4.9-stable review patch. If anyone has any objections, please let me know.
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From: Kees Cook keescook@chromium.org
commit fae1fa0fc6cca8beee3ab8ed71d54f9a78fa3f64 upstream
As done with seccomp and no_new_privs, also show speculation flaw mitigation state in /proc/$pid/status.
Signed-off-by: Kees Cook keescook@chromium.org Signed-off-by: Thomas Gleixner tglx@linutronix.de Signed-off-by: David Woodhouse dwmw@amazon.co.uk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/proc/array.c | 24 +++++++++++++++++++++++- 1 file changed, 23 insertions(+), 1 deletion(-)
--- a/fs/proc/array.c +++ b/fs/proc/array.c @@ -80,6 +80,7 @@ #include <linux/delayacct.h> #include <linux/seq_file.h> #include <linux/pid_namespace.h> +#include <linux/prctl.h> #include <linux/ptrace.h> #include <linux/tracehook.h> #include <linux/string_helpers.h> @@ -345,8 +346,29 @@ static inline void task_seccomp(struct s { #ifdef CONFIG_SECCOMP seq_put_decimal_ull(m, "Seccomp:\t", p->seccomp.mode); - seq_putc(m, '\n'); #endif + seq_printf(m, "\nSpeculation Store Bypass:\t"); + switch (arch_prctl_spec_ctrl_get(p, PR_SPEC_STORE_BYPASS)) { + case -EINVAL: + seq_printf(m, "unknown"); + break; + case PR_SPEC_NOT_AFFECTED: + seq_printf(m, "not vulnerable"); + break; + case PR_SPEC_PRCTL | PR_SPEC_DISABLE: + seq_printf(m, "thread mitigated"); + break; + case PR_SPEC_PRCTL | PR_SPEC_ENABLE: + seq_printf(m, "thread vulnerable"); + break; + case PR_SPEC_DISABLE: + seq_printf(m, "globally mitigated"); + break; + default: + seq_printf(m, "vulnerable"); + break; + } + seq_putc(m, '\n'); }
static inline void task_context_switch_counts(struct seq_file *m,