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adapt to clang/arm64 naming

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New toolchain/arch, new conventions for section/label/etc names

gcc's .LCx symbols point to string literals in '.rodata.<func>.str1.*'
sections. Clang creates similar .Ltmp%d symbols in '.rodata.str'

The function is_string_literal_section()
generalized (too much?) to match either
- clang's/arm64 /^\.rodata\.str$/
- gcc's /^\.rodata\./ && /\.str1\./

Various matchers for .data.unlikely .bss.unlikely
replaced by is_data_unlikely_section()
generalized to match
- gcc's ".data.unlikely"
- clang's ".(data|bss).module_name.unlikely"

.data.once handled similarly

Signed-off-by: Pete Swain <swine@google.com>
This commit is contained in:
Pete Swain 2023-01-09 02:18:33 -08:00 committed by Mihails Strasuns
parent 6b69975991
commit db9c3abb4e
1 changed files with 30 additions and 4 deletions
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34
kpatch-build/create-diff-object.c
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@ -354,6 +354,28 @@ static bool is_string_literal_section(struct section *sec)
return !strncmp(sec->name, ".rodata.", 8) && strstr(sec->name, ".str");
}
/* gcc's ".data.unlikely" or clang's ".(data|bss).module_name.unlikely" */
static bool is_data_unlikely_section(const char *name)
{
size_t len = strlen(name);
return (len >= 5 + 8 &&
((!strncmp(name, ".data.", 6) ||
!strncmp(name, ".bss.", 5)) &&
strstr(name + len - 9, ".unlikely")));
}
/* either ".data.once" or clang's ".(data|bss).module_name.once" */
static bool is_data_once_section(const char *name)
{
size_t len = strlen(name);
return (len >= 5 + 4 &&
(!strncmp(name, ".data.", 6) ||
!strncmp(name, ".bss.", 5)) &&
strstr(name + len - 5, ".once"));
}
/*
* This function detects whether the given symbol is a "special" static local
* variable (for lack of a better term).
@ -395,7 +417,7 @@ static bool is_special_static(struct symbol *sym)
if (sym->type != STT_OBJECT || sym->bind != STB_LOCAL)
return false;
if (!strcmp(sym->sec->name, ".data.once"))
if (is_data_once_section(sym->sec->name))
return true;
for (var_name = var_names; *var_name; var_name++) {
@ -1200,9 +1222,11 @@ static void kpatch_correlate_symbols(struct kpatch_elf *kelf_orig,
* The .LCx symbols point to string literals in
* '.rodata.<func>.str1.*' sections. They get included
* in kpatch_include_standard_elements().
* Clang creates similar .Ltmp%d symbols in .rodata.str
*/
if (sym_orig->type == STT_NOTYPE &&
!strncmp(sym_orig->name, ".LC", 3))
!(strncmp(sym_orig->name, ".LC", 3) &&
strncmp(sym_orig->name, ".Ltmp", 5)))
continue;
if (kpatch_is_mapping_symbol(kelf_orig, sym_orig))
@ -1847,8 +1871,10 @@ static void kpatch_verify_patchability(struct kpatch_elf *kelf)
* (.data.unlikely and .data.once is ok b/c it only has __warned vars)
*/
if (sec->include && sec->status != NEW &&
(!strncmp(sec->name, ".data", 5) || !strncmp(sec->name, ".bss", 4)) &&
(strcmp(sec->name, ".data.unlikely") && strcmp(sec->name, ".data.once"))) {
(!strncmp(sec->name, ".data", 5) ||
!strncmp(sec->name, ".bss", 4)) &&
!is_data_once_section(sec->name) &&
!is_data_unlikely_section(sec->name)) {
log_normal("data section %s selected for inclusion\n",
sec->name);
errs++;