linux-stable.git/arch/powerpc/kernel/vdso, branch linux-6.10.y Linux kernel stable tree powerpc/vdso: Fix VDSO data access when running in a non-root time namespace 2024-10-10T10:00:44+00:00 Christophe Leroy christophe.leroy@csgroup.eu 2024-09-06T08:33:43+00:00 7270e5f957faa3e57878042984c1443486385c22 [ Upstream commit c73049389e58c01e2e3bbfae900c8daeee177191 ] When running in a non-root time namespace, the global VDSO data page is replaced by a dedicated namespace data page and the global data page is mapped next to it. Detailed explanations can be found at commit 660fd04f9317 ("lib/vdso: Prepare for time namespace support"). When it happens, __kernel_get_syscall_map and __kernel_get_tbfreq and __kernel_sync_dicache don't work anymore because they read 0 instead of the data they need. To address that, clock_mode has to be read. When it is set to VDSO_CLOCKMODE_TIMENS, it means it is a dedicated namespace data page and the global data is located on the following page. Add a macro called get_realdatapage which reads clock_mode and add PAGE_SIZE to the pointer provided by get_datapage macro when clock_mode is equal to VDSO_CLOCKMODE_TIMENS. Use this new macro instead of get_datapage macro except for time functions as they handle it internally. Fixes: 74205b3fc2ef ("powerpc/vdso: Add support for time namespaces") Reported-by: Jason A. Donenfeld <Jason@zx2c4.com> Closes: https://lore.kernel.org/all/ZtnYqZI-nrsNslwy@zx2c4.com/ Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit c73049389e58c01e2e3bbfae900c8daeee177191 ]

When running in a non-root time namespace, the global VDSO data page
is replaced by a dedicated namespace data page and the global data
page is mapped next to it. Detailed explanations can be found at
commit 660fd04f9317 ("lib/vdso: Prepare for time namespace support").

When it happens, __kernel_get_syscall_map and __kernel_get_tbfreq
and __kernel_sync_dicache don't work anymore because they read 0
instead of the data they need.

To address that, clock_mode has to be read. When it is set to
VDSO_CLOCKMODE_TIMENS, it means it is a dedicated namespace data page
and the global data is located on the following page.

Add a macro called get_realdatapage which reads clock_mode and add
PAGE_SIZE to the pointer provided by get_datapage macro when
clock_mode is equal to VDSO_CLOCKMODE_TIMENS. Use this new macro
instead of get_datapage macro except for time functions as they handle
it internally.

Fixes: 74205b3fc2ef ("powerpc/vdso: Add support for time namespaces")
Reported-by: Jason A. Donenfeld <Jason@zx2c4.com>
Closes: https://lore.kernel.org/all/ZtnYqZI-nrsNslwy@zx2c4.com/
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
powerpc/vdso: Inconditionally use CFUNC macro 2024-10-04T14:32:45+00:00 Christophe Leroy christophe.leroy@csgroup.eu 2024-08-22T08:00:29+00:00 b001d0e023e1089387b2fbd143e29100da15858f [ Upstream commit 65948b0e716a47382731889ee6bbb18642b8b003 ] During merge of commit 4e991e3c16a3 ("powerpc: add CFUNC assembly label annotation") a fallback version of CFUNC macro was added at the last minute, so it can be used inconditionally. Fixes: 4e991e3c16a3 ("powerpc: add CFUNC assembly label annotation") Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/0fa863f2f69b2ca4094ae066fcf1430fb31110c9.1724313540.git.christophe.leroy@csgroup.eu Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 65948b0e716a47382731889ee6bbb18642b8b003 ]

During merge of commit 4e991e3c16a3 ("powerpc: add CFUNC assembly
label annotation") a fallback version of CFUNC macro was added at
the last minute, so it can be used inconditionally.

