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-rw-r--r--tools/perf/util/symbol-elf.c2915
1 files changed, 2915 insertions, 0 deletions
diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
new file mode 100644
index 0000000000..95e99c332d
--- /dev/null
+++ b/tools/perf/util/symbol-elf.c
@@ -0,0 +1,2915 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <fcntl.h>
+#include <stdio.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <inttypes.h>
+
+#include "dso.h"
+#include "map.h"
+#include "maps.h"
+#include "symbol.h"
+#include "symsrc.h"
+#include "demangle-cxx.h"
+#include "demangle-ocaml.h"
+#include "demangle-java.h"
+#include "demangle-rust.h"
+#include "machine.h"
+#include "vdso.h"
+#include "debug.h"
+#include "util/copyfile.h"
+#include <linux/ctype.h>
+#include <linux/kernel.h>
+#include <linux/zalloc.h>
+#include <symbol/kallsyms.h>
+#include <internal/lib.h>
+
+#ifdef HAVE_LIBBFD_SUPPORT
+#define PACKAGE 'perf'
+#include <bfd.h>
+#endif
+
+#if defined(HAVE_LIBBFD_SUPPORT) || defined(HAVE_CPLUS_DEMANGLE_SUPPORT)
+#ifndef DMGL_PARAMS
+#define DMGL_PARAMS (1 << 0) /* Include function args */
+#define DMGL_ANSI (1 << 1) /* Include const, volatile, etc */
+#endif
+#endif
+
+#ifndef EM_AARCH64
+#define EM_AARCH64 183 /* ARM 64 bit */
+#endif
+
+#ifndef EM_LOONGARCH
+#define EM_LOONGARCH 258
+#endif
+
+#ifndef ELF32_ST_VISIBILITY
+#define ELF32_ST_VISIBILITY(o) ((o) & 0x03)
+#endif
+
+/* For ELF64 the definitions are the same. */
+#ifndef ELF64_ST_VISIBILITY
+#define ELF64_ST_VISIBILITY(o) ELF32_ST_VISIBILITY (o)
+#endif
+
+/* How to extract information held in the st_other field. */
+#ifndef GELF_ST_VISIBILITY
+#define GELF_ST_VISIBILITY(val) ELF64_ST_VISIBILITY (val)
+#endif
+
+typedef Elf64_Nhdr GElf_Nhdr;
+
+
+#ifndef HAVE_ELF_GETPHDRNUM_SUPPORT
+static int elf_getphdrnum(Elf *elf, size_t *dst)
+{
+ GElf_Ehdr gehdr;
+ GElf_Ehdr *ehdr;
+
+ ehdr = gelf_getehdr(elf, &gehdr);
+ if (!ehdr)
+ return -1;
+
+ *dst = ehdr->e_phnum;
+
+ return 0;
+}
+#endif
+
+#ifndef HAVE_ELF_GETSHDRSTRNDX_SUPPORT
+static int elf_getshdrstrndx(Elf *elf __maybe_unused, size_t *dst __maybe_unused)
+{
+ pr_err("%s: update your libelf to > 0.140, this one lacks elf_getshdrstrndx().\n", __func__);
+ return -1;
+}
+#endif
+
+#ifndef NT_GNU_BUILD_ID
+#define NT_GNU_BUILD_ID 3
+#endif
+
+/**
+ * elf_symtab__for_each_symbol - iterate thru all the symbols
+ *
+ * @syms: struct elf_symtab instance to iterate
+ * @idx: uint32_t idx
+ * @sym: GElf_Sym iterator
+ */
+#define elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) \
+ for (idx = 0, gelf_getsym(syms, idx, &sym);\
+ idx < nr_syms; \
+ idx++, gelf_getsym(syms, idx, &sym))
+
+static inline uint8_t elf_sym__type(const GElf_Sym *sym)
+{
+ return GELF_ST_TYPE(sym->st_info);
+}
+
+static inline uint8_t elf_sym__visibility(const GElf_Sym *sym)
+{
+ return GELF_ST_VISIBILITY(sym->st_other);
+}
+
+#ifndef STT_GNU_IFUNC
+#define STT_GNU_IFUNC 10
+#endif
+
+static inline int elf_sym__is_function(const GElf_Sym *sym)
+{
+ return (elf_sym__type(sym) == STT_FUNC ||
+ elf_sym__type(sym) == STT_GNU_IFUNC) &&
+ sym->st_name != 0 &&
+ sym->st_shndx != SHN_UNDEF;
+}
+
+static inline bool elf_sym__is_object(const GElf_Sym *sym)
+{
+ return elf_sym__type(sym) == STT_OBJECT &&
+ sym->st_name != 0 &&
+ sym->st_shndx != SHN_UNDEF;
+}
+
+static inline int elf_sym__is_label(const GElf_Sym *sym)
+{
+ return elf_sym__type(sym) == STT_NOTYPE &&
+ sym->st_name != 0 &&
+ sym->st_shndx != SHN_UNDEF &&
+ sym->st_shndx != SHN_ABS &&
+ elf_sym__visibility(sym) != STV_HIDDEN &&
+ elf_sym__visibility(sym) != STV_INTERNAL;
+}
+
+static bool elf_sym__filter(GElf_Sym *sym)
+{
+ return elf_sym__is_function(sym) || elf_sym__is_object(sym);
+}
+
+static inline const char *elf_sym__name(const GElf_Sym *sym,
+ const Elf_Data *symstrs)
+{
+ return symstrs->d_buf + sym->st_name;
+}
+
+static inline const char *elf_sec__name(const GElf_Shdr *shdr,
+ const Elf_Data *secstrs)
+{
+ return secstrs->d_buf + shdr->sh_name;
+}
+
+static inline int elf_sec__is_text(const GElf_Shdr *shdr,
+ const Elf_Data *secstrs)
+{
+ return strstr(elf_sec__name(shdr, secstrs), "text") != NULL;
+}
+
+static inline bool elf_sec__is_data(const GElf_Shdr *shdr,
+ const Elf_Data *secstrs)
+{
+ return strstr(elf_sec__name(shdr, secstrs), "data") != NULL;
+}
+
+static bool elf_sec__filter(GElf_Shdr *shdr, Elf_Data *secstrs)
+{
+ return elf_sec__is_text(shdr, secstrs) ||
+ elf_sec__is_data(shdr, secstrs);
+}
+
+static size_t elf_addr_to_index(Elf *elf, GElf_Addr addr)
+{
+ Elf_Scn *sec = NULL;
+ GElf_Shdr shdr;
+ size_t cnt = 1;
+
+ while ((sec = elf_nextscn(elf, sec)) != NULL) {
+ gelf_getshdr(sec, &shdr);
+
+ if ((addr >= shdr.sh_addr) &&
+ (addr < (shdr.sh_addr + shdr.sh_size)))
+ return cnt;
+
+ ++cnt;
+ }
+
+ return -1;
+}
+
+Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep,
+ GElf_Shdr *shp, const char *name, size_t *idx)
+{
+ Elf_Scn *sec = NULL;
+ size_t cnt = 1;
+
+ /* ELF is corrupted/truncated, avoid calling elf_strptr. */
+ if (!elf_rawdata(elf_getscn(elf, ep->e_shstrndx), NULL))
+ return NULL;
+
+ while ((sec = elf_nextscn(elf, sec)) != NULL) {
+ char *str;
+
+ gelf_getshdr(sec, shp);
+ str = elf_strptr(elf, ep->e_shstrndx, shp->sh_name);
+ if (str && !strcmp(name, str)) {
+ if (idx)
+ *idx = cnt;
+ return sec;
+ }
+ ++cnt;
+ }
+
+ return NULL;
+}
+
+bool filename__has_section(const char *filename, const char *sec)
+{
+ int fd;
+ Elf *elf;
+ GElf_Ehdr ehdr;
+ GElf_Shdr shdr;
+ bool found = false;
+
+ fd = open(filename, O_RDONLY);
+ if (fd < 0)
+ return false;
+
+ elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
+ if (elf == NULL)
+ goto out;
+
+ if (gelf_getehdr(elf, &ehdr) == NULL)
+ goto elf_out;
+
+ found = !!elf_section_by_name(elf, &ehdr, &shdr, sec, NULL);
+
+elf_out:
+ elf_end(elf);
+out:
+ close(fd);
+ return found;
+}
+
+static int elf_read_program_header(Elf *elf, u64 vaddr, GElf_Phdr *phdr)
+{
+ size_t i, phdrnum;
+ u64 sz;
+
+ if (elf_getphdrnum(elf, &phdrnum))
+ return -1;
+
+ for (i = 0; i < phdrnum; i++) {
+ if (gelf_getphdr(elf, i, phdr) == NULL)
+ return -1;
+
+ if (phdr->p_type != PT_LOAD)
+ continue;
+
+ sz = max(phdr->p_memsz, phdr->p_filesz);
+ if (!sz)
+ continue;
+
+ if (vaddr >= phdr->p_vaddr && (vaddr < phdr->p_vaddr + sz))
+ return 0;
+ }
+
+ /* Not found any valid program header */
+ return -1;
+}
+
+static bool want_demangle(bool is_kernel_sym)
+{
+ return is_kernel_sym ? symbol_conf.demangle_kernel : symbol_conf.demangle;
+}
+
+/*
+ * Demangle C++ function signature, typically replaced by demangle-cxx.cpp
+ * version.
+ */
+__weak char *cxx_demangle_sym(const char *str __maybe_unused, bool params __maybe_unused,
+ bool modifiers __maybe_unused)
+{
+#ifdef HAVE_LIBBFD_SUPPORT
+ int flags = (params ? DMGL_PARAMS : 0) | (modifiers ? DMGL_ANSI : 0);
+
+ return bfd_demangle(NULL, str, flags);
+#elif defined(HAVE_CPLUS_DEMANGLE_SUPPORT)
+ int flags = (params ? DMGL_PARAMS : 0) | (modifiers ? DMGL_ANSI : 0);
+
+ return cplus_demangle(str, flags);
+#else
+ return NULL;
+#endif
+}
+
+static char *demangle_sym(struct dso *dso, int kmodule, const char *elf_name)
+{
+ char *demangled = NULL;
+
+ /*
+ * We need to figure out if the object was created from C++ sources
+ * DWARF DW_compile_unit has this, but we don't always have access
+ * to it...
+ */
+ if (!want_demangle(dso->kernel || kmodule))
+ return demangled;
+
+ demangled = cxx_demangle_sym(elf_name, verbose > 0, verbose > 0);
+ if (demangled == NULL) {
+ demangled = ocaml_demangle_sym(elf_name);
+ if (demangled == NULL) {
+ demangled = java_demangle_sym(elf_name, JAVA_DEMANGLE_NORET);
+ }
+ }
+ else if (rust_is_mangled(demangled))
+ /*
+ * Input to Rust demangling is the BFD-demangled
+ * name which it Rust-demangles in place.
+ */
+ rust_demangle_sym(demangled);
+
+ return demangled;
+}
+
+struct rel_info {
+ u32 nr_entries;
+ u32 *sorted;
+ bool is_rela;
+ Elf_Data *reldata;
+ GElf_Rela rela;
+ GElf_Rel rel;
+};
+
+static u32 get_rel_symidx(struct rel_info *ri, u32 idx)
+{
+ idx = ri->sorted ? ri->sorted[idx] : idx;
+ if (ri->is_rela) {
+ gelf_getrela(ri->reldata, idx, &ri->rela);
+ return GELF_R_SYM(ri->rela.r_info);
+ }
+ gelf_getrel(ri->reldata, idx, &ri->rel);
+ return GELF_R_SYM(ri->rel.r_info);
+}
+
+static u64 get_rel_offset(struct rel_info *ri, u32 x)
+{
+ if (ri->is_rela) {
+ GElf_Rela rela;
+
+ gelf_getrela(ri->reldata, x, &rela);
+ return rela.r_offset;
+ } else {
+ GElf_Rel rel;
+
+ gelf_getrel(ri->reldata, x, &rel);
+ return rel.r_offset;
+ }
+}
+
+static int rel_cmp(const void *a, const void *b, void *r)
+{
+ struct rel_info *ri = r;
+ u64 a_offset = get_rel_offset(ri, *(const u32 *)a);
+ u64 b_offset = get_rel_offset(ri, *(const u32 *)b);
+
+ return a_offset < b_offset ? -1 : (a_offset > b_offset ? 1 : 0);
+}
+
+static int sort_rel(struct rel_info *ri)
+{
+ size_t sz = sizeof(ri->sorted[0]);
+ u32 i;
+
+ ri->sorted = calloc(ri->nr_entries, sz);
+ if (!ri->sorted)
+ return -1;
+ for (i = 0; i < ri->nr_entries; i++)
+ ri->sorted[i] = i;
+ qsort_r(ri->sorted, ri->nr_entries, sz, rel_cmp, ri);
+ return 0;
+}
+
+/*
+ * For x86_64, the GNU linker is putting IFUNC information in the relocation
+ * addend.
