1 files changed, 114 insertions, 54 deletions

diff --git a/scripts/recordmcount.c b/scripts/recordmcount.c
index f9f6f52db77..ee52cb8e17a 100644
--- a/scripts/recordmcount.c
+++ b/scripts/recordmcount.c
@@ -24,6 +24,7 @@
 #include <sys/types.h>
 #include <sys/mman.h>
 #include <sys/stat.h>
+#include <getopt.h>
 #include <elf.h>
 #include <fcntl.h>
 #include <setjmp.h>
@@ -39,6 +40,7 @@ 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 */
 
 /* setjmp() return values */
 enum {
@@ -78,7 +80,7 @@ static off_t
 ulseek(int const fd, off_t const offset, int const whence)
 {
         off_t const w = lseek(fd, offset, whence);
-        if ((off_t)-1 == w) {
+        if (w == (off_t)-1) {
                 perror("lseek");
                 fail_file();
         }
@@ -111,13 +113,41 @@ static void *
 umalloc(size_t size)
 {
         void *const addr = malloc(size);
-        if (0 == addr) {
+        if (addr == 0) {
                 fprintf(stderr, "malloc failed: %zu bytes\n", size);
                 fail_file();
         }
         return addr;
 }
 
+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;
+
+static char rel_type_nop;
+
+static int (*make_nop)(void *map, size_t const offset);
+
+static int make_nop_x86(void *map, size_t const offset)
+{
+        uint32_t *ptr;
+        unsigned char *op;
+
+        /* Confirm we have 0xe8 0x0 0x0 0x0 0x0 */
+        ptr = map + offset;
+        if (*ptr != 0)
+                return -1;
+
+        op = map + offset - 1;
+        if (*op != 0xe8)
+                return -1;
+
+        /* convert to nop */
+        ulseek(fd_map, offset - 1, SEEK_SET);
+        uwrite(fd_map, ideal_nop, 5);
+        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
@@ -136,7 +166,7 @@ static void *mmap_file(char const *fname)
         void *addr;
 
         fd_map = open(fname, O_RDWR);
-        if (0 > fd_map || 0 > fstat(fd_map, &sb)) {
+        if (fd_map < 0 || fstat(fd_map, &sb) < 0) {
                 perror(fname);
                 fail_file();
         }
@@ -147,7 +177,7 @@ static void *mmap_file(char const *fname)
         addr = mmap(0, sb.st_size, PROT_READ|PROT_WRITE, MAP_PRIVATE,
                     fd_map, 0);
         mmap_failed = 0;
-        if (MAP_FAILED == addr) {
+        if (addr == MAP_FAILED) {
                 mmap_failed = 1;
                 addr = umalloc(sb.st_size);
                 uread(fd_map, addr, sb.st_size);
@@ -206,12 +236,13 @@ static uint32_t (*w2)(uint16_t);
 static int
 is_mcounted_section_name(char const *const txtname)
 {
-        return 0 == strcmp(".text",           txtname) ||
-                0 == strcmp(".ref.text",      txtname) ||
-                0 == strcmp(".sched.text",    txtname) ||
-                0 == strcmp(".spinlock.text", txtname) ||
-                0 == strcmp(".irqentry.text", txtname) ||
-                0 == strcmp(".text.unlikely", txtname);
+        return strcmp(".text",           txtname) == 0 ||
+                strcmp(".ref.text",      txtname) == 0 ||
+                strcmp(".sched.text",    txtname) == 0 ||
+                strcmp(".spinlock.text", txtname) == 0 ||
+                strcmp(".irqentry.text", txtname) == 0 ||
+                strcmp(".kprobes.text", txtname) == 0 ||
+                strcmp(".text.unlikely", txtname) == 0;
 }
 
 /* 32 bit and 64 bit are very similar */
@@ -264,43 +295,48 @@ do_file(char const *const fname)
         w8 = w8nat;
         switch (ehdr->e_ident[EI_DATA]) {
                 static unsigned int const endian = 1;
-        default: {
+        default:
                 fprintf(stderr, "unrecognized ELF data encoding %d: %s\n",
                         ehdr->e_ident[EI_DATA], fname);
                 fail_file();
-        } break;
-        case ELFDATA2LSB: {
-                if (1 != *(unsigned char const *)&endian) {
+                break;
+        case ELFDATA2LSB:
+                if (*(unsigned char const *)&endian != 1) {
                         /* main() is big endian, file.o is little endian. */
                         w = w4rev;
                         w2 = w2rev;
                         w8 = w8rev;
                 }
-        } break;
-        case ELFDATA2MSB: {
-                if (0 != *(unsigned char const *)&endian) {
+                break;
+        case ELFDATA2MSB:
+                if (*(unsigned char const *)&endian != 0) {
                         /* main() is little endian, file.o is big endian. */
                         w = w4rev;
                         w2 = w2rev;
                         w8 = w8rev;
                 }
-        } break;
+                break;
         }  /* end switch */
-        if (0 != memcmp(ELFMAG, ehdr->e_ident, SELFMAG)
-        ||  ET_REL != w2(ehdr->e_type)
-        ||  EV_CURRENT != ehdr->e_ident[EI_VERSION]) {
+        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();
         }
 
