diff options
Diffstat (limited to 'cddl/contrib/opensolaris/lib/libdtrace/common/drti.c')
| -rw-r--r-- | cddl/contrib/opensolaris/lib/libdtrace/common/drti.c | 168 |
1 files changed, 161 insertions, 7 deletions
diff --git a/cddl/contrib/opensolaris/lib/libdtrace/common/drti.c b/cddl/contrib/opensolaris/lib/libdtrace/common/drti.c index 1ae8283..bce8038 100644 --- a/cddl/contrib/opensolaris/lib/libdtrace/common/drti.c +++ b/cddl/contrib/opensolaris/lib/libdtrace/common/drti.c @@ -34,6 +34,8 @@ #include <stdlib.h> #include <string.h> #include <errno.h> +#include <libelf.h> +#include <gelf.h> /* * In Solaris 10 GA, the only mechanism for communicating helper information @@ -53,12 +55,16 @@ */ static const char *devnamep = "/dev/dtrace/helper"; +#if defined(sun) static const char *olddevname = "/devices/pseudo/dtrace@0:helper"; +#endif static const char *modname; /* Name of this load object */ static int gen; /* DOF helper generation */ +#if defined(sun) extern dof_hdr_t __SUNW_dof; /* DOF defined in the .SUNW_dof section */ -static boolean_t dof_init_debug = B_FALSE; /* From DTRACE_DOF_INIT_DEBUG */ +#endif +static boolean_t dof_init_debug = B_TRUE; /* From DTRACE_DOF_INIT_DEBUG */ static void dprintf(int debug, const char *fmt, ...) @@ -83,6 +89,36 @@ dprintf(int debug, const char *fmt, ...) va_end(ap); } +#if !defined(sun) +static void +fixsymbol(Elf *e, Elf_Data *data, size_t idx, int nprobes, char *buf, + dof_sec_t *sec, int *fixedprobes, char *dofstrtab) +{ + GElf_Sym sym; + char *s; + unsigned char *funcname; + dof_probe_t *prb; + int j = 0; + int ndx; + + while (gelf_getsym(data, j++, &sym) != NULL) { + prb = (dof_probe_t *)(buf + sec->dofs_offset); + + for (ndx = nprobes; ndx; ndx--, prb += 1) { + funcname = dofstrtab + prb->dofpr_func; + s = elf_strptr(e, idx, sym.st_name); + if (strcmp(s, funcname) == 0) { + dprintf(1, "fixing %s() symbol\n", s); + prb->dofpr_addr = sym.st_value; + (*fixedprobes)++; + } + } + if (*fixedprobes == nprobes) + break; + } +} +#endif + #if defined(sun) #pragma init(dtrace_dof_init) #else @@ -92,22 +128,39 @@ static void dtrace_dof_init(void) __attribute__ ((constructor)); static void dtrace_dof_init(void) { +#if defined(sun) dof_hdr_t *dof = &__SUNW_dof; +#else + dof_hdr_t *dof = NULL; +#endif #ifdef _LP64 Elf64_Ehdr *elf; #else Elf32_Ehdr *elf; #endif dof_helper_t dh; -#if defined(sun) Link_map *lmp; +#if defined(sun) Lmid_t lmid; #else - struct link_map *lmp; u_long lmid = 0; + dof_sec_t *sec; + size_t i; #endif int fd; const char *p; +#if !defined(sun) + Elf *e; + Elf_Scn *scn = NULL; + Elf_Data *symtabdata = NULL, *dynsymdata = NULL; + GElf_Shdr shdr; + int efd, nprobes; + char *s; + size_t shstridx, symtabidx = 0, dynsymidx = 0; + unsigned char *dofstrtab = NULL; + unsigned char *buf; + int fixedprobes = 0; +#endif if (getenv("DTRACE_DOF_INIT_DISABLE") != NULL) return; @@ -127,10 +180,46 @@ dtrace_dof_init(void) } #endif + if ((modname = strrchr(lmp->l_name, '/')) == NULL) modname = lmp->l_name; else modname++; +#if !defined(sun) + elf_version(EV_CURRENT); + if ((efd = open(lmp->l_name, O_RDONLY, 0)) < 0) { + dprintf(1, "couldn't open file for reading\n"); + return; + } + if ((e = elf_begin(efd, ELF_C_READ, NULL)) == NULL) { + dprintf(1, "elf_begin failed\n"); + close(efd); + return; + } + elf_getshdrstrndx(e, &shstridx); + dof = NULL; + while ((scn = elf_nextscn(e, scn)) != NULL) { + gelf_getshdr(scn, &shdr); + if (shdr.sh_type == SHT_SYMTAB) { + symtabidx = shdr.sh_link; + symtabdata = elf_getdata(scn, NULL); + } else if (shdr.sh_type == SHT_DYNSYM) { + dynsymidx = shdr.sh_link; + dynsymdata = elf_getdata(scn, NULL); + } else if (shdr.sh_type == SHT_PROGBITS) { + s = elf_strptr(e, shstridx, shdr.sh_name); + if (s && strcmp(s, ".SUNW_dof") == 0) { + dof = elf_getdata(scn, NULL)->d_buf; + } + } + } + if (dof == NULL) { + dprintf(1, "SUNW_dof section not found\n"); + elf_end(e); + close(efd); + return; + } +#endif if (dof->dofh_ident[DOF_ID_MAG0] != DOF_MAG_MAG0 || dof->dofh_ident[DOF_ID_MAG1] != DOF_MAG_MAG1 || @@ -158,7 +247,7 @@ dtrace_dof_init(void) if ((fd = open64(devnamep, O_RDWR)) < 0) { dprintf(1, "failed to open helper device %s", devnamep); - +#if defined(sun) /* * If the device path wasn't explicitly set, try again with * the old device path. @@ -172,14 +261,79 @@ dtrace_dof_init(void) dprintf(1, "failed to open helper device %s", devnamep); return; } +#else + return; +#endif } - +#if !defined(sun) + /* + * We need to fix the base address of each probe since this wasn't + * done by ld(1). (ld(1) needs to grow support for parsing the + * SUNW_dof section). + * + * The complexity of this is not that great. The first for loop + * iterates over the sections inside the DOF file. There are usually + * 10 sections here. We asume the STRTAB section comes first and the + * PROBES section comes after. Since we are only interested in fixing + * data inside the PROBES section we quit the for loop after processing + * the PROBES section. It's usually the case that the first section + * is the STRTAB section and the second section is the PROBES section, + * so this for loop is not meaningful when doing complexity analysis. + * + * After finding the probes section, we iterate over the symbols + * in the symtab section. When we find a symbol name that matches + * the probe function name, we fix it. If we have fixed all the + * probes, we exit all the loops and we are done. + * The number of probes is given by the variable 'nprobes' and this + * depends entirely on the user, but some optimizations were done. + * + * We are assuming the number of probes is less than the number of + * symbols (libc can have 4k symbols, for example). + */ + sec = (dof_sec_t *)(dof + 1); + buf = (char *)dof; + for (i = 0; i < dof->dofh_secnum; i++, sec++) { + if (sec->dofs_type == DOF_SECT_STRTAB) + dofstrtab = (unsigned char *)(buf + sec->dofs_offset); + else if (sec->dofs_type == DOF_SECT_PROBES && dofstrtab) + break; + + } + nprobes = sec->dofs_size / sec->dofs_entsize; + fixsymbol(e, symtabdata, symtabidx, nprobes, buf, sec, &fixedprobes, + dofstrtab); + if (fixedprobes != nprobes) { + /* + * If we haven't fixed all the probes using the + * symtab section, look inside the dynsym + * section. + */ + fixsymbol(e, dynsymdata, dynsymidx, nprobes, buf, sec, + &fixedprobes, dofstrtab); + } + if (fixedprobes != nprobes) { + fprintf(stderr, "WARNING: number of probes " + "fixed does not match the number of " + "defined probes (%d != %d, " + "respectively)\n", fixedprobes, nprobes); + fprintf(stderr, "WARNING: some probes might " + "not fire or your program might crash\n"); + } +#endif if ((gen = ioctl(fd, DTRACEHIOC_ADDDOF, &dh)) == -1) dprintf(1, "DTrace ioctl failed for DOF at %p", dof); - else + else { dprintf(1, "DTrace ioctl succeeded for DOF at %p\n", dof); +#if !defined(sun) + gen = dh.gen; +#endif + } (void) close(fd); +#if !defined(sun) + elf_end(e); + (void) close(efd); +#endif } #if defined(sun) @@ -198,7 +352,7 @@ dtrace_dof_fini(void) return; } - if ((gen = ioctl(fd, DTRACEHIOC_REMOVE, gen)) == -1) + if ((gen = ioctl(fd, DTRACEHIOC_REMOVE, &gen)) == -1) dprintf(1, "DTrace ioctl failed to remove DOF (%d)\n", gen); else dprintf(1, "DTrace ioctl removed DOF (%d)\n", gen); |
