ -452,8 +469,7 @@ do_file(char const *const fname)
        default:
                fprintf(stderr, "unrecognized ELF data encoding %d: %s\n",
                        ehdr->e_ident[EI_DATA], fname);
-               fail_file();
-               break;
+               goto out;
        case ELFDATA2LSB:
                if (*(unsigned char const *)&endian != 1) {
                        /* main() is big endian, file.o is little endian. */
@@ -481,52 +497,54 @@ do_file(char const *const fname)
                push_bl_mcount_thumb = push_bl_mcount_thumb_be;
                break;
        }  /* end switch */
-       if (memcmp(ELFMAG, ehdr->e_ident, SELFMAG) != 0
-       ||  w2(ehdr->e_type) != ET_REL
-       ||  ehdr->e_ident[EI_VERSION] != EV_CURRENT) {
+       if (memcmp(ELFMAG, ehdr->e_ident, SELFMAG) != 0 ||
+           w2(ehdr->e_type) != ET_REL ||
+           ehdr->e_ident[EI_VERSION] != EV_CURRENT) {
                fprintf(stderr, "unrecognized ET_REL file %s\n", fname);
-               fail_file();
+               goto out;
        }
 
-       gpfx = 0;
+       gpfx = '_';
        switch (w2(ehdr->e_machine)) {
        default:
                fprintf(stderr, "unrecognized e_machine %u %s\n",
                        w2(ehdr->e_machine), fname);
-               fail_file();
-               break;
+               goto out;
        case EM_386:
                reltype = R_386_32;
                rel_type_nop = R_386_NONE;
                make_nop = make_nop_x86;
                ideal_nop = ideal_nop5_x86_32;
                mcount_adjust_32 = -1;
+               gpfx = 0;
+               break;
+       case EM_ARM:
+               reltype = R_ARM_ABS32;
+               altmcount = "__gnu_mcount_nc";
+               make_nop = make_nop_arm;
+               rel_type_nop = R_ARM_NONE;
+               gpfx = 0;
                break;
-       case EM_ARM:     reltype = R_ARM_ABS32;
-                        altmcount = "__gnu_mcount_nc";
-                        make_nop = make_nop_arm;
-                        rel_type_nop = R_ARM_NONE;
-                        break;
        case EM_AARCH64:
-                       reltype = R_AARCH64_ABS64;
-                       make_nop = make_nop_arm64;
-                       rel_type_nop = R_AARCH64_NONE;
-                       ideal_nop = ideal_nop4_arm64;
-                       gpfx = '_';
-                       break;
-       case EM_IA_64:   reltype = R_IA64_IMM64;   gpfx = '_'; break;
-       case EM_MIPS:    /* reltype: e_class    */ gpfx = '_'; break;
-       case EM_PPC:     reltype = R_PPC_ADDR32;   gpfx = '_'; break;
-       case EM_PPC64:   reltype = R_PPC64_ADDR64; gpfx = '_'; break;
-       case EM_S390:    /* reltype: e_class    */ gpfx = '_'; break;
-       case EM_SH:      reltype = R_SH_DIR32;                 break;
-       case EM_SPARCV9: reltype = R_SPARC_64;     gpfx = '_'; break;
+               reltype = R_AARCH64_ABS64;
+               make_nop = make_nop_arm64;
+               rel_type_nop = R_AARCH64_NONE;
+               ideal_nop = ideal_nop4_arm64;
+               break;
+       case EM_IA_64:  reltype = R_IA64_IMM64; break;
+       case EM_MIPS:   /* reltype: e_class    */ break;
+       case EM_PPC:    reltype = R_PPC_ADDR32; break;
+       case EM_PPC64:  reltype = R_PPC64_ADDR64; break;
+       case EM_S390:   /* reltype: e_class    */ break;
+       case EM_SH:     reltype = R_SH_DIR32; gpfx = 0; break;
+       case EM_SPARCV9: reltype = R_SPARC_64; break;
        case EM_X86_64:
                make_nop = make_nop_x86;
                ideal_nop = ideal_nop5_x86_64;
                reltype = R_X86_64_64;
                rel_type_nop = R_X86_64_NONE;
                mcount_adjust_64 = -1;
+               gpfx = 0;
                break;
        }  /* end switch */
 
@@ -534,20 +552,20 @@ do_file(char const *const fname)
        default:
                fprintf(stderr, "unrecognized ELF class %d %s\n",
                        ehdr->e_ident[EI_CLASS], fname);
-               fail_file();
-               break;
+               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);
-                       fail_file();
+                       goto out;
                }
                if (w2(ehdr->e_machine) == EM_MIPS) {
                        reltype = R_MIPS_32;
                        is_fake_mcount32 = MIPS32_is_fake_mcount;
                }
-               do32(ehdr, fname, reltype);
+               if (do32(ehdr, fname, reltype) < 0)
+                       goto out;
                break;
        case ELFCLASS64: {
                Elf64_Ehdr *const ghdr = (Elf64_Ehdr *)ehdr;
@@ -555,7 +573,7 @@ do_file(char const *const fname)
                ||  w2(ghdr->e_shentsize) != sizeof(Elf64_Shdr)) {
                        fprintf(stderr,
                                "unrecognized ET_REL file: %s\n", fname);
-                       fail_file();
+                       goto out;
                }
                if (w2(ghdr->e_machine) == EM_S390) {
                        reltype = R_390_64;
@@ -567,17 +585,20 @@ do_file(char const *const fname)
                        Elf64_r_info = MIPS64_r_info;
                        is_fake_mcount64 = MIPS64_is_fake_mcount;
                }
-               do64(ghdr, fname, reltype);
+               if (do64(ghdr, fname, reltype) < 0)
+                       goto out;
                break;
        }
        }  /* end switch */
 
-       write_file(fname);
-       cleanup();
+       rc = write_file(fname);
+out:
+       file_append_cleanup();
+       mmap_cleanup();
+       return rc;
 }
 
-int
-main(int argc, char *argv[])
+int main(int argc, char *argv[])
 {
        const char ftrace[] = "/ftrace.o";
        int ftrace_size = sizeof(ftrace) - 1;
@@ -604,7 +625,6 @@ main(int argc, char *argv[])
        /* Process each file in turn, allowing deep failure. */
        for (i = optind; i < argc; i++) {
                char *file = argv[i];
-               int const sjval = setjmp(jmpenv);
                int len;
 
                /*
@@ -617,28 +637,10 @@ main(int argc, char *argv[])
                    strcmp(file + (len - ftrace_size), ftrace) == 0)
                        continue;
 
-               switch (sjval) {
-               default:
-                       fprintf(stderr, "internal error: %s\n", file);
-                       exit(1);
-                       break;
-               case SJ_SETJMP:    /* normal sequence */
-                       /* Avoid problems if early cleanup() */
-                       fd_map = -1;
-                       mmap_failed = 1;
-                       file_map = NULL;
-                       file_ptr = NULL;
-                       file_updated = 0;
-                       do_file(file);
-                       break;
-               case SJ_FAIL:    /* error in do_file or below */
+               if (do_file(file)) {
                        fprintf(stderr, "%s: failed\n", file);
                        ++n_error;
-                       break;
-               case SJ_SUCCEED:    /* premature success */
-                       /* do nothing */
-                       break;
-               }  /* end switch */
+               }
        }
        return !!n_error;
 }