+ */
+static bool addend_may_be_ifunc(GElf_Ehdr *ehdr, struct rel_info *ri)
+{
+ return ehdr->e_machine == EM_X86_64 && ri->is_rela &&
+ GELF_R_TYPE(ri->rela.r_info) == R_X86_64_IRELATIVE;
+}
+
+static bool get_ifunc_name(Elf *elf, struct dso *dso, GElf_Ehdr *ehdr,
+ struct rel_info *ri, char *buf, size_t buf_sz)
+{
+ u64 addr = ri->rela.r_addend;
+ struct symbol *sym;
+ GElf_Phdr phdr;
+
+ if (!addend_may_be_ifunc(ehdr, ri))
+ return false;
+
+ if (elf_read_program_header(elf, addr, &phdr))
+ return false;
+
+ addr -= phdr.p_vaddr - phdr.p_offset;
+
+ sym = dso__find_symbol_nocache(dso, addr);
+
+ /* Expecting the address to be an IFUNC or IFUNC alias */
+ if (!sym || sym->start != addr || (sym->type != STT_GNU_IFUNC && !sym->ifunc_alias))
+ return false;
+
+ snprintf(buf, buf_sz, "%s@plt", sym->name);
+
+ return true;
+}
+
+static void exit_rel(struct rel_info *ri)
+{
+ zfree(&ri->sorted);
+}
+
+static bool get_plt_sizes(struct dso *dso, GElf_Ehdr *ehdr, GElf_Shdr *shdr_plt,
+ u64 *plt_header_size, u64 *plt_entry_size)
+{
+ switch (ehdr->e_machine) {
+ case EM_ARM:
+ *plt_header_size = 20;
+ *plt_entry_size = 12;
+ return true;
+ case EM_AARCH64:
+ *plt_header_size = 32;
+ *plt_entry_size = 16;
+ return true;
+ case EM_LOONGARCH:
+ *plt_header_size = 32;
+ *plt_entry_size = 16;
+ return true;
+ case EM_SPARC:
+ *plt_header_size = 48;
+ *plt_entry_size = 12;
+ return true;
+ case EM_SPARCV9:
+ *plt_header_size = 128;
+ *plt_entry_size = 32;
+ return true;
+ case EM_386:
+ case EM_X86_64:
+ *plt_entry_size = shdr_plt->sh_entsize;
+ /* Size is 8 or 16, if not, assume alignment indicates size */
+ if (*plt_entry_size != 8 && *plt_entry_size != 16)
+ *plt_entry_size = shdr_plt->sh_addralign == 8 ? 8 : 16;
+ *plt_header_size = *plt_entry_size;
+ break;
+ default: /* FIXME: s390/alpha/mips/parisc/poperpc/sh/xtensa need to be checked */
+ *plt_header_size = shdr_plt->sh_entsize;
+ *plt_entry_size = shdr_plt->sh_entsize;
+ break;
+ }
+ if (*plt_entry_size)
+ return true;
+ pr_debug("Missing PLT entry size for %s\n", dso->long_name);
+ return false;
+}
+
+static bool machine_is_x86(GElf_Half e_machine)
+{
+ return e_machine == EM_386 || e_machine == EM_X86_64;
+}
+
+struct rela_dyn {
+ GElf_Addr offset;
+ u32 sym_idx;
+};
+
+struct rela_dyn_info {
+ struct dso *dso;
+ Elf_Data *plt_got_data;
+ u32 nr_entries;
+ struct rela_dyn *sorted;
+ Elf_Data *dynsym_data;
+ Elf_Data *dynstr_data;
+ Elf_Data *rela_dyn_data;
+};
+
+static void exit_rela_dyn(struct rela_dyn_info *di)
+{
+ zfree(&di->sorted);
+}
+
+static int cmp_offset(const void *a, const void *b)
+{
+ const struct rela_dyn *va = a;
+ const struct rela_dyn *vb = b;
+
+ return va->offset < vb->offset ? -1 : (va->offset > vb->offset ? 1 : 0);
+}
+
+static int sort_rela_dyn(struct rela_dyn_info *di)
+{
+ u32 i, n;
+
+ di->sorted = calloc(di->nr_entries, sizeof(di->sorted[0]));
+ if (!di->sorted)
+ return -1;
+
+ /* Get data for sorting: the offset and symbol index */
+ for (i = 0, n = 0; i < di->nr_entries; i++) {
+ GElf_Rela rela;
+ u32 sym_idx;
+
+ gelf_getrela(di->rela_dyn_data, i, &rela);
+ sym_idx = GELF_R_SYM(rela.r_info);
+ if (sym_idx) {
+ di->sorted[n].sym_idx = sym_idx;
+ di->sorted[n].offset = rela.r_offset;
+ n += 1;
+ }
+ }
+
+ /* Sort by offset */
+ di->nr_entries = n;
+ qsort(di->sorted, n, sizeof(di->sorted[0]), cmp_offset);
+
+ return 0;
+}
+
+static void get_rela_dyn_info(Elf *elf, GElf_Ehdr *ehdr, struct rela_dyn_info *di, Elf_Scn *scn)
+{
+ GElf_Shdr rela_dyn_shdr;
+ GElf_Shdr shdr;
+
+ di->plt_got_data = elf_getdata(scn, NULL);
+
+ scn = elf_section_by_name(elf, ehdr, &rela_dyn_shdr, ".rela.dyn", NULL);
+ if (!scn || !rela_dyn_shdr.sh_link || !rela_dyn_shdr.sh_entsize)
+ return;
+
+ di->nr_entries = rela_dyn_shdr.sh_size / rela_dyn_shdr.sh_entsize;
+ di->rela_dyn_data = elf_getdata(scn, NULL);
+
+ scn = elf_getscn(elf, rela_dyn_shdr.sh_link);
+ if (!scn || !gelf_getshdr(scn, &shdr) || !shdr.sh_link)
+ return;
+
+ di->dynsym_data = elf_getdata(scn, NULL);
+ di->dynstr_data = elf_getdata(elf_getscn(elf, shdr.sh_link), NULL);
+
+ if (!di->plt_got_data || !di->dynstr_data || !di->dynsym_data || !di->rela_dyn_data)
+ return;
+
+ /* Sort into offset order */
+ sort_rela_dyn(di);
+}
+
+/* Get instruction displacement from a plt entry for x86_64 */
+static u32 get_x86_64_plt_disp(const u8 *p)
+{
+ u8 endbr64[] = {0xf3, 0x0f, 0x1e, 0xfa};
+ int n = 0;
+
+ /* Skip endbr64 */
+ if (!memcmp(p, endbr64, sizeof(endbr64)))
+ n += sizeof(endbr64);
+ /* Skip bnd prefix */
+ if (p[n] == 0xf2)
+ n += 1;
+ /* jmp with 4-byte displacement */
+ if (p[n] == 0xff && p[n + 1] == 0x25) {
+ u32 disp;
+
+ n += 2;
+ /* Also add offset from start of entry to end of instruction */
+ memcpy(&disp, p + n, sizeof(disp));
+ return n + 4 + le32toh(disp);
+ }
+ return 0;
+}
+
+static bool get_plt_got_name(GElf_Shdr *shdr, size_t i,
+ struct rela_dyn_info *di,
+ char *buf, size_t buf_sz)
+{
+ struct rela_dyn vi, *vr;
+ const char *sym_name;
+ char *demangled;
+ GElf_Sym sym;
+ bool result;
+ u32 disp;
+
+ if (!di->sorted)
+ return false;
+
+ disp = get_x86_64_plt_disp(di->plt_got_data->d_buf + i);
+ if (!disp)
+ return false;
+
+ /* Compute target offset of the .plt.got entry */
+ vi.offset = shdr->sh_offset + di->plt_got_data->d_off + i + disp;
+
+ /* Find that offset in .rela.dyn (sorted by offset) */
+ vr = bsearch(&vi, di->sorted, di->nr_entries, sizeof(di->sorted[0]), cmp_offset);
+ if (!vr)
+ return false;
+
+ /* Get the associated symbol */
+ gelf_getsym(di->dynsym_data, vr->sym_idx, &sym);
+ sym_name = elf_sym__name(&sym, di->dynstr_data);
+ demangled = demangle_sym(di->dso, 0, sym_name);
+ if (demangled != NULL)
+ sym_name = demangled;
+
+ snprintf(buf, buf_sz, "%s@plt", sym_name);
+
+ result = *sym_name;
+
+ free(demangled);
+
+ return result;
+}
+
+static int dso__synthesize_plt_got_symbols(struct dso *dso, Elf *elf,
+ GElf_Ehdr *ehdr,
+ char *buf, size_t buf_sz)
+{
+ struct rela_dyn_info di = { .dso = dso };
+ struct symbol *sym;
+ GElf_Shdr shdr;
+ Elf_Scn *scn;
+ int err = -1;
+ size_t i;
+
+ scn = elf_section_by_name(elf, ehdr, &shdr, ".plt.got", NULL);
+ if (!scn || !shdr.sh_entsize)
+ return 0;
+
+ if (ehdr->e_machine == EM_X86_64)
+ get_rela_dyn_info(elf, ehdr, &di, scn);
+
+ for (i = 0; i < shdr.sh_size; i += shdr.sh_entsize) {
+ if (!get_plt_got_name(&shdr, i, &di, buf, buf_sz))
+ snprintf(buf, buf_sz, "offset_%#" PRIx64 "@plt", (u64)shdr.sh_offset + i);
+ sym = symbol__new(shdr.sh_offset + i, shdr.sh_entsize, STB_GLOBAL, STT_FUNC, buf);
+ if (!sym)
+ goto out;
+ symbols__insert(&dso->symbols, sym);
+ }
+ err = 0;
+out:
+ exit_rela_dyn(&di);
+ return err;
+}
+
+/*
+ * We need to check if we have a .dynsym, so that we can handle the
+ * .plt, synthesizing its symbols, that aren't on the symtabs (be it
+ * .dynsym or .symtab).
+ * And always look at the original dso, not at debuginfo packages, that
+ * have the PLT data stripped out (shdr_rel_plt.sh_type == SHT_NOBITS).
+ */
+int dso__synthesize_plt_symbols(struct dso *dso, struct symsrc *ss)
+{
+ uint32_t idx;
+ GElf_Sym sym;
+ u64 plt_offset, plt_header_size, plt_entry_size;
+ GElf_Shdr shdr_plt, plt_sec_shdr;
+ struct symbol *f, *plt_sym;
+ GElf_Shdr shdr_rel_plt, shdr_dynsym;
+ Elf_Data *syms, *symstrs;
+ Elf_Scn *scn_plt_rel, *scn_symstrs, *scn_dynsym;
+ GElf_Ehdr ehdr;
+ char sympltname[1024];
+ Elf *elf;
+ int nr = 0, err = -1;
+ struct rel_info ri = { .is_rela = false };
+ bool lazy_plt;
+
+ elf = ss->elf;
+ ehdr = ss->ehdr;
+
+ if (!elf_section_by_name(elf, &ehdr, &shdr_plt, ".plt", NULL))
+ return 0;
+
+ /*
+ * A symbol from a previous section (e.g. .init) can have been expanded
+ * by symbols__fixup_end() to overlap .plt. Truncate it before adding
+ * a symbol for .plt header.
