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Diffstat (limited to 'arch/arm64/kernel/module-plts.c')
-rw-r--r--arch/arm64/kernel/module-plts.c50
1 files changed, 14 insertions, 36 deletions
diff --git a/arch/arm64/kernel/module-plts.c b/arch/arm64/kernel/module-plts.c
index d05dbe658409..ea640f92fe5a 100644
--- a/arch/arm64/kernel/module-plts.c
+++ b/arch/arm64/kernel/module-plts.c
@@ -11,21 +11,6 @@
#include <linux/module.h>
#include <linux/sort.h>
-struct plt_entry {
- /*
- * A program that conforms to the AArch64 Procedure Call Standard
- * (AAPCS64) must assume that a veneer that alters IP0 (x16) and/or
- * IP1 (x17) may be inserted at any branch instruction that is
- * exposed to a relocation that supports long branches. Since that
- * is exactly what we are dealing with here, we are free to use x16
- * as a scratch register in the PLT veneers.
- */
- __le32 mov0; /* movn x16, #0x.... */
- __le32 mov1; /* movk x16, #0x...., lsl #16 */
- __le32 mov2; /* movk x16, #0x...., lsl #32 */
- __le32 br; /* br x16 */
-};
-
static bool in_init(const struct module *mod, void *loc)
{
return (u64)loc - (u64)mod->init_layout.base < mod->init_layout.size;
@@ -40,33 +25,14 @@ u64 module_emit_plt_entry(struct module *mod, void *loc, const Elf64_Rela *rela,
int i = pltsec->plt_num_entries;
u64 val = sym->st_value + rela->r_addend;
- /*
- * MOVK/MOVN/MOVZ opcode:
- * +--------+------------+--------+-----------+-------------+---------+
- * | sf[31] | opc[30:29] | 100101 | hw[22:21] | imm16[20:5] | Rd[4:0] |
- * +--------+------------+--------+-----------+-------------+---------+
- *
- * Rd := 0x10 (x16)
- * hw := 0b00 (no shift), 0b01 (lsl #16), 0b10 (lsl #32)
- * opc := 0b11 (MOVK), 0b00 (MOVN), 0b10 (MOVZ)
- * sf := 1 (64-bit variant)
- */
- plt[i] = (struct plt_entry){
- cpu_to_le32(0x92800010 | (((~val ) & 0xffff)) << 5),
- cpu_to_le32(0xf2a00010 | ((( val >> 16) & 0xffff)) << 5),
- cpu_to_le32(0xf2c00010 | ((( val >> 32) & 0xffff)) << 5),
- cpu_to_le32(0xd61f0200)
- };
+ plt[i] = get_plt_entry(val);
/*
* Check if the entry we just created is a duplicate. Given that the
* relocations are sorted, this will be the last entry we allocated.
* (if one exists).
*/
- if (i > 0 &&
- plt[i].mov0 == plt[i - 1].mov0 &&
- plt[i].mov1 == plt[i - 1].mov1 &&
- plt[i].mov2 == plt[i - 1].mov2)
+ if (i > 0 && plt_entries_equal(plt + i, plt + i - 1))
return (u64)&plt[i - 1];
pltsec->plt_num_entries++;
@@ -154,6 +120,7 @@ int module_frob_arch_sections(Elf_Ehdr *ehdr, Elf_Shdr *sechdrs,
unsigned long core_plts = 0;
unsigned long init_plts = 0;
Elf64_Sym *syms = NULL;
+ Elf_Shdr *tramp = NULL;
int i;
/*
@@ -165,6 +132,10 @@ int module_frob_arch_sections(Elf_Ehdr *ehdr, Elf_Shdr *sechdrs,
mod->arch.core.plt = sechdrs + i;
else if (!strcmp(secstrings + sechdrs[i].sh_name, ".init.plt"))
mod->arch.init.plt = sechdrs + i;
+ else if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE) &&
+ !strcmp(secstrings + sechdrs[i].sh_name,
+ ".text.ftrace_trampoline"))
+ tramp = sechdrs + i;
else if (sechdrs[i].sh_type == SHT_SYMTAB)
syms = (Elf64_Sym *)sechdrs[i].sh_addr;
}
@@ -215,5 +186,12 @@ int module_frob_arch_sections(Elf_Ehdr *ehdr, Elf_Shdr *sechdrs,
mod->arch.init.plt_num_entries = 0;
mod->arch.init.plt_max_entries = init_plts;
+ if (tramp) {
+ tramp->sh_type = SHT_NOBITS;
+ tramp->sh_flags = SHF_EXECINSTR | SHF_ALLOC;
+ tramp->sh_addralign = __alignof__(struct plt_entry);
+ tramp->sh_size = sizeof(struct plt_entry);
+ }
+
return 0;
}