Sync with Linux kernel 6.6 shadow stack interface. Since only x86-64 is
supported, i386 shadow stack codes are unchanged and CET shouldn't be
enabled for i386.
1. When the shadow stack base in TCB is unset, the default shadow stack
is in use. Use the current shadow stack pointer as the marker for the
default shadow stack. It is used to identify if the current shadow stack
is the same as the target shadow stack when switching ucontexts. If yes,
INCSSP will be used to unwind shadow stack. Otherwise, shadow stack
restore token will be used.
2. Allocate shadow stack with the map_shadow_stack syscall. Since there
is no function to explicitly release ucontext, there is no place to
release shadow stack allocated by map_shadow_stack in ucontext functions.
Such shadow stacks will be leaked.
3. Rename arch_prctl CET commands to ARCH_SHSTK_XXX.
4. Rewrite the CET control functions with the current kernel shadow stack
interface.
Since CET is no longer enabled by kernel, a separate patch will enable
shadow stack during startup.
I used these shell commands:
../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")
and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 7061 files FOO.
I then removed trailing white space from math/tgmath.h,
support/tst-support-open-dev-null-range.c, and
sysdeps/x86_64/multiarch/strlen-vec.S, to work around the following
obscure pre-commit check failure diagnostics from Savannah. I don't
know why I run into these diagnostics whereas others evidently do not.
remote: *** 912-#endif
remote: *** 913:
remote: *** 914-
remote: *** error: lines with trailing whitespace found
...
remote: *** error: sysdeps/unix/sysv/linux/statx_cp.c: trailing lines
I used these shell commands:
../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")
and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 6694 files FOO.
I then removed trailing white space from benchtests/bench-pthread-locks.c
and iconvdata/tst-iconv-big5-hkscs-to-2ucs4.c, to work around this
diagnostic from Savannah:
remote: *** pre-commit check failed ...
remote: *** error: lines with trailing whitespace found
remote: error: hook declined to update refs/heads/master
Continuing bits/mman.h unification between architectures using the
Linux kernel, this patch arranges for the common set of MAP_* flags to
be used by two more architectures. That common set is moved to
bits/mman-map-flags-generic.h, which is included by bits/mman.h, to
allow architectures to use that common set even if they also have
architecture-specific additions to it. As well as the generic
bits/mman.h, the versions for x86 and ia64 are also then made to
include bits/mman-map-flags-generic.h, so while they still need
architecture-specific bits/mman.h (for MAP_32BIT and MAP_GROWSUP
respectively), they do not need to duplicate the generic flag
definitions in there.
Tested for x86_64 and x86, and with build-many-glibcs.py.
* sysdeps/unix/sysv/linux/bits/mman-map-flags-generic.h: New
file. Most contents moved from ....
* sysdeps/unix/sysv/linux/bits/mman.h: ... here. Move contents to
and include <bits/mman-map-flags-generic.h>.
* sysdeps/unix/sysv/linux/Makefile [$(subdir) = misc]
(sysdep_headers): Add bits/mman-map-flags-generic.h.
* sysdeps/unix/sysv/linux/ia64/bits/mman.h: Include
<bits/mman-map-flags-generic.h>.
[__USE_MISC] (MAP_GROWSUP): Only define this macro, not other
macros defined in <bits/mman-map-flags-generic.h>.
* sysdeps/unix/sysv/linux/x86/bits/mman.h: Include
<bits/mman-map-flags-generic.h>.
[__USE_MISC] (MAP_32BIT): Only define this macro, not other macros
defined in <bits/mman-map-flags-generic.h>.
This patch adds the MAP_SYNC macro from Linux 4.15 to various
bits/mman.h headers. Note that this is *not* added to all
architectures: in Linux 4.15, this macro is only in
asm-generic/mman.h, and only some architectures' asm/mman.h include
the asm-generic file - the architectures not using the asm-generic
file will need their own values of MAP_SYNC allocated to support this
functionality (some of them also already have conflicting mmap flags
so the value there will have to be different from the generic
0x80000). Specifically, for glibc architectures, alpha hppa mips
powerpc sparc tile lack allocations of values for MAP_SYNC.
Tested for x86_64.
* sysdeps/unix/sysv/linux/aarch64/bits/mman.h [__USE_MISC]
(MAP_SYNC): New macro.
* sysdeps/unix/sysv/linux/arm/bits/mman.h [__USE_MISC] (MAP_SYNC):
Likewise.
* sysdeps/unix/sysv/linux/ia64/bits/mman.h [__USE_MISC]
(MAP_SYNC): Likewise.
* sysdeps/unix/sysv/linux/m68k/bits/mman.h [__USE_MISC]
(MAP_SYNC): Likewise.
* sysdeps/unix/sysv/linux/microblaze/bits/mman.h [__USE_MISC]
(MAP_SYNC): Likewise.
* sysdeps/unix/sysv/linux/nios2/bits/mman.h [__USE_MISC]
(MAP_SYNC): Likewise.
* sysdeps/unix/sysv/linux/riscv/bits/mman.h [__USE_MISC]
(MAP_SYNC): Likewise.
* sysdeps/unix/sysv/linux/s390/bits/mman.h [__USE_MISC]
(MAP_SYNC): Likewise.
* sysdeps/unix/sysv/linux/sh/bits/mman.h [__USE_MISC] (MAP_SYNC):
Likewise.
* sysdeps/unix/sysv/linux/x86/bits/mman.h [__USE_MISC] (MAP_SYNC):
Likewise.
* sysdeps/unix/sysv/linux/s390/bits/mman.h: Include
<bits/mman-linux.h>.
(MCL_CURRENT, MCL_FUTURE): Do not define here, the generic value
is fine.
* sysdeps/unix/sysv/linux/sh/bits/mman.h: Move include of
<bits/mman-linux.h> to end of file.
(MCL_CURRENT, MCL_FUTURE): Do not define here, the generic value
is fine.
* sysdeps/unix/sysv/linux/x86/bits/mman.h: Move include of
<bits/mman-linux.h> to end of file.
(MCL_CURRENT, MCL_FUTURE): Do not define here, the generic value
is fine.
* sysdeps/unix/sysv/linux/sparc/bits/mman.h: Move include of
<bits/mman-linux.h> to end of file.
* sysdeps/unix/sysv/linux/bits/mman-linux.h [!MCL_CURRENT]
(MCL_CURRENT, MCL_FUTURE): Define here.
* sysdeps/unix/sysv/linux/bits/mman-linux.h: New file, with
Linux common definitions.
* sysdeps/unix/sysv/linux/sh/bits/mman.h: Remove all defines
provided by bits/mman-linux.h and include <bits/mman-linux.h>.
* sysdeps/unix/sysv/linux/x86/bits/mman.h: Likewise.
* sysdeps/unix/sysv/linux/s390/bits/mman.h: Likewise.
* sysdeps/unix/sysv/linux/powerpc/bits/mman.h: Likewise.
* sysdeps/unix/sysv/linux/sh/bits/mman.h: Likewise.
* sysdeps/unix/sysv/linux/sparc/bits/mman.h: Likewise.
