On Mon, Sep 02, 2024 at 03:12:47PM +0200, Christophe Leroy wrote:
Le 02/09/2024 à 14:41, Jason A. Donenfeld a écrit :
On Mon, Sep 02, 2024 at 02:04:42PM +0200, Christophe Leroy wrote:
SYM_FUNC_START(__arch_chacha20_blocks_nostack) #ifdef __powerpc64__
- blr
- std r5, -216(r1)
- std r14, -144(r1)
- std r15, -136(r1)
- std r16, -128(r1)
- std r17, -120(r1)
- std r18, -112(r1)
- std r19, -104(r1)
- std r20, -96(r1)
- std r21, -88(r1)
- std r22, -80(r1)
- std r23, -72(r1)
- std r24, -64(r1)
- std r25, -56(r1)
- std r26, -48(r1)
- std r27, -40(r1)
- std r28, -32(r1)
- std r29, -24(r1)
- std r30, -16(r1)
- std r31, -8(r1) #else stwu r1, -96(r1) stw r5, 20(r1)
+#ifdef __BIG_ENDIAN__ stmw r14, 24(r1) +#else
- stw r14, 24(r1)
- stw r15, 28(r1)
- stw r16, 32(r1)
- stw r17, 36(r1)
- stw r18, 40(r1)
- stw r19, 44(r1)
- stw r20, 48(r1)
- stw r21, 52(r1)
- stw r22, 56(r1)
- stw r23, 60(r1)
- stw r24, 64(r1)
- stw r25, 68(r1)
- stw r26, 72(r1)
- stw r27, 76(r1)
- stw r28, 80(r1)
- stw r29, 84(r1)
- stw r30, 88(r1)
- stw r31, 92(r1)
+#endif +#endif
This confuses me. Why are you adding code to the !__powerpc64__ branch in this commit? (Also, why does stmw not work on LE?)
That's for the VDSO32 ie running 32 bits binaries on a 64 bits kernel.
"Programming Environments Manual for 32-Bit Implementations of the PowerPC™ Architecture" say: In some implementations operating with little-endian byte order, execution of an lmw or stmw instruction causes the system alignment error handler to be invoked
And GCC doesn't like it either:
tools/arch/powerpc/vdso/vgetrandom-chacha.S:84: Error: `stmw' invalid when little-endian
Does it make sense to do all the 32-bit stuff in the PPC32 commit (and then you can introduce the selftests there without the error you mentioned), and then add the 64-bit stuff in this commit?