diff options
| -rw-r--r-- | Makefile | 1 | ||||
| -rw-r--r-- | arch/s390/include/asm/ftrace.h | 4 | ||||
| -rw-r--r-- | arch/x86/include/asm/ftrace.h | 7 | ||||
| -rw-r--r-- | arch/x86/include/asm/setup.h | 2 | ||||
| -rw-r--r-- | include/linux/init.h | 14 | ||||
| -rw-r--r-- | scripts/Makefile.build | 5 | ||||
| -rw-r--r-- | scripts/recordmcount.c | 168 | ||||
| -rw-r--r-- | scripts/recordmcount.h | 174 | ||||
| -rwxr-xr-x | scripts/recordmcount.pl | 5 |
9 files changed, 274 insertions, 106 deletions
@@ -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' diff --git a/arch/s390/include/asm/ftrace.h b/arch/s390/include/asm/ftrace.h index 3c29be4..b7931fa 100644 --- a/arch/s390/include/asm/ftrace.h +++ b/arch/s390/include/asm/ftrace.h @@ -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__ */ diff --git a/arch/x86/include/asm/ftrace.h b/arch/x86/include/asm/ftrace.h index db24c22..268c783 100644 --- a/arch/x86/include/asm/ftrace.h +++ b/arch/x86/include/asm/ftrace.h @@ -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 diff --git a/arch/x86/include/asm/setup.h b/arch/x86/include/asm/setup.h index db8aa19..647d8a0 100644 --- a/arch/x86/include/asm/setup.h +++ b/arch/x86/include/asm/setup.h @@ -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;" \ diff --git a/include/linux/init.h b/include/linux/init.h index 577671c..9146f39 100644 --- a/include/linux/init.h +++ b/include/linux/init.h @@ -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) diff --git a/scripts/Makefile.build b/scripts/Makefile.build index d5f925a..fdca952 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -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)" \ diff --git a/scripts/recordmcount.c b/scripts/recordmcount.c index f9f6f52..ee52cb8 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 baf187b..4be6036 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 4be0dee..858966a 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"; |