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Merge branch 'tip/perf/core-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/core

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This commit is contained in:
Ingo Molnar 2011-05-18 19:46:10 +02:00
commit af2d03d4aa
9 changed files with 274 additions and 106 deletions
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1
Makefile
View File

@ -1268,6 +1268,7 @@ help:
@echo ' make C=1 [targets] Check all c source with $$CHECK (sparse by default)'
@echo ' make C=2 [targets] Force check of all c source with $$CHECK'
@echo ' make W=1 [targets] Enable extra gcc checks'
@echo ' make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
@echo ''
@echo 'Execute "make" or "make all" to build all targets marked with [*] '
@echo 'For further info see the ./README file'

4
arch/s390/include/asm/ftrace.h
View File

@ -11,15 +11,13 @@ struct dyn_arch_ftrace { };
#ifdef CONFIG_64BIT
#define MCOUNT_INSN_SIZE 12
#define MCOUNT_OFFSET 8
#else
#define MCOUNT_INSN_SIZE 20
#define MCOUNT_OFFSET 4
#endif
static inline unsigned long ftrace_call_adjust(unsigned long addr)
{
return addr - MCOUNT_OFFSET;
return addr;
}
#endif /* __ASSEMBLY__ */

7
arch/x86/include/asm/ftrace.h
View File

@ -38,11 +38,10 @@ extern void mcount(void);
static inline unsigned long ftrace_call_adjust(unsigned long addr)
{
/*
* call mcount is "e8 <4 byte offset>"
* The addr points to the 4 byte offset and the caller of this
* function wants the pointer to e8. Simply subtract one.
* addr is the address of the mcount call instruction.
* recordmcount does the necessary offset calculation.
*/
return addr - 1;
return addr;
}
#ifdef CONFIG_DYNAMIC_FTRACE

2
arch/x86/include/asm/setup.h
View File

@ -88,7 +88,7 @@ void *extend_brk(size_t size, size_t align);
* executable.)
*/
#define RESERVE_BRK(name,sz) \
static void __section(.discard.text) __used \
static void __section(.discard.text) __used notrace \
__brk_reservation_fn_##name##__(void) { \
asm volatile ( \
".pushsection .brk_reservation,\"aw\",@nobits;" \

14
include/linux/init.h
View File

@ -79,29 +79,29 @@
#define __exitused __used
#endif
#define __exit __section(.exit.text) __exitused __cold
#define __exit __section(.exit.text) __exitused __cold notrace
/* Used for HOTPLUG */
#define __devinit __section(.devinit.text) __cold
#define __devinit __section(.devinit.text) __cold notrace
#define __devinitdata __section(.devinit.data)
#define __devinitconst __section(.devinit.rodata)
#define __devexit __section(.devexit.text) __exitused __cold
#define __devexit __section(.devexit.text) __exitused __cold notrace
#define __devexitdata __section(.devexit.data)
#define __devexitconst __section(.devexit.rodata)
/* Used for HOTPLUG_CPU */
#define __cpuinit __section(.cpuinit.text) __cold
#define __cpuinit __section(.cpuinit.text) __cold notrace
#define __cpuinitdata __section(.cpuinit.data)
#define __cpuinitconst __section(.cpuinit.rodata)
#define __cpuexit __section(.cpuexit.text) __exitused __cold
#define __cpuexit __section(.cpuexit.text) __exitused __cold notrace
#define __cpuexitdata __section(.cpuexit.data)
#define __cpuexitconst __section(.cpuexit.rodata)
/* Used for MEMORY_HOTPLUG */
#define __meminit __section(.meminit.text) __cold
#define __meminit __section(.meminit.text) __cold notrace
#define __meminitdata __section(.meminit.data)
#define __meminitconst __section(.meminit.rodata)
#define __memexit __section(.memexit.text) __exitused __cold
#define __memexit __section(.memexit.text) __exitused __cold notrace
#define __memexitdata __section(.memexit.data)
#define __memexitconst __section(.memexit.rodata)

5
scripts/Makefile.build
View File

@ -244,13 +244,16 @@ endif
ifdef CONFIG_FTRACE_MCOUNT_RECORD
ifdef BUILD_C_RECORDMCOUNT
ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
RECORDMCOUNT_FLAGS = -w
endif
# Due to recursion, we must skip empty.o.
# The empty.o file is created in the make process in order to determine
# the target endianness and word size. It is made before all other C
# files, including recordmcount.
sub_cmd_record_mcount = \
if [ $(@) != "scripts/mod/empty.o" ]; then \
$(objtree)/scripts/recordmcount "$(@)"; \
$(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)"; \
fi;
else
sub_cmd_record_mcount = set -e ; perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \

