x86/crypto/crc32c-pcl-intel: Standardize jump table

Simplify the jump table code so that it resembles a compiler-generated table. This enables ORC unwinding by allowing objtool to follow all the potential code paths. Signed-off-by: Josh Poimboeuf <[email protected]> Tested-by: Ard Biesheuvel <[email protected]> Acked-by: Ard Biesheuvel <[email protected]> Tested-by: Sami Tolvanen <[email protected]> Acked-by: Peter Zijlstra (Intel) <[email protected]> Acked-by: Herbert Xu <[email protected]> Link: https://lore.kernel.org/r/5357a039def90b8ef6b5874ef12cda008ecf18ba.1614182415.git.jpoimboe@redhat.com
bignaux · Apr 19, 2021 · 2b02ed5 · 2b02ed5
1 parent dabe516
commit 2b02ed5
Showing 1 changed file with 2 additions and 5 deletions.
diff --git a/arch/x86/crypto/crc32c-pcl-intel-asm_64.S b/arch/x86/crypto/crc32c-pcl-intel-asm_64.S
@@ -53,7 +53,7 @@
 .endm
 
 .macro JMPTBL_ENTRY i
-.word crc_\i - crc_array
+.quad crc_\i
 .endm
 
 .macro JNC_LESS_THAN j
@@ -168,10 +168,7 @@ continue_block:
 	xor     crc2, crc2
 
 	## branch into array
-	lea	jump_table(%rip), %bufp
-	movzwq  (%bufp, %rax, 2), len
-	lea	crc_array(%rip), %bufp
-	lea     (%bufp, len, 1), %bufp
+	mov	jump_table(,%rax,8), %bufp
 	JMP_NOSPEC bufp
 
 	################################################################