From: Michal Suchanek <msuchanek@suse.de>
To: linuxppc-dev@lists.ozlabs.org
Cc: "Benjamin Herrenschmidt" <benh@kernel.crashing.org>,
"Paul Mackerras" <paulus@samba.org>,
"Michael Ellerman" <mpe@ellerman.id.au>,
"Peter Zijlstra" <peterz@infradead.org>,
"Michal Suchanek" <msuchanek@suse.de>,
"Kate Stewart" <kstewart@linuxfoundation.org>,
"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
"Philippe Ombredanne" <pombredanne@nexb.com>,
"Nicholas Piggin" <npiggin@gmail.com>,
"Tobin C. Harding" <me@tobin.cc>,
"Mahesh Salgaonkar" <mahesh@linux.vnet.ibm.com>,
"David Gibson" <david@gibson.dropbear.id.au>,
"Al Viro" <viro@zeniv.linux.org.uk>,
"Michael Neuling" <mikey@neuling.org>,
"Oliver O'Halloran" <oohall@gmail.com>,
"Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>,
"Madhavan Srinivasan" <maddy@linux.vnet.ibm.com>,
"Masami Hiramatsu" <mhiramat@kernel.org>,
"Andrew Morton" <akpm@linux-foundation.org>,
"Balbir Singh" <bsingharora@gmail.com>,
"Sergey Senozhatsky" <sergey.senozhatsky@gmail.com>,
"Christophe Leroy" <christophe.leroy@c-s.fr>,
"Andrew Donnellan" <andrew.donnellan@au1.ibm.com>,
"Daniel Axtens" <dja@axtens.net>,
"Russell Currey" <ruscur@russell.cc>,
"Joe Perches" <joe@perches.com>,
"Bryant G. Ly" <bryantly@linux.vnet.ibm.com>,
"Cédric Le Goater" <clg@kaod.org>,
linux-kernel@vger.kernel.org
Subject: [PATCH RFC 4/8] powerpc/64s: Add support for ori barrier_nospec
Date: Tue, 13 Mar 2018 19:33:02 +0100 [thread overview]
Message-ID: <50e3f58ffadc2ffdda68df768610816734b30ddd.1520965380.git.msuchanek@suse.de> (raw)
In-Reply-To: <cover.1520965380.git.msuchanek@suse.de>
In-Reply-To: <cover.1520965380.git.msuchanek@suse.de>
Copypasta from rfi implementation
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
---
arch/powerpc/include/asm/barrier.h | 4 ++--
arch/powerpc/include/asm/feature-fixups.h | 9 +++++++++
arch/powerpc/include/asm/setup.h | 8 ++++++++
arch/powerpc/kernel/setup_64.c | 29 +++++++++++++++++++++++++++++
arch/powerpc/kernel/vmlinux.lds.S | 7 +++++++
arch/powerpc/lib/feature-fixups.c | 27 +++++++++++++++++++++++++++
6 files changed, 82 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/include/asm/barrier.h b/arch/powerpc/include/asm/barrier.h
index 8e47b3abe405..4079a95e84c2 100644
--- a/arch/powerpc/include/asm/barrier.h
+++ b/arch/powerpc/include/asm/barrier.h
@@ -75,9 +75,9 @@ do { \
___p1; \
})
-/* TODO: add patching so this can be disabled */
/* Prevent speculative execution past this barrier. */
-#define barrier_nospec_asm ori 31,31,0
+#define barrier_nospec_asm SPEC_BARRIER_FIXUP_SECTION; \
+ nop
#ifdef __ASSEMBLY__
#define barrier_nospec barrier_nospec_asm
#else
diff --git a/arch/powerpc/include/asm/feature-fixups.h b/arch/powerpc/include/asm/feature-fixups.h
index 1e82eb3caabd..9d3382618ffd 100644
--- a/arch/powerpc/include/asm/feature-fixups.h
+++ b/arch/powerpc/include/asm/feature-fixups.h
@@ -195,11 +195,20 @@ label##3: \
FTR_ENTRY_OFFSET 951b-952b; \
.popsection;
+#define SPEC_BARRIER_FIXUP_SECTION \
+953: \
+ .pushsection __spec_barrier_fixup,"a"; \
+ .align 2; \
+954: \
+ FTR_ENTRY_OFFSET 953b-954b; \
+ .popsection;
