mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-24 17:59:32 +00:00
![Adrian Hunter](/assets/img/avatar_default.png)
x86 PTI entry trampolines all map to the same physical page. If that is reflected in the program headers of /proc/kcore, then do the same for the copy of kcore. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: x86@kernel.org Link: http://lkml.kernel.org/r/1526986485-6562-18-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2227 lines
50 KiB
C
2227 lines
50 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <fcntl.h>
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#include <stdio.h>
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#include <errno.h>
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#include <string.h>
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#include <unistd.h>
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#include <inttypes.h>
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#include "symbol.h"
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#include "demangle-java.h"
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#include "demangle-rust.h"
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#include "machine.h"
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#include "vdso.h"
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#include "debug.h"
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#include "sane_ctype.h"
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#include <symbol/kallsyms.h>
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#ifndef EM_AARCH64
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#define EM_AARCH64 183 /* ARM 64 bit */
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#endif
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typedef Elf64_Nhdr GElf_Nhdr;
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#ifdef HAVE_CPLUS_DEMANGLE_SUPPORT
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extern char *cplus_demangle(const char *, int);
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static inline char *bfd_demangle(void __maybe_unused *v, const char *c, int i)
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{
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return cplus_demangle(c, i);
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}
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#else
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#ifdef NO_DEMANGLE
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static inline char *bfd_demangle(void __maybe_unused *v,
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const char __maybe_unused *c,
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int __maybe_unused i)
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{
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return NULL;
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}
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#else
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#define PACKAGE 'perf'
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#include <bfd.h>
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#endif
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#endif
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#ifndef HAVE_ELF_GETPHDRNUM_SUPPORT
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static int elf_getphdrnum(Elf *elf, size_t *dst)
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{
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GElf_Ehdr gehdr;
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GElf_Ehdr *ehdr;
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ehdr = gelf_getehdr(elf, &gehdr);
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if (!ehdr)
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return -1;
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*dst = ehdr->e_phnum;
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return 0;
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}
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#endif
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#ifndef HAVE_ELF_GETSHDRSTRNDX_SUPPORT
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static int elf_getshdrstrndx(Elf *elf __maybe_unused, size_t *dst __maybe_unused)
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{
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pr_err("%s: update your libelf to > 0.140, this one lacks elf_getshdrstrndx().\n", __func__);
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return -1;
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}
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#endif
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#ifndef NT_GNU_BUILD_ID
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#define NT_GNU_BUILD_ID 3
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#endif
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/**
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* elf_symtab__for_each_symbol - iterate thru all the symbols
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*
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* @syms: struct elf_symtab instance to iterate
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* @idx: uint32_t idx
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* @sym: GElf_Sym iterator
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*/
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#define elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) \
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for (idx = 0, gelf_getsym(syms, idx, &sym);\
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idx < nr_syms; \
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idx++, gelf_getsym(syms, idx, &sym))
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static inline uint8_t elf_sym__type(const GElf_Sym *sym)
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{
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return GELF_ST_TYPE(sym->st_info);
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}
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#ifndef STT_GNU_IFUNC
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#define STT_GNU_IFUNC 10
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#endif
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static inline int elf_sym__is_function(const GElf_Sym *sym)
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{
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return (elf_sym__type(sym) == STT_FUNC ||
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elf_sym__type(sym) == STT_GNU_IFUNC) &&
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sym->st_name != 0 &&
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sym->st_shndx != SHN_UNDEF;
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}
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static inline bool elf_sym__is_object(const GElf_Sym *sym)
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{
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return elf_sym__type(sym) == STT_OBJECT &&
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sym->st_name != 0 &&
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sym->st_shndx != SHN_UNDEF;
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}
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static inline int elf_sym__is_label(const GElf_Sym *sym)
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{
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return elf_sym__type(sym) == STT_NOTYPE &&
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sym->st_name != 0 &&
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sym->st_shndx != SHN_UNDEF &&
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sym->st_shndx != SHN_ABS;
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}
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static bool elf_sym__filter(GElf_Sym *sym)
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{
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return elf_sym__is_function(sym) || elf_sym__is_object(sym);
