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authorLinus Torvalds <torvalds@linux-foundation.org>2021-01-24 09:40:51 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2021-01-24 09:40:51 -0800
commit14c50a66183856672d822f25dbb73ad26d1e8f11 (patch)
treed92dfbbdab48ed7197abfc317431be5d6a93e95a /arch
parentc509ce2378e196758095c292f7a1df826d971796 (diff)
parent08685be7761d69914f08c3d6211c543a385a5b9c (diff)
Merge tag 'powerpc-5.11-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fixes from Michael Ellerman: - Fix a bad interaction between the scv handling and the fallback L1D flush, which could lead to user register corruption. Only affects people using scv (~no one) on machines with old firmware that are missing the L1D flush. - Two small selftest fixes. Thanks to Eirik Fuller, Libor Pechacek, Nicholas Piggin, Sandipan Das, and Tulio Magno Quites Machado Filho. * tag 'powerpc-5.11-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/64s: fix scv entry fallback flush vs interrupt selftests/powerpc: Only test lwm/stmw on big endian selftests/powerpc: Fix exit status of pkey tests
Diffstat (limited to 'arch')
-rw-r--r--arch/powerpc/include/asm/exception-64s.h13
-rw-r--r--arch/powerpc/include/asm/feature-fixups.h10
-rw-r--r--arch/powerpc/kernel/entry_64.S2
-rw-r--r--arch/powerpc/kernel/exceptions-64s.S19
-rw-r--r--arch/powerpc/kernel/vmlinux.lds.S7
-rw-r--r--arch/powerpc/lib/feature-fixups.c24
6 files changed, 71 insertions, 4 deletions
diff --git a/arch/powerpc/include/asm/exception-64s.h b/arch/powerpc/include/asm/exception-64s.h
index 1d32b174ab6a..c1a8aac01cf9 100644
--- a/arch/powerpc/include/asm/exception-64s.h
+++ b/arch/powerpc/include/asm/exception-64s.h
@@ -63,6 +63,12 @@
nop; \
nop;
+#define SCV_ENTRY_FLUSH_SLOT \
+ SCV_ENTRY_FLUSH_FIXUP_SECTION; \
+ nop; \
+ nop; \
+ nop;
+
/*
* r10 must be free to use, r13 must be paca
*/
@@ -71,6 +77,13 @@
ENTRY_FLUSH_SLOT
/*
+ * r10, ctr must be free to use, r13 must be paca
+ */
+#define SCV_INTERRUPT_TO_KERNEL \
+ STF_ENTRY_BARRIER_SLOT; \
+ SCV_ENTRY_FLUSH_SLOT
+
+/*
* Macros for annotating the expected destination of (h)rfid
*
* The nop instructions allow us to insert one or more instructions to flush the
diff --git a/arch/powerpc/include/asm/feature-fixups.h b/arch/powerpc/include/asm/feature-fixups.h
index f6d2acb57425..ac605fc369c4 100644
--- a/arch/powerpc/include/asm/feature-fixups.h
+++ b/arch/powerpc/include/asm/feature-fixups.h
@@ -240,6 +240,14 @@ label##3: \
FTR_ENTRY_OFFSET 957b-958b; \
.popsection;
+#define SCV_ENTRY_FLUSH_FIXUP_SECTION \
+957: \
+ .pushsection __scv_entry_flush_fixup,"a"; \
+ .align 2; \
+958: \
+ FTR_ENTRY_OFFSET 957b-958b; \
+ .popsection;
+
#define RFI_FLUSH_FIXUP_SECTION \
951: \
.pushsection __rfi_flush_fixup,"a"; \
@@ -273,10 +281,12 @@ label##3: \
extern long stf_barrier_fallback;
extern long entry_flush_fallback;
+extern long scv_entry_flush_fallback;
extern long __start___stf_entry_barrier_fixup, __stop___stf_entry_barrier_fixup;
extern long __start___stf_exit_barrier_fixup, __stop___stf_exit_barrier_fixup;
extern long __start___uaccess_flush_fixup, __stop___uaccess_flush_fixup;
extern long __start___entry_flush_fixup, __stop___entry_flush_fixup;
+extern long __start___scv_entry_flush_fixup, __stop___scv_entry_flush_fixup;
extern long __start___rfi_flush_fixup, __stop___rfi_flush_fixup;
extern long __start___barrier_nospec_fixup, __stop___barrier_nospec_fixup;
extern long __start__btb_flush_fixup, __stop__btb_flush_fixup;
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index aa1af139d947..33ddfeef4fe9 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -75,7 +75,7 @@ BEGIN_FTR_SECTION
bne .Ltabort_syscall
END_FTR_SECTION_IFSET(CPU_FTR_TM)
#endif
- INTERRUPT_TO_KERNEL
+ SCV_INTERRUPT_TO_KERNEL
mr r10,r1
ld r1,PACAKSAVE(r13)
std r10,0(r1)
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index e02ad6fefa46..6e53f7638737 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -2993,6 +2993,25 @@ TRAMP_REAL_BEGIN(entry_flush_fallback)
ld r11,PACA_EXRFI+EX_R11(r13)
blr
+/*
+ * The SCV entry flush happens with interrupts enabled, so it must disable
+ * to prevent EXRFI being clobbered by NMIs (e.g., soft_nmi_common). r10
+ * (containing LR) does not need to be preserved here because scv entry
+ * puts 0 in the pt_regs, CTR can be clobbered for the same reason.
