From 815069ca57c142eb71d27439bc27f41a433a67b3 Mon Sep 17 00:00:00 2001 From: Michal Suchanek Date: Tue, 24 Apr 2018 14:15:56 +1000 Subject: [PATCH] powerpc/64s: Patch barrier_nospec in modules 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 Signed-off-by: Michael Ellerman --- 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(-) diff --git a/arch/powerpc/include/asm/setup.h b/arch/powerpc/include/asm/setup.h index afc7280cce3b..a24c3c9053cc 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 3f7ba0f5bf29..1b3c6835e730 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 b963eae0b0a0..39cc9eae8d7f 100644 --- a/arch/powerpc/kernel/security.c +++ b/arch/powerpc/kernel/security.c @@ -14,7 +14,7 @@ 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 ae911dad9b16..2b9173d09f24 100644 --- a/arch/powerpc/lib/feature-fixups.c +++ b/arch/powerpc/lib/feature-fixups.c @@ -163,14 +163,14 @@ 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 */ @@ -189,6 +189,16 @@ 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) -- 2.20.1