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}
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static inline const char *elf_sym__name(const GElf_Sym *sym,
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const Elf_Data *symstrs)
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{
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return symstrs->d_buf + sym->st_name;
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}
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static inline const char *elf_sec__name(const GElf_Shdr *shdr,
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const Elf_Data *secstrs)
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{
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return secstrs->d_buf + shdr->sh_name;
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}
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static inline int elf_sec__is_text(const GElf_Shdr *shdr,
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const Elf_Data *secstrs)
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{
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return strstr(elf_sec__name(shdr, secstrs), "text") != NULL;
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}
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static inline bool elf_sec__is_data(const GElf_Shdr *shdr,
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const Elf_Data *secstrs)
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{
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return strstr(elf_sec__name(shdr, secstrs), "data") != NULL;
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}
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static bool elf_sec__filter(GElf_Shdr *shdr, Elf_Data *secstrs)
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{
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return elf_sec__is_text(shdr, secstrs) ||
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elf_sec__is_data(shdr, secstrs);
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}
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static size_t elf_addr_to_index(Elf *elf, GElf_Addr addr)
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{
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Elf_Scn *sec = NULL;
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GElf_Shdr shdr;
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size_t cnt = 1;
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while ((sec = elf_nextscn(elf, sec)) != NULL) {
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gelf_getshdr(sec, &shdr);
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if ((addr >= shdr.sh_addr) &&
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(addr < (shdr.sh_addr + shdr.sh_size)))
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return cnt;
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++cnt;
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}
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return -1;
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}
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Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep,
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GElf_Shdr *shp, const char *name, size_t *idx)
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{
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Elf_Scn *sec = NULL;
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size_t cnt = 1;
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/* Elf is corrupted/truncated, avoid calling elf_strptr. */
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if (!elf_rawdata(elf_getscn(elf, ep->e_shstrndx), NULL))
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return NULL;
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while ((sec = elf_nextscn(elf, sec)) != NULL) {
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char *str;
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gelf_getshdr(sec, shp);
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str = elf_strptr(elf, ep->e_shstrndx, shp->sh_name);
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if (str && !strcmp(name, str)) {
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if (idx)
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*idx = cnt;
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return sec;
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}
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++cnt;
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}
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return NULL;
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}
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static bool want_demangle(bool is_kernel_sym)
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{
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return is_kernel_sym ? symbol_conf.demangle_kernel : symbol_conf.demangle;
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}
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static char *demangle_sym(struct dso *dso, int kmodule, const char *elf_name)
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{
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int demangle_flags = verbose > 0 ? (DMGL_PARAMS | DMGL_ANSI) : DMGL_NO_OPTS;
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char *demangled = NULL;
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/*
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* We need to figure out if the object was created from C++ sources
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* DWARF DW_compile_unit has this, but we don't always have access
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* to it...
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*/
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if (!want_demangle(dso->kernel || kmodule))
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return demangled;
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demangled = bfd_demangle(NULL, elf_name, demangle_flags);
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if (demangled == NULL)
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demangled = java_demangle_sym(elf_name, JAVA_DEMANGLE_NORET);
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else if (rust_is_mangled(demangled))
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/*
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* Input to Rust demangling is the BFD-demangled
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* name which it Rust-demangles in place.
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*/
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rust_demangle_sym(demangled);
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return demangled;
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}
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#define elf_section__for_each_rel(reldata, pos, pos_mem, idx, nr_entries) \
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for (idx = 0, pos = gelf_getrel(reldata, 0, &pos_mem); \
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idx < nr_entries; \
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++idx, pos = gelf_getrel(reldata, idx, &pos_mem))
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#define elf_section__for_each_rela(reldata, pos, pos_mem, idx, nr_entries) \
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for (idx = 0, pos = gelf_getrela(reldata, 0, &pos_mem); \
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idx < nr_entries; \
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++idx, pos = gelf_getrela(reldata, idx, &pos_mem))
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/*
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* We need to check if we have a .dynsym, so that we can handle the
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* .plt, synthesizing its symbols, that aren't on the symtabs (be it
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* .dynsym or .symtab).
