According to the documentation of fcntl, some commands take an int as
argument. In practice not all of them enforce this behaviour, as they
instead accept a more permissive long and in most cases not even a
range check is performed.
An issue could possibly arise from a combination of the handling of the
varargs in user space and the ABI rules of the target, which may