@@ -72,8 +72,8 @@ static inline void dynamic_scs_init(void)
static inline void dynamic_scs_init(void) {}
#endif
-int scs_patch(const u8 eh_frame[], int size);
-asmlinkage void scs_patch_vmlinux(void);
+int __pi_scs_patch(const u8 eh_frame[], int size);
+asmlinkage void __pi_scs_patch_vmlinux(void);
#endif /* __ASSEMBLY __ */
@@ -71,14 +71,6 @@ obj-$(CONFIG_ARM64_PTR_AUTH) += pointer_auth.o
obj-$(CONFIG_ARM64_MTE) += mte.o
obj-y += vdso-wrap.o
obj-$(CONFIG_COMPAT_VDSO) += vdso32-wrap.o
-obj-$(CONFIG_UNWIND_PATCH_PAC_INTO_SCS) += patch-scs.o
-
-# We need to prevent the SCS patching code from patching itself. Using
-# -mbranch-protection=none here to avoid the patchable PAC opcodes from being
-# generated triggers an issue with full LTO on Clang, which stops emitting PAC
-# instructions altogether. So instead, omit the unwind tables used by the
-# patching code, so it will not be able to locate its own PAC instructions.
-CFLAGS_patch-scs.o += -fno-asynchronous-unwind-tables -fno-unwind-tables
# Force dependency (vdso*-wrap.S includes vdso.so through incbin)
$(obj)/vdso-wrap.o: $(obj)/vdso/vdso.so
@@ -490,9 +490,6 @@ SYM_FUNC_START_LOCAL(__primary_switched)
#endif
#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
bl kasan_early_init
-#endif
-#ifdef CONFIG_UNWIND_PATCH_PAC_INTO_SCS
- bl scs_patch_vmlinux
#endif
mov x0, x20
bl finalise_el2 // Prefer VHE if possible
@@ -794,6 +791,11 @@ SYM_FUNC_START_LOCAL(__primary_switch)
#ifdef CONFIG_RELOCATABLE
mov x0, x23
bl __pi_relocate_kernel
+#endif
+#ifdef CONFIG_UNWIND_PATCH_PAC_INTO_SCS
+ ldr x0, =__eh_frame_start
+ ldr x1, =__eh_frame_end
+ bl __pi_scs_patch_vmlinux
#endif
ldr x8, =__primary_switched
adrp x0, KERNEL_START // __pa(KERNEL_START)
@@ -595,7 +595,7 @@ int module_finalize(const Elf_Ehdr *hdr,
if (scs_is_dynamic()) {
s = find_section(hdr, sechdrs, ".init.eh_frame");
if (s)
- scs_patch((void *)s->sh_addr, s->sh_size);
+ __pi_scs_patch((void *)s->sh_addr, s->sh_size);
}
return module_init_ftrace_plt(hdr, sechdrs, me);
@@ -38,7 +38,9 @@ $(obj)/lib-%.pi.o: OBJCOPYFLAGS += --prefix-alloc-sections=.init
$(obj)/lib-%.o: $(srctree)/lib/%.c FORCE
$(call if_changed_rule,cc_o_c)
-obj-y := idreg-override.pi.o lib-fdt.pi.o lib-fdt_ro.pi.o
-obj-$(CONFIG_RELOCATABLE) += relocate.pi.o
-obj-$(CONFIG_RANDOMIZE_BASE) += kaslr_early.pi.o
-extra-y := $(patsubst %.pi.o,%.o,$(obj-y))
+obj-y := idreg-override.pi.o \
+ lib-fdt.pi.o lib-fdt_ro.pi.o
+obj-$(CONFIG_RELOCATABLE) += relocate.pi.o
+obj-$(CONFIG_RANDOMIZE_BASE) += kaslr_early.pi.o
+obj-$(CONFIG_UNWIND_PATCH_PAC_INTO_SCS) += patch-scs.pi.o
+extra-y := $(patsubst %.pi.o,%.o,$(obj-y))
similarity index 91%
rename from arch/arm64/kernel/patch-scs.c
rename to arch/arm64/kernel/pi/patch-scs.c
@@ -4,14 +4,11 @@
* Author: Ard Biesheuvel <ardb@google.com>
*/
-#include <linux/bug.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/linkage.h>
-#include <linux/printk.h>
#include <linux/types.h>
-#include <asm/cacheflush.h>
#include <asm/scs.h>
//
@@ -81,7 +78,11 @@ static void __always_inline scs_patch_loc(u64 loc)
*/
return;
}
- dcache_clean_pou(loc, loc + sizeof(u32));
+ if (IS_ENABLED(CONFIG_ARM64_WORKAROUND_CLEAN_CACHE))
+ asm("dc civac, %0" :: "r"(loc));
+ else
+ asm(ALTERNATIVE("dc cvau, %0", "nop", ARM64_HAS_CACHE_IDC)
+ :: "r"(loc));
}
/*
@@ -128,10 +129,10 @@ struct eh_frame {
};
};
-static int noinstr scs_handle_fde_frame(const struct eh_frame *frame,
- bool fde_has_augmentation_data,
- int code_alignment_factor,
- bool dry_run)
+static int scs_handle_fde_frame(const struct eh_frame *frame,
+ bool fde_has_augmentation_data,
+ int code_alignment_factor,
+ bool dry_run)
{
int size = frame->size - offsetof(struct eh_frame, opcodes) + 4;
u64 loc = (u64)offset_to_ptr(&frame->initial_loc);
@@ -198,14 +199,13 @@ static int noinstr scs_handle_fde_frame(const struct eh_frame *frame,
break;
default:
- pr_err("unhandled opcode: %02x in FDE frame %lx\n", opcode[-1], (uintptr_t)frame);
return -ENOEXEC;
}
}
return 0;
}
-int noinstr scs_patch(const u8 eh_frame[], int size)
+int scs_patch(const u8 eh_frame[], int size)
{
const u8 *p = eh_frame;
@@ -251,12 +251,12 @@ int noinstr scs_patch(const u8 eh_frame[], int size)
return 0;
}
-asmlinkage void __init scs_patch_vmlinux(void)
+asmlinkage void __init scs_patch_vmlinux(const u8 start[], const u8 end[])
{
if (!should_patch_pac_into_scs())
return;
- WARN_ON(scs_patch(__eh_frame_start, __eh_frame_end - __eh_frame_start));
- icache_inval_all_pou();
+ scs_patch(start, end - start);
+ asm("ic ialluis");
isb();
}