From 3672db9de548ed4ed5e87089a1263f6b5ddc4a11 Mon Sep 17 00:00:00 2001 From: Song Liu Date: Mon, 13 Feb 2023 15:14:32 -0800 Subject: [PATCH 101/107] create-diff-object: handle __initcall_stub with CONFIG_LTO_CLANG The kernel use a special __initcall_stub() with CONFIG_LTO_CLANG to avoid name collisions. Handle it in kpatch_mangled_strcmp() by ignoring all digits for symbols start with __initstub__kmod_syscall__. Signed-off-by: Song Liu --- kpatch-build/create-diff-object.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) diff --git a/kpatch-build/create-diff-object.c b/kpatch-build/create-diff-object.c index 2d7b072..fec57b8 100644 --- a/kpatch-build/create-diff-object.c +++ b/kpatch-build/create-diff-object.c @@ -430,6 +430,23 @@ static int __kpatch_unique_id_strcmp(char *s1, char *s2) return 1; } +static int __kpatch_skip_digits_strcmp(char *s1, char *s2) +{ + while (*s1 == *s2) { + if (!*s1) + return 0; + s1++; + s2++; + + while (isdigit(*s1)) + s1++; + while (isdigit(*s2)) + s2++; + } + + return 1; +} + /* * This is like strcmp, but for gcc-mangled symbols. It skips the comparison * of any substring which consists of '.' followed by any number of digits. @@ -446,6 +463,19 @@ static int kpatch_mangled_strcmp(char *s1, char *s2) if (!strncmp(s1, "__UNIQUE_ID_", 12)) return __kpatch_unique_id_strcmp(s1, s2); + /* + * Hack for __initcall_stub() with CONFIG_LTO_CLANG. + * The following should match: + * + * __initstub__kmod_syscall__728_5326_bpf_syscall_sysctl_init7 + * __initstub__kmod_syscall__728_5324_bpf_syscall_sysctl_init7 + * + * Please refer to __initcall_stub() in include/linux/init.h for + * more details. + */ + if (!strncmp(s1, "__initstub__kmod_syscall__", 26)) + return __kpatch_skip_digits_strcmp(s1, s2); + while (*s1 == *s2) { if (!*s1) return 0; -- 2.37.3