Merge tag 'powerpc-6.7-3' of git://git.kernel.org/pub/scm/linux/kerne…

…l/git/powerpc/linux Pull powerpc fixes from Michael Ellerman: - Fix corruption of f0/vs0 during FP/Vector save, seen as userspace crashes when using io-uring workers (in particular with MariaDB) - Fix KVM_RUN potentially clobbering all host userspace FP/Vector registers Thanks to Timothy Pearson, Jens Axboe, and Nicholas Piggin. * tag 'powerpc-6.7-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: KVM: PPC: Book3S HV: Fix KVM_RUN clobbering FP/VEC user registers powerpc: Don't clobber f0/vs0 during fp|altivec register save
mariux64 · Dec 2, 2023 · 1b8af65 · 1b8af65
2 parents 17b17be + dc158d2
commit 1b8af65
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Showing 3 changed files with 18 additions and 3 deletions.
diff --git a/arch/powerpc/kernel/fpu.S b/arch/powerpc/kernel/fpu.S
@@ -23,6 +23,15 @@
 #include <asm/feature-fixups.h>
 
 #ifdef CONFIG_VSX
+#define __REST_1FPVSR(n,c,base)						\
+BEGIN_FTR_SECTION							\
+	b	2f;							\
+END_FTR_SECTION_IFSET(CPU_FTR_VSX);					\
+	REST_FPR(n,base);						\
+	b	3f;							\
+2:	REST_VSR(n,c,base);						\
+3:
+
 #define __REST_32FPVSRS(n,c,base)					\
 BEGIN_FTR_SECTION							\
 	b	2f;							\
@@ -41,9 +50,11 @@ END_FTR_SECTION_IFSET(CPU_FTR_VSX);					\
 2:	SAVE_32VSRS(n,c,base);						\
 3:
 #else
+#define __REST_1FPVSR(n,b,base)		REST_FPR(n, base)
 #define __REST_32FPVSRS(n,b,base)	REST_32FPRS(n, base)
 #define __SAVE_32FPVSRS(n,b,base)	SAVE_32FPRS(n, base)
 #endif
+#define REST_1FPVSR(n,c,base)   __REST_1FPVSR(n,__REG_##c,__REG_##base)
 #define REST_32FPVSRS(n,c,base) __REST_32FPVSRS(n,__REG_##c,__REG_##base)
 #define SAVE_32FPVSRS(n,c,base) __SAVE_32FPVSRS(n,__REG_##c,__REG_##base)
 
@@ -67,6 +78,7 @@ _GLOBAL(store_fp_state)
 	SAVE_32FPVSRS(0, R4, R3)
 	mffs	fr0
 	stfd	fr0,FPSTATE_FPSCR(r3)
+	REST_1FPVSR(0, R4, R3)
 	blr
 EXPORT_SYMBOL(store_fp_state)
 
@@ -138,4 +150,5 @@ _GLOBAL(save_fpu)
 2:	SAVE_32FPVSRS(0, R4, R6)
 	mffs	fr0
 	stfd	fr0,FPSTATE_FPSCR(r6)
+	REST_1FPVSR(0, R4, R6)
 	blr
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
@@ -1198,11 +1198,11 @@ void kvmppc_save_user_regs(void)
 
 	usermsr = current->thread.regs->msr;
 
+	/* Caller has enabled FP/VEC/VSX/TM in MSR */
 	if (usermsr & MSR_FP)
-		save_fpu(current);
-
+		__giveup_fpu(current);
 	if (usermsr & MSR_VEC)
-		save_altivec(current);
+		__giveup_altivec(current);
 
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 	if (usermsr & MSR_TM) {

diff --git a/arch/powerpc/kernel/vector.S b/arch/powerpc/kernel/vector.S
@@ -33,6 +33,7 @@ _GLOBAL(store_vr_state)
 	mfvscr	v0
 	li	r4, VRSTATE_VSCR
 	stvx	v0, r4, r3
+	lvx	v0, 0, r3
 	blr
 EXPORT_SYMBOL(store_vr_state)
 
@@ -109,6 +110,7 @@ _GLOBAL(save_altivec)
 	mfvscr	v0
 	li	r4,VRSTATE_VSCR
 	stvx	v0,r4,r7
+	lvx	v0,0,r7
 	blr
 
 #ifdef CONFIG_VSX