The patch titled
Subject: proc: provide details on indirect branch speculation
has been added to the -mm tree. Its filename is
proc-provide-details-on-indirect-branch-speculation.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/proc-provide-details-on-indirect-branch-speculation.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/proc-provide-details-on-indirect-branch-speculation.patch
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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Anand K Mistry <amistry@xxxxxxxxxx>
Subject: proc: provide details on indirect branch speculation
Similar to speculation store bypass, show information about the indirect
branch speculation mode of a task in /proc/$pid/status.
Link: https://lkml.kernel.org/r/20201030172731.1.I7782b0cedb705384a634cfd8898eb7523562da99@changeid
Signed-off-by: Anand K Mistry <amistry@xxxxxxxxxx>
Cc: Anthony Steinhauser <asteinhauser@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Anand K Mistry <amistry@xxxxxxxxxx>
Cc: Alexey Dobriyan <adobriyan@xxxxxxxxx>
Cc: Alexey Gladkov <gladkov.alexey@xxxxxxxxx>
Cc: Jonathan Corbet <corbet@xxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Mike Rapoport <rppt@xxxxxxxxxx>
Cc: NeilBrown <neilb@xxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
Documentation/filesystems/proc.rst | 2 +
fs/proc/array.c | 28 +++++++++++++++++++++++++++
2 files changed, 30 insertions(+)
--- a/Documentation/filesystems/proc.rst~proc-provide-details-on-indirect-branch-speculation
+++ a/Documentation/filesystems/proc.rst
@@ -210,6 +210,7 @@ read the file /proc/PID/status::
NoNewPrivs: 0
Seccomp: 0
Speculation_Store_Bypass: thread vulnerable
+ Speculation_Indirect_Branch: conditional enabled
voluntary_ctxt_switches: 0
nonvoluntary_ctxt_switches: 1
@@ -292,6 +293,7 @@ It's slow but very precise.
NoNewPrivs no_new_privs, like prctl(PR_GET_NO_NEW_PRIV, ...)
Seccomp seccomp mode, like prctl(PR_GET_SECCOMP, ...)
Speculation_Store_Bypass speculative store bypass mitigation status
+ Speculation_Indirect_Branch indirect branch speculation mode
Cpus_allowed mask of CPUs on which this process may run
Cpus_allowed_list Same as previous, but in "list format"
Mems_allowed mask of memory nodes allowed to this process
--- a/fs/proc/array.c~proc-provide-details-on-indirect-branch-speculation
+++ a/fs/proc/array.c
@@ -368,6 +368,34 @@ static inline void task_seccomp(struct s
seq_puts(m, "vulnerable");
break;
}
+
+ seq_puts(m, "\nSpeculation_Indirect_Branch:\t");
+ switch (arch_prctl_spec_ctrl_get(p, PR_SPEC_INDIRECT_BRANCH)) {
+ case -EINVAL:
+ seq_puts(m, "unsupported");
+ break;
+ case PR_SPEC_NOT_AFFECTED:
+ seq_puts(m, "not affected");
+ break;
+ case PR_SPEC_PRCTL | PR_SPEC_FORCE_DISABLE:
+ seq_puts(m, "conditional force disabled");
+ break;
+ case PR_SPEC_PRCTL | PR_SPEC_DISABLE:
+ seq_puts(m, "conditional disabled");
+ break;
+ case PR_SPEC_PRCTL | PR_SPEC_ENABLE:
+ seq_puts(m, "conditional enabled");
+ break;
+ case PR_SPEC_ENABLE:
+ seq_puts(m, "always enabled");
+ break;
+ case PR_SPEC_DISABLE:
+ seq_puts(m, "always disabled");
+ break;
+ default:
+ seq_puts(m, "unknown");
+ break;
+ }
seq_putc(m, '\n');
}
_
Patches currently in -mm which might be from amistry@xxxxxxxxxx are
proc-provide-details-on-indirect-branch-speculation.patch
