Merge tag 'objtool-core-2021-10-31' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull objtool updates from Thomas Gleixner:

 - Improve retpoline code patching by separating it from alternatives
   which reduces memory footprint and allows to do better optimizations
   in the actual runtime patching.

 - Add proper retpoline support for x86/BPF

 - Address noinstr warnings in x86/kvm, lockdep and paravirtualization
   code

 - Add support to handle pv_opsindirect calls in the noinstr analysis

 - Classify symbols upfront and cache the result to avoid redundant
   str*cmp() invocations.

 - Add a CFI hash to reduce memory consumption which also reduces
   runtime on a allyesconfig by ~50%

 - Adjust XEN code to make objtool handling more robust and as a side
   effect to prevent text fragmentation due to placement of the
   hypercall page.

* tag 'objtool-core-2021-10-31' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (41 commits)
  bpf,x86: Respect X86_FEATURE_RETPOLINE*
  bpf,x86: Simplify computing label offsets
  x86,bugs: Unconditionally allow spectre_v2=retpoline,amd
  x86/alternative: Add debug prints to apply_retpolines()
  x86/alternative: Try inline spectre_v2=retpoline,amd
  x86/alternative: Handle Jcc __x86_indirect_thunk_\reg
  x86/alternative: Implement .retpoline_sites support
  x86/retpoline: Create a retpoline thunk array
  x86/retpoline: Move the retpoline thunk declarations to nospec-branch.h
  x86/asm: Fixup odd GEN-for-each-reg.h usage
  x86/asm: Fix register order
  x86/retpoline: Remove unused replacement symbols
  objtool,x86: Replace alternatives with .retpoline_sites
  objtool: Shrink struct instruction
  objtool: Explicitly avoid self modifying code in .altinstr_replacement
  objtool: Classify symbols
  objtool: Support pv_opsindirect calls for noinstr
  x86/xen: Rework the xen_{cpu,irq,mmu}_opsarrays
  x86/xen: Mark xen_force_evtchn_callback() noinstr
  x86/xen: Make irq_disable() noinstr
  ...

1 files changed, 0 insertions, 84 deletions

diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c
index fee03b744a6e..81a4c543ff7e 100644
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -741,90 +741,6 @@ static int elf_add_string(struct elf *elf, struct section *strtab, char *str)
 	return len;
 }
 
-struct symbol *elf_create_undef_symbol(struct elf *elf, const char *name)
-{
-	struct section *symtab, *symtab_shndx;
-	struct symbol *sym;
-	Elf_Data *data;
-	Elf_Scn *s;
-
-	sym = malloc(sizeof(*sym));
-	if (!sym) {
-		perror("malloc");
-		return NULL;
-	}
-	memset(sym, 0, sizeof(*sym));
-
-	sym->name = strdup(name);
-
-	sym->sym.st_name = elf_add_string(elf, NULL, sym->name);
-	if (sym->sym.st_name == -1)
-		return NULL;
-
-	sym->sym.st_info = GELF_ST_INFO(STB_GLOBAL, STT_NOTYPE);
-	// st_other 0
-	// st_shndx 0
-	// st_value 0
-	// st_size 0
-
-	symtab = find_section_by_name(elf, ".symtab");
-	if (!symtab) {
-		WARN("can't find .symtab");
-		return NULL;
-	}
-
-	s = elf_getscn(elf->elf, symtab->idx);
-	if (!s) {
-		WARN_ELF("elf_getscn");
-		return NULL;
-	}
-
-	data = elf_newdata(s);
-	if (!data) {
-		WARN_ELF("elf_newdata");
-		return NULL;
-	}
-
-	data->d_buf = &sym->sym;
-	data->d_size = sizeof(sym->sym);
-	data->d_align = 1;
-	data->d_type = ELF_T_SYM;
-
-	sym->idx = symtab->sh.sh_size / sizeof(sym->sym);
-
-	symtab->sh.sh_size += data->d_size;
-	symtab->changed = true;
-
-	symtab_shndx = find_section_by_name(elf, ".symtab_shndx");
-	if (symtab_shndx) {
-		s = elf_getscn(elf->elf, symtab_shndx->idx);
-		if (!s) {
-			WARN_ELF("elf_getscn");
-			return NULL;
-		}
-
-		data = elf_newdata(s);
-		if (!data) {
-			WARN_ELF("elf_newdata");
-			return NULL;
-		}
-
-		data->d_buf = &sym->sym.st_size; /* conveniently 0 */
-		data->d_size = sizeof(Elf32_Word);
-		data->d_align = 4;
-		data->d_type = ELF_T_WORD;
-
-		symtab_shndx->sh.sh_size += 4;
-		symtab_shndx->changed = true;
-	}
-
-	sym->sec = find_section_by_index(elf, 0);
-
-	elf_add_symbol(elf, sym);
-
-	return sym;
-}
-
 struct section *elf_create_section(struct elf *elf, const char *name,
 				   unsigned int sh_flags, size_t entsize, int nr)
 {