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authorTim Chen <tim.c.chen@linux.intel.com>2018-11-25 19:33:32 +0100
committerThomas Gleixner <tglx@linutronix.de>2018-11-28 11:57:05 +0100
commita8f76ae41cd633ac00be1b3019b1eb4741be3828 (patch)
treecf3c7b8b2e737305967ffbb1afe52f63ffc1ad4e
parentx86/speculation: Remove unnecessary ret variable in cpu_show_common() (diff)
downloadlinux-a8f76ae41cd633ac00be1b3019b1eb4741be3828.tar.xz
linux-a8f76ae41cd633ac00be1b3019b1eb4741be3828.zip
x86/speculation: Move STIPB/IBPB string conditionals out of cpu_show_common()
The Spectre V2 printout in cpu_show_common() handles conditionals for the various mitigation methods directly in the sprintf() argument list. That's hard to read and will become unreadable if more complex decisions need to be made for a particular method. Move the conditionals for STIBP and IBPB string selection into helper functions, so they can be extended later on. Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: David Woodhouse <dwmw@amazon.co.uk> Cc: Andi Kleen <ak@linux.intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Casey Schaufler <casey.schaufler@intel.com> Cc: Asit Mallick <asit.k.mallick@intel.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Jon Masters <jcm@redhat.com> Cc: Waiman Long <longman9394@gmail.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Dave Stewart <david.c.stewart@intel.com> Cc: Kees Cook <keescook@chromium.org> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20181125185003.874479208@linutronix.de
-rw-r--r--arch/x86/kernel/cpu/bugs.c20
1 files changed, 18 insertions, 2 deletions
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index b52a48966e01..a1502bce9eb8 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -844,6 +844,22 @@ static ssize_t l1tf_show_state(char *buf)
}
#endif
+static char *stibp_state(void)
+{
+ if (x86_spec_ctrl_base & SPEC_CTRL_STIBP)
+ return ", STIBP";
+ else
+ return "";
+}
+
+static char *ibpb_state(void)
+{
+ if (boot_cpu_has(X86_FEATURE_USE_IBPB))
+ return ", IBPB";
+ else
+ return "";
+}
+
static ssize_t cpu_show_common(struct device *dev, struct device_attribute *attr,
char *buf, unsigned int bug)
{
@@ -865,9 +881,9 @@ static ssize_t cpu_show_common(struct device *dev, struct device_attribute *attr
case X86_BUG_SPECTRE_V2:
return sprintf(buf, "%s%s%s%s%s%s\n", spectre_v2_strings[spectre_v2_enabled],
- boot_cpu_has(X86_FEATURE_USE_IBPB) ? ", IBPB" : "",
+ ibpb_state(),
boot_cpu_has(X86_FEATURE_USE_IBRS_FW) ? ", IBRS_FW" : "",
- (x86_spec_ctrl_base & SPEC_CTRL_STIBP) ? ", STIBP" : "",
+ stibp_state(),
boot_cpu_has(X86_FEATURE_RSB_CTXSW) ? ", RSB filling" : "",
spectre_v2_module_string());