+ */
+TRAMP_REAL_BEGIN(scv_entry_flush_fallback)
+ li r10,0
+ mtmsrd r10,1
+ lbz r10,PACAIRQHAPPENED(r13)
+ ori r10,r10,PACA_IRQ_HARD_DIS
+ stb r10,PACAIRQHAPPENED(r13)
+ std r11,PACA_EXRFI+EX_R11(r13)
+ L1D_DISPLACEMENT_FLUSH
+ ld r11,PACA_EXRFI+EX_R11(r13)
+ li r10,MSR_RI
+ mtmsrd r10,1
+ blr
+
TRAMP_REAL_BEGIN(rfi_flush_fallback)
SET_SCRATCH0(r13);
GET_PACA(r13);
diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S
index 4ab426b8b0e0..72fa3c00229a 100644
--- a/arch/powerpc/kernel/vmlinux.lds.S
+++ b/arch/powerpc/kernel/vmlinux.lds.S
@@ -146,6 +146,13 @@ SECTIONS
}
. = ALIGN(8);
+ __scv_entry_flush_fixup : AT(ADDR(__scv_entry_flush_fixup) - LOAD_OFFSET) {
+ __start___scv_entry_flush_fixup = .;
+ *(__scv_entry_flush_fixup)
+ __stop___scv_entry_flush_fixup = .;
+ }
+
+ . = ALIGN(8);
__stf_exit_barrier_fixup : AT(ADDR(__stf_exit_barrier_fixup) - LOAD_OFFSET) {
__start___stf_exit_barrier_fixup = .;
*(__stf_exit_barrier_fixup)
diff --git a/arch/powerpc/lib/feature-fixups.c b/arch/powerpc/lib/feature-fixups.c
index 47821055b94c..1fd31b4b0e13 100644
--- a/arch/powerpc/lib/feature-fixups.c
+++ b/arch/powerpc/lib/feature-fixups.c
@@ -290,9 +290,6 @@ void do_entry_flush_fixups(enum l1d_flush_type types)
long *start, *end;
int i;
- start = PTRRELOC(&__start___entry_flush_fixup);
- end = PTRRELOC(&__stop___entry_flush_fixup);
-
instrs[0] = 0x60000000; /* nop */
instrs[1] = 0x60000000; /* nop */
instrs[2] = 0x60000000; /* nop */
@@ -312,6 +309,8 @@ void do_entry_flush_fixups(enum l1d_flush_type types)
if (types & L1D_FLUSH_MTTRIG)
instrs[i++] = 0x7c12dba6; /* mtspr TRIG2,r0 (SPR #882) */
+ start = PTRRELOC(&__start___entry_flush_fixup);
+ end = PTRRELOC(&__stop___entry_flush_fixup);
for (i = 0; start < end; start++, i++) {
dest = (void *)start + *start;
@@ -328,6 +327,25 @@ void do_entry_flush_fixups(enum l1d_flush_type types)
patch_instruction((struct ppc_inst *)(dest + 2), ppc_inst(instrs[2]));
}
+ start = PTRRELOC(&__start___scv_entry_flush_fixup);
+ end = PTRRELOC(&__stop___scv_entry_flush_fixup);
+ for (; start < end; start++, i++) {
+ dest = (void *)start + *start;
+
+ pr_devel("patching dest %lx\n", (unsigned long)dest);
+
+ patch_instruction((struct ppc_inst *)dest, ppc_inst(instrs[0]));
+
+ if (types == L1D_FLUSH_FALLBACK)
+ patch_branch((struct ppc_inst *)(dest + 1), (unsigned long)&scv_entry_flush_fallback,
+ BRANCH_SET_LINK);
+ else
+ patch_instruction((struct ppc_inst *)(dest + 1), ppc_inst(instrs[1]));
+
+ patch_instruction((struct ppc_inst *)(dest + 2), ppc_inst(instrs[2]));
+ }
+
+
printk(KERN_DEBUG "entry-flush: patched %d locations (%s flush)\n", i,
(types == L1D_FLUSH_NONE) ? "no" :
(types == L1D_FLUSH_FALLBACK) ? "fallback displacement" :