+ */
+ f = dso__find_symbol_nocache(dso, shdr_plt.sh_offset);
+ if (f && f->start < shdr_plt.sh_offset && f->end > shdr_plt.sh_offset)
+ f->end = shdr_plt.sh_offset;
+
+ if (!get_plt_sizes(dso, &ehdr, &shdr_plt, &plt_header_size, &plt_entry_size))
+ return 0;
+
+ /* Add a symbol for .plt header */
+ plt_sym = symbol__new(shdr_plt.sh_offset, plt_header_size, STB_GLOBAL, STT_FUNC, ".plt");
+ if (!plt_sym)
+ goto out_elf_end;
+ symbols__insert(&dso->symbols, plt_sym);
+
+ /* Only x86 has .plt.got */
+ if (machine_is_x86(ehdr.e_machine) &&
+ dso__synthesize_plt_got_symbols(dso, elf, &ehdr, sympltname, sizeof(sympltname)))
+ goto out_elf_end;
+
+ /* Only x86 has .plt.sec */
+ if (machine_is_x86(ehdr.e_machine) &&
+ elf_section_by_name(elf, &ehdr, &plt_sec_shdr, ".plt.sec", NULL)) {
+ if (!get_plt_sizes(dso, &ehdr, &plt_sec_shdr, &plt_header_size, &plt_entry_size))
+ return 0;
+ /* Extend .plt symbol to entire .plt */
+ plt_sym->end = plt_sym->start + shdr_plt.sh_size;
+ /* Use .plt.sec offset */
+ plt_offset = plt_sec_shdr.sh_offset;
+ lazy_plt = false;
+ } else {
+ plt_offset = shdr_plt.sh_offset;
+ lazy_plt = true;
+ }
+
+ scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
+ ".rela.plt", NULL);
+ if (scn_plt_rel == NULL) {
+ scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
+ ".rel.plt", NULL);
+ if (scn_plt_rel == NULL)
+ return 0;
+ }
+
+ if (shdr_rel_plt.sh_type != SHT_RELA &&
+ shdr_rel_plt.sh_type != SHT_REL)
+ return 0;
+
+ if (!shdr_rel_plt.sh_link)
+ return 0;
+
+ if (shdr_rel_plt.sh_link == ss->dynsym_idx) {
+ scn_dynsym = ss->dynsym;
+ shdr_dynsym = ss->dynshdr;
+ } else if (shdr_rel_plt.sh_link == ss->symtab_idx) {
+ /*
+ * A static executable can have a .plt due to IFUNCs, in which
+ * case .symtab is used not .dynsym.
+ */
+ scn_dynsym = ss->symtab;
+ shdr_dynsym = ss->symshdr;
+ } else {
+ goto out_elf_end;
+ }
+
+ if (!scn_dynsym)
+ return 0;
+
+ /*
+ * Fetch the relocation section to find the idxes to the GOT
+ * and the symbols in the .dynsym they refer to.
+ */
+ ri.reldata = elf_getdata(scn_plt_rel, NULL);
+ if (!ri.reldata)
+ goto out_elf_end;
+
+ syms = elf_getdata(scn_dynsym, NULL);
+ if (syms == NULL)
+ goto out_elf_end;
+
+ scn_symstrs = elf_getscn(elf, shdr_dynsym.sh_link);
+ if (scn_symstrs == NULL)
+ goto out_elf_end;
+
+ symstrs = elf_getdata(scn_symstrs, NULL);
+ if (symstrs == NULL)
+ goto out_elf_end;
+
+ if (symstrs->d_size == 0)
+ goto out_elf_end;
+
+ ri.nr_entries = shdr_rel_plt.sh_size / shdr_rel_plt.sh_entsize;
+
+ ri.is_rela = shdr_rel_plt.sh_type == SHT_RELA;
+
+ if (lazy_plt) {
+ /*
+ * Assume a .plt with the same number of entries as the number
+ * of relocation entries is not lazy and does not have a header.
+ */
+ if (ri.nr_entries * plt_entry_size == shdr_plt.sh_size)
+ dso__delete_symbol(dso, plt_sym);
+ else
+ plt_offset += plt_header_size;
+ }
+
+ /*
+ * x86 doesn't insert IFUNC relocations in .plt order, so sort to get
+ * back in order.
+ */
+ if (machine_is_x86(ehdr.e_machine) && sort_rel(&ri))
+ goto out_elf_end;
+
+ for (idx = 0; idx < ri.nr_entries; idx++) {
+ const char *elf_name = NULL;
+ char *demangled = NULL;
+
+ gelf_getsym(syms, get_rel_symidx(&ri, idx), &sym);
+
+ elf_name = elf_sym__name(&sym, symstrs);
+ demangled = demangle_sym(dso, 0, elf_name);
+ if (demangled)
+ elf_name = demangled;
+ if (*elf_name)
+ snprintf(sympltname, sizeof(sympltname), "%s@plt", elf_name);
+ else if (!get_ifunc_name(elf, dso, &ehdr, &ri, sympltname, sizeof(sympltname)))
+ snprintf(sympltname, sizeof(sympltname),
+ "offset_%#" PRIx64 "@plt", plt_offset);
+ free(demangled);
+
+ f = symbol__new(plt_offset, plt_entry_size, STB_GLOBAL, STT_FUNC, sympltname);
+ if (!f)
+ goto out_elf_end;
+
+ plt_offset += plt_entry_size;
+ symbols__insert(&dso->symbols, f);
+ ++nr;
+ }
+
+ err = 0;
+out_elf_end:
+ exit_rel(&ri);
+ if (err == 0)
+ return nr;
+ pr_debug("%s: problems reading %s PLT info.\n",
+ __func__, dso->long_name);
+ return 0;
+}
+
+char *dso__demangle_sym(struct dso *dso, int kmodule, const char *elf_name)
+{
+ return demangle_sym(dso, kmodule, elf_name);
+}
+
+/*
+ * Align offset to 4 bytes as needed for note name and descriptor data.
+ */
+#define NOTE_ALIGN(n) (((n) + 3) & -4U)
+
+static int elf_read_build_id(Elf *elf, void *bf, size_t size)
+{
+ int err = -1;
+ GElf_Ehdr ehdr;
+ GElf_Shdr shdr;
+ Elf_Data *data;
+ Elf_Scn *sec;
+ Elf_Kind ek;
+ void *ptr;
+
+ if (size < BUILD_ID_SIZE)
+ goto out;
+
+ ek = elf_kind(elf);
+ if (ek != ELF_K_ELF)
+ goto out;
+
+ if (gelf_getehdr(elf, &ehdr) == NULL) {
+ pr_err("%s: cannot get elf header.\n", __func__);
+ goto out;
+ }
+
+ /*
+ * Check following sections for notes:
+ * '.note.gnu.build-id'
+ * '.notes'
+ * '.note' (VDSO specific)
+ */
+ do {
+ sec = elf_section_by_name(elf, &ehdr, &shdr,
+ ".note.gnu.build-id", NULL);
+ if (sec)
+ break;
+
+ sec = elf_section_by_name(elf, &ehdr, &shdr,
+ ".notes", NULL);
+ if (sec)
+ break;
+
+ sec = elf_section_by_name(elf, &ehdr, &shdr,
+ ".note", NULL);
+ if (sec)
+ break;
+
+ return err;
+
+ } while (0);
+
+ data = elf_getdata(sec, NULL);
+ if (data == NULL)
+ goto out;
+
+ ptr = data->d_buf;
+ while (ptr < (data->d_buf + data->d_size)) {
+ GElf_Nhdr *nhdr = ptr;
+ size_t namesz = NOTE_ALIGN(nhdr->n_namesz),
+ descsz = NOTE_ALIGN(nhdr->n_descsz);
+ const char *name;
+
+ ptr += sizeof(*nhdr);
+ name = ptr;
+ ptr += namesz;
+ if (nhdr->n_type == NT_GNU_BUILD_ID &&
+ nhdr->n_namesz == sizeof("GNU")) {
+ if (memcmp(name, "GNU", sizeof("GNU")) == 0) {
+ size_t sz = min(size, descsz);
+ memcpy(bf, ptr, sz);
+ memset(bf + sz, 0, size - sz);
+ err = sz;
+ break;
+ }
+ }
+ ptr += descsz;
+ }
+
+out:
+ return err;
+}
+
+#ifdef HAVE_LIBBFD_BUILDID_SUPPORT
+
+static int read_build_id(const char *filename, struct build_id *bid)
+{
+ size_t size = sizeof(bid->data);
+ int err = -1;
+ bfd *abfd;
+
+ abfd = bfd_openr(filename, NULL);
+ if (!abfd)
+ return -1;
+
+ if (!bfd_check_format(abfd, bfd_object)) {
+ pr_debug2("%s: cannot read %s bfd file.\n", __func__, filename);
+ goto out_close;
+ }
+
+ if (!abfd->build_id || abfd->build_id->size > size)
+ goto out_close;
+
+ memcpy(bid->data, abfd->build_id->data, abfd->build_id->size);
+ memset(bid->data + abfd->build_id->size, 0, size - abfd->build_id->size);
+ err = bid->size = abfd->build_id->size;
+
+out_close:
+ bfd_close(abfd);
+ return err;
+}
+
+#else // HAVE_LIBBFD_BUILDID_SUPPORT
+
+static int read_build_id(const char *filename, struct build_id *bid)
+{
+ size_t size = sizeof(bid->data);
+ int fd, err = -1;
+ Elf *elf;
+
+ if (size < BUILD_ID_SIZE)
+ goto out;
+
+ fd = open(filename, O_RDONLY);
+ if (fd < 0)
+ goto out;
+
+ elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
+ if (elf == NULL) {
+ pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
+ goto out_close;
+ }
+
+ err = elf_read_build_id(elf, bid->data, size);
+ if (err > 0)
+ bid->size = err;
+
+ elf_end(elf);
+out_close:
+ close(fd);
+out:
+ return err;
+}
+
+#endif // HAVE_LIBBFD_BUILDID_SUPPORT
+
+int filename__read_build_id(const char *filename, struct build_id *bid)
+{
+ struct kmod_path m = { .name = NULL, };
+ char path[PATH_MAX];
+ int err;
+
+ if (!filename)
+ return -EFAULT;
+
+ err = kmod_path__parse(&m, filename);
+ if (err)
+ return -1;
+
+ if (m.comp) {
+ int error = 0, fd;
+
+ fd = filename__decompress(filename, path, sizeof(path), m.comp, &error);
+ if (fd < 0) {
+ pr_debug("Failed to decompress (error %d) %s\n",
+ error, filename);
+ return -1;
+ }
+ close(fd);
+ filename = path;
+ }
+
+ err = read_build_id(filename, bid);
+
+ if (m.comp)
+ unlink(filename);
+ return err;
+}
+
+int sysfs__read_build_id(const char *filename, struct build_id *bid)
+{
+ size_t size = sizeof(bid->data);
+ int fd, err = -1;
+
+ fd = open(filename, O_RDONLY);
+ if (fd < 0)
+ goto out;
+
+ while (1) {
+ char bf[BUFSIZ];
+ GElf_Nhdr nhdr;
+ size_t namesz, descsz;
+
+ if (read(fd, &nhdr, sizeof(nhdr)) != sizeof(nhdr))
+ break;
+
+ namesz = NOTE_ALIGN(nhdr.n_namesz);
+ descsz = NOTE_ALIGN(nhdr.n_descsz);
+ if (nhdr.n_type == NT_GNU_BUILD_ID &&
+ nhdr.n_namesz == sizeof("GNU")) {
+ if (read(fd, bf, namesz) != (ssize_t)namesz)
+ break;
+ if (memcmp(bf, "GNU", sizeof("GNU")) == 0) {
+ size_t sz = min(descsz, size);
+ if (read(fd, bid->data, sz) == (ssize_t)sz) {
+ memset(bid->data + sz, 0, size - sz);
+ bid->size = sz;