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* And always look at the original dso, not at debuginfo packages, that
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* have the PLT data stripped out (shdr_rel_plt.sh_type == SHT_NOBITS).
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*/
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int dso__synthesize_plt_symbols(struct dso *dso, struct symsrc *ss)
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{
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uint32_t nr_rel_entries, idx;
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GElf_Sym sym;
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u64 plt_offset, plt_header_size, plt_entry_size;
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GElf_Shdr shdr_plt;
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struct symbol *f;
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GElf_Shdr shdr_rel_plt, shdr_dynsym;
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Elf_Data *reldata, *syms, *symstrs;
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Elf_Scn *scn_plt_rel, *scn_symstrs, *scn_dynsym;
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size_t dynsym_idx;
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GElf_Ehdr ehdr;
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char sympltname[1024];
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Elf *elf;
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int nr = 0, symidx, err = 0;
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if (!ss->dynsym)
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return 0;
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elf = ss->elf;
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ehdr = ss->ehdr;
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scn_dynsym = ss->dynsym;
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shdr_dynsym = ss->dynshdr;
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dynsym_idx = ss->dynsym_idx;
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if (scn_dynsym == NULL)
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goto out_elf_end;
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scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
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".rela.plt", NULL);
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if (scn_plt_rel == NULL) {
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scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
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".rel.plt", NULL);
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if (scn_plt_rel == NULL)
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goto out_elf_end;
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}
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err = -1;
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if (shdr_rel_plt.sh_link != dynsym_idx)
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goto out_elf_end;
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if (elf_section_by_name(elf, &ehdr, &shdr_plt, ".plt", NULL) == NULL)
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goto out_elf_end;
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/*
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* Fetch the relocation section to find the idxes to the GOT
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* and the symbols in the .dynsym they refer to.
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*/
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reldata = elf_getdata(scn_plt_rel, NULL);
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if (reldata == NULL)
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goto out_elf_end;
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syms = elf_getdata(scn_dynsym, NULL);
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if (syms == NULL)
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goto out_elf_end;
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scn_symstrs = elf_getscn(elf, shdr_dynsym.sh_link);
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if (scn_symstrs == NULL)
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goto out_elf_end;
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symstrs = elf_getdata(scn_symstrs, NULL);
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if (symstrs == NULL)
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goto out_elf_end;
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if (symstrs->d_size == 0)
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goto out_elf_end;
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nr_rel_entries = shdr_rel_plt.sh_size / shdr_rel_plt.sh_entsize;
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plt_offset = shdr_plt.sh_offset;
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switch (ehdr.e_machine) {
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case EM_ARM:
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plt_header_size = 20;
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plt_entry_size = 12;
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break;
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|
