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Diffstat (limited to 'arch/arm64/kernel/module-plts.c')
-rw-r--r--arch/arm64/kernel/module-plts.c79
1 files changed, 54 insertions, 25 deletions
diff --git a/arch/arm64/kernel/module-plts.c b/arch/arm64/kernel/module-plts.c
index 65b08a74aec6..bde32979c06a 100644
--- a/arch/arm64/kernel/module-plts.c
+++ b/arch/arm64/kernel/module-plts.c
@@ -7,6 +7,7 @@
#include <linux/ftrace.h>
#include <linux/kernel.h>
#include <linux/module.h>
+#include <linux/moduleloader.h>
#include <linux/sort.h>
static struct plt_entry __get_adrp_add_pair(u64 dst, u64 pc,
@@ -37,7 +38,8 @@ struct plt_entry get_plt_entry(u64 dst, void *pc)
return plt;
}
-bool plt_entries_equal(const struct plt_entry *a, const struct plt_entry *b)
+static bool plt_entries_equal(const struct plt_entry *a,
+ const struct plt_entry *b)
{
u64 p, q;
@@ -64,17 +66,12 @@ bool plt_entries_equal(const struct plt_entry *a, const struct plt_entry *b)
(q + aarch64_insn_adrp_get_offset(le32_to_cpu(b->adrp)));
}
-static bool in_init(const struct module *mod, void *loc)
-{
- return (u64)loc - (u64)mod->init_layout.base < mod->init_layout.size;
-}
-
u64 module_emit_plt_entry(struct module *mod, Elf64_Shdr *sechdrs,
void *loc, const Elf64_Rela *rela,
Elf64_Sym *sym)
{
- struct mod_plt_sec *pltsec = !in_init(mod, loc) ? &mod->arch.core :
- &mod->arch.init;
+ struct mod_plt_sec *pltsec = !within_module_init((unsigned long)loc, mod) ?
+ &mod->arch.core : &mod->arch.init;
struct plt_entry *plt = (struct plt_entry *)sechdrs[pltsec->plt_shndx].sh_addr;
int i = pltsec->plt_num_entries;
int j = i - 1;
@@ -104,8 +101,8 @@ u64 module_emit_plt_entry(struct module *mod, Elf64_Shdr *sechdrs,
u64 module_emit_veneer_for_adrp(struct module *mod, Elf64_Shdr *sechdrs,
void *loc, u64 val)
{
- struct mod_plt_sec *pltsec = !in_init(mod, loc) ? &mod->arch.core :
- &mod->arch.init;
+ struct mod_plt_sec *pltsec = !within_module_init((unsigned long)loc, mod) ?
+ &mod->arch.core : &mod->arch.init;
struct plt_entry *plt = (struct plt_entry *)sechdrs[pltsec->plt_shndx].sh_addr;
int i = pltsec->plt_num_entries++;
u32 br;
@@ -131,7 +128,7 @@ u64 module_emit_veneer_for_adrp(struct module *mod, Elf64_Shdr *sechdrs,
}
#endif
-#define cmp_3way(a,b) ((a) < (b) ? -1 : (a) > (b))
+#define cmp_3way(a, b) ((a) < (b) ? -1 : (a) > (b))
static int cmp_rela(const void *a, const void *b)
{
@@ -170,9 +167,6 @@ static unsigned int count_plts(Elf64_Sym *syms, Elf64_Rela *rela, int num,
switch (ELF64_R_TYPE(rela[i].r_info)) {
case R_AARCH64_JUMP26:
case R_AARCH64_CALL26:
- if (!IS_ENABLED(CONFIG_RANDOMIZE_BASE))
- break;
-
/*
* We only have to consider branch targets that resolve
* to symbols that are defined in a different section.