168
scripts/recordmcount.c
View File

@ -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;
if (argc <= 1) {
fprintf(stderr, "usage: recordmcount file.o...\n");
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 - 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;

174
scripts/recordmcount.h
View File

@ -22,11 +22,15 @@
#undef is_fake_mcount
#undef fn_is_fake_mcount
#undef MIPS_is_fake_mcount
#undef mcount_adjust
#undef sift_rel_mcount
#undef nop_mcount
#undef find_secsym_ndx
#undef __has_rel_mcount
#undef has_rel_mcount
#undef tot_relsize
#undef get_mcountsym
#undef get_sym_str_and_relp
#undef do_func
#undef Elf_Addr
#undef Elf_Ehdr
@ -49,14 +53,18 @@
#ifdef RECORD_MCOUNT_64
# define append_func append64
# define sift_rel_mcount sift64_rel_mcount
# define nop_mcount nop_mcount_64
# define find_secsym_ndx find64_secsym_ndx
# define __has_rel_mcount __has64_rel_mcount
# define has_rel_mcount has64_rel_mcount
# define tot_relsize tot64_relsize
# define get_sym_str_and_relp get_sym_str_and_relp_64
# define do_func do64
# define get_mcountsym get_mcountsym_64
# define is_fake_mcount is_fake_mcount64
# define fn_is_fake_mcount fn_is_fake_mcount64
# define MIPS_is_fake_mcount MIPS64_is_fake_mcount
# define mcount_adjust mcount_adjust_64
# define Elf_Addr Elf64_Addr
# define Elf_Ehdr Elf64_Ehdr
# define Elf_Shdr Elf64_Shdr
@ -77,14 +85,18 @@
#else
# define append_func append32
# define sift_rel_mcount sift32_rel_mcount
# define nop_mcount nop_mcount_32
# define find_secsym_ndx find32_secsym_ndx
# define __has_rel_mcount __has32_rel_mcount
# define has_rel_mcount has32_rel_mcount
# define tot_relsize tot32_relsize
# define get_sym_str_and_relp get_sym_str_and_relp_32
# define do_func do32
# define get_mcountsym get_mcountsym_32
# define is_fake_mcount is_fake_mcount32
# define fn_is_fake_mcount fn_is_fake_mcount32
# define MIPS_is_fake_mcount MIPS32_is_fake_mcount
# define mcount_adjust mcount_adjust_32
# define Elf_Addr Elf32_Addr
# define Elf_Ehdr Elf32_Ehdr
# define Elf_Shdr Elf32_Shdr
@ -123,6 +135,8 @@ static void fn_ELF_R_INFO(Elf_Rel *const rp, unsigned sym, unsigned type)
}
static void (*Elf_r_info)(Elf_Rel *const rp, unsigned sym, unsigned type) = fn_ELF_R_INFO;
static int mcount_adjust = 0;
/*
* MIPS mcount long call has 2 _mcount symbols, only the position of the 1st
* _mcount symbol is needed for dynamic function tracer, with it, to disable
@ -234,6 +248,49 @@ static void append_func(Elf_Ehdr *const ehdr,
uwrite(fd_map, ehdr, sizeof(*ehdr));
}
static unsigned get_mcountsym(Elf_Sym const *const sym0,
Elf_Rel const *relp,
char const *const str0)
{
unsigned mcountsym = 0;
Elf_Sym const *const symp =
&sym0[Elf_r_sym(relp)];
char const *symname = &str0[w(symp->st_name)];
char const *mcount = gpfx == '_' ? "_mcount" : "mcount";
if (symname[0] == '.')
++symname; /* ppc64 hack */
if (strcmp(mcount, symname) == 0 ||
(altmcount && strcmp(altmcount, symname) == 0))
mcountsym = Elf_r_sym(relp);
return mcountsym;
}
static void get_sym_str_and_relp(Elf_Shdr const *const relhdr,
Elf_Ehdr const *const ehdr,
Elf_Sym const **sym0,
char const **str0,
Elf_Rel const **relp)
{
Elf_Shdr *const shdr0 = (Elf_Shdr *)(_w(ehdr->e_shoff)
+ (void *)ehdr);
unsigned const symsec_sh_link = w(relhdr->sh_link);
Elf_Shdr const *const symsec = &shdr0[symsec_sh_link];
Elf_Shdr const *const strsec = &shdr0[w(symsec->sh_link)];
Elf_Rel const *const rel0 = (Elf_Rel const *)(_w(relhdr->sh_offset)
+ (void *)ehdr);
*sym0 = (Elf_Sym const *)(_w(symsec->sh_offset)
+ (void *)ehdr);
*str0 = (char const *)(_w(strsec->sh_offset)
+ (void *)ehdr);
*relp = rel0;
}
/*
* Look at the relocations in order to find the calls to mcount.
* Accumulate the section offsets that are found, and their relocation info,
@ -250,47 +307,27 @@ static uint_t *sift_rel_mcount(uint_t *mlocp,
{
uint_t *const mloc0 = mlocp;
Elf_Rel *mrelp = *mrelpp;
Elf_Shdr *const shdr0 = (Elf_Shdr *)(_w(ehdr->e_shoff)
+ (void *)ehdr);
unsigned const symsec_sh_link = w(relhdr->sh_link);
Elf_Shdr const *const symsec = &shdr0[symsec_sh_link];
Elf_Sym const *const sym0 = (Elf_Sym const *)(_w(symsec->sh_offset)
+ (void *)ehdr);
Elf_Shdr const *const strsec = &shdr0[w(symsec->sh_link)];
char const *const str0 = (char const *)(_w(strsec->sh_offset)
+ (void *)ehdr);
Elf_Rel const *const rel0 = (Elf_Rel const *)(_w(relhdr->sh_offset)
+ (void *)ehdr);
Elf_Sym const *sym0;
char const *str0;
Elf_Rel const *relp;
unsigned rel_entsize = _w(relhdr->sh_entsize);
unsigned const nrel = _w(relhdr->sh_size) / rel_entsize;
Elf_Rel const *relp = rel0;
unsigned mcountsym = 0;
unsigned t;
for (t = nrel; t; --t) {
if (!mcountsym) {