+
#ifndef __ASSEMBLY__
#include <linux/types.h>
extern long __start___rfi_flush_fixup, __stop___rfi_flush_fixup;
+extern long __start___spec_barrier_fixup, __stop___spec_barrier_fixup;
void apply_feature_fixups(void);
void setup_feature_keys(void);
diff --git a/arch/powerpc/include/asm/setup.h b/arch/powerpc/include/asm/setup.h
index 469b7fdc9be4..486d02e4a310 100644
--- a/arch/powerpc/include/asm/setup.h
+++ b/arch/powerpc/include/asm/setup.h
@@ -49,8 +49,16 @@ enum l1d_flush_type {
L1D_FLUSH_MTTRIG = 0x8,
};
+/* These are bit flags */
+enum spec_barrier_type {
+ SPEC_BARRIER_NONE = 0x1,
+ SPEC_BARRIER_ORI = 0x2,
+};
+
void __init setup_rfi_flush(enum l1d_flush_type, bool enable);
void do_rfi_flush_fixups(enum l1d_flush_type types);
+void __init setup_barrier_nospec(enum spec_barrier_type, bool enable);
+void do_barrier_nospec_fixups(enum spec_barrier_type type);
#endif /* !__ASSEMBLY__ */
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index c388cc3357fa..09f21a954bfc 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -815,6 +815,10 @@ static enum l1d_flush_type enabled_flush_types;
static void *l1d_flush_fallback_area;
static bool no_rfi_flush;
bool rfi_flush;
+enum spec_barrier_type powerpc_barrier_nospec;
+static enum spec_barrier_type barrier_nospec_type;
+static bool no_nospec;
+bool barrier_nospec_enabled;
static int __init handle_no_rfi_flush(char *p)
{
@@ -899,6 +903,31 @@ void __init setup_rfi_flush(enum l1d_flush_type types, bool enable)
rfi_flush_enable(enable);
}
+void barrier_nospec_enable(bool enable)
+{
+ barrier_nospec_enabled = enable;
+
+ if (enable) {
+ powerpc_barrier_nospec = barrier_nospec_type;
+ do_barrier_nospec_fixups(powerpc_barrier_nospec);
+ on_each_cpu(do_nothing, NULL, 1);
+ } else {
+ powerpc_barrier_nospec = SPEC_BARRIER_NONE;
+ do_barrier_nospec_fixups(powerpc_barrier_nospec);
+ }
+}
+
+void __init setup_barrier_nospec(enum spec_barrier_type type, bool enable)
+{
+ if (type & SPEC_BARRIER_ORI)
+ pr_info("barrier_nospec: Using ori type flush\n");
+
+ barrier_nospec_type = type;
+
+ if (!no_nospec)
+ barrier_nospec_enable(enable);
+}
+
#ifdef CONFIG_DEBUG_FS
static int rfi_flush_set(void *data, u64 val)
{
diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S
index c8af90ff49f0..744b58ff77f1 100644
--- a/arch/powerpc/kernel/vmlinux.lds.S
+++ b/arch/powerpc/kernel/vmlinux.lds.S
@@ -139,6 +139,13 @@ SECTIONS
*(__rfi_flush_fixup)
__stop___rfi_flush_fixup = .;
}
+
+ . = ALIGN(8);
+ __spec_barrier_fixup : AT(ADDR(__spec_barrier_fixup) - LOAD_OFFSET) {
+ __start___spec_barrier_fixup = .;
+ *(__spec_barrier_fixup)
+ __stop___spec_barrier_fixup = .;
+ }
#endif
EXCEPTION_TABLE(0)
diff --git a/arch/powerpc/lib/feature-fixups.c b/arch/powerpc/lib/feature-fixups.c
index 73697c4e3468..000e153184ad 100644
--- a/arch/powerpc/lib/feature-fixups.c
+++ b/arch/powerpc/lib/feature-fixups.c
@@ -155,6 +155,33 @@ void do_rfi_flush_fixups(enum l1d_flush_type types)
printk(KERN_DEBUG "rfi-flush: patched %d locations\n", i);
}
+
+void do_barrier_nospec_fixups(enum spec_barrier_type type)
+{
+ unsigned int instr, *dest;
