From: Michal Suchanek <msuchanek@xxxxxxx>
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@xxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/powerpc/include/asm/setup.h | 7 +++++++
arch/powerpc/kernel/module.c | 6 ++++++
arch/powerpc/kernel/security.c | 2 +-
arch/powerpc/lib/feature-fixups.c | 16 +++++++++++++---
4 files changed, 27 insertions(+), 4 deletions(-)
--- a/arch/powerpc/include/asm/setup.h
+++ b/arch/powerpc/include/asm/setup.h
@@ -39,6 +39,13 @@ 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__ */
--- a/arch/powerpc/kernel/module.c
+++ b/arch/powerpc/kernel/module.c
@@ -67,6 +67,12 @@ 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");
--- a/arch/powerpc/kernel/security.c
+++ b/arch/powerpc/kernel/security.c
@@ -16,7 +16,7 @@
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)
{
--- a/arch/powerpc/lib/feature-fixups.c
+++ b/arch/powerpc/lib/feature-fixups.c
@@ -275,14 +275,14 @@ void do_rfi_flush_fixups(enum l1d_flush_
: "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 */
@@ -301,6 +301,16 @@ void do_barrier_nospec_fixups(bool enabl
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)
