diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/devicetree/bindings/arm/omap/omap.txt | 1 | ||||
| -rw-r--r-- | Documentation/kernel-parameters.txt | 11 | ||||
| -rw-r--r-- | Documentation/sysctl/kernel.txt | 21 | ||||
| -rw-r--r-- | Documentation/virtual/kvm/mmu.txt | 3 | ||||
| -rw-r--r-- | Documentation/x86/exception-tables.txt | 35 | ||||
| -rw-r--r-- | Documentation/x86/x86_64/boot-options.txt | 2 |
6 files changed, 71 insertions, 2 deletions
diff --git a/Documentation/devicetree/bindings/arm/omap/omap.txt b/Documentation/devicetree/bindings/arm/omap/omap.txt index a2bd593881ca..66422d663184 100644 --- a/Documentation/devicetree/bindings/arm/omap/omap.txt +++ b/Documentation/devicetree/bindings/arm/omap/omap.txt @@ -23,6 +23,7 @@ Optional properties: during suspend. - ti,no-reset-on-init: When present, the module should not be reset at init - ti,no-idle-on-init: When present, the module should not be idled at init +- ti,no-idle: When present, the module is never allowed to idle. Example: diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 9a53c929f017..084775f7b052 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -666,7 +666,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted. clearcpuid=BITNUM [X86] Disable CPUID feature X for the kernel. See - arch/x86/include/asm/cpufeature.h for the valid bit + arch/x86/include/asm/cpufeatures.h for the valid bit numbers. Note the Linux specific bits are not necessarily stable over kernel options, but the vendor specific ones should be. @@ -3491,6 +3491,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted. ro [KNL] Mount root device read-only on boot + rodata= [KNL] + on Mark read-only kernel memory as read-only (default). + off Leave read-only kernel memory writable for debugging. + root= [KNL] Root filesystem See name_to_dev_t comment in init/do_mounts.c. @@ -3528,6 +3532,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted. sched_debug [KNL] Enables verbose scheduler debug messages. + schedstats= [KNL,X86] Enable or disable scheduled statistics. + Allowed values are enable and disable. This feature + incurs a small amount of overhead in the scheduler + but is useful for debugging and performance tuning. + skew_tick= [KNL] Offset the periodic timer tick per cpu to mitigate xtime_lock contention on larger systems, and/or RCU lock contention on all systems with CONFIG_MAXSMP set. diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt index a93b414672a7..f4444c94ff28 100644 --- a/Documentation/sysctl/kernel.txt +++ b/Documentation/sysctl/kernel.txt @@ -58,6 +58,8 @@ show up in /proc/sys/kernel: - panic_on_stackoverflow - panic_on_unrecovered_nmi - panic_on_warn +- perf_cpu_time_max_percent +- perf_event_paranoid - pid_max - powersave-nap [ PPC only ] - printk @@ -639,6 +641,17 @@ allowed to execute. ============================================================== +perf_event_paranoid: + +Controls use of the performance events system by unprivileged +users (without CAP_SYS_ADMIN). The default value is 1. + + -1: Allow use of (almost) all events by all users +>=0: Disallow raw tracepoint access by users without CAP_IOC_LOCK +>=1: Disallow CPU event access by users without CAP_SYS_ADMIN +>=2: Disallow kernel profiling by users without CAP_SYS_ADMIN + +============================================================== pid_max: @@ -760,6 +773,14 @@ rtsig-nr shows the number of RT signals currently queued. ============================================================== +sched_schedstats: + +Enables/disables scheduler statistics. Enabling this feature +incurs a small amount of overhead in the scheduler but is +useful for debugging and performance tuning. + +============================================================== + sg-big-buff: This file shows the size of the generic SCSI (sg) buffer. diff --git a/Documentation/virtual/kvm/mmu.txt b/Documentation/virtual/kvm/mmu.txt index daf9c0f742d2..c81731096a43 100644 --- a/Documentation/virtual/kvm/mmu.txt +++ b/Documentation/virtual/kvm/mmu.txt @@ -358,7 +358,8 @@ In the first case there are two additional complications: - if CR4.SMEP is enabled: since we've turned the page into a kernel page, the kernel may now execute it. We handle this by also setting spte.nx. If we get a user fetch or read fault, we'll change spte.u=1 and - spte.nx=gpte.nx back. + spte.nx=gpte.nx back. For this to work, KVM forces EFER.NX to 1 when + shadow paging is in use. - if CR4.SMAP is disabled: since the page has been changed to a kernel page, it can not be reused when CR4.SMAP is enabled. We set CR4.SMAP && !CR0.WP into shadow page's role to avoid this case. Note, diff --git a/Documentation/x86/exception-tables.txt b/Documentation/x86/exception-tables.txt index 32901aa36f0a..e396bcd8d830 100644 --- a/Documentation/x86/exception-tables.txt +++ b/Documentation/x86/exception-tables.txt @@ -290,3 +290,38 @@ Due to the way that the exception table is built and needs to be ordered, only use exceptions for code in the .text section. Any other section will cause the exception table to not be sorted correctly, and the exceptions will fail. + +Things changed when 64-bit support was added to x86 Linux. Rather than +double the size of the exception table by expanding the two entries +from 32-bits to 64 bits, a clever trick was used to store addresses +as relative offsets from the table itself. The assembly code changed +from: + .long 1b,3b +to: + .long (from) - . + .long (to) - . + +and the C-code that uses these values converts back to absolute addresses +like this: + + ex_insn_addr(const struct exception_table_entry *x) + { + return (unsigned long)&x->insn + x->insn; + } + +In v4.6 the exception table entry was expanded with a new field "handler". +This is also 32-bits wide and contains a third relative function +pointer which points to one of: + +1) int ex_handler_default(const struct exception_table_entry *fixup) + This is legacy case that just jumps to the fixup code +2) int ex_handler_fault(const struct exception_table_entry *fixup) + This case provides the fault number of the trap that occurred at + entry->insn. It is used to distinguish page faults from machine + check. +3) int ex_handler_ext(const struct exception_table_entry *fixup) + This case is used for uaccess_err ... we need to set a flag + in the task structure. Before the handler functions existed this + case was handled by adding a large offset to the fixup to tag + it as special. +More functions can easily be added. diff --git a/Documentation/x86/x86_64/boot-options.txt b/Documentation/x86/x86_64/boot-options.txt index 68ed3114c363..0965a71f9942 100644 --- a/Documentation/x86/x86_64/boot-options.txt +++ b/Documentation/x86/x86_64/boot-options.txt @@ -60,6 +60,8 @@ Machine check threshold to 1. Enabling this may make memory predictive failure analysis less effective if the bios sets thresholds for memory errors since we will not see details for all errors. + mce=recovery + Force-enable recoverable machine check code paths nomce (for compatibility with i386): same as mce=off |