linux.git/arch/x86/kernel/process_32.c, branch v5.17

x86/fpu: Move context switch and exit to user inlines into sched.h

2021-10-20T13:27:27+00:00

internal.h is a kitchen sink which needs to get out of the way to prepare
for the upcoming changes.

Move the context switch and exit to user inlines into a separate header,
which is all that code needs.

Signed-off-by: Thomas Gleixner 
Signed-off-by: Borislav Petkov 
Link: https://lkml.kernel.org/r/20211015011539.349132461@linutronix.de

x86/fpu: Remove pointless argument from switch_fpu_finish()

2021-10-20T13:27:25+00:00

Unused since the FPU switching rework.

Signed-off-by: Thomas Gleixner 
Signed-off-by: Borislav Petkov 
Link: https://lkml.kernel.org/r/20211015011538.433135710@linutronix.de

x86/dumpstack: Add log_lvl to __show_regs()

2020-07-22T21:56:53+00:00

show_trace_log_lvl() provides x86 platform-specific way to unwind
backtrace with a given log level. Unfortunately, registers dump(s) are
not printed with the same log level - instead, KERN_DEFAULT is always
used.

Arista's switches uses quite common setup with rsyslog, where only
urgent messages goes to console (console_log_level=KERN_ERR), everything
else goes into /var/log/ as the console baud-rate often is indecently
slow (9600 bps).

Backtrace dumps without registers printed have proven to be as useful as
morning standups. Furthermore, in order to introduce KERN_UNSUPPRESSED
(which I believe is still the most elegant way to fix raciness of sysrq[1])
the log level should be passed down the stack to register dumping
functions. Besides, there is a potential use-case for printing traces
with KERN_DEBUG level [2] (where registers dump shouldn't appear with
higher log level).

Add log_lvl parameter to __show_regs().
Keep the used log level intact to separate visible change.

[1]: https://lore.kernel.org/lkml/20190528002412.1625-1-dima@arista.com/
[2]: https://lore.kernel.org/linux-doc/20190724170249.9644-1-dima@arista.com/

Signed-off-by: Dmitry Safonov 
Signed-off-by: Thomas Gleixner 
Acked-by: Petr Mladek 
Link: https://lkml.kernel.org/r/20200629144847.492794-3-dima@arista.com

mm: don't include asm/pgtable.h if linux/mm.h is already included

2020-06-09T16:39:13+00:00

Patch series "mm: consolidate definitions of page table accessors", v2.

The low level page table accessors (pXY_index(), pXY_offset()) are
duplicated across all architectures and sometimes more than once.  For
instance, we have 31 definition of pgd_offset() for 25 supported
architectures.

Most of these definitions are actually identical and typically it boils
down to, e.g.

static inline unsigned long pmd_index(unsigned long address)
{
        return (address >> PMD_SHIFT) & (PTRS_PER_PMD - 1);
}

static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address)
{
        return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(address);
}

These definitions can be shared among 90% of the arches provided
XYZ_SHIFT, PTRS_PER_XYZ and xyz_page_vaddr() are defined.

For architectures that really need a custom version there is always
possibility to override the generic version with the usual ifdefs magic.

These patches introduce include/linux/pgtable.h that replaces
include/asm-generic/pgtable.h and add the definitions of the page table
accessors to the new header.

This patch (of 12):

The linux/mm.h header includes  to allow inlining of the
functions involving page table manipulations, e.g.  pte_alloc() and
pmd_alloc().  So, there is no point to explicitly include 
in the files that include .

The include statements in such cases are remove with a simple loop:

