The 64bit helper are marked to clobber the memory, but the 32bit ones
are not. Add the appropriate clobber to the 32bit helper routines so
that the compiler cannot do invalid optimizations.
Signed-off-by: Benjamin Berg <benjamin@sipsolutions.net>
Signed-off-by: Richard Weinberger <richard@nod.at>
The stub executable page is remapped to a different location in the
userland process. As these functions may be used by the stub, they
really need to be always inlined rather than permitting the compiler to
emit a function.
Signed-off-by: Benjamin Berg <benjamin@sipsolutions.net>
Signed-off-by: Richard Weinberger <richard@nod.at>
These features have existed since Linux 2.6.14 and can be considered
widely available at this point. Also drop the backward compatibility
code for PTRACE_SETOPTIONS.
Signed-off-by: Benjamin Berg <benjamin@sipsolutions.net>
----
v2:
* Continue to define PTRACE_SYSEMU_SINGLESTEP as glibc only added it in
version 2.27.
Signed-off-by: Richard Weinberger <richard@nod.at>
There's a lot of code here that hard-codes that the
data is a single page, and right now that seems to
be sufficient, but to make it easier to change this
in the future, add a new STUB_DATA_PAGES constant
and use it throughout the code.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Like in f4f03f299a
"um: Cleanup syscall_handler_t definition/cast, fix warning",
remove the cast to to fix the compiler warning.
Signed-off-by: Lukas Straub <lukasstraub2@web.de>
Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Signed-off-by: Richard Weinberger <richard@nod.at>
When compiling against musl, their shipped <stddef.h> doesn't have
__always_inline. So instead explicitly include the kernel uapi header,
<linux/stddef.h>, which does.
This prevents the following build error:
In file included from arch/x86/um/shared/sysdep/stub.h:11,
from arch/um/kernel/skas/clone.c:14:
arch/x86/um/shared/sysdep/stub_64.h:111:23: error: expected ‘;’ before ‘void’
111 | static __always_inline void *get_stub_page(void)
| ^~~~~
| ;
make[4]: *** [scripts/Makefile.build:249: arch/um/kernel/skas/clone.o] Error 1
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
The syscall_handler_t type for x86_64 was defined as 'long (*)(void)',
but always cast to 'long (*)(long, long, long, long, long, long)' before
use. This now triggers a warning (see below).
Define syscall_handler_t as the latter instead, and remove the cast.
This simplifies the code, and fixes the warning.
Warning:
In file included from ../arch/um/include/asm/processor-generic.h:13
from ../arch/x86/um/asm/processor.h:41
from ../include/linux/rcupdate.h:30
from ../include/linux/rculist.h:11
from ../include/linux/pid.h:5
from ../include/linux/sched.h:14
from ../include/linux/ptrace.h:6
from ../arch/um/kernel/skas/syscall.c:7:
../arch/um/kernel/skas/syscall.c: In function ‘handle_syscall’:
../arch/x86/um/shared/sysdep/syscalls_64.h:18:11: warning: cast between incompatible function types from ‘long int (*)(void)’ to ‘long int (*)(long int, long int, long int, long int, long int, long int)’ [
-Wcast-function-type]
18 | (((long (*)(long, long, long, long, long, long)) \
| ^
../arch/x86/um/asm/ptrace.h:36:62: note: in definition of macro ‘PT_REGS_SET_SYSCALL_RETURN’
36 | #define PT_REGS_SET_SYSCALL_RETURN(r, res) (PT_REGS_AX(r) = (res))
| ^~~
../arch/um/kernel/skas/syscall.c:46:33: note: in expansion of macro ‘EXECUTE_SYSCALL’
46 | EXECUTE_SYSCALL(syscall, regs));
| ^~~~~~~~~~~~~~~
Signed-off-by: David Gow <davidgow@google.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
In commit 9f0b4807a4 ("um: rework userspace stubs to not hard-code
stub location") I changed stub_segv_handler() to do a calculation with
a pointer to a stack variable to find the data page that we're using
for the stack and the rest of the data. This same commit was meant to
do it as well for stub_clone_handler(), but the change inadvertently
went into commit 84b2789d61 ("um: separate child and parent errors
in clone stub") instead.
This was reported to not be compiled correctly by gcc 5, causing the
code to crash here. I'm not sure why, perhaps it's UB because the var
isn't initialized? In any case, this trick always seemed bad, so just
create a new inline function that does the calculation in assembly.
Reported-by: subashab@codeaurora.org
Fixes: 9f0b4807a4 ("um: rework userspace stubs to not hard-code stub location")
Fixes: 84b2789d61 ("um: separate child and parent errors in clone stub")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
"static void inline" is the wrong way around, fix that.
Reported-by: kernel test robot <lkp@intel.com>
Fixes: 9f0b4807a4 ("um: rework userspace stubs to not hard-code stub location")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
The userspace stacks mostly have a stack (and in the case of the
syscall stub we can just set their stack pointer) that points to
the location of the stub data page already.