@@ -206,8 +200,7 @@ static unsigned int count_plts(Elf64_Sym *syms, Elf64_Rela *rela, int num,
break;
case R_AARCH64_ADR_PREL_PG_HI21_NC:
case R_AARCH64_ADR_PREL_PG_HI21:
- if (!IS_ENABLED(CONFIG_ARM64_ERRATUM_843419) ||
- !cpus_have_const_cap(ARM64_WORKAROUND_843419))
+ if (!cpus_have_final_cap(ARM64_WORKAROUND_843419))
break;
/*
@@ -220,7 +213,7 @@ static unsigned int count_plts(Elf64_Sym *syms, Elf64_Rela *rela, int num,
* increasing the section's alignment so that the
* resulting address of this instruction is guaranteed
* to equal the offset in that particular bit (as well
- * as all less signficant bits). This ensures that the
+ * as all less significant bits). This ensures that the
* address modulo 4 KB != 0xfff8 or 0xfffc (which would
* have all ones in bits [11:3])
*/
@@ -242,17 +235,48 @@ static unsigned int count_plts(Elf64_Sym *syms, Elf64_Rela *rela, int num,
}
}
- if (IS_ENABLED(CONFIG_ARM64_ERRATUM_843419) &&
- cpus_have_const_cap(ARM64_WORKAROUND_843419))
+ if (cpus_have_final_cap(ARM64_WORKAROUND_843419)) {
/*
* Add some slack so we can skip PLT slots that may trigger
* the erratum due to the placement of the ADRP instruction.
*/
ret += DIV_ROUND_UP(ret, (SZ_4K / sizeof(struct plt_entry)));
+ }
return ret;
}
+static bool branch_rela_needs_plt(Elf64_Sym *syms, Elf64_Rela *rela,
+ Elf64_Word dstidx)
+{
+
+ Elf64_Sym *s = syms + ELF64_R_SYM(rela->r_info);
+
+ if (s->st_shndx == dstidx)
+ return false;
+
+ return ELF64_R_TYPE(rela->r_info) == R_AARCH64_JUMP26 ||
+ ELF64_R_TYPE(rela->r_info) == R_AARCH64_CALL26;
+}
+
+/* Group branch PLT relas at the front end of the array. */
+static int partition_branch_plt_relas(Elf64_Sym *syms, Elf64_Rela *rela,
+ int numrels, Elf64_Word dstidx)
+{
+ int i = 0, j = numrels - 1;
+
+ while (i < j) {
+ if (branch_rela_needs_plt(syms, &rela[i], dstidx))
+ i++;
+ else if (branch_rela_needs_plt(syms, &rela[j], dstidx))
+ swap(rela[i], rela[j]);
+ else
+ j--;
+ }
+
+ return i;
+}
+
int module_frob_arch_sections(Elf_Ehdr *ehdr, Elf_Shdr *sechdrs,
char *secstrings, struct module *mod)
{
@@ -271,8 +295,7 @@ int module_frob_arch_sections(Elf_Ehdr *ehdr, Elf_Shdr *sechdrs,
mod->arch.core.plt_shndx = i;
else if (!strcmp(secstrings + sechdrs[i].sh_name, ".init.plt"))
mod->arch.init.plt_shndx = i;
- else if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE) &&
- !strcmp(secstrings + sechdrs[i].sh_name,
+ else if (!strcmp(secstrings + sechdrs[i].sh_name,
".text.ftrace_trampoline"))
tramp = sechdrs + i;
else if (sechdrs[i].sh_type == SHT_SYMTAB)
@@ -290,7 +313,7 @@ int module_frob_arch_sections(Elf_Ehdr *ehdr, Elf_Shdr *sechdrs,
for (i = 0; i < ehdr->e_shnum; i++) {
Elf64_Rela *rels = (void *)ehdr + sechdrs[i].sh_offset;
- int numrels = sechdrs[i].sh_size / sizeof(Elf64_Rela);
+ int nents, numrels = sechdrs[i].sh_size / sizeof(Elf64_Rela);
Elf64_Shdr *dstsec = sechdrs + sechdrs[i].sh_info;
if (sechdrs[i].sh_type != SHT_RELA)
@@ -300,10 +323,16 @@ int module_frob_arch_sections(Elf_Ehdr *ehdr, Elf_Shdr *sechdrs,
if (!(dstsec->sh_flags & SHF_EXECINSTR))
continue;
- /* sort by type, symbol index and addend */
- sort(rels, numrels, sizeof(Elf64_Rela), cmp_rela, NULL);
+ /*
+ * sort branch relocations requiring a PLT by type, symbol index
+ * and addend
+ */
+ nents = partition_branch_plt_relas(syms, rels, numrels,
+ sechdrs[i].sh_info);
+ if (nents)
+ sort(rels, nents, sizeof(Elf64_Rela), cmp_rela, NULL);
- if (!str_has_prefix(secstrings + dstsec->sh_name, ".init"))
+ if (!module_init_layout_section(secstrings + dstsec->sh_name))
core_plts += count_plts(syms, rels, numrels,
sechdrs[i].sh_info, dstsec);
else
generated by cgit (git 2.34.1) at 2025-07-30 08:49:46 +0000