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-rw-r--r--Documentation/filesystems/proc.txt13
1 files changed, 12 insertions, 1 deletions
diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt
index b24fd9bccc99..66cad5c86171 100644
--- a/Documentation/filesystems/proc.txt
+++ b/Documentation/filesystems/proc.txt
@@ -125,6 +125,13 @@ process running on the system, which is named after the process ID (PID).
The link self points to the process reading the file system. Each process
subdirectory has the entries listed in Table 1-1.
+Note that an open a file descriptor to /proc/<pid> or to any of its
+contained files or subdirectories does not prevent <pid> being reused
+for some other process in the event that <pid> exits. Operations on
+open /proc/<pid> file descriptors corresponding to dead processes
+never act on any new process that the kernel may, through chance, have
+also assigned the process ID <pid>. Instead, operations on these FDs
+usually fail with ESRCH.
Table 1-1: Process specific entries in /proc
..............................................................................
@@ -194,8 +201,10 @@ read the file /proc/PID/status:
CapPrm: 0000000000000000
CapEff: 0000000000000000
CapBnd: ffffffffffffffff
+ CapAmb: 0000000000000000
NoNewPrivs: 0
Seccomp: 0
+ Speculation_Store_Bypass: thread vulnerable
voluntary_ctxt_switches: 0
nonvoluntary_ctxt_switches: 1
@@ -215,7 +224,7 @@ asynchronous manner and the value may not be very precise. To see a precise
snapshot of a moment, you can see /proc/<pid>/smaps file and scan page table.
It's slow but very precise.
-Table 1-2: Contents of the status files (as of 4.8)
+Table 1-2: Contents of the status files (as of 4.19)
..............................................................................
Field Content
Name filename of the executable
@@ -270,8 +279,10 @@ Table 1-2: Contents of the status files (as of 4.8)
CapPrm bitmap of permitted capabilities
CapEff bitmap of effective capabilities
CapBnd bitmap of capabilities bounding set
+ CapAmb bitmap of ambient capabilities
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
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