         gpfx = 0;
         switch (w2(ehdr->e_machine)) {
-        default: {
+        default:
                 fprintf(stderr, "unrecognized e_machine %d %s\n",
                         w2(ehdr->e_machine), fname);
                 fail_file();
-        } break;
-        case EM_386:     reltype = R_386_32;                   break;
+                break;
+        case EM_386:
+                reltype = R_386_32;
+                make_nop = make_nop_x86;
+                ideal_nop = ideal_nop5_x86_32;
+                mcount_adjust_32 = -1;
+                break;
         case EM_ARM:     reltype = R_ARM_ABS32;
                          altmcount = "__gnu_mcount_nc";
                          break;
@@ -311,67 +347,91 @@ do_file(char const *const fname)
         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;
-        case EM_X86_64:  reltype = R_X86_64_64;                break;
+        case EM_X86_64:
+                make_nop = make_nop_x86;
+                ideal_nop = ideal_nop5_x86_64;
+                reltype = R_X86_64_64;
+                mcount_adjust_64 = -1;
+                break;
         }  /* end switch */
 
         switch (ehdr->e_ident[EI_CLASS]) {
-        default: {
+        default:
                 fprintf(stderr, "unrecognized ELF class %d %s\n",
                         ehdr->e_ident[EI_CLASS], fname);
                 fail_file();
-        } break;
-        case ELFCLASS32: {
-                if (sizeof(Elf32_Ehdr) != w2(ehdr->e_ehsize)
-                ||  sizeof(Elf32_Shdr) != w2(ehdr->e_shentsize)) {
+                break;
+        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();
                 }
-                if (EM_S390 == w2(ehdr->e_machine))
+                if (w2(ehdr->e_machine) == EM_S390) {
                         reltype = R_390_32;
-                if (EM_MIPS == w2(ehdr->e_machine)) {
+                        mcount_adjust_32 = -4;
+                }
+                if (w2(ehdr->e_machine) == EM_MIPS) {
                         reltype = R_MIPS_32;
                         is_fake_mcount32 = MIPS32_is_fake_mcount;
                 }
                 do32(ehdr, fname, reltype);
-        } break;
+                break;
         case ELFCLASS64: {
                 Elf64_Ehdr *const ghdr = (Elf64_Ehdr *)ehdr;
-                if (sizeof(Elf64_Ehdr) != w2(ghdr->e_ehsize)
-                ||  sizeof(Elf64_Shdr) != w2(ghdr->e_shentsize)) {
+                if (w2(ghdr->e_ehsize) != sizeof(Elf64_Ehdr)
+                ||  w2(ghdr->e_shentsize) != sizeof(Elf64_Shdr)) {
                         fprintf(stderr,
                                 "unrecognized ET_REL file: %s\n", fname);
                         fail_file();
                 }
-                if (EM_S390 == w2(ghdr->e_machine))
+                if (w2(ghdr->e_machine) == EM_S390) {
                         reltype = R_390_64;
-                if (EM_MIPS == w2(ghdr->e_machine)) {
+                        mcount_adjust_64 = -8;
+                }
+                if (w2(ghdr->e_machine) == EM_MIPS) {
                         reltype = R_MIPS_64;
                         Elf64_r_sym = MIPS64_r_sym;
                         Elf64_r_info = MIPS64_r_info;
                         is_fake_mcount64 = MIPS64_is_fake_mcount;
                 }
                 do64(ghdr, fname, reltype);
-        } break;
+                break;
+        }
         }  /* end switch */
 
         cleanup();
 }
 
 int
-main(int argc, char const *argv[])
+main(int argc, char *argv[])
 {
         const char ftrace[] = "/ftrace.o";
         int ftrace_size = sizeof(ftrace) - 1;
         int n_error = 0;  /* gcc-4.3.0 false positive complaint */
+        int c;
+        int i;
+
+        while ((c = getopt(argc, argv, "w")) >= 0) {
+                switch (c) {
+                case 'w':
+                        warn_on_notrace_sect = 1;
+                        break;
+                default:
+                        fprintf(stderr, "usage: recordmcount [-w] file.o...\n");
+                        return 0;
+                }
+        }
 
-        if (argc <= 1) {
-                fprintf(stderr, "usage: recordmcount file.o...\n");
+        if ((argc - optind) < 1) {
+                fprintf(stderr, "usage: recordmcount [-w] file.o...\n");
                 return 0;
         }
 
         /* Process each file in turn, allowing deep failure. */
-        for (--argc, ++argv; 0 < argc; --argc, ++argv) {
+        for (i = optind; i < argc; i++) {
+                char *file = argv[i];
                 int const sjval = setjmp(jmpenv);
                 int len;
 
@@ -380,29 +440,29 @@ main(int argc, char const *argv[])
                  * function but does not call it. Since ftrace.o should
                  * not be traced anyway, we just skip it.
                  */
-                len = strlen(argv[0]);
+                len = strlen(file);
                 if (len >= ftrace_size &&
-                    strcmp(argv[0] + (len - ftrace_size), ftrace) == 0)
+                    strcmp(file + (len - ftrace_size), ftrace) == 0)
                         continue;
 
                 switch (sjval) {
-                default: {
-                        fprintf(stderr, "internal error: %s\n", argv[0]);
+                default:
+                        fprintf(stderr, "internal error: %s\n", file);
                         exit(1);
-                } break;
-                case SJ_SETJMP: {  /* normal sequence */
+                        break;
+                case SJ_SETJMP:    /* normal sequence */
                         /* Avoid problems if early cleanup() */
                         fd_map = -1;
                         ehdr_curr = NULL;
                         mmap_failed = 1;
-                        do_file(argv[0]);
-                } break;
-                case SJ_FAIL: {  /* error in do_file or below */
+                        do_file(file);
+                        break;
+                case SJ_FAIL:    /* error in do_file or below */
                         ++n_error;
-                } break;
-                case SJ_SUCCEED: {  /* premature success */
+                        break;
+                case SJ_SUCCEED:    /* premature success */
                         /* do nothing */
-                } break;
+                        break;
                 }  /* end switch */
         }
         return !!n_error;