Fixes: 4e991e3c16a3 ("powerpc: add CFUNC assembly label annotation")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/0fa863f2f69b2ca4094ae066fcf1430fb31110c9.1724313540.git.christophe.leroy@csgroup.eu
Signed-off-by: Sasha Levin <sashal@kernel.org>
powerpc/vdso: Don't discard rela sections 2024-09-12T09:13:10+00:00 Christophe Leroy christophe.leroy@csgroup.eu 2024-08-20T11:28:07+00:00 55fe39810bead547dbbc24980e880fd314dcd3fb [ Upstream commit 6114139c3bdde992f4a19264e4f9bfc100d8d776 ] After building the VDSO, there is a verification that it contains no dynamic relocation, see commit aff69273af61 ("vdso: Improve cmd_vdso_check to check all dynamic relocations"). This verification uses readelf -r and doesn't work if rela sections are discarded. Fixes: 8ad57add77d3 ("powerpc/build: vdso linker warning for orphan sections") Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/45c3e6fc76cad05ad2cac0f5b5dfb4fae86dc9d6.1724153239.git.christophe.leroy@csgroup.eu Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 6114139c3bdde992f4a19264e4f9bfc100d8d776 ]

After building the VDSO, there is a verification that it contains
no dynamic relocation, see commit aff69273af61 ("vdso: Improve
cmd_vdso_check to check all dynamic relocations").

This verification uses readelf -r and doesn't work if rela sections
are discarded.

Fixes: 8ad57add77d3 ("powerpc/build: vdso linker warning for orphan sections")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/45c3e6fc76cad05ad2cac0f5b5dfb4fae86dc9d6.1724153239.git.christophe.leroy@csgroup.eu
Signed-off-by: Sasha Levin <sashal@kernel.org>
Makefile: remove redundant tool coverage variables 2024-05-14T14:35:48+00:00 Masahiro Yamada masahiroy@kernel.org 2024-05-06T13:35:43+00:00 7f7f6f7ad654b326897c9f54438a06f03454bd0d Now Kbuild provides reasonable defaults for objtool, sanitizers, and profilers. Remove redundant variables. Note: This commit changes the coverage for some objects: - include arch/mips/vdso/vdso-image.o into UBSAN, GCOV, KCOV - include arch/sparc/vdso/vdso-image-*.o into UBSAN - include arch/sparc/vdso/vma.o into UBSAN - include arch/x86/entry/vdso/extable.o into KASAN, KCSAN, UBSAN, GCOV, KCOV - include arch/x86/entry/vdso/vdso-image-*.o into KASAN, KCSAN, UBSAN, GCOV, KCOV - include arch/x86/entry/vdso/vdso32-setup.o into KASAN, KCSAN, UBSAN, GCOV, KCOV - include arch/x86/entry/vdso/vma.o into GCOV, KCOV - include arch/x86/um/vdso/vma.o into KASAN, GCOV, KCOV I believe these are positive effects because all of them are kernel space objects. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Tested-by: Roberto Sassu <roberto.sassu@huawei.com> 
Now Kbuild provides reasonable defaults for objtool, sanitizers, and
profilers.

Remove redundant variables.

Note:

This commit changes the coverage for some objects:

  - include arch/mips/vdso/vdso-image.o into UBSAN, GCOV, KCOV
  - include arch/sparc/vdso/vdso-image-*.o into UBSAN
  - include arch/sparc/vdso/vma.o into UBSAN
  - include arch/x86/entry/vdso/extable.o into KASAN, KCSAN, UBSAN, GCOV, KCOV
  - include arch/x86/entry/vdso/vdso-image-*.o into KASAN, KCSAN, UBSAN, GCOV, KCOV
  - include arch/x86/entry/vdso/vdso32-setup.o into KASAN, KCSAN, UBSAN, GCOV, KCOV
  - include arch/x86/entry/vdso/vma.o into GCOV, KCOV
  - include arch/x86/um/vdso/vma.o into KASAN, GCOV, KCOV