	for f in $(git grep -l "include ") ; do
		sed -i -e '/include / d' $f
	done

Signed-off-by: Mike Rapoport 
Signed-off-by: Andrew Morton 
Cc: Arnd Bergmann 
Cc: Borislav Petkov 
Cc: Brian Cain 
Cc: Catalin Marinas 
Cc: Chris Zankel 
Cc: "David S. Miller" 
Cc: Geert Uytterhoeven 
Cc: Greentime Hu 
Cc: Greg Ungerer 
Cc: Guan Xuetao 
Cc: Guo Ren 
Cc: Heiko Carstens 
Cc: Helge Deller 
Cc: Ingo Molnar 
Cc: Ley Foon Tan 
Cc: Mark Salter 
Cc: Matthew Wilcox 
Cc: Matt Turner 
Cc: Max Filippov 
Cc: Michael Ellerman 
Cc: Michal Simek 
Cc: Mike Rapoport 
Cc: Nick Hu 
Cc: Paul Walmsley 
Cc: Richard Weinberger 
Cc: Rich Felker 
Cc: Russell King 
Cc: Stafford Horne 
Cc: Thomas Bogendoerfer 
Cc: Thomas Gleixner 
Cc: Tony Luck 
Cc: Vincent Chen 
Cc: Vineet Gupta 
Cc: Will Deacon 
Cc: Yoshinori Sato 
Link: http://lkml.kernel.org/r/20200514170327.31389-1-rppt@kernel.org
Link: http://lkml.kernel.org/r/20200514170327.31389-2-rppt@kernel.org
Signed-off-by: Linus Torvalds

x86/resctrl: Rename asm/resctrl_sched.h to asm/resctrl.h

2020-05-06T15:45:22+00:00

asm/resctrl_sched.h is dedicated to the code used for configuration
of the CPU resource control state when a task is scheduled.

Rename resctrl_sched.h to resctrl.h in preparation of additions that
will no longer make this file dedicated to work done during scheduling.

No functional change.

Suggested-by: Borislav Petkov 
Signed-off-by: Reinette Chatre 
Signed-off-by: Borislav Petkov 
Link: https://lkml.kernel.org/r/6914e0ef880b539a82a6d889f9423496d471ad1d.1588715690.git.reinette.chatre@intel.com

x86: Remove unneeded includes

2020-03-21T15:03:25+00:00

Clean up includes of and in 

Signed-off-by: Brian Gerst 
Signed-off-by: Thomas Gleixner 
Link: https://lkml.kernel.org/r/20200313195144.164260-19-brgerst@gmail.com

x86: Remove force_iret()

2020-01-08T18:40:51+00:00

force_iret() was originally intended to prevent the return to user mode with
the SYSRET or SYSEXIT instructions, in cases where the register state could
have been changed to be incompatible with those instructions.  The entry code
has been significantly reworked since then, and register state is validated
before SYSRET or SYSEXIT are used.  force_iret() no longer serves its original
purpose and can be eliminated.

Signed-off-by: Brian Gerst 
Signed-off-by: Borislav Petkov 
Acked-by: Oleg Nesterov 
Link: https://lkml.kernel.org/r/20191219115812.102620-1-brgerst@gmail.com

x86/iopl: Remove legacy IOPL option

2019-11-16T10:24:05+00:00

The IOPL emulation via the I/O bitmap is sufficient. Remove the legacy
cruft dealing with the (e)flags based IOPL mechanism.

Signed-off-by: Thomas Gleixner 
Reviewed-by: Juergen Gross  (Paravirt and Xen parts)
Acked-by: Andy Lutomirski

x86/process: Unify copy_thread_tls()

2019-11-16T10:23:59+00:00

While looking at the TSS io bitmap it turned out that any change in that
area would require identical changes to copy_thread_tls(). The 32 and 64
bit variants share sufficient code to consolidate them into a common
function to avoid duplication of upcoming modifications.

Signed-off-by: Thomas Gleixner 
Acked-by: Andy Lutomirski

x86/stackframe/32: Provide consistent pt_regs

2019-06-25T08:23:47+00:00

Currently pt_regs on x86_32 has an oddity in that kernel regs
(!user_mode(regs)) are short two entries (esp/ss). This means that any
code trying to use them (typically: regs->sp) needs to jump through
some unfortunate hoops.

Change the entry code to fix this up and create a full pt_regs frame.

This then simplifies various trampolines in ftrace and kprobes, the
stack unwinder, ptrace, kdump and kgdb.

Much thanks to Josh for help with the cleanups!

Signed-off-by: Peter Zijlstra (Intel) 
Reviewed-by: Josh Poimboeuf 
Acked-by: Masami Hiramatsu 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Signed-off-by: Ingo Molnar