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author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-06-28 10:16:15 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-06-28 10:16:15 -0700 |
commit | 7ecb59a56666506ebb1197f89ca7d587bd83309e (patch) | |
tree | 81ad7f30114cd4f2ada4a5631636581f9ff7544e /tools/objtool/elf.c | |
parent | a358505d8af3ab43763e1b49549619528783d2bf (diff) | |
parent | 0f1441b44e823a74f3f3780902a113e07c73fbf6 (diff) | |
download | linux-7ecb59a56666506ebb1197f89ca7d587bd83309e.tar.bz2 |
Merge tag 'objtool_urgent_for_5.8_rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull objtool fixes from Borislav Petkov:
"Three fixes from Peter Zijlstra suppressing KCOV instrumentation in
noinstr sections.
Peter Zijlstra says:
"Address KCOV vs noinstr. There is no function attribute to
selectively suppress KCOV instrumentation, instead teach objtool
to NOP out the calls in noinstr functions"
This cures a bunch of KCOV crashes (as used by syzcaller)"
* tag 'objtool_urgent_for_5.8_rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
objtool: Fix noinstr vs KCOV
objtool: Provide elf_write_{insn,reloc}()
objtool: Clean up elf_write() condition
Diffstat (limited to 'tools/objtool/elf.c')
-rw-r--r-- | tools/objtool/elf.c | 53 |
1 files changed, 50 insertions, 3 deletions
diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c index 84225679f96d..26d11d821941 100644 --- a/tools/objtool/elf.c +++ b/tools/objtool/elf.c @@ -529,8 +529,9 @@ static int read_relas(struct elf *elf) rela->addend = rela->rela.r_addend; rela->offset = rela->rela.r_offset; symndx = GELF_R_SYM(rela->rela.r_info); - rela->sym = find_symbol_by_index(elf, symndx); rela->sec = sec; + rela->idx = i; + rela->sym = find_symbol_by_index(elf, symndx); if (!rela->sym) { WARN("can't find rela entry symbol %d for %s", symndx, sec->name); @@ -713,6 +714,8 @@ struct section *elf_create_section(struct elf *elf, const char *name, elf_hash_add(elf->section_hash, &sec->hash, sec->idx); elf_hash_add(elf->section_name_hash, &sec->name_hash, str_hash(sec->name)); + elf->changed = true; + return sec; } @@ -746,7 +749,7 @@ struct section *elf_create_rela_section(struct elf *elf, struct section *base) return sec; } -int elf_rebuild_rela_section(struct section *sec) +int elf_rebuild_rela_section(struct elf *elf, struct section *sec) { struct rela *rela; int nr, idx = 0, size; @@ -763,6 +766,9 @@ int elf_rebuild_rela_section(struct section *sec) return -1; } + sec->changed = true; + elf->changed = true; + sec->data->d_buf = relas; sec->data->d_size = size; @@ -779,7 +785,44 @@ int elf_rebuild_rela_section(struct section *sec) return 0; } -int elf_write(const struct elf *elf) +int elf_write_insn(struct elf *elf, struct section *sec, + unsigned long offset, unsigned int len, + const char *insn) +{ + Elf_Data *data = sec->data; + + if (data->d_type != ELF_T_BYTE || data->d_off) { + WARN("write to unexpected data for section: %s", sec->name); + return -1; + } + + memcpy(data->d_buf + offset, insn, len); + elf_flagdata(data, ELF_C_SET, ELF_F_DIRTY); + + elf->changed = true; + + return 0; +} + +int elf_write_rela(struct elf *elf, struct rela *rela) +{ + struct section *sec = rela->sec; + + rela->rela.r_info = GELF_R_INFO(rela->sym->idx, rela->type); + rela->rela.r_addend = rela->addend; + rela->rela.r_offset = rela->offset; + + if (!gelf_update_rela(sec->data, rela->idx, &rela->rela)) { + WARN_ELF("gelf_update_rela"); + return -1; + } + + elf->changed = true; + + return 0; +} + +int elf_write(struct elf *elf) { struct section *sec; Elf_Scn *s; @@ -796,6 +839,8 @@ int elf_write(const struct elf *elf) WARN_ELF("gelf_update_shdr"); return -1; } + + sec->changed = false; } } @@ -808,6 +853,8 @@ int elf_write(const struct elf *elf) return -1; } + elf->changed = false; + return 0; } |