Elf_Sym const *const symp =
&sym0[Elf_r_sym(relp)];
char const *symname = &str0[w(symp->st_name)];
char const *mcount = '_' == gpfx ? "_mcount" : "mcount";
get_sym_str_and_relp(relhdr, ehdr, &sym0, &str0, &relp);
if ('.' == symname[0])
++symname; /* ppc64 hack */
if (0 == strcmp(mcount, symname) ||
(altmcount && 0 == strcmp(altmcount, symname)))
mcountsym = Elf_r_sym(relp);
}
for (t = nrel; t; --t) {
if (!mcountsym)
mcountsym = get_mcountsym(sym0, relp, str0);
if (mcountsym == Elf_r_sym(relp) && !is_fake_mcount(relp)) {
uint_t const addend = _w(_w(relp->r_offset) - recval);
uint_t const addend =
_w(_w(relp->r_offset) - recval + mcount_adjust);
mrelp->r_offset = _w(offbase
+ ((void *)mlocp - (void *)mloc0));
Elf_r_info(mrelp, recsym, reltype);
if (sizeof(Elf_Rela) == rel_entsize) {
if (rel_entsize == sizeof(Elf_Rela)) {
((Elf_Rela *)mrelp)->r_addend = addend;
*mlocp++ = 0;
} else
@ -304,6 +341,63 @@ static uint_t *sift_rel_mcount(uint_t *mlocp,
return mlocp;
}
/*
* Read the relocation table again, but this time its called on sections
* that are not going to be traced. The mcount calls here will be converted
* into nops.
*/
static void nop_mcount(Elf_Shdr const *const relhdr,
Elf_Ehdr const *const ehdr,
const char *const txtname)
{
Elf_Shdr *const shdr0 = (Elf_Shdr *)(_w(ehdr->e_shoff)
+ (void *)ehdr);
Elf_Sym const *sym0;
char const *str0;
Elf_Rel const *relp;
Elf_Shdr const *const shdr = &shdr0[w(relhdr->sh_info)];
unsigned rel_entsize = _w(relhdr->sh_entsize);
unsigned const nrel = _w(relhdr->sh_size) / rel_entsize;
unsigned mcountsym = 0;
unsigned t;
int once = 0;
get_sym_str_and_relp(relhdr, ehdr, &sym0, &str0, &relp);
for (t = nrel; t; --t) {
int ret = -1;
if (!mcountsym)
mcountsym = get_mcountsym(sym0, relp, str0);
if (mcountsym == Elf_r_sym(relp) && !is_fake_mcount(relp)) {
if (make_nop)
ret = make_nop((void *)ehdr, shdr->sh_offset + relp->r_offset);
if (warn_on_notrace_sect && !once) {
printf("Section %s has mcount callers being ignored\n",
txtname);
once = 1;
/* just warn? */
if (!make_nop)
return;
}
}
/*
* If we successfully removed the mcount, mark the relocation
* as a nop (don't do anything with it).
*/
if (!ret) {
Elf_Rel rel;
rel = *(Elf_Rel *)relp;
Elf_r_info(&rel, Elf_r_sym(relp), rel_type_nop);
ulseek(fd_map, (void *)relp - (void *)ehdr, SEEK_SET);
uwrite(fd_map, &rel, sizeof(rel));
}
relp = (Elf_Rel const *)(rel_entsize + (void *)relp);
}
}
/*
* Find a symbol in the given section, to be used as the base for relocating
@ -354,13 +448,13 @@ __has_rel_mcount(Elf_Shdr const *const relhdr, /* is SHT_REL or SHT_RELA */
Elf_Shdr const *const txthdr = &shdr0[w(relhdr->sh_info)];
char const *const txtname = &shstrtab[w(txthdr->sh_name)];
if (0 == strcmp("__mcount_loc", txtname)) {
if (strcmp("__mcount_loc", txtname) == 0) {
fprintf(stderr, "warning: __mcount_loc already exists: %s\n",
fname);
succeed_file();
}
if (SHT_PROGBITS != w(txthdr->sh_type) ||
!is_mcounted_section_name(txtname))
if (w(txthdr->sh_type) != SHT_PROGBITS ||
!(w(txthdr->sh_flags) & SHF_EXECINSTR))
return NULL;
return txtname;
}
@ -370,7 +464,7 @@ static char const *has_rel_mcount(Elf_Shdr const *const relhdr,
char const *const shstrtab,
char const *const fname)
{
if (SHT_REL != w(relhdr->sh_type) && SHT_RELA != w(relhdr->sh_type))
if (w(relhdr->sh_type) != SHT_REL && w(relhdr->sh_type) != SHT_RELA)
return NULL;
return __has_rel_mcount(relhdr, shdr0, shstrtab, fname);
}
@ -383,9 +477,11 @@ static unsigned tot_relsize(Elf_Shdr const *const shdr0,
{
unsigned totrelsz = 0;
Elf_Shdr const *shdrp = shdr0;
char const *txtname;
for (; nhdr; --nhdr, ++shdrp) {
if (has_rel_mcount(shdrp, shdr0, shstrtab, fname))
txtname = has_rel_mcount(shdrp, shdr0, shstrtab, fname);
if (txtname && is_mcounted_section_name(txtname))
totrelsz += _w(shdrp->sh_size);
}
return totrelsz;
@ -421,7 +517,7 @@ do_func(Elf_Ehdr *const ehdr, char const *const fname, unsigned const reltype)
for (relhdr = shdr0, k = nhdr; k; --k, ++relhdr) {
char const *const txtname = has_rel_mcount(relhdr, shdr0,
shstrtab, fname);
if (txtname) {
if (txtname && is_mcounted_section_name(txtname)) {
uint_t recval = 0;
unsigned const recsym = find_secsym_ndx(
w(relhdr->sh_info), txtname, &recval,
@ -432,6 +528,12 @@ do_func(Elf_Ehdr *const ehdr, char const *const fname, unsigned const reltype)
mlocp = sift_rel_mcount(mlocp,
(void *)mlocp - (void *)mloc0, &mrelp,
relhdr, ehdr, recsym, recval, reltype);
} else if (txtname && (warn_on_notrace_sect || make_nop)) {
/*
* This section is ignored by ftrace, but still
* has mcount calls. Convert them to nops now.
*/
nop_mcount(relhdr, ehdr, txtname);
}
}
if (mloc0 != mlocp) {