+ err = 0;
+ break;
+ }
+ } else if (read(fd, bf, descsz) != (ssize_t)descsz)
+ break;
+ } else {
+ int n = namesz + descsz;
+
+ if (n > (int)sizeof(bf)) {
+ n = sizeof(bf);
+ pr_debug("%s: truncating reading of build id in sysfs file %s: n_namesz=%u, n_descsz=%u.\n",
+ __func__, filename, nhdr.n_namesz, nhdr.n_descsz);
+ }
+ if (read(fd, bf, n) != n)
+ break;
+ }
+ }
+ close(fd);
+out:
+ return err;
+}
+
+#ifdef HAVE_LIBBFD_SUPPORT
+
+int filename__read_debuglink(const char *filename, char *debuglink,
+ size_t size)
+{
+ int err = -1;
+ asection *section;
+ bfd *abfd;
+
+ abfd = bfd_openr(filename, NULL);
+ if (!abfd)
+ return -1;
+
+ if (!bfd_check_format(abfd, bfd_object)) {
+ pr_debug2("%s: cannot read %s bfd file.\n", __func__, filename);
+ goto out_close;
+ }
+
+ section = bfd_get_section_by_name(abfd, ".gnu_debuglink");
+ if (!section)
+ goto out_close;
+
+ if (section->size > size)
+ goto out_close;
+
+ if (!bfd_get_section_contents(abfd, section, debuglink, 0,
+ section->size))
+ goto out_close;
+
+ err = 0;
+
+out_close:
+ bfd_close(abfd);
+ return err;
+}
+
+#else
+
+int filename__read_debuglink(const char *filename, char *debuglink,
+ size_t size)
+{
+ int fd, err = -1;
+ Elf *elf;
+ GElf_Ehdr ehdr;
+ GElf_Shdr shdr;
+ Elf_Data *data;
+ Elf_Scn *sec;
+ Elf_Kind ek;
+
+ fd = open(filename, O_RDONLY);
+ if (fd < 0)
+ goto out;
+
+ elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
+ if (elf == NULL) {
+ pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
+ goto out_close;
+ }
+
+ ek = elf_kind(elf);
+ if (ek != ELF_K_ELF)
+ goto out_elf_end;
+
+ if (gelf_getehdr(elf, &ehdr) == NULL) {
+ pr_err("%s: cannot get elf header.\n", __func__);
+ goto out_elf_end;
+ }
+
+ sec = elf_section_by_name(elf, &ehdr, &shdr,
+ ".gnu_debuglink", NULL);
+ if (sec == NULL)
+ goto out_elf_end;
+
+ data = elf_getdata(sec, NULL);
+ if (data == NULL)
+ goto out_elf_end;
+
+ /* the start of this section is a zero-terminated string */
+ strncpy(debuglink, data->d_buf, size);
+
+ err = 0;
+
+out_elf_end:
+ elf_end(elf);
+out_close:
+ close(fd);
+out:
+ return err;
+}
+
+#endif
+
+static int dso__swap_init(struct dso *dso, unsigned char eidata)
+{
+ static unsigned int const endian = 1;
+
+ dso->needs_swap = DSO_SWAP__NO;
+
+ switch (eidata) {
+ case ELFDATA2LSB:
+ /* We are big endian, DSO is little endian. */
+ if (*(unsigned char const *)&endian != 1)
+ dso->needs_swap = DSO_SWAP__YES;
+ break;
+
+ case ELFDATA2MSB:
+ /* We are little endian, DSO is big endian. */
+ if (*(unsigned char const *)&endian != 0)
+ dso->needs_swap = DSO_SWAP__YES;
+ break;
+
+ default:
+ pr_err("unrecognized DSO data encoding %d\n", eidata);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+bool symsrc__possibly_runtime(struct symsrc *ss)
+{
+ return ss->dynsym || ss->opdsec;
+}
+
+bool symsrc__has_symtab(struct symsrc *ss)
+{
+ return ss->symtab != NULL;
+}
+
+void symsrc__destroy(struct symsrc *ss)
+{
+ zfree(&ss->name);
+ elf_end(ss->elf);
+ close(ss->fd);
+}
+
+bool elf__needs_adjust_symbols(GElf_Ehdr ehdr)
+{
+ /*
+ * Usually vmlinux is an ELF file with type ET_EXEC for most
+ * architectures; except Arm64 kernel is linked with option
+ * '-share', so need to check type ET_DYN.
+ */
+ return ehdr.e_type == ET_EXEC || ehdr.e_type == ET_REL ||
+ ehdr.e_type == ET_DYN;
+}
+
+int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name,
+ enum dso_binary_type type)
+{
+ GElf_Ehdr ehdr;
+ Elf *elf;
+ int fd;
+
+ if (dso__needs_decompress(dso)) {
+ fd = dso__decompress_kmodule_fd(dso, name);
+ if (fd < 0)
+ return -1;
+
+ type = dso->symtab_type;
+ } else {
+ fd = open(name, O_RDONLY);
+ if (fd < 0) {
+ dso->load_errno = errno;
+ return -1;
+ }
+ }
+
+ elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
+ if (elf == NULL) {
+ pr_debug("%s: cannot read %s ELF file.\n", __func__, name);
+ dso->load_errno = DSO_LOAD_ERRNO__INVALID_ELF;
+ goto out_close;
+ }
+
+ if (gelf_getehdr(elf, &ehdr) == NULL) {
+ dso->load_errno = DSO_LOAD_ERRNO__INVALID_ELF;
+ pr_debug("%s: cannot get elf header.\n", __func__);
+ goto out_elf_end;
+ }
+
+ if (dso__swap_init(dso, ehdr.e_ident[EI_DATA])) {
+ dso->load_errno = DSO_LOAD_ERRNO__INTERNAL_ERROR;
+ goto out_elf_end;
+ }
+
+ /* Always reject images with a mismatched build-id: */
+ if (dso->has_build_id && !symbol_conf.ignore_vmlinux_buildid) {
+ u8 build_id[BUILD_ID_SIZE];
+ struct build_id bid;
+ int size;
+
+ size = elf_read_build_id(elf, build_id, BUILD_ID_SIZE);
+ if (size <= 0) {
+ dso->load_errno = DSO_LOAD_ERRNO__CANNOT_READ_BUILDID;
+ goto out_elf_end;
+ }
+
+ build_id__init(&bid, build_id, size);
+ if (!dso__build_id_equal(dso, &bid)) {
+ pr_debug("%s: build id mismatch for %s.\n", __func__, name);
+ dso->load_errno = DSO_LOAD_ERRNO__MISMATCHING_BUILDID;
+ goto out_elf_end;
+ }
+ }
+
+ ss->is_64_bit = (gelf_getclass(elf) == ELFCLASS64);
+
+ ss->symtab_idx = 0;
+ ss->symtab = elf_section_by_name(elf, &ehdr, &ss->symshdr, ".symtab",
+ &ss->symtab_idx);
+ if (ss->symshdr.sh_type != SHT_SYMTAB)
+ ss->symtab = NULL;
+
+ ss->dynsym_idx = 0;
+ ss->dynsym = elf_section_by_name(elf, &ehdr, &ss->dynshdr, ".dynsym",
+ &ss->dynsym_idx);
+ if (ss->dynshdr.sh_type != SHT_DYNSYM)
+ ss->dynsym = NULL;
+
+ ss->opdidx = 0;
+ ss->opdsec = elf_section_by_name(elf, &ehdr, &ss->opdshdr, ".opd",
+ &ss->opdidx);
+ if (ss->opdshdr.sh_type != SHT_PROGBITS)
+ ss->opdsec = NULL;
+
+ if (dso->kernel == DSO_SPACE__USER)
+ ss->adjust_symbols = true;
+ else
+ ss->adjust_symbols = elf__needs_adjust_symbols(ehdr);
+
+ ss->name = strdup(name);
+ if (!ss->name) {
+ dso->load_errno = errno;
+ goto out_elf_end;
+ }
+
+ ss->elf = elf;
+ ss->fd = fd;
+ ss->ehdr = ehdr;
+ ss->type = type;
+
+ return 0;
+
+out_elf_end:
+ elf_end(elf);
+out_close:
+ close(fd);
+ return -1;
+}
+
+/**
+ * ref_reloc_sym_not_found - has kernel relocation symbol been found.
+ * @kmap: kernel maps and relocation reference symbol
+ *
+ * This function returns %true if we are dealing with the kernel maps and the
+ * relocation reference symbol has not yet been found. Otherwise %false is
+ * returned.
+ */
+static bool ref_reloc_sym_not_found(struct kmap *kmap)
+{
+ return kmap && kmap->ref_reloc_sym && kmap->ref_reloc_sym->name &&
+ !kmap->ref_reloc_sym->unrelocated_addr;
+}
+
+/**
+ * ref_reloc - kernel relocation offset.
+ * @kmap: kernel maps and relocation reference symbol
+ *
+ * This function returns the offset of kernel addresses as determined by using
+ * the relocation reference symbol i.e. if the kernel has not been relocated
+ * then the return value is zero.
+ */
+static u64 ref_reloc(struct kmap *kmap)
+{
+ if (kmap && kmap->ref_reloc_sym &&
+ kmap->ref_reloc_sym->unrelocated_addr)
+ return kmap->ref_reloc_sym->addr -
+ kmap->ref_reloc_sym->unrelocated_addr;
+ return 0;
+}
+
+void __weak arch__sym_update(struct symbol *s __maybe_unused,
+ GElf_Sym *sym __maybe_unused) { }
+
+static int dso__process_kernel_symbol(struct dso *dso, struct map *map,
+ GElf_Sym *sym, GElf_Shdr *shdr,
+ struct maps *kmaps, struct kmap *kmap,
+ struct dso **curr_dsop, struct map **curr_mapp,
+ const char *section_name,
+ bool adjust_kernel_syms, bool kmodule, bool *remap_kernel)
+{
+ struct dso *curr_dso = *curr_dsop;
+ struct map *curr_map;
+ char dso_name[PATH_MAX];
+
+ /* Adjust symbol to map to file offset */
+ if (adjust_kernel_syms)
+ sym->st_value -= shdr->sh_addr - shdr->sh_offset;
+
+ if (strcmp(section_name, (curr_dso->short_name + dso->short_name_len)) == 0)
+ return 0;
+
+ if (strcmp(section_name, ".text") == 0) {
+ /*
+ * The initial kernel mapping is based on
+ * kallsyms and identity maps. Overwrite it to
+ * map to the kernel dso.
+ */
+ if (*remap_kernel && dso->kernel && !kmodule) {
+ *remap_kernel = false;
+ map__set_start(map, shdr->sh_addr + ref_reloc(kmap));
+ map__set_end(map, map__start(map) + shdr->sh_size);
+ map__set_pgoff(map, shdr->sh_offset);
+ map__set_map_ip(map, map__dso_map_ip);
+ map__set_unmap_ip(map, map__dso_unmap_ip);
+ /* Ensure maps are correctly ordered */
+ if (kmaps) {
+ int err;
+ struct map *tmp = map__get(map);
+
+ maps__remove(kmaps, map);
+ err = maps__insert(kmaps, map);
+ map__put(tmp);
+ if (err)
+ return err;
+ }
+ }
+
+ /*
+ * The initial module mapping is based on
+ * /proc/modules mapped to offset zero.
+ * Overwrite it to map to the module dso.