I believe these are positive effects because all of them are kernel
space objects.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Roberto Sassu <roberto.sassu@huawei.com>
kbuild: use $(src) instead of $(srctree)/$(src) for source directory 2024-05-09T19:34:52+00:00 Masahiro Yamada masahiroy@kernel.org 2024-04-27T14:55:02+00:00 b1992c3772e69a6fd0e3fc81cd4d2820c8b6eca0 Kbuild conventionally uses $(obj)/ for generated files, and $(src)/ for checked-in source files. It is merely a convention without any functional difference. In fact, $(obj) and $(src) are exactly the same, as defined in scripts/Makefile.build: src := $(obj) When the kernel is built in a separate output directory, $(src) does not accurately reflect the source directory location. While Kbuild resolves this discrepancy by specifying VPATH=$(srctree) to search for source files, it does not cover all cases. For example, when adding a header search path for local headers, -I$(srctree)/$(src) is typically passed to the compiler. This introduces inconsistency between upstream and downstream Makefiles because $(src) is used instead of $(srctree)/$(src) for the latter. To address this inconsistency, this commit changes the semantics of $(src) so that it always points to the directory in the source tree. Going forward, the variables used in Makefiles will have the following meanings: $(obj) - directory in the object tree $(src) - directory in the source tree (changed by this commit) $(objtree) - the top of the kernel object tree $(srctree) - the top of the kernel source tree Consequently, $(srctree)/$(src) in upstream Makefiles need to be replaced with $(src). Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nicolas Schier <nicolas@fjasle.eu> 
Kbuild conventionally uses $(obj)/ for generated files, and $(src)/ for
checked-in source files. It is merely a convention without any functional
difference. In fact, $(obj) and $(src) are exactly the same, as defined
in scripts/Makefile.build:

    src := $(obj)

When the kernel is built in a separate output directory, $(src) does
not accurately reflect the source directory location. While Kbuild
resolves this discrepancy by specifying VPATH=$(srctree) to search for
source files, it does not cover all cases. For example, when adding a
header search path for local headers, -I$(srctree)/$(src) is typically
passed to the compiler.

This introduces inconsistency between upstream and downstream Makefiles
because $(src) is used instead of $(srctree)/$(src) for the latter.

To address this inconsistency, this commit changes the semantics of
$(src) so that it always points to the directory in the source tree.

Going forward, the variables used in Makefiles will have the following
meanings:

  $(obj)     - directory in the object tree
  $(src)     - directory in the source tree  (changed by this commit)
  $(objtree) - the top of the kernel object tree
  $(srctree) - the top of the kernel source tree

Consequently, $(srctree)/$(src) in upstream Makefiles need to be replaced
with $(src).

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
arch: use $(obj)/ instead of $(src)/ for preprocessed linker scripts 2024-05-02T11:14:16+00:00 Masahiro Yamada masahiroy@kernel.org 2024-04-27T14:54:59+00:00 b957df3b858d16ba3d4291233569bba09cfd08c7 These are generated files. Prefix them with $(obj)/ instead of $(src)/. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Helge Deller <deller@gmx.de> Reviewed-by: Nicolas Schier <nicolas@fjasle.eu> 
These are generated files. Prefix them with $(obj)/ instead of $(src)/.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Helge Deller <deller@gmx.de>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
powerpc/vdso: No need to undef powerpc for 64-bit build 2023-12-07T12:34:38+00:00 Michael Ellerman mpe@ellerman.id.au 2023-12-06T11:55:46+00:00 42449052c94f22e18e01d71147d8fd75cb58132a The vdso Makefile adds -U$(ARCH) to CPPFLAGS for the vdso64.lds linker script. ARCH is always powerpc, so it becomes -Upowerpc, which means undefine the "powerpc" symbol. But the 64-bit compiler doesn't define powerpc in the first place, compare: $ gcc-5.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux-gcc -m32 -E -dM - </dev/null | grep -w powerpc #define powerpc 1 $ gcc-5.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux-gcc -m64 -E -dM - </dev/null | grep -w powerpc $ So there's no need to undefine it for the 64-bit linker script. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20231206115548.1466874-2-mpe@ellerman.id.au 
The vdso Makefile adds -U$(ARCH) to CPPFLAGS for the vdso64.lds linker
script. ARCH is always powerpc, so it becomes -Upowerpc, which means
undefine the "powerpc" symbol.

