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-rw-r--r--scripts/recordmcount.c168
1 files changed, 114 insertions, 54 deletions
diff --git a/scripts/recordmcount.c b/scripts/recordmcount.c
index f9f6f52db772..ee52cb8e17ad 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;
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.