+ */
+ if (*remap_kernel && kmodule) {
+ *remap_kernel = false;
+ map__set_pgoff(map, shdr->sh_offset);
+ }
+
+ *curr_mapp = map;
+ *curr_dsop = dso;
+ return 0;
+ }
+
+ if (!kmap)
+ return 0;
+
+ snprintf(dso_name, sizeof(dso_name), "%s%s", dso->short_name, section_name);
+
+ curr_map = maps__find_by_name(kmaps, dso_name);
+ if (curr_map == NULL) {
+ u64 start = sym->st_value;
+
+ if (kmodule)
+ start += map__start(map) + shdr->sh_offset;
+
+ curr_dso = dso__new(dso_name);
+ if (curr_dso == NULL)
+ return -1;
+ curr_dso->kernel = dso->kernel;
+ curr_dso->long_name = dso->long_name;
+ curr_dso->long_name_len = dso->long_name_len;
+ curr_dso->binary_type = dso->binary_type;
+ curr_dso->adjust_symbols = dso->adjust_symbols;
+ curr_map = map__new2(start, curr_dso);
+ dso__put(curr_dso);
+ if (curr_map == NULL)
+ return -1;
+
+ if (curr_dso->kernel)
+ map__kmap(curr_map)->kmaps = kmaps;
+
+ if (adjust_kernel_syms) {
+ map__set_start(curr_map, shdr->sh_addr + ref_reloc(kmap));
+ map__set_end(curr_map, map__start(curr_map) + shdr->sh_size);
+ map__set_pgoff(curr_map, shdr->sh_offset);
+ } else {
+ map__set_map_ip(curr_map, identity__map_ip);
+ map__set_unmap_ip(curr_map, identity__map_ip);
+ }
+ curr_dso->symtab_type = dso->symtab_type;
+ if (maps__insert(kmaps, curr_map))
+ return -1;
+ /*
+ * Add it before we drop the reference to curr_map, i.e. while
+ * we still are sure to have a reference to this DSO via
+ * *curr_map->dso.
+ */
+ dsos__add(&maps__machine(kmaps)->dsos, curr_dso);
+ /* kmaps already got it */
+ map__put(curr_map);
+ dso__set_loaded(curr_dso);
+ *curr_mapp = curr_map;
+ *curr_dsop = curr_dso;
+ } else
+ *curr_dsop = map__dso(curr_map);
+
+ return 0;
+}
+
+static int
+dso__load_sym_internal(struct dso *dso, struct map *map, struct symsrc *syms_ss,
+ struct symsrc *runtime_ss, int kmodule, int dynsym)
+{
+ struct kmap *kmap = dso->kernel ? map__kmap(map) : NULL;
+ struct maps *kmaps = kmap ? map__kmaps(map) : NULL;
+ struct map *curr_map = map;
+ struct dso *curr_dso = dso;
+ Elf_Data *symstrs, *secstrs, *secstrs_run, *secstrs_sym;
+ uint32_t nr_syms;
+ int err = -1;
+ uint32_t idx;
+ GElf_Ehdr ehdr;
+ GElf_Shdr shdr;
+ GElf_Shdr tshdr;
+ Elf_Data *syms, *opddata = NULL;
+ GElf_Sym sym;
+ Elf_Scn *sec, *sec_strndx;
+ Elf *elf;
+ int nr = 0;
+ bool remap_kernel = false, adjust_kernel_syms = false;
+
+ if (kmap && !kmaps)
+ return -1;
+
+ elf = syms_ss->elf;
+ ehdr = syms_ss->ehdr;
+ if (dynsym) {
+ sec = syms_ss->dynsym;
+ shdr = syms_ss->dynshdr;
+ } else {
+ sec = syms_ss->symtab;
+ shdr = syms_ss->symshdr;
+ }
+
+ if (elf_section_by_name(runtime_ss->elf, &runtime_ss->ehdr, &tshdr,
+ ".text", NULL))
+ dso->text_offset = tshdr.sh_addr - tshdr.sh_offset;
+
+ if (runtime_ss->opdsec)
+ opddata = elf_rawdata(runtime_ss->opdsec, NULL);
+
+ syms = elf_getdata(sec, NULL);
+ if (syms == NULL)
+ goto out_elf_end;
+
+ sec = elf_getscn(elf, shdr.sh_link);
+ if (sec == NULL)
+ goto out_elf_end;
+
+ symstrs = elf_getdata(sec, NULL);
+ if (symstrs == NULL)
+ goto out_elf_end;
+
+ sec_strndx = elf_getscn(runtime_ss->elf, runtime_ss->ehdr.e_shstrndx);
+ if (sec_strndx == NULL)
+ goto out_elf_end;
+
+ secstrs_run = elf_getdata(sec_strndx, NULL);
+ if (secstrs_run == NULL)
+ goto out_elf_end;
+
+ sec_strndx = elf_getscn(elf, ehdr.e_shstrndx);
+ if (sec_strndx == NULL)
+ goto out_elf_end;
+
+ secstrs_sym = elf_getdata(sec_strndx, NULL);
+ if (secstrs_sym == NULL)
+ goto out_elf_end;
+
+ nr_syms = shdr.sh_size / shdr.sh_entsize;
+
+ memset(&sym, 0, sizeof(sym));
+
+ /*
+ * The kernel relocation symbol is needed in advance in order to adjust
+ * kernel maps correctly.
+ */
+ if (ref_reloc_sym_not_found(kmap)) {
+ elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) {
+ const char *elf_name = elf_sym__name(&sym, symstrs);
+
+ if (strcmp(elf_name, kmap->ref_reloc_sym->name))
+ continue;
+ kmap->ref_reloc_sym->unrelocated_addr = sym.st_value;
+ map__set_reloc(map, kmap->ref_reloc_sym->addr - kmap->ref_reloc_sym->unrelocated_addr);
+ break;
+ }
+ }
+
+ /*
+ * Handle any relocation of vdso necessary because older kernels
+ * attempted to prelink vdso to its virtual address.
+ */
+ if (dso__is_vdso(dso))
+ map__set_reloc(map, map__start(map) - dso->text_offset);
+
+ dso->adjust_symbols = runtime_ss->adjust_symbols || ref_reloc(kmap);
+ /*
+ * Initial kernel and module mappings do not map to the dso.
+ * Flag the fixups.
+ */
+ if (dso->kernel) {
+ remap_kernel = true;
+ adjust_kernel_syms = dso->adjust_symbols;
+ }
+ elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) {
+ struct symbol *f;
+ const char *elf_name = elf_sym__name(&sym, symstrs);
+ char *demangled = NULL;
+ int is_label = elf_sym__is_label(&sym);
+ const char *section_name;
+ bool used_opd = false;
+
+ if (!is_label && !elf_sym__filter(&sym))
+ continue;
+
+ /* Reject ARM ELF "mapping symbols": these aren't unique and
+ * don't identify functions, so will confuse the profile
+ * output: */
+ if (ehdr.e_machine == EM_ARM || ehdr.e_machine == EM_AARCH64) {
+ if (elf_name[0] == '$' && strchr("adtx", elf_name[1])
+ && (elf_name[2] == '\0' || elf_name[2] == '.'))
+ continue;
+ }
+
+ if (runtime_ss->opdsec && sym.st_shndx == runtime_ss->opdidx) {
+ u32 offset = sym.st_value - syms_ss->opdshdr.sh_addr;
+ u64 *opd = opddata->d_buf + offset;
+ sym.st_value = DSO__SWAP(dso, u64, *opd);
+ sym.st_shndx = elf_addr_to_index(runtime_ss->elf,
+ sym.st_value);
+ used_opd = true;
+ }
+
+ /*
+ * When loading symbols in a data mapping, ABS symbols (which
+ * has a value of SHN_ABS in its st_shndx) failed at
+ * elf_getscn(). And it marks the loading as a failure so
+ * already loaded symbols cannot be fixed up.
+ *
+ * I'm not sure what should be done. Just ignore them for now.
+ * - Namhyung Kim
+ */
+ if (sym.st_shndx == SHN_ABS)
+ continue;
+
+ sec = elf_getscn(syms_ss->elf, sym.st_shndx);
+ if (!sec)
+ goto out_elf_end;
+
+ gelf_getshdr(sec, &shdr);
+
+ /*
+ * If the attribute bit SHF_ALLOC is not set, the section
+ * doesn't occupy memory during process execution.
+ * E.g. ".gnu.warning.*" section is used by linker to generate
+ * warnings when calling deprecated functions, the symbols in
+ * the section aren't loaded to memory during process execution,
+ * so skip them.
+ */
+ if (!(shdr.sh_flags & SHF_ALLOC))
+ continue;
+
+ secstrs = secstrs_sym;
+
+ /*
+ * We have to fallback to runtime when syms' section header has
+ * NOBITS set. NOBITS results in file offset (sh_offset) not
+ * being incremented. So sh_offset used below has different
+ * values for syms (invalid) and runtime (valid).
+ */
+ if (shdr.sh_type == SHT_NOBITS) {
+ sec = elf_getscn(runtime_ss->elf, sym.st_shndx);
+ if (!sec)
+ goto out_elf_end;
+
+ gelf_getshdr(sec, &shdr);
+ secstrs = secstrs_run;
+ }
+
+ if (is_label && !elf_sec__filter(&shdr, secstrs))
+ continue;
+
+ section_name = elf_sec__name(&shdr, secstrs);
+
+ /* On ARM, symbols for thumb functions have 1 added to
+ * the symbol address as a flag - remove it */
+ if ((ehdr.e_machine == EM_ARM) &&
+ (GELF_ST_TYPE(sym.st_info) == STT_FUNC) &&
+ (sym.st_value & 1))
+ --sym.st_value;
+
+ if (dso->kernel) {
+ if (dso__process_kernel_symbol(dso, map, &sym, &shdr, kmaps, kmap, &curr_dso, &curr_map,
+ section_name, adjust_kernel_syms, kmodule, &remap_kernel))
+ goto out_elf_end;
+ } else if ((used_opd && runtime_ss->adjust_symbols) ||
+ (!used_opd && syms_ss->adjust_symbols)) {
+ GElf_Phdr phdr;
+
+ if (elf_read_program_header(runtime_ss->elf,
+ (u64)sym.st_value, &phdr)) {
+ pr_debug4("%s: failed to find program header for "
+ "symbol: %s st_value: %#" PRIx64 "\n",
+ __func__, elf_name, (u64)sym.st_value);
+ pr_debug4("%s: adjusting symbol: st_value: %#" PRIx64 " "
+ "sh_addr: %#" PRIx64 " sh_offset: %#" PRIx64 "\n",
+ __func__, (u64)sym.st_value, (u64)shdr.sh_addr,
+ (u64)shdr.sh_offset);
+ /*
+ * Fail to find program header, let's rollback
+ * to use shdr.sh_addr and shdr.sh_offset to
+ * calibrate symbol's file address, though this
+ * is not necessary for normal C ELF file, we
+ * still need to handle java JIT symbols in this
+ * case.
+ */
+ sym.st_value -= shdr.sh_addr - shdr.sh_offset;
+ } else {
+ pr_debug4("%s: adjusting symbol: st_value: %#" PRIx64 " "
+ "p_vaddr: %#" PRIx64 " p_offset: %#" PRIx64 "\n",
+ __func__, (u64)sym.st_value, (u64)phdr.p_vaddr,
+ (u64)phdr.p_offset);
+ sym.st_value -= phdr.p_vaddr - phdr.p_offset;
+ }
+ }
+
+ demangled = demangle_sym(dso, kmodule, elf_name);
+ if (demangled != NULL)
+ elf_name = demangled;
+
+ f = symbol__new(sym.st_value, sym.st_size,
+ GELF_ST_BIND(sym.st_info),
+ GELF_ST_TYPE(sym.st_info), elf_name);
+ free(demangled);
+ if (!f)
+ goto out_elf_end;
+
+ arch__sym_update(f, &sym);
+
+ __symbols__insert(&curr_dso->symbols, f, dso->kernel);
+ nr++;
+ }
+
+ /*
+ * For misannotated, zeroed, ASM function sizes.
+ */
+ if (nr > 0) {
+ symbols__fixup_end(&dso->symbols, false);
+ symbols__fixup_duplicate(&dso->symbols);
+ if (kmap) {
+ /*
+ * We need to fixup this here too because we create new
+ * maps here, for things like vsyscall sections.