Rework the stubs to use the stack pointer to derive the start of
the data page, rather than requiring it to be hard-coded.
In the clone stub, also integrate the int3 into the stack remap,
since we really must not use the stack while we remap it.
This prepares for putting the stub at a variable location that's
not part of the normal address space of the userspace processes
running inside the UML machine.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
If the two are mixed up, then it looks as though the parent
returned an error if the child failed (before) the mmap(),
and then the resulting process never gets killed. Fix this
by splitting the child and parent errors, reporting and
using them appropriately.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
32bit UML used to define PTRACE_SYSEMU and PTRACE_SYSEMU_SINGLESTEP
own its own because many years ago not all libcs had these request codes
in their UAPI.
These days PTRACE_SYSEMU/_SINGLESTEP is well known and part of glibc
and our own define becomes problematic.
With change c48831d0eebf ("linux/x86: sync sys/ptrace.h with Linux 4.14
[BZ #22433]") glibc turned PTRACE_SYSEMU/_SINGLESTEP into a enum and
UML failed to build.
Let's drop our define and rely on the fact that every libc has
PTRACE_SYSEMU/_SINGLESTEP.
Cc: <stable@vger.kernel.org>
Cc: Ritesh Raj Sarraf <rrs@researchut.com>
Reported-and-tested-by: Ritesh Raj Sarraf <rrs@researchut.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.
By default all files without license information are under the default
license of the kernel, which is GPL version 2.
Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.
This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.
How this work was done:
Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,
Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.
The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.
The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.
Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).
All documentation files were explicitly excluded.
The following heuristics were used to determine which SPDX license
identifiers to apply.
- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.
For non */uapi/* files that summary was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139
and resulted in the first patch in this series.
If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930
and resulted in the second patch in this series.
- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:
SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1
and that resulted in the third patch in this series.
- when the two scanners agreed on the detected license(s), that became
the concluded license(s).
- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.
- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).
- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.
- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.
In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.
Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.
Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.
In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.
Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct
This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.
These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch extends save_fp_registers() and restore_fp_registers() to use
PTRACE_GETREGSET and PTRACE_SETREGSET with the XSTATE note type, adding
support for new processor state extensions between context switches.
When the new ptrace requests are unavailable, it falls back to the old
PTRACE_GETFPREGS and PTRACE_SETFPREGS methods, which have been renamed to
save_i387_registers() and restore_i387_registers().
Now these functions expect *fp_regs to have the space of an _xstate struct.
Thus, this also makes ptrace in UML responde to PTRACE_GETFPREGS/_SETFPREG
requests with a user_i387_struct (thus independent from HOST_FP_SIZE), and
by calling save_i387_registers() and restore_i387_registers() instead of
the extended save_fp_registers() and restore_fp_registers() functions.
Signed-off-by: Eli Cooper <elicooper@gmx.com>
Currently UML is abusing __KERNEL__ to distinguish between
kernel and host code (os-Linux). It is better to use a custom
define such that existing users of __KERNEL__ don't get confused.
Signed-off-by: Richard Weinberger <richard@nod.at>
Before we had SKAS0 UML had two modes of operation
TT (tracing thread) and SKAS3/4 (separated kernel address space).
TT was known to be insecure and got removed a long time ago.
SKAS3/4 required a few (3 or 4) patches on the host side which never went
mainline. The last host patch is 10 years old.
With SKAS0 mode (separated kernel address space using 0 host patches),
default since 2005, SKAS3/4 is obsolete and can be removed.
Signed-off-by: Richard Weinberger <richard@nod.at>
Switch from __ARCH_WANT_SYS_RT_SIGACTION to opposite
(!CONFIG_ODD_RT_SIGACTION); the only two architectures that
need it are alpha and sparc. The reason for use of CONFIG_...
instead of __ARCH_... is that it's needed only kernel-side
and doing it that way avoids a mess with include order on many
architectures.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The userspace part of UML uses the asm-offsets.h generator mechanism to
create definitions for UM_KERN_<LEVEL> that match the in-kernel
KERN_<LEVEL> constant definitions.
As of commit 04d2c8c83d ("printk: convert
the format for KERN_<LEVEL> to a 2 byte pattern"), KERN_<LEVEL> is no
longer expanded to the literal '"<LEVEL>"', but to '"\001" "LEVEL"', i.e.
it contains two parts.
However, the combo of DEFINE_STR() in
arch/x86/um/shared/sysdep/kernel-offsets.h and sed-y in Kbuild doesn't
support string literals consisting of multiple parts. Hence for all
UM_KERN_<LEVEL> definitions, only the SOH character is retained in the actual
definition, while the remainder ends up in the comment. E.g. in
include/generated/asm-offsets.h we get
#define UM_KERN_INFO "\001" /* "6" KERN_INFO */
instead of
#define UM_KERN_INFO "\001" "6" /* KERN_INFO */
This causes spurious '^A' output in some kernel messages:
Calibrating delay loop... 4640.76 BogoMIPS (lpj=23203840)
pid_max: default: 32768 minimum: 301
Mount-cache hash table entries: 256
^AChecking that host ptys support output SIGIO...Yes
^AChecking that host ptys support SIGIO on close...No, enabling workaround
^AUsing 2.6 host AIO
NET: Registered protocol family 16
bio: create slab <bio-0> at 0
Switching to clocksource itimer
To fix this:
- Move the mapping from UM_KERN_<LEVEL> to KERN_<LEVEL> from
arch/um/include/shared/common-offsets.h to
arch/um/include/shared/user.h, which is preincluded for all userspace
parts,
- Preinclude include/linux/kern_levels.h for all userspace parts, to
obtain the in-kernel KERN_<LEVEL> constant definitions. This doesn't
violate the kernel/userspace separation, as include/linux/kern_levels.h
is self-contained and doesn't expose any other kernel internals.
- Remove the now unused STR() and DEFINE_STR() macros.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
we only use that to tell copy_thread() done by syscall from that
done by kernel_thread(). However, it's easier to do simply by
checking PF_KTHREAD in thread flags.
Merge sys_clone() guts for 32bit and 64bit, while we are at it...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Randy Dunlap reports that we get
arch/x86/um/shared/sysdep/ptrace.h:7:20: error: redefinition of 'regs_return_value'
arch/x86/um/shared/sysdep/ptrace.h:7:20: note: previous definition of 'regs_return_value' was here
when compiling UML for x86-64.
Stephen Rothwell root-caused it and says:
"Caused by commit d7e7528bcd ("Audit: push audit success and retcode
into arch ptrace.h") (another patch that was never in linux-next :-().
This file now needs protection against double inclusion."
so let's do as the man says.
Reported-by: Randy Dunlap <rdunlap@xenotime.net>
Analyzed-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The audit system previously expected arches calling to audit_syscall_exit to
supply as arguments if the syscall was a success and what the return code was.
Audit also provides a helper AUDITSC_RESULT which was supposed to simplify things
by converting from negative retcodes to an audit internal magic value stating
success or failure. This helper was wrong and could indicate that a valid
pointer returned to userspace was a failed syscall. The fix is to fix the
layering foolishness. We now pass audit_syscall_exit a struct pt_reg and it
in turns calls back into arch code to collect the return value and to
determine if the syscall was a success or failure. We also define a generic
is_syscall_success() macro which determines success/failure based on if the
value is < -MAX_ERRNO. This works for arches like x86 which do not use a
separate mechanism to indicate syscall failure.
We make both the is_syscall_success() and regs_return_value() static inlines
instead of macros. The reason is because the audit function must take a void*
for the regs. (uml calls theirs struct uml_pt_regs instead of just struct
pt_regs so audit_syscall_exit can't take a struct pt_regs). Since the audit
function takes a void* we need to use static inlines to cast it back to the
arch correct structure to dereference it.
The other major change is that on some arches, like ia64, MIPS and ppc, we
change regs_return_value() to give us the negative value on syscall failure.
THE only other user of this macro, kretprobe_example.c, won't notice and it
makes the value signed consistently for the audit functions across all archs.
In arch/sh/kernel/ptrace_64.c I see that we were using regs[9] in the old
audit code as the return value. But the ptrace_64.h code defined the macro
regs_return_value() as regs[3]. I have no idea which one is correct, but this
patch now uses the regs_return_value() function, so it now uses regs[3].
For powerpc we previously used regs->result but now use the
regs_return_value() function which uses regs->gprs[3]. regs->gprs[3] is
always positive so the regs_return_value(), much like ia64 makes it negative
before calling the audit code when appropriate.
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: H. Peter Anvin <hpa@zytor.com> [for x86 portion]
Acked-by: Tony Luck <tony.luck@intel.com> [for ia64]
Acked-by: Richard Weinberger <richard@nod.at> [for uml]
Acked-by: David S. Miller <davem@davemloft.net> [for sparc]
Acked-by: Ralf Baechle <ralf@linux-mips.org> [for mips]
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [for ppc]
it's x86-only and we have no business playing with it in asm/mmu.h; make
the latter have
struct uml_arch_mm_context arch;
instead of
struct uml_ldt ldt;
and let arch/<subarch>/um/asm/mm_context.h decide what'll be in there.
While we are at it, kill host_ldt.h - it's not needed in part of places
that include it (we want asm/ldt.h in those) and it can be trivially
expanded into the single remaining one.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
it's i386-specific; moreover, analogs on other targets have
incompatible interface - PTRACE_GET_THREAD_AREA does exist
elsewhere, but struct user_desc does *not*
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