+ long *start, *end;
+ int i;
+
+ start = PTRRELOC(&__start___spec_barrier_fixup),
+ end = PTRRELOC(&__stop___spec_barrier_fixup);
+
+ instr = 0x60000000; /* nop */
+
+ if (type == SPEC_BARRIER_ORI) {
+ pr_info("barrier_nospec: using ORI speculation barrier\n");
+ instr = 0x63ff0000; /* ori 31,31,0 speculation barrier */
+ }
+
+ for (i = 0; start < end; start++, i++) {
+ dest = (void *)start + *start;
+
+ pr_devel("patching dest %lx\n", (unsigned long)dest);
+ patch_instruction(dest, instr);
+ }
+
+ printk(KERN_DEBUG "barrier-nospec: patched %d locations\n", i);
+}
+
#endif /* CONFIG_PPC_BOOK3S_64 */
void do_lwsync_fixups(unsigned long value, void *fixup_start, void *fixup_end)
--
2.13.6
next prev parent reply other threads:[~2018-03-13 18:33 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-13 18:32 [PATCH RFC 0/8] powerpc barrier_nospec Michal Suchanek
2018-03-13 18:32 ` [PATCH RFC 1/8] powerpc: Add barrier_nospec Michal Suchanek
2018-03-13 20:01 ` Peter Zijlstra
2018-03-15 19:15 ` [PATCH RFC rebase 0/9] powerpc barrier_nospec Michal Suchanek
2018-03-15 19:15 ` [PATCH RFC rebase 1/9] powerpc: Add barrier_nospec Michal Suchanek
2018-03-15 19:15 ` [PATCH RFC rebase 2/9] powerpc: Use barrier_nospec in copy_from_user Michal Suchanek
2018-03-15 21:37 ` Linus Torvalds
2018-03-16 13:22 ` Michael Ellerman
2018-03-15 19:15 ` [PATCH RFC rebase 3/9] powerpc/64: Use barrier_nospec in syscall entry Michal Suchanek
2018-03-16 5:18 ` Nicholas Piggin
2018-03-16 9:15 ` Michal Suchánek
2018-03-16 10:46 ` Nicholas Piggin
2018-03-16 13:28 ` Michael Ellerman
2018-03-16 17:08 ` Linus Torvalds
2018-03-15 19:15 ` [PATCH RFC rebase 4/9] powerpc/64s: Use barrier_nospec in RFI_FLUSH_SLOT Michal Suchanek
2018-03-15 19:15 ` [PATCH RFC rebase 5/9] powerpc/64s: Add support for ori barrier_nospec patching Michal Suchanek
2018-03-15 19:15 ` [PATCH RFC rebase 6/9] powerpc/64: Patch barrier_nospec in modules Michal Suchanek
2018-03-15 19:15 ` [PATCH RFC rebase 7/9] powerpc/64: barrier_nospec: Add debugfs trigger Michal Suchanek
2018-03-15 19:15 ` [PATCH RFC rebase 8/9] powerpc/64s: barrier_nospec: Add hcall triggerr Michal Suchanek
2018-03-15 19:15 ` [PATCH RFC rebase 9/9] powerpc/64: barrier_nospec: Add commandline trigger Michal Suchanek
2018-03-23 15:59 ` Diana Madalina Craciun
2018-03-16 8:08 ` [PATCH RFC rebase 0/9] powerpc barrier_nospec Greg Kroah-Hartman
2018-03-16 9:31 ` Michal Suchánek
2018-03-13 18:33 ` [PATCH RFC 2/8] powerpc: Use barrier_nospec in copy_from_user Michal Suchanek
2018-03-13 18:33 ` [PATCH RFC 3/8] powerpc/64: Use barrier_nospec in syscall entry Michal Suchanek
2018-03-13 18:33 ` Michal Suchanek [this message]
2018-03-13 18:33 ` [PATCH RFC 5/8] powerpc/64: Patch barrier_nospec in modules Michal Suchanek
2018-03-13 18:33 ` [PATCH RFC 6/8] powerpc/64: barrier_nospec: Add debugfs trigger Michal Suchanek
2018-03-13 18:33 ` [PATCH RFC 7/8] powerpc/64s: barrier_nospec: Add hcall triggerr Michal Suchanek
2018-03-13 18:33 ` [PATCH RFC 8/8] powerpc/64: barrier_nospec: Add commandline trigger Michal Suchanek
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