+ */
+ maps__fixup_end(kmaps);
+ }
+ }
+ err = nr;
+out_elf_end:
+ return err;
+}
+
+int dso__load_sym(struct dso *dso, struct map *map, struct symsrc *syms_ss,
+ struct symsrc *runtime_ss, int kmodule)
+{
+ int nr = 0;
+ int err = -1;
+
+ dso->symtab_type = syms_ss->type;
+ dso->is_64_bit = syms_ss->is_64_bit;
+ dso->rel = syms_ss->ehdr.e_type == ET_REL;
+
+ /*
+ * Modules may already have symbols from kallsyms, but those symbols
+ * have the wrong values for the dso maps, so remove them.
+ */
+ if (kmodule && syms_ss->symtab)
+ symbols__delete(&dso->symbols);
+
+ if (!syms_ss->symtab) {
+ /*
+ * If the vmlinux is stripped, fail so we will fall back
+ * to using kallsyms. The vmlinux runtime symbols aren't
+ * of much use.
+ */
+ if (dso->kernel)
+ return err;
+ } else {
+ err = dso__load_sym_internal(dso, map, syms_ss, runtime_ss,
+ kmodule, 0);
+ if (err < 0)
+ return err;
+ nr = err;
+ }
+
+ if (syms_ss->dynsym) {
+ err = dso__load_sym_internal(dso, map, syms_ss, runtime_ss,
+ kmodule, 1);
+ if (err < 0)
+ return err;
+ err += nr;
+ }
+
+ return err;
+}
+
+static int elf_read_maps(Elf *elf, bool exe, mapfn_t mapfn, void *data)
+{
+ GElf_Phdr phdr;
+ size_t i, phdrnum;
+ int err;
+ u64 sz;
+
+ if (elf_getphdrnum(elf, &phdrnum))
+ return -1;
+
+ for (i = 0; i < phdrnum; i++) {
+ if (gelf_getphdr(elf, i, &phdr) == NULL)
+ return -1;
+ if (phdr.p_type != PT_LOAD)
+ continue;
+ if (exe) {
+ if (!(phdr.p_flags & PF_X))
+ continue;
+ } else {
+ if (!(phdr.p_flags & PF_R))
+ continue;
+ }
+ sz = min(phdr.p_memsz, phdr.p_filesz);
+ if (!sz)
+ continue;
+ err = mapfn(phdr.p_vaddr, sz, phdr.p_offset, data);
+ if (err)
+ return err;
+ }
+ return 0;
+}
+
+int file__read_maps(int fd, bool exe, mapfn_t mapfn, void *data,
+ bool *is_64_bit)
+{
+ int err;
+ Elf *elf;
+
+ elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
+ if (elf == NULL)
+ return -1;
+
+ if (is_64_bit)
+ *is_64_bit = (gelf_getclass(elf) == ELFCLASS64);
+
+ err = elf_read_maps(elf, exe, mapfn, data);
+
+ elf_end(elf);
+ return err;
+}
+
+enum dso_type dso__type_fd(int fd)
+{
+ enum dso_type dso_type = DSO__TYPE_UNKNOWN;
+ GElf_Ehdr ehdr;
+ Elf_Kind ek;
+ Elf *elf;
+
+ elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
+ if (elf == NULL)
+ goto out;
+
+ ek = elf_kind(elf);
+ if (ek != ELF_K_ELF)
+ goto out_end;
+
+ if (gelf_getclass(elf) == ELFCLASS64) {
+ dso_type = DSO__TYPE_64BIT;
+ goto out_end;
+ }
+
+ if (gelf_getehdr(elf, &ehdr) == NULL)
+ goto out_end;
+
+ if (ehdr.e_machine == EM_X86_64)
+ dso_type = DSO__TYPE_X32BIT;
+ else
+ dso_type = DSO__TYPE_32BIT;
+out_end:
+ elf_end(elf);
+out:
+ return dso_type;
+}
+
+static int copy_bytes(int from, off_t from_offs, int to, off_t to_offs, u64 len)
+{
+ ssize_t r;
+ size_t n;
+ int err = -1;
+ char *buf = malloc(page_size);
+
+ if (buf == NULL)
+ return -1;
+
+ if (lseek(to, to_offs, SEEK_SET) != to_offs)
+ goto out;
+
+ if (lseek(from, from_offs, SEEK_SET) != from_offs)
+ goto out;
+
+ while (len) {
+ n = page_size;
+ if (len < n)
+ n = len;
+ /* Use read because mmap won't work on proc files */
+ r = read(from, buf, n);
+ if (r < 0)
+ goto out;
+ if (!r)
+ break;
+ n = r;
+ r = write(to, buf, n);
+ if (r < 0)
+ goto out;
+ if ((size_t)r != n)
+ goto out;
+ len -= n;
+ }
+
+ err = 0;
+out:
+ free(buf);
+ return err;
+}
+
+struct kcore {
+ int fd;
+ int elfclass;
+ Elf *elf;
+ GElf_Ehdr ehdr;
+};
+
+static int kcore__open(struct kcore *kcore, const char *filename)
+{
+ GElf_Ehdr *ehdr;
+
+ kcore->fd = open(filename, O_RDONLY);
+ if (kcore->fd == -1)
+ return -1;
+
+ kcore->elf = elf_begin(kcore->fd, ELF_C_READ, NULL);
+ if (!kcore->elf)
+ goto out_close;
+
+ kcore->elfclass = gelf_getclass(kcore->elf);
+ if (kcore->elfclass == ELFCLASSNONE)
+ goto out_end;
+
+ ehdr = gelf_getehdr(kcore->elf, &kcore->ehdr);
+ if (!ehdr)
+ goto out_end;
+
+ return 0;
+
+out_end:
+ elf_end(kcore->elf);
+out_close:
+ close(kcore->fd);
+ return -1;
+}
+
+static int kcore__init(struct kcore *kcore, char *filename, int elfclass,
+ bool temp)
+{
+ kcore->elfclass = elfclass;
+
+ if (temp)
+ kcore->fd = mkstemp(filename);
+ else
+ kcore->fd = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0400);
+ if (kcore->fd == -1)
+ return -1;
+
+ kcore->elf = elf_begin(kcore->fd, ELF_C_WRITE, NULL);
+ if (!kcore->elf)
+ goto out_close;
+
+ if (!gelf_newehdr(kcore->elf, elfclass))
+ goto out_end;
+
+ memset(&kcore->ehdr, 0, sizeof(GElf_Ehdr));
+
+ return 0;
+
+out_end:
+ elf_end(kcore->elf);
+out_close:
+ close(kcore->fd);
+ unlink(filename);
+ return -1;
+}
+
+static void kcore__close(struct kcore *kcore)
+{
+ elf_end(kcore->elf);
+ close(kcore->fd);
+}
+
+static int kcore__copy_hdr(struct kcore *from, struct kcore *to, size_t count)
+{
+ GElf_Ehdr *ehdr = &to->ehdr;
+ GElf_Ehdr *kehdr = &from->ehdr;
+
+ memcpy(ehdr->e_ident, kehdr->e_ident, EI_NIDENT);
+ ehdr->e_type = kehdr->e_type;
+ ehdr->e_machine = kehdr->e_machine;
+ ehdr->e_version = kehdr->e_version;
+ ehdr->e_entry = 0;
+ ehdr->e_shoff = 0;
+ ehdr->e_flags = kehdr->e_flags;
+ ehdr->e_phnum = count;
+ ehdr->e_shentsize = 0;
+ ehdr->e_shnum = 0;
+ ehdr->e_shstrndx = 0;
+
+ if (from->elfclass == ELFCLASS32) {
+ ehdr->e_phoff = sizeof(Elf32_Ehdr);
+ ehdr->e_ehsize = sizeof(Elf32_Ehdr);
+ ehdr->e_phentsize = sizeof(Elf32_Phdr);
+ } else {
+ ehdr->e_phoff = sizeof(Elf64_Ehdr);
+ ehdr->e_ehsize = sizeof(Elf64_Ehdr);
+ ehdr->e_phentsize = sizeof(Elf64_Phdr);
+ }
+
+ if (!gelf_update_ehdr(to->elf, ehdr))
+ return -1;
+
+ if (!gelf_newphdr(to->elf, count))
+ return -1;
+
+ return 0;
+}
+
+static int kcore__add_phdr(struct kcore *kcore, int idx, off_t offset,
+ u64 addr, u64 len)
+{
+ GElf_Phdr phdr = {
+ .p_type = PT_LOAD,
+ .p_flags = PF_R | PF_W | PF_X,
+ .p_offset = offset,
+ .p_vaddr = addr,
+ .p_paddr = 0,
+ .p_filesz = len,
+ .p_memsz = len,
+ .p_align = page_size,
+ };
+
+ if (!gelf_update_phdr(kcore->elf, idx, &phdr))
+ return -1;
+
+ return 0;
+}
+
+static off_t kcore__write(struct kcore *kcore)
+{
+ return elf_update(kcore->elf, ELF_C_WRITE);
+}
+
+struct phdr_data {
+ off_t offset;
+ off_t rel;
+ u64 addr;
+ u64 len;
+ struct list_head node;
+ struct phdr_data *remaps;
+};
+
+struct sym_data {
+ u64 addr;
+ struct list_head node;
+};
+
+struct kcore_copy_info {
+ u64 stext;
+ u64 etext;
+ u64 first_symbol;
+ u64 last_symbol;
+ u64 first_module;
+ u64 first_module_symbol;
+ u64 last_module_symbol;
+ size_t phnum;
+ struct list_head phdrs;
+ struct list_head syms;
+};
+
+#define kcore_copy__for_each_phdr(k, p) \
+ list_for_each_entry((p), &(k)->phdrs, node)
+
+static struct phdr_data *phdr_data__new(u64 addr, u64 len, off_t offset)
+{
+ struct phdr_data *p = zalloc(sizeof(*p));
+
+ if (p) {
+ p->addr = addr;
+ p->len = len;
+ p->offset = offset;
+ }
+
+ return p;
+}
+
+static struct phdr_data *kcore_copy_info__addnew(struct kcore_copy_info *kci,
+ u64 addr, u64 len,
+ off_t offset)
+{
+ struct phdr_data *p = phdr_data__new(addr, len, offset);
+
+ if (p)
+ list_add_tail(&p->node, &kci->phdrs);
+
+ return p;
+}
+
+static void kcore_copy__free_phdrs(struct kcore_copy_info *kci)
+{
+ struct phdr_data *p, *tmp;
+
+ list_for_each_entry_safe(p, tmp, &kci->phdrs, node) {
+ list_del_init(&p->node);
+ free(p);
+ }
+}
+
+static struct sym_data *kcore_copy__new_sym(struct kcore_copy_info *kci,
+ u64 addr)
+{
+ struct sym_data *s = zalloc(sizeof(*s));
+
+ if (s) {
+ s->addr = addr;
+ list_add_tail(&s->node, &kci->syms);
+ }
+
+ return s;
+}
+
+static void kcore_copy__free_syms(struct kcore_copy_info *kci)
+{
+ struct sym_data *s, *tmp;
+
+ list_for_each_entry_safe(s, tmp, &kci->syms, node) {
+ list_del_init(&s->node);
+ free(s);
+ }
+}
+
+static int kcore_copy__process_kallsyms(void *arg, const char *name, char type,
+ u64 start)
+{
+ struct kcore_copy_info *kci = arg;
+
+ if (!kallsyms__is_function(type))
+ return 0;
+
+ if (strchr(name, '[')) {
+ if (!kci->first_module_symbol || start < kci->first_module_symbol)
+ kci->first_module_symbol = start;
+ if (start > kci->last_module_symbol)
+ kci->last_module_symbol = start;
+ return 0;
+ }
+
+ if (!kci->first_symbol || start < kci->first_symbol)
+ kci->first_symbol = start;
+
+ if (!kci->last_symbol || start > kci->last_symbol)
+ kci->last_symbol = start;
+
+ if (!strcmp(name, "_stext")) {
+ kci->stext = start;
+ return 0;
+ }
+
+ if (!strcmp(name, "_etext")) {
+ kci->etext = start;
+ return 0;
+ }
+
+ if (is_entry_trampoline(name) && !kcore_copy__new_sym(kci, start))
+ return -1;
+
+ return 0;
+}
+
+static int kcore_copy__parse_kallsyms(struct kcore_copy_info *kci,
+ const char *dir)
+{
+ char kallsyms_filename[PATH_MAX];
+
+ scnprintf(kallsyms_filename, PATH_MAX, "%s/kallsyms", dir);
+
+ if (symbol__restricted_filename(kallsyms_filename, "/proc/kallsyms"))
+ return -1;
+
+ if (kallsyms__parse(kallsyms_filename, kci,
+ kcore_copy__process_kallsyms) < 0)
+ return -1;
+
+ return 0;
+}
+
+static int kcore_copy__process_modules(void *arg,
+ const char *name __maybe_unused,
+ u64 start, u64 size __maybe_unused)
+{
+ struct kcore_copy_info *kci = arg;
+
+ if (!kci->first_module || start < kci->first_module)
+ kci->first_module = start;
+
+ return 0;
+}
+
+static int kcore_copy__parse_modules(struct kcore_copy_info *kci,
+ const char *dir)
+{
+ char modules_filename[PATH_MAX];
+
+ scnprintf(modules_filename, PATH_MAX, "%s/modules", dir);
+
+ if (symbol__restricted_filename(modules_filename, "/proc/modules"))
+ return -1;
+
+ if (modules__parse(modules_filename, kci,
+ kcore_copy__process_modules) < 0)
+ return -1;
+
+ return 0;
+}
+
+static int kcore_copy__map(struct kcore_copy_info *kci, u64 start, u64 end,
+ u64 pgoff, u64 s, u64 e)
+{
+ u64 len, offset;
+
+ if (s < start || s >= end)
+ return 0;
+
+ offset = (s - start) + pgoff;
+ len = e < end ? e - s : end - s;
+
+ return kcore_copy_info__addnew(kci, s, len, offset) ? 0 : -1;
+}
+
+static int kcore_copy__read_map(u64 start, u64 len, u64 pgoff, void *data)
+{
+ struct kcore_copy_info *kci = data;
+ u64 end = start + len;
+ struct sym_data *sdat;
+
+ if (kcore_copy__map(kci, start, end, pgoff, kci->stext, kci->etext))
+ return -1;
+
+ if (kcore_copy__map(kci, start, end, pgoff, kci->first_module,
+ kci->last_module_symbol))
+ return -1;
+
+ list_for_each_entry(sdat, &kci->syms, node) {
+ u64 s = round_down(sdat->addr, page_size);
+
+ if (kcore_copy__map(kci, start, end, pgoff, s, s + len))
+ return -1;
+ }
+
+ return 0;
+}
+
+static int kcore_copy__read_maps(struct kcore_copy_info *kci, Elf *elf)
+{
+ if (elf_read_maps(elf, true, kcore_copy__read_map, kci) < 0)
+ return -1;
+
+ return 0;
+}
+
+static void kcore_copy__find_remaps(struct kcore_copy_info *kci)
+{
+ struct phdr_data *p, *k = NULL;
+ u64 kend;
+
+ if (!kci->stext)
+ return;
+
+ /* Find phdr that corresponds to the kernel map (contains stext) */
+ kcore_copy__for_each_phdr(kci, p) {
+ u64 pend = p->addr + p->len - 1;
+
+ if (p->addr <= kci->stext && pend >= kci->stext) {
+ k = p;
+ break;
+ }
+ }
+
+ if (!k)
+ return;
+
+ kend = k->offset + k->len;
+
+ /* Find phdrs that remap the kernel */
+ kcore_copy__for_each_phdr(kci, p) {
+ u64 pend = p->offset + p->len;
+
+ if (p == k)
+ continue;
+
+ if (p->offset >= k->offset && pend <= kend)
+ p->remaps = k;
+ }
+}
+
+static void kcore_copy__layout(struct kcore_copy_info *kci)
+{
+ struct phdr_data *p;
+ off_t rel = 0;
+
+ kcore_copy__find_remaps(kci);
+
+ kcore_copy__for_each_phdr(kci, p) {
+ if (!p->remaps) {
+ p->rel = rel;
+ rel += p->len;
+ }
+ kci->phnum += 1;
+ }
+
+ kcore_copy__for_each_phdr(kci, p) {
+ struct phdr_data *k = p->remaps;
+
+ if (k)
+ p->rel = p->offset - k->offset + k->rel;
+ }
+}
+
+static int kcore_copy__calc_maps(struct kcore_copy_info *kci, const char *dir,
+ Elf *elf)
+{
+ if (kcore_copy__parse_kallsyms(kci, dir))
+ return -1;
+
+ if (kcore_copy__parse_modules(kci, dir))
+ return -1;
+
+ if (kci->stext)
+ kci->stext = round_down(kci->stext, page_size);
+ else
+ kci->stext = round_down(kci->first_symbol, page_size);
+
+ if (kci->etext) {
+ kci->etext = round_up(kci->etext, page_size);
+ } else if (kci->last_symbol) {
+ kci->etext = round_up(kci->last_symbol, page_size);
+ kci->etext += page_size;
+ }
+
+ if (kci->first_module_symbol &&
+ (!kci->first_module || kci->first_module_symbol < kci->first_module))
+ kci->first_module = kci->first_module_symbol;
+
+ kci->first_module = round_down(kci->first_module, page_size);
+
+ if (kci->last_module_symbol) {
+ kci->last_module_symbol = round_up(kci->last_module_symbol,
+ page_size);
+ kci->last_module_symbol += page_size;
+ }
+
+ if (!kci->stext || !kci->etext)
+ return -1;
+
+ if (kci->first_module && !kci->last_module_symbol)
+ return -1;
+
+ if (kcore_copy__read_maps(kci, elf))
+ return -1;
+
+ kcore_copy__layout(kci);
+
+ return 0;
+}
+
+static int kcore_copy__copy_file(const char *from_dir, const char *to_dir,
+ const char *name)
+{
+ char from_filename[PATH_MAX];
+ char to_filename[PATH_MAX];
+
+ scnprintf(from_filename, PATH_MAX, "%s/%s", from_dir, name);
+ scnprintf(to_filename, PATH_MAX, "%s/%s", to_dir, name);
+
+ return copyfile_mode(from_filename, to_filename, 0400);
+}
+
+static int kcore_copy__unlink(const char *dir, const char *name)
+{
+ char filename[PATH_MAX];
+
+ scnprintf(filename, PATH_MAX, "%s/%s", dir, name);
+
+ return unlink(filename);
+}
+
+static int kcore_copy__compare_fds(int from, int to)
+{
+ char *buf_from;
+ char *buf_to;
+ ssize_t ret;
+ size_t len;
+ int err = -1;
+
+ buf_from = malloc(page_size);
+ buf_to = malloc(page_size);
+ if (!buf_from || !buf_to)
+ goto out;
+
+ while (1) {
+ /* Use read because mmap won't work on proc files */
+ ret = read(from, buf_from, page_size);
+ if (ret < 0)
+ goto out;
+
+ if (!ret)
+ break;
+
+ len = ret;
+
+ if (readn(to, buf_to, len) != (int)len)
+ goto out;
+
+ if (memcmp(buf_from, buf_to, len))
+ goto out;
+ }
+
+ err = 0;
+out:
+ free(buf_to);
+ free(buf_from);
+ return err;
+}
+
+static int kcore_copy__compare_files(const char *from_filename,
+ const char *to_filename)
+{
+ int from, to, err = -1;
+
+ from = open(from_filename, O_RDONLY);
+ if (from < 0)
+ return -1;
+
+ to = open(to_filename, O_RDONLY);
+ if (to < 0)
+ goto out_close_from;
+
+ err = kcore_copy__compare_fds(from, to);
+
+ close(to);
+out_close_from:
+ close(from);
+ return err;
+}
+
+static int kcore_copy__compare_file(const char *from_dir, const char *to_dir,
+ const char *name)
+{
+ char from_filename[PATH_MAX];
+ char to_filename[PATH_MAX];
+
+ scnprintf(from_filename, PATH_MAX, "%s/%s", from_dir, name);
+ scnprintf(to_filename, PATH_MAX, "%s/%s", to_dir, name);
+
+ return kcore_copy__compare_files(from_filename, to_filename);
+}
+
+/**
+ * kcore_copy - copy kallsyms, modules and kcore from one directory to another.
+ * @from_dir: from directory
+ * @to_dir: to directory
+ *
+ * This function copies kallsyms, modules and kcore files from one directory to
+ * another. kallsyms and modules are copied entirely. Only code segments are
+ * copied from kcore. It is assumed that two segments suffice: one for the
+ * kernel proper and one for all the modules. The code segments are determined
+ * from kallsyms and modules files. The kernel map starts at _stext or the
+ * lowest function symbol, and ends at _etext or the highest function symbol.
+ * The module map starts at the lowest module address and ends at the highest
+ * module symbol. Start addresses are rounded down to the nearest page. End
+ * addresses are rounded up to the nearest page. An extra page is added to the
+ * highest kernel symbol and highest module symbol to, hopefully, encompass that
+ * symbol too. Because it contains only code sections, the resulting kcore is
+ * unusual. One significant peculiarity is that the mapping (start -> pgoff)
+ * is not the same for the kernel map and the modules map. That happens because
+ * the data is copied adjacently whereas the original kcore has gaps. Finally,
+ * kallsyms file is compared with its copy to check that modules have not been
+ * loaded or unloaded while the copies were taking place.
+ *
+ * Return: %0 on success, %-1 on failure.
+ */
+int kcore_copy(const char *from_dir, const char *to_dir)
+{
+ struct kcore kcore;
+ struct kcore extract;
+ int idx = 0, err = -1;
+ off_t offset, sz;
+ struct kcore_copy_info kci = { .stext = 0, };
+ char kcore_filename[PATH_MAX];
+ char extract_filename[PATH_MAX];
+ struct phdr_data *p;
+
+ INIT_LIST_HEAD(&kci.phdrs);
+ INIT_LIST_HEAD(&kci.syms);
+
+ if (kcore_copy__copy_file(from_dir, to_dir, "kallsyms"))
+ return -1;
+
+ if (kcore_copy__copy_file(from_dir, to_dir, "modules"))
+ goto out_unlink_kallsyms;
+
+ scnprintf(kcore_filename, PATH_MAX, "%s/kcore", from_dir);
+ scnprintf(extract_filename, PATH_MAX, "%s/kcore", to_dir);
+
+ if (kcore__open(&kcore, kcore_filename))
+ goto out_unlink_modules;
+
+ if (kcore_copy__calc_maps(&kci, from_dir, kcore.elf))
+ goto out_kcore_close;
+
+ if (kcore__init(&extract, extract_filename, kcore.elfclass, false))
+ goto out_kcore_close;
+
+ if (kcore__copy_hdr(&kcore, &extract, kci.phnum))
+ goto out_extract_close;
+
+ offset = gelf_fsize(extract.elf, ELF_T_EHDR, 1, EV_CURRENT) +
+ gelf_fsize(extract.elf, ELF_T_PHDR, kci.phnum, EV_CURRENT);
+ offset = round_up(offset, page_size);
+
+ kcore_copy__for_each_phdr(&kci, p) {
+ off_t offs = p->rel + offset;
+
+ if (kcore__add_phdr(&extract, idx++, offs, p->addr, p->len))
+ goto out_extract_close;
+ }
+
+ sz = kcore__write(&extract);
+ if (sz < 0 || sz > offset)
+ goto out_extract_close;
+
+ kcore_copy__for_each_phdr(&kci, p) {
+ off_t offs = p->rel + offset;
+
+ if (p->remaps)
+ continue;
+ if (copy_bytes(kcore.fd, p->offset, extract.fd, offs, p->len))
+ goto out_extract_close;
+ }
+
+ if (kcore_copy__compare_file(from_dir, to_dir, "kallsyms"))
+ goto out_extract_close;
+
+ err = 0;
+
+out_extract_close:
+ kcore__close(&extract);
+ if (err)
+ unlink(extract_filename);
+out_kcore_close:
+ kcore__close(&kcore);
+out_unlink_modules:
+ if (err)
+ kcore_copy__unlink(to_dir, "modules");
+out_unlink_kallsyms:
+ if (err)
+ kcore_copy__unlink(to_dir, "kallsyms");
+
+ kcore_copy__free_phdrs(&kci);
+ kcore_copy__free_syms(&kci);
+
+ return err;
+}
+
+int kcore_extract__create(struct kcore_extract *kce)
+{
+ struct kcore kcore;
+ struct kcore extract;
+ size_t count = 1;
+ int idx = 0, err = -1;
+ off_t offset = page_size, sz;
+
+ if (kcore__open(&kcore, kce->kcore_filename))
+ return -1;
+
+ strcpy(kce->extract_filename, PERF_KCORE_EXTRACT);
+ if (kcore__init(&extract, kce->extract_filename, kcore.elfclass, true))
+ goto out_kcore_close;
+
+ if (kcore__copy_hdr(&kcore, &extract, count))
+ goto out_extract_close;
+
+ if (kcore__add_phdr(&extract, idx, offset, kce->addr, kce->len))
+ goto out_extract_close;
+
+ sz = kcore__write(&extract);
+ if (sz < 0 || sz > offset)
+ goto out_extract_close;
+
+ if (copy_bytes(kcore.fd, kce->offs, extract.fd, offset, kce->len))
+ goto out_extract_close;
+
+ err = 0;
+
+out_extract_close:
+ kcore__close(&extract);
+ if (err)
+ unlink(kce->extract_filename);
+out_kcore_close:
+ kcore__close(&kcore);
+
+ return err;
+}
+
+void kcore_extract__delete(struct kcore_extract *kce)
+{
+ unlink(kce->extract_filename);
+}
+
+#ifdef HAVE_GELF_GETNOTE_SUPPORT
+
+static void sdt_adjust_loc(struct sdt_note *tmp, GElf_Addr base_off)
+{
+ if (!base_off)
+ return;
+
+ if (tmp->bit32)
+ tmp->addr.a32[SDT_NOTE_IDX_LOC] =
+ tmp->addr.a32[SDT_NOTE_IDX_LOC] + base_off -
+ tmp->addr.a32[SDT_NOTE_IDX_BASE];
+ else
+ tmp->addr.a64[SDT_NOTE_IDX_LOC] =
+ tmp->addr.a64[SDT_NOTE_IDX_LOC] + base_off -
+ tmp->addr.a64[SDT_NOTE_IDX_BASE];
+}
+
+static void sdt_adjust_refctr(struct sdt_note *tmp, GElf_Addr base_addr,
+ GElf_Addr base_off)
+{
+ if (!base_off)
+ return;
+
+ if (tmp->bit32 && tmp->addr.a32[SDT_NOTE_IDX_REFCTR])
+ tmp->addr.a32[SDT_NOTE_IDX_REFCTR] -= (base_addr - base_off);
+ else if (tmp->addr.a64[SDT_NOTE_IDX_REFCTR])
+ tmp->addr.a64[SDT_NOTE_IDX_REFCTR] -= (base_addr - base_off);
+}
+
+/**
+ * populate_sdt_note : Parse raw data and identify SDT note
+ * @elf: elf of the opened file
+ * @data: raw data of a section with description offset applied
+ * @len: note description size
+ * @type: type of the note
+ * @sdt_notes: List to add the SDT note
+ *
+ * Responsible for parsing the @data in section .note.stapsdt in @elf and
+ * if its an SDT note, it appends to @sdt_notes list.
+ */
+static int populate_sdt_note(Elf **elf, const char *data, size_t len,
+ struct list_head *sdt_notes)
+{
+ const char *provider, *name, *args;
+ struct sdt_note *tmp = NULL;
+ GElf_Ehdr ehdr;
+ GElf_Shdr shdr;
+ int ret = -EINVAL;
+
+ union {
+ Elf64_Addr a64[NR_ADDR];
+ Elf32_Addr a32[NR_ADDR];
+ } buf;
+
+ Elf_Data dst = {
+ .d_buf = &buf, .d_type = ELF_T_ADDR, .d_version = EV_CURRENT,
+ .d_size = gelf_fsize((*elf), ELF_T_ADDR, NR_ADDR, EV_CURRENT),
+ .d_off = 0, .d_align = 0
+ };
+ Elf_Data src = {
+ .d_buf = (void *) data, .d_type = ELF_T_ADDR,
+ .d_version = EV_CURRENT, .d_size = dst.d_size, .d_off = 0,
+ .d_align = 0
+ };
+
+ tmp = (struct sdt_note *)calloc(1, sizeof(struct sdt_note));
+ if (!tmp) {
+ ret = -ENOMEM;
+ goto out_err;
+ }
+
+ INIT_LIST_HEAD(&tmp->note_list);
+
+ if (len < dst.d_size + 3)
+ goto out_free_note;
+
+ /* Translation from file representation to memory representation */
+ if (gelf_xlatetom(*elf, &dst, &src,
+ elf_getident(*elf, NULL)[EI_DATA]) == NULL) {
+ pr_err("gelf_xlatetom : %s\n", elf_errmsg(-1));
+ goto out_free_note;
+ }
+
+ /* Populate the fields of sdt_note */
+ provider = data + dst.d_size;
+
+ name = (const char *)memchr(provider, '\0', data + len - provider);
+ if (name++ == NULL)
+ goto out_free_note;
+
+ tmp->provider = strdup(provider);
+ if (!tmp->provider) {
+ ret = -ENOMEM;
+ goto out_free_note;
+ }
+ tmp->name = strdup(name);
+ if (!tmp->name) {
+ ret = -ENOMEM;
+ goto out_free_prov;
+ }
+
+ args = memchr(name, '\0', data + len - name);
+
+ /*
+ * There is no argument if:
+ * - We reached the end of the note;
+ * - There is not enough room to hold a potential string;
+ * - The argument string is empty or just contains ':'.
+ */
+ if (args == NULL || data + len - args < 2 ||
+ args[1] == ':' || args[1] == '\0')
+ tmp->args = NULL;
+ else {
+ tmp->args = strdup(++args);
+ if (!tmp->args) {
+ ret = -ENOMEM;
+ goto out_free_name;
+ }
+ }
+
+ if (gelf_getclass(*elf) == ELFCLASS32) {
+ memcpy(&tmp->addr, &buf, 3 * sizeof(Elf32_Addr));
+ tmp->bit32 = true;
+ } else {
+ memcpy(&tmp->addr, &buf, 3 * sizeof(Elf64_Addr));
+ tmp->bit32 = false;
+ }
+
+ if (!gelf_getehdr(*elf, &ehdr)) {
+ pr_debug("%s : cannot get elf header.\n", __func__);
+ ret = -EBADF;
+ goto out_free_args;
+ }
+
+ /* Adjust the prelink effect :
+ * Find out the .stapsdt.base section.
+ * This scn will help us to handle prelinking (if present).
+ * Compare the retrieved file offset of the base section with the
+ * base address in the description of the SDT note. If its different,
+ * then accordingly, adjust the note location.
+ */
+ if (elf_section_by_name(*elf, &ehdr, &shdr, SDT_BASE_SCN, NULL))
+ sdt_adjust_loc(tmp, shdr.sh_offset);
+
+ /* Adjust reference counter offset */
+ if (elf_section_by_name(*elf, &ehdr, &shdr, SDT_PROBES_SCN, NULL))
+ sdt_adjust_refctr(tmp, shdr.sh_addr, shdr.sh_offset);
+
+ list_add_tail(&tmp->note_list, sdt_notes);
+ return 0;
+
+out_free_args:
+ zfree(&tmp->args);
+out_free_name:
+ zfree(&tmp->name);
+out_free_prov:
+ zfree(&tmp->provider);
+out_free_note:
+ free(tmp);
+out_err:
+ return ret;
+}
+
+/**
+ * construct_sdt_notes_list : constructs a list of SDT notes
+ * @elf : elf to look into
+ * @sdt_notes : empty list_head
+ *
+ * Scans the sections in 'elf' for the section
+ * .note.stapsdt. It, then calls populate_sdt_note to find
+ * out the SDT events and populates the 'sdt_notes'.
+ */
+static int construct_sdt_notes_list(Elf *elf, struct list_head *sdt_notes)
+{
+ GElf_Ehdr ehdr;
+ Elf_Scn *scn = NULL;
+ Elf_Data *data;
+ GElf_Shdr shdr;
+ size_t shstrndx, next;
+ GElf_Nhdr nhdr;
+ size_t name_off, desc_off, offset;
+ int ret = 0;
+
+ if (gelf_getehdr(elf, &ehdr) == NULL) {
+ ret = -EBADF;
+ goto out_ret;
+ }
+ if (elf_getshdrstrndx(elf, &shstrndx) != 0) {
+ ret = -EBADF;
+ goto out_ret;
+ }
+
+ /* Look for the required section */
+ scn = elf_section_by_name(elf, &ehdr, &shdr, SDT_NOTE_SCN, NULL);
+ if (!scn) {
+ ret = -ENOENT;
+ goto out_ret;
+ }
+
+ if ((shdr.sh_type != SHT_NOTE) || (shdr.sh_flags & SHF_ALLOC)) {
+ ret = -ENOENT;
+ goto out_ret;
+ }
+
+ data = elf_getdata(scn, NULL);
+
+ /* Get the SDT notes */
+ for (offset = 0; (next = gelf_getnote(data, offset, &nhdr, &name_off,
+ &desc_off)) > 0; offset = next) {
+ if (nhdr.n_namesz == sizeof(SDT_NOTE_NAME) &&
+ !memcmp(data->d_buf + name_off, SDT_NOTE_NAME,
+ sizeof(SDT_NOTE_NAME))) {
+ /* Check the type of the note */
+ if (nhdr.n_type != SDT_NOTE_TYPE)
+ goto out_ret;
+
+ ret = populate_sdt_note(&elf, ((data->d_buf) + desc_off),
+ nhdr.n_descsz, sdt_notes);
+ if (ret < 0)
+ goto out_ret;
+ }
+ }
+ if (list_empty(sdt_notes))
+ ret = -ENOENT;
+
+out_ret:
+ return ret;
+}
+
+/**
+ * get_sdt_note_list : Wrapper to construct a list of sdt notes
+ * @head : empty list_head
+ * @target : file to find SDT notes from
+ *
+ * This opens the file, initializes
+ * the ELF and then calls construct_sdt_notes_list.
+ */
+int get_sdt_note_list(struct list_head *head, const char *target)
+{
+ Elf *elf;
+ int fd, ret;
+
+ fd = open(target, O_RDONLY);
+ if (fd < 0)
+ return -EBADF;
+
+ elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
+ if (!elf) {
+ ret = -EBADF;
+ goto out_close;
+ }
+ ret = construct_sdt_notes_list(elf, head);
+ elf_end(elf);
+out_close:
+ close(fd);
+ return ret;
+}
+
+/**
+ * cleanup_sdt_note_list : free the sdt notes' list
+ * @sdt_notes: sdt notes' list
+ *
+ * Free up the SDT notes in @sdt_notes.
+ * Returns the number of SDT notes free'd.
+ */
+int cleanup_sdt_note_list(struct list_head *sdt_notes)
+{
+ struct sdt_note *tmp, *pos;
+ int nr_free = 0;
+
+ list_for_each_entry_safe(pos, tmp, sdt_notes, note_list) {
+ list_del_init(&pos->note_list);
+ zfree(&pos->args);
+ zfree(&pos->name);
+ zfree(&pos->provider);
+ free(pos);
+ nr_free++;
+ }
+ return nr_free;
+}
+
+/**
+ * sdt_notes__get_count: Counts the number of sdt events
+ * @start: list_head to sdt_notes list
+ *
+ * Returns the number of SDT notes in a list
+ */
+int sdt_notes__get_count(struct list_head *start)
+{
+ struct sdt_note *sdt_ptr;
+ int count = 0;
+
+ list_for_each_entry(sdt_ptr, start, note_list)
+ count++;
+ return count;
+}
+#endif
+
+void symbol__elf_init(void)
+{
+ elf_version(EV_CURRENT);
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-05 17:07:48 +0000