But the 64-bit compiler doesn't define powerpc in the first place,
compare:

  $ gcc-5.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux-gcc -m32 -E -dM - </dev/null | grep -w powerpc
  #define powerpc 1
  $ gcc-5.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux-gcc -m64 -E -dM - </dev/null | grep -w powerpc
  $

So there's no need to undefine it for the 64-bit linker script.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231206115548.1466874-2-mpe@ellerman.id.au
Merge tag 'kbuild-v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild 2023-07-01T16:24:31+00:00 Linus Torvalds torvalds@linux-foundation.org 2023-07-01T16:24:31+00:00 ad2885979ea6657fa8d3da51a301ec0e998ad8e7 Pull Kbuild updates from Masahiro Yamada: - Remove the deprecated rule to build *.dtbo from *.dts - Refactor section mismatch detection in modpost - Fix bogus ARM section mismatch detections - Fix error of 'make gtags' with O= option - Add Clang's target triple to KBUILD_CPPFLAGS to fix a build error with the latest LLVM version - Rebuild the built-in initrd when KBUILD_BUILD_TIMESTAMP is changed - Ignore more compiler-generated symbols for kallsyms - Fix 'make local*config' to handle the ${CONFIG_FOO} form in Makefiles - Enable more kernel-doc warnings with W=2 - Refactor <linux/export.h> by generating KSYMTAB data by modpost - Deprecate <asm/export.h> and <asm-generic/export.h> - Remove the EXPORT_DATA_SYMBOL macro - Move the check for static EXPORT_SYMBOL back to modpost, which makes the build faster - Re-implement CONFIG_TRIM_UNUSED_KSYMS with one-pass algorithm - Warn missing MODULE_DESCRIPTION when building modules with W=1 - Make 'make clean' robust against too long argument error - Exclude more objects from GCOV to fix CFI failures with GCOV - Allow 'make modules_install' to install modules.builtin and modules.builtin.modinfo even when CONFIG_MODULES is disabled - Include modules.builtin and modules.builtin.modinfo in the linux-image Debian package even when CONFIG_MODULES is disabled - Revive "Entering directory" logging for the latest Make version * tag 'kbuild-v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (72 commits) modpost: define more R_ARM_* for old distributions kbuild: revive "Entering directory" for Make >= 4.4.1 kbuild: set correct abs_srctree and abs_objtree for package builds scripts/mksysmap: Ignore prefixed KCFI symbols kbuild: deb-pkg: remove the CONFIG_MODULES check in buildeb kbuild: builddeb: always make modules_install, to install modules.builtin* modpost: continue even with unknown relocation type modpost: factor out Elf_Sym pointer calculation to section_rel() modpost: factor out inst location calculation to section_rel() kbuild: Disable GCOV for *.mod.o kbuild: Fix CFI failures with GCOV kbuild: make clean rule robust against too long argument error script: modpost: emit a warning when the description is missing kbuild: make modules_install copy modules.builtin(.modinfo) linux/export.h: rename 'sec' argument to 'license' modpost: show offset from symbol for section mismatch warnings modpost: merge two similar section mismatch warnings kbuild: implement CONFIG_TRIM_UNUSED_KSYMS without recursion modpost: use null string instead of NULL pointer for default namespace modpost: squash sym_update_namespace() into sym_add_exported() ... 
Pull Kbuild updates from Masahiro Yamada:

 - Remove the deprecated rule to build *.dtbo from *.dts

 - Refactor section mismatch detection in modpost

 - Fix bogus ARM section mismatch detections

 - Fix error of 'make gtags' with O= option

 - Add Clang's target triple to KBUILD_CPPFLAGS to fix a build error
   with the latest LLVM version

 - Rebuild the built-in initrd when KBUILD_BUILD_TIMESTAMP is changed

 - Ignore more compiler-generated symbols for kallsyms

 - Fix 'make local*config' to handle the ${CONFIG_FOO} form in Makefiles

 - Enable more kernel-doc warnings with W=2

 - Refactor <linux/export.h> by generating KSYMTAB data by modpost

 - Deprecate <asm/export.h> and <asm-generic/export.h>

 - Remove the EXPORT_DATA_SYMBOL macro

 - Move the check for static EXPORT_SYMBOL back to modpost, which makes
   the build faster

