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authorPeter Zijlstra <peterz@infradead.org>2021-12-02 23:45:34 +0300
committerBorislav Petkov <bp@suse.de>2021-12-03 11:11:42 +0300
commit988f01683c7f2bf9f8fe2bae1cf4010fcd1baaf5 (patch)
tree7f348e2cd7069cf1c3a77fadaeba47effa4cd1b6
parentb50db7095fe002fa3e16605546cba66bf1b68a3e (diff)
downloadlinux-988f01683c7f2bf9f8fe2bae1cf4010fcd1baaf5.tar.xz
objtool: Fix pv_ops noinstr validation
Boris reported that in one of his randconfig builds, objtool got infinitely stuck. Turns out there's trivial list corruption in the pv_ops tracking when a function is both in a static table and in a code assignment. Avoid re-adding function to the pv_ops[] lists when they're already on it. Fixes: db2b0c5d7b6f ("objtool: Support pv_opsindirect calls for noinstr") Reported-by: Borislav Petkov <bp@alien8.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Borislav Petkov <bp@suse.de> Tested-by: Borislav Petkov <bp@alien8.de> Link: https://lkml.kernel.org/r/20211202204534.GA16608@worktop.programming.kicks-ass.net
-rw-r--r--tools/objtool/elf.c1
-rw-r--r--tools/objtool/objtool.c4
2 files changed, 5 insertions, 0 deletions
diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c
index 81a4c543ff7e..4b384c907027 100644
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -375,6 +375,7 @@ static int read_symbols(struct elf *elf)
return -1;
}
memset(sym, 0, sizeof(*sym));
+ INIT_LIST_HEAD(&sym->pv_target);
sym->alias = sym;
sym->idx = i;
diff --git a/tools/objtool/objtool.c b/tools/objtool/objtool.c
index c90c7084e45a..bdf699f6552b 100644
--- a/tools/objtool/objtool.c
+++ b/tools/objtool/objtool.c
@@ -153,6 +153,10 @@ void objtool_pv_add(struct objtool_file *f, int idx, struct symbol *func)
!strcmp(func->name, "_paravirt_ident_64"))
return;
+ /* already added this function */
+ if (!list_empty(&func->pv_target))
+ return;
+
list_add(&func->pv_target, &f->pv_ops[idx].targets);
f->pv_ops[idx].clean = false;
}