5
scripts/recordmcount.pl
View File

@ -134,6 +134,7 @@ my %text_sections = (
".sched.text" => 1,
".spinlock.text" => 1,
".irqentry.text" => 1,
".kprobes.text" => 1,
".text.unlikely" => 1,
);
@ -222,6 +223,7 @@ if ($arch eq "x86_64") {
$mcount_regex = "^\\s*([0-9a-fA-F]+):.*\\smcount([+-]0x[0-9a-zA-Z]+)?\$";
$type = ".quad";
$alignment = 8;
$mcount_adjust = -1;
# force flags for this arch
$ld .= " -m elf_x86_64";
@ -231,6 +233,7 @@ if ($arch eq "x86_64") {
} elsif ($arch eq "i386") {
$alignment = 4;
$mcount_adjust = -1;
# force flags for this arch
$ld .= " -m elf_i386";
@ -240,12 +243,14 @@ if ($arch eq "x86_64") {
} elsif ($arch eq "s390" && $bits == 32) {
$mcount_regex = "^\\s*([0-9a-fA-F]+):\\s*R_390_32\\s+_mcount\$";
$mcount_adjust = -4;
$alignment = 4;
$ld .= " -m elf_s390";
$cc .= " -m31";
} elsif ($arch eq "s390" && $bits == 64) {
$mcount_regex = "^\\s*([0-9a-fA-F]+):\\s*R_390_(PC|PLT)32DBL\\s+_mcount\\+0x2\$";
$mcount_adjust = -8;
$alignment = 8;
$type = ".quad";
$ld .= " -m elf64_s390";