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case EM_AARCH64:
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plt_header_size = 32;
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plt_entry_size = 16;
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break;
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default: /* FIXME: s390/alpha/mips/parisc/poperpc/sh/sparc/xtensa need to be checked */
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plt_header_size = shdr_plt.sh_entsize;
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plt_entry_size = shdr_plt.sh_entsize;
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break;
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}
|
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plt_offset += plt_header_size;
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|
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if (shdr_rel_plt.sh_type == SHT_RELA) {
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GElf_Rela pos_mem, *pos;
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elf_section__for_each_rela(reldata, pos, pos_mem, idx,
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nr_rel_entries) {
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const char *elf_name = NULL;
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char *demangled = NULL;
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symidx = GELF_R_SYM(pos->r_info);
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gelf_getsym(syms, symidx, &sym);
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elf_name = elf_sym__name(&sym, symstrs);
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demangled = demangle_sym(dso, 0, elf_name);
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if (demangled != NULL)
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elf_name = demangled;
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snprintf(sympltname, sizeof(sympltname),
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"%s@plt", elf_name);
|
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free(demangled);
|
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|
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f = symbol__new(plt_offset, plt_entry_size,
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STB_GLOBAL, STT_FUNC, sympltname);
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if (!f)
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goto out_elf_end;
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plt_offset += plt_entry_size;
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symbols__insert(&dso->symbols, f);
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++nr;
|
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}
|
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} else if (shdr_rel_plt.sh_type == SHT_REL) {
|
|
GElf_Rel pos_mem, *pos;
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|
elf_section__for_each_rel(reldata, pos, pos_mem, idx,
|
|
nr_rel_entries) {
|
|
const char *elf_name = NULL;
|
|
char *demangled = NULL;
|
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symidx = GELF_R_SYM(pos->r_info);
|
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gelf_getsym(syms, symidx, &sym);
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elf_name = elf_sym__name(&sym, symstrs);
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demangled = demangle_sym(dso, 0, elf_name);
|
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if (demangled != NULL)
|
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elf_name = demangled;
|
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snprintf(sympltname, sizeof(sympltname),
|
|
"%s@plt", elf_name);
|
|
free(demangled);
|
|
|
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f = symbol__new(plt_offset, plt_entry_size,
|
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STB_GLOBAL, STT_FUNC, sympltname);
|
|
if (!f)
|
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goto out_elf_end;
|
|
|
|
plt_offset += plt_entry_size;
|
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symbols__insert(&dso->symbols, f);
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++nr;
|
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}
|
|
}
|
|
|
|
err = 0;
|
|
out_elf_end:
|
|
if (err == 0)
|
|
return nr;
|
|
pr_debug("%s: problems reading %s PLT info.\n",
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|
__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 = descsz;
|
|
break;
|
|
}
|
|
}
|
|
ptr += descsz;
|
|
}
|
|
|
|
out:
|
|
return err;
|
|
}
|
|
|
|
int filename__read_build_id(const char *filename, void *bf, size_t size)
|
|
{
|
|
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, bf, size);
|
|
|
|
elf_end(elf);
|
|
out_close:
|
|
close(fd);
|
|
out:
|
|
return err;
|
|
}
|
|
|
|
int sysfs__read_build_id(const char *filename, void *build_id, size_t size)
|
|
{
|
|
int fd, err = -1;
|
|
|
|
if (size < BUILD_ID_SIZE)
|
|
goto out;
|
|
|
|
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, build_id, sz) == (ssize_t)sz) {
|
|
memset(build_id + sz, 0, 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;
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
