summaryrefslogtreecommitdiff
path: root/scripts
diff options
context:
space:
mode:
Diffstat (limited to 'scripts')
-rw-r--r--scripts/Makefile.build12
-rw-r--r--scripts/mod/modpost.c16
-rw-r--r--scripts/mod/modpost.h27
-rw-r--r--scripts/module-common.lds11
-rw-r--r--scripts/recordmcount.c168
-rw-r--r--scripts/recordmcount.h174
-rwxr-xr-xscripts/recordmcount.pl5
7 files changed, 291 insertions, 122 deletions
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index d5f925abe4d2..6165622c3e29 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -244,14 +244,19 @@ 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;
+recordmcount_source := $(srctree)/scripts/recordmcount.c \
+ $(srctree)/scripts/recordmcount.h
else
sub_cmd_record_mcount = set -e ; perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
"$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
@@ -259,6 +264,7 @@ sub_cmd_record_mcount = set -e ; perl $(srctree)/scripts/recordmcount.pl "$(ARCH
"$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CFLAGS)" \
"$(LD)" "$(NM)" "$(RM)" "$(MV)" \
"$(if $(part-of-module),1,0)" "$(@)";
+recordmcount_source := $(srctree)/scripts/recordmcount.pl
endif
cmd_record_mcount = \
if [ "$(findstring -pg,$(_c_flags))" = "-pg" ]; then \
@@ -279,13 +285,13 @@ define rule_cc_o_c
endef
# Built-in and composite module parts
-$(obj)/%.o: $(src)/%.c FORCE
+$(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE
$(call cmd,force_checksrc)
$(call if_changed_rule,cc_o_c)
# Single-part modules are special since we need to mark them in $(MODVERDIR)
-$(single-used-m): $(obj)/%.o: $(src)/%.c FORCE
+$(single-used-m): $(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE
$(call cmd,force_checksrc)
$(call if_changed_rule,cc_o_c)
@{ echo $(@:.o=.ko); echo $@; } > $(MODVERDIR)/$(@F:.o=.mod)
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index cd104afcc5f2..413c53693e62 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -420,11 +420,10 @@ static int parse_elf(struct elf_info *info, const char *filename)
return 0;
}
- if (hdr->e_shnum == 0) {
+ if (hdr->e_shnum == SHN_UNDEF) {
/*
* There are more than 64k sections,
* read count from .sh_size.
- * note: it doesn't need shndx2secindex()
*/
info->num_sections = TO_NATIVE(sechdrs[0].sh_size);
}
@@ -432,8 +431,7 @@ static int parse_elf(struct elf_info *info, const char *filename)
info->num_sections = hdr->e_shnum;
}
if (hdr->e_shstrndx == SHN_XINDEX) {
- info->secindex_strings =
- shndx2secindex(TO_NATIVE(sechdrs[0].sh_link));
+ info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link);
}
else {
info->secindex_strings = hdr->e_shstrndx;
@@ -489,7 +487,7 @@ static int parse_elf(struct elf_info *info, const char *filename)
sechdrs[i].sh_offset;
info->symtab_stop = (void *)hdr +
sechdrs[i].sh_offset + sechdrs[i].sh_size;
- sh_link_idx = shndx2secindex(sechdrs[i].sh_link);
+ sh_link_idx = sechdrs[i].sh_link;
info->strtab = (void *)hdr +
sechdrs[sh_link_idx].sh_offset;
}
@@ -516,11 +514,9 @@ static int parse_elf(struct elf_info *info, const char *filename)
if (symtab_shndx_idx != ~0U) {
Elf32_Word *p;
- if (symtab_idx !=
- shndx2secindex(sechdrs[symtab_shndx_idx].sh_link))
+ if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link)
fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n",
- filename,
- shndx2secindex(sechdrs[symtab_shndx_idx].sh_link),
+ filename, sechdrs[symtab_shndx_idx].sh_link,
symtab_idx);
/* Fix endianness */
for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop;
@@ -1446,7 +1442,7 @@ static unsigned int *reloc_location(struct elf_info *elf,
Elf_Shdr *sechdr, Elf_Rela *r)
{
Elf_Shdr *sechdrs = elf->sechdrs;
- int section = shndx2secindex(sechdr->sh_info);
+ int section = sechdr->sh_info;
return (void *)elf->hdr + sechdrs[section].sh_offset +
r->r_offset;
diff --git a/scripts/mod/modpost.h b/scripts/mod/modpost.h
index 0388cfccac8d..2031119080dc 100644
--- a/scripts/mod/modpost.h
+++ b/scripts/mod/modpost.h
@@ -145,33 +145,22 @@ static inline int is_shndx_special(unsigned int i)
return i != SHN_XINDEX && i >= SHN_LORESERVE && i <= SHN_HIRESERVE;
}
-/* shndx is in [0..SHN_LORESERVE) U (SHN_HIRESERVE, 0xfffffff], thus:
- * shndx == 0 <=> sechdrs[0]
- * ......
