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-rw-r--r--arch/arm64/include/asm/alternative.h72
1 files changed, 72 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/alternative.h b/arch/arm64/include/asm/alternative.h
index e4962f04201e..a9fc24ec1aa9 100644
--- a/arch/arm64/include/asm/alternative.h
+++ b/arch/arm64/include/asm/alternative.h
@@ -1,6 +1,8 @@
#ifndef __ASM_ALTERNATIVE_H
#define __ASM_ALTERNATIVE_H
+#include <asm/cpufeature.h>
+
#ifndef __ASSEMBLY__
#include <linux/init.h>
@@ -63,6 +65,8 @@ void apply_alternatives(void *start, size_t length);
#else
+#include <asm/assembler.h>
+
.macro altinstruction_entry orig_offset alt_offset feature orig_len alt_len
.word \orig_offset - .
.word \alt_offset - .
@@ -136,6 +140,74 @@ void apply_alternatives(void *start, size_t length);
alternative_insn insn1, insn2, cap, IS_ENABLED(cfg)
+/*
+ * Generate the assembly for UAO alternatives with exception table entries.
+ * This is complicated as there is no post-increment or pair versions of the
+ * unprivileged instructions, and USER() only works for single instructions.
+ */
+#ifdef CONFIG_ARM64_UAO
+ .macro uao_ldp l, reg1, reg2, addr, post_inc
+ alternative_if_not ARM64_HAS_UAO
+8888: ldp \reg1, \reg2, [\addr], \post_inc;
+8889: nop;
+ nop;
+ alternative_else
+ ldtr \reg1, [\addr];
+ ldtr \reg2, [\addr, #8];
+ add \addr, \addr, \post_inc;
+ alternative_endif
+
+ .section __ex_table,"a";
+ .align 3;
+ .quad 8888b,\l;
+ .quad 8889b,\l;
+ .previous;
+ .endm
+
+ .macro uao_stp l, reg1, reg2, addr, post_inc
+ alternative_if_not ARM64_HAS_UAO
+8888: stp \reg1, \reg2, [\addr], \post_inc;
+8889: nop;
+ nop;
+ alternative_else
+ sttr \reg1, [\addr];
+ sttr \reg2, [\addr, #8];
+ add \addr, \addr, \post_inc;
+ alternative_endif
+
+ .section __ex_table,"a";
+ .align 3;
+ .quad 8888b,\l;
+ .quad 8889b,\l;
+ .previous
+ .endm
+
+ .macro uao_user_alternative l, inst, alt_inst, reg, addr, post_inc
+ alternative_if_not ARM64_HAS_UAO
+8888: \inst \reg, [\addr], \post_inc;
+ nop;
+ alternative_else
+ \alt_inst \reg, [\addr];
+ add \addr, \addr, \post_inc;
+ alternative_endif
+
+ .section __ex_table,"a";
+ .align 3;
+ .quad 8888b,\l;
+ .previous
+ .endm
+#else
+ .macro uao_ldp l, reg1, reg2, addr, post_inc
+ USER(\l, ldp \reg1, \reg2, [\addr], \post_inc)
+ .endm
+ .macro uao_stp l, reg1, reg2, addr, post_inc
+ USER(\l, stp \reg1, \reg2, [\addr], \post_inc)
+ .endm
+ .macro uao_user_alternative l, inst, alt_inst, reg, addr, post_inc
+ USER(\l, \inst \reg, [\addr], \post_inc)
+ .endm
+#endif
+
#endif /* __ASSEMBLY__ */
/*