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| author |  Josh Poimboeuf <jpoimboe@redhat.com>
| 2020-02-17 21:41:54 -0600 |
|---|---|---|
| committer |  Borislav Petkov <bp@suse.de>
| 2020-02-21 10:20:34 +0100 |
| commit | 7acfe5315312fc56c2a94c9216448087b38ae909 (patch) | |
| tree | e3187f3209664e907dabf0fa7a0151d1a82e487f /tools/objtool/check.c | |
| parent | objtool: Fix clang switch table edge case (diff) | |
| download | linux-7acfe5315312fc56c2a94c9216448087b38ae909.tar.gz linux-7acfe5315312fc56c2a94c9216448087b38ae909.tar.bz2 linux-7acfe5315312fc56c2a94c9216448087b38ae909.zip | |
objtool: Improve call destination function detection
A recent clang change, combined with a binutils bug, can trigger a
situation where a ".Lprintk$local" STT_NOTYPE symbol gets created at the
same offset as the "printk" STT_FUNC symbol. This confuses objtool:
kernel/printk/printk.o: warning: objtool: ignore_loglevel_setup()+0x10: can't find call dest symbol at .text+0xc67
Improve the call destination detection by looking specifically for an
STT_FUNC symbol.
Reported-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nathan Chancellor <natechancellor@gmail.com>
Link: https://github.com/ClangBuiltLinux/linux/issues/872
Link: https://sourceware.org/bugzilla/show_bug.cgi?id=25551
Link: https://lkml.kernel.org/r/0a7ee320bc0ea4469bd3dc450a7b4725669e0ea9.1581997059.git.jpoimboe@redhat.com
Diffstat (limited to 'tools/objtool/check.c')
| -rw-r--r-- | tools/objtool/check.c | 27 |
1 files changed, 18 insertions, 9 deletions
diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 4d6e283951ec..6b6178ef4464 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -420,8 +420,8 @@ static void add_ignores(struct objtool_file *file) break; case STT_SECTION: - func = find_symbol_by_offset(rela->sym->sec, rela->addend); - if (!func || func->type != STT_FUNC) + func = find_func_by_offset(rela->sym->sec, rela->addend); + if (!func) continue; break; @@ -665,10 +665,14 @@ static int add_call_destinations(struct objtool_file *file) insn->len); if (!rela) { dest_off = insn->offset + insn->len + insn->immediate; - insn->call_dest = find_symbol_by_offset(insn->sec, - dest_off); + insn->call_dest = find_func_by_offset(insn->sec, dest_off); + if (!insn->call_dest) + insn->call_dest = find_symbol_by_offset(insn->sec, dest_off); - if (!insn->call_dest && !insn->ignore) { + if (insn->ignore) + continue; + + if (!insn->call_dest) { WARN_FUNC("unsupported intra-function call", insn->sec, insn->offset); if (retpoline) @@ -676,11 +680,16 @@ static int add_call_destinations(struct objtool_file *file) return -1; } + if (insn->func && insn->call_dest->type != STT_FUNC) { + WARN_FUNC("unsupported call to non-function", + insn->sec, insn->offset); + return -1; + } + } else if (rela->sym->type == STT_SECTION) { - insn->call_dest = find_symbol_by_offset(rela->sym->sec, - rela->addend+4); - if (!insn->call_dest || - insn->call_dest->type != STT_FUNC) { + insn->call_dest = find_func_by_offset(rela->sym->sec, + rela->addend+4); + if (!insn->call_dest) { WARN_FUNC("can't find call dest symbol at %s+0x%x", insn->sec, insn->offset, rela->sym->sec->name, |