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 __weak elf__needs_adjust_symbols(GElf_Ehdr ehdr)
|
|
{
|
|
return ehdr.e_type == ET_EXEC || ehdr.e_type == ET_REL;
|
|
}
|
|
|
|
int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name,
|
|
enum dso_binary_type type)
|
|
{
|
|
int err = -1;
|
|
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];
|
|
|
|
if (elf_read_build_id(elf, build_id, BUILD_ID_SIZE) < 0) {
|
|
dso->load_errno = DSO_LOAD_ERRNO__CANNOT_READ_BUILDID;
|
|
goto out_elf_end;
|
|
}
|
|
|
|
if (!dso__build_id_equal(dso, build_id)) {
|
|
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 = elf_section_by_name(elf, &ehdr, &ss->symshdr, ".symtab",
|
|
NULL);
|
|
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_TYPE_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 err;
|
|
}
|
|
|
|
/**
|
|
* 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 map_groups *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) {
|
|
*remap_kernel = false;
|
|
map->start = shdr->sh_addr + ref_reloc(kmap);
|
|
map->end = map->start + shdr->sh_size;
|
|
map->pgoff = shdr->sh_offset;
|
|
map->map_ip = map__map_ip;
|
|
map->unmap_ip = map__unmap_ip;
|
|
/* Ensure maps are correctly ordered */
|
|
if (kmaps) {
|
|
map__get(map);
|
|
map_groups__remove(kmaps, map);
|
|
map_groups__insert(kmaps, map);
|
|
map__put(map);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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->pgoff = 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 = map_groups__find_by_name(kmaps, dso_name);
|
|
if (curr_map == NULL) {
|
|
u64 start = sym->st_value;
|
|
|
|
if (kmodule)
|
|
start += map->start + 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_map = map__new2(start, curr_dso);
|
|
dso__put(curr_dso);
|
|
if (curr_map == NULL)
|
|
return -1;
|
|
|
|
if (adjust_kernel_syms) {
|
|
curr_map->start = shdr->sh_addr + ref_reloc(kmap);
|
|
curr_map->end = curr_map->start + shdr->sh_size;
|
|
curr_map->pgoff = shdr->sh_offset;
|
|
} else {
|
|
curr_map->map_ip = curr_map->unmap_ip = identity__map_ip;
|
|
}
|
|
curr_dso->symtab_type = dso->symtab_type;
|
|
map_groups__insert(kmaps, curr_map);
|
|
/*
|
|
* Add it before we drop the referece to curr_map, i.e. while
|
|
* we still are sure to have a reference to this DSO via
|
|
* *curr_map->dso.
|
|
*/
|
|
dsos__add(&map->groups->machine->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 = curr_map->dso;
|
|
|
|
return 0;
|
|
}
|
|
|
|
int dso__load_sym(struct dso *dso, struct map *map, struct symsrc *syms_ss,
|
|
struct symsrc *runtime_ss, int kmodule)
|
|
{
|
|
struct kmap *kmap = dso->kernel ? map__kmap(map) : NULL;
|
|
struct map_groups *kmaps = kmap ? map__kmaps(map) : NULL;
|
|
struct map *curr_map = map;
|
|
struct dso *curr_dso = dso;
|
|
Elf_Data *symstrs, *secstrs;
|
|
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;
|
|
|
|
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)
|
|
goto out_elf_end;
|
|
|
|
syms_ss->symtab = syms_ss->dynsym;
|
|
syms_ss->symshdr = syms_ss->dynshdr;
|
|
}
|
|
|
|
elf = syms_ss->elf;
|
|
ehdr = syms_ss->ehdr;
|
|
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 = elf_getdata(sec_strndx, NULL);
|
|
if (secstrs == 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->reloc = 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->reloc = map->start - 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 || kmodule) {
|
|
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(runtime_ss->elf, sym.st_shndx);
|
|
if (!sec)
|
|
goto out_elf_end;
|
|
|
|
gelf_getshdr(sec, &shdr);
|
|
|
|
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 || kmodule) {
|
|
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)) {
|
|
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);
|
|
sym.st_value -= shdr.sh_addr - shdr.sh_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);
|
|
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.
|
|
*/
|
|
map_groups__fixup_end(kmaps);
|
|
}
|
|
}
|
|
err = nr;
|
|
out_elf_end:
|
|
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 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(&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(&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 (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;
|
|
}
|
|
|
|
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 and modules files are compared with their copies 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, "modules"))
|
|
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
|
|
/**
|
|
* 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_Addr base_off = 0;
|
|
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)) {
|
|
base_off = shdr.sh_offset;
|
|
if (base_off) {
|
|
if (tmp->bit32)
|
|
tmp->addr.a32[0] = tmp->addr.a32[0] + base_off -
|
|
tmp->addr.a32[1];
|
|
else
|
|
tmp->addr.a64[0] = tmp->addr.a64[0] + base_off -
|
|
tmp->addr.a64[1];
|
|
}
|
|
}
|
|
|
|
list_add_tail(&tmp->note_list, sdt_notes);
|
|
return 0;
|
|
|
|
out_free_args:
|
|
free(tmp->args);
|
|
out_free_name:
|
|
free(tmp->name);
|
|
out_free_prov:
|
|
free(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(&pos->note_list);
|
|
free(pos->name);
|
|
free(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);
|
|
}
|