mirrors/linux
2
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2026-08-27 16:28:58 -04:00
Code Issues Packages Projects Releases Wiki Activity

objtool/klp: Explicitly disallow patching or referencing init code/data

Browse Source 
Explicitly disallow the patching and referencing of init code/data.
Otherwise it could potentially introduce some odd edge cases depending
on whether the target object's init section has been freed yet (note
that the init code still exists in the target module when doing late
module patching).

Such edge cases include sympos calculation and the patching and/or
referencing of non-existent (init-freed) code/data.  Not to mention the
inherent differences in behavior that occur when the init code is only
patched *some* of the time depending on module loading order or kernel
config.

Acked-by: Joe Lawrence <joe.lawrence@redhat.com>
Acked-by: Song Liu <song@kernel.org>
Link: https://patch.msgid.link/516e14f84cfbffa27dc19d3dcf35097504097966.1786138493.git.jpoimboe@kernel.org
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
This commit is contained in:
Josh Poimboeuf
2026-08-07 14:37:49 -07:00
parent 636f230ce2
commit 69f361b8a7
1 changed files with 10 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

10
tools/objtool/klp-sympos.c
View File

@@ -367,6 +367,11 @@ static unsigned long find_vmlinux_sympos(struct symbol *sym)
return sympos;
}
static bool is_init_sym(struct symbol *sym)
{
return strstarts(sym->sec->name, ".init");
}
/*
* "sympos" is used by livepatch to disambiguate duplicate symbol names.
*/
@@ -376,6 +381,11 @@ unsigned long klp_find_sympos(struct elf *elf, struct symbol *sym)
bool has_dup = false;
struct symbol *s;
if (is_init_sym(sym)) {
ERROR("%s: can't patch or reference init code/data", sym->name);
return ULONG_MAX;
}
if (sym->bind != STB_LOCAL)
return 0;