- * shndx == SHN_LORESERVE-1 <=> sechdrs[SHN_LORESERVE-1]
- * shndx == SHN_HIRESERVE+1 <=> sechdrs[SHN_LORESERVE]
- * shndx == SHN_HIRESERVE+2 <=> sechdrs[SHN_LORESERVE+1]
- * ......
- * fyi: sym->st_shndx is uint16, SHN_LORESERVE = ff00, SHN_HIRESERVE = ffff,
- * so basically we map 0000..feff -> 0000..feff
- * ff00..ffff -> (you are a bad boy, dont do it)
- * 10000..xxxx -> ff00..(xxxx-0x100)
+/*
+ * Move reserved section indices SHN_LORESERVE..SHN_HIRESERVE out of
+ * the way to -256..-1, to avoid conflicting with real section
+ * indices.
*/
-static inline unsigned int shndx2secindex(unsigned int i)
-{
- if (i <= SHN_HIRESERVE)
- return i;
- return i - (SHN_HIRESERVE + 1 - SHN_LORESERVE);
-}
+#define SPECIAL(i) ((i) - (SHN_HIRESERVE + 1))
/* Accessor for sym->st_shndx, hides ugliness of "64k sections" */
static inline unsigned int get_secindex(const struct elf_info *info,
const Elf_Sym *sym)
{
+ if (is_shndx_special(sym->st_shndx))
+ return SPECIAL(sym->st_shndx);
if (sym->st_shndx != SHN_XINDEX)
return sym->st_shndx;
- return shndx2secindex(info->symtab_shndx_start[sym -
- info->symtab_start]);
+ return info->symtab_shndx_start[sym - info->symtab_start];
}
/* file2alias.c */
diff --git a/scripts/module-common.lds b/scripts/module-common.lds
index 47a1f9ae0ede..0865b3e752be 100644
--- a/scripts/module-common.lds
+++ b/scripts/module-common.lds
@@ -5,4 +5,15 @@
*/
SECTIONS {
/DISCARD/ : { *(.discard) }
+
+ __ksymtab : { *(SORT(___ksymtab+*)) }
+ __ksymtab_gpl : { *(SORT(___ksymtab_gpl+*)) }
+ __ksymtab_unused : { *(SORT(___ksymtab_unused+*)) }
+ __ksymtab_unused_gpl : { *(SORT(___ksymtab_unused_gpl+*)) }
+ __ksymtab_gpl_future : { *(SORT(___ksymtab_gpl_future+*)) }
+ __kcrctab : { *(SORT(___kcrctab+*)) }
+ __kcrctab_gpl : { *(SORT(___kcrctab_gpl+*)) }
+ __kcrctab_unused : { *(SORT(___kcrctab_unused+*)) }
+ __kcrctab_unused_gpl : { *(SORT(___kcrctab_unused_gpl+*)) }
+ __kcrctab_gpl_future : { *(SORT(___kcrctab_gpl_future+*)) }
}
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;
diff --git a/scripts/recordmcount.h b/scripts/recordmcount.h
index baf187bee983..4be60364a405 100644
--- a/scripts/recordmcount.h
+++ b/scripts/recordmcount.h
@@ -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;
+ get_sym_str_and_relp(relhdr, ehdr, &sym0, &str0, &relp);
+
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";
-
- if ('.' == symname[0])
- ++symname; /* ppc64 hack */
- if (0 == strcmp(mcount, symname) ||
- (altmcount && 0 == strcmp(altmcount, symname)))
- mcountsym = Elf_r_sym(relp);
- }
+ 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) {
diff --git a/scripts/recordmcount.pl b/scripts/recordmcount.pl
index 4be0deea71ca..858966ab019c 100755
--- a/scripts/recordmcount.pl
+++ b/scripts/recordmcount.pl
@@ -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";
generated by cgit v1.2.3 (git 2.39.0) at 2024-12-25 10:01:24 +0300