From: Michal Suchanek msuchanek@suse.de
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 --- 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)