From: Michal Suchanek <msuchanek@suse.de>
Date: Fri, 29 Mar 2019 11:25:50 +0000 (+1100)
Subject: powerpc/64s: Patch barrier_nospec in modules
X-Git-Tag: v4.14.110~83
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=31c3a1e81171f03c7df48aac3efc1d417a18c708;p=thirdparty%2Fkernel%2Fstable.git

powerpc/64s: Patch barrier_nospec in modules

commit 815069ca57c142eb71d27439bc27f41a433a67b3 upstream.

Note that unlike RFI which is patched only in kernel the nospec state
reflects settings at the time the module was loaded.

Iterating all modules and re-patching every time the settings change
is not implemented.

Based on lwsync patching.

Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/arch/powerpc/include/asm/setup.h b/arch/powerpc/include/asm/setup.h
index 88018e4423863..8f3e5f6de0dd0 100644
--- a/arch/powerpc/include/asm/setup.h
+++ b/arch/powerpc/include/asm/setup.h
@@ -53,6 +53,13 @@ enum l1d_flush_type {
 void setup_rfi_flush(enum l1d_flush_type, bool enable);
 void do_rfi_flush_fixups(enum l1d_flush_type types);
 void do_barrier_nospec_fixups(bool enable);
+extern bool barrier_nospec_enabled;
+
+#ifdef CONFIG_PPC_BOOK3S_64
+void do_barrier_nospec_fixups_range(bool enable, void *start, void *end);
+#else
+static inline void do_barrier_nospec_fixups_range(bool enable, void *start, void *end) { };
+#endif
 
 #endif /* !__ASSEMBLY__ */
 
diff --git a/arch/powerpc/kernel/module.c b/arch/powerpc/kernel/module.c
index 3f7ba0f5bf29f..1b3c6835e7303 100644
--- a/arch/powerpc/kernel/module.c
+++ b/arch/powerpc/kernel/module.c
@@ -72,6 +72,12 @@ int module_finalize(const Elf_Ehdr *hdr,
 		do_feature_fixups(powerpc_firmware_features,
 				  (void *)sect->sh_addr,
 				  (void *)sect->sh_addr + sect->sh_size);
+
+	sect = find_section(hdr, sechdrs, "__spec_barrier_fixup");
+	if (sect != NULL)
+		do_barrier_nospec_fixups_range(barrier_nospec_enabled,
+				  (void *)sect->sh_addr,
+				  (void *)sect->sh_addr + sect->sh_size);
 #endif
 
 	sect = find_section(hdr, sechdrs, "__lwsync_fixup");
diff --git a/arch/powerpc/kernel/security.c b/arch/powerpc/kernel/security.c
index 4f18a447ab70e..4eb9d2b252e34 100644
--- a/arch/powerpc/kernel/security.c
+++ b/arch/powerpc/kernel/security.c
@@ -15,7 +15,7 @@
 
 unsigned long powerpc_security_features __read_mostly = SEC_FTR_DEFAULT;
 
-static bool barrier_nospec_enabled;
+bool barrier_nospec_enabled;
 
 static void enable_barrier_nospec(bool enable)
 {
diff --git a/arch/powerpc/lib/feature-fixups.c b/arch/powerpc/lib/feature-fixups.c
index 65b4e8276bdd0..d78421174ab68 100644
--- a/arch/powerpc/lib/feature-fixups.c
+++ b/arch/powerpc/lib/feature-fixups.c
@@ -278,14 +278,14 @@ void do_rfi_flush_fixups(enum l1d_flush_type types)
 						: "unknown");
 }
 
-void do_barrier_nospec_fixups(bool enable)
+void do_barrier_nospec_fixups_range(bool enable, void *fixup_start, void *fixup_end)
 {
 	unsigned int instr, *dest;
 	long *start, *end;
 	int i;
 
-	start = PTRRELOC(&__start___barrier_nospec_fixup),
-	end = PTRRELOC(&__stop___barrier_nospec_fixup);
+	start = fixup_start;
+	end = fixup_end;
 
 	instr = 0x60000000; /* nop */
 
@@ -304,6 +304,16 @@ void do_barrier_nospec_fixups(bool enable)
 	printk(KERN_DEBUG "barrier-nospec: patched %d locations\n", i);
 }
 
+void do_barrier_nospec_fixups(bool enable)
+{
+	void *start, *end;
+
+	start = PTRRELOC(&__start___barrier_nospec_fixup),
+	end = PTRRELOC(&__stop___barrier_nospec_fixup);
+
+	do_barrier_nospec_fixups_range(enable, start, end);
+}
+
 #endif /* CONFIG_PPC_BOOK3S_64 */
 
 void do_lwsync_fixups(unsigned long value, void *fixup_start, void *fixup_end)