 - Re-implement CONFIG_TRIM_UNUSED_KSYMS with one-pass algorithm

 - Warn missing MODULE_DESCRIPTION when building modules with W=1

 - Make 'make clean' robust against too long argument error

 - Exclude more objects from GCOV to fix CFI failures with GCOV

 - Allow 'make modules_install' to install modules.builtin and
   modules.builtin.modinfo even when CONFIG_MODULES is disabled

 - Include modules.builtin and modules.builtin.modinfo in the
   linux-image Debian package even when CONFIG_MODULES is disabled

 - Revive "Entering directory" logging for the latest Make version

* tag 'kbuild-v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (72 commits)
  modpost: define more R_ARM_* for old distributions
  kbuild: revive "Entering directory" for Make >= 4.4.1
  kbuild: set correct abs_srctree and abs_objtree for package builds
  scripts/mksysmap: Ignore prefixed KCFI symbols
  kbuild: deb-pkg: remove the CONFIG_MODULES check in buildeb
  kbuild: builddeb: always make modules_install, to install modules.builtin*
  modpost: continue even with unknown relocation type
  modpost: factor out Elf_Sym pointer calculation to section_rel()
  modpost: factor out inst location calculation to section_rel()
  kbuild: Disable GCOV for *.mod.o
  kbuild: Fix CFI failures with GCOV
  kbuild: make clean rule robust against too long argument error
  script: modpost: emit a warning when the description is missing
  kbuild: make modules_install copy modules.builtin(.modinfo)
  linux/export.h: rename 'sec' argument to 'license'
  modpost: show offset from symbol for section mismatch warnings
  modpost: merge two similar section mismatch warnings
  kbuild: implement CONFIG_TRIM_UNUSED_KSYMS without recursion
  modpost: use null string instead of NULL pointer for default namespace
  modpost: squash sym_update_namespace() into sym_add_exported()
  ...
powerpc/build: vdso linker warning for orphan sections 2023-06-15T04:04:19+00:00 Nicholas Piggin npiggin@gmail.com 2023-06-09T05:10:02+00:00 8ad57add77d352102ba9edd500b00bc851c2e261 Add --orphan-handlin for vdsos, and adjust vdso linker scripts to deal with orphan sections. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20230609051002.3342-1-npiggin@gmail.com 
Add --orphan-handlin for vdsos, and adjust vdso linker scripts to deal
with orphan sections.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230609051002.3342-1-npiggin@gmail.com
powerpc/vdso: Include CLANG_FLAGS explicitly in ldflags-y 2023-06-05T00:49:58+00:00 Nathan Chancellor nathan@kernel.org 2023-06-01T18:46:33+00:00 a7e5eb53bf9b800d086e2ebcfebd9a3bb16bd1b0 A future change will move CLANG_FLAGS from KBUILD_{A,C}FLAGS to KBUILD_CPPFLAGS so that '--target' is available while preprocessing. When that occurs, the following error appears when building the compat PowerPC vDSO: clang: error: unsupported option '-mbig-endian' for target 'x86_64-pc-linux-gnu' make[3]: *** [.../arch/powerpc/kernel/vdso/Makefile:76: arch/powerpc/kernel/vdso/vdso32.so.dbg] Error 1 Explicitly add CLANG_FLAGS to ldflags-y, so that '--target' will always be present. Signed-off-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> 
A future change will move CLANG_FLAGS from KBUILD_{A,C}FLAGS to
KBUILD_CPPFLAGS so that '--target' is available while preprocessing.
When that occurs, the following error appears when building the compat
PowerPC vDSO:

  clang: error: unsupported option '-mbig-endian' for target 'x86_64-pc-linux-gnu'
  make[3]: *** [.../arch/powerpc/kernel/vdso/Makefile:76: arch/powerpc/kernel/vdso/vdso32.so.dbg] Error 1

Explicitly add CLANG_FLAGS to ldflags-y, so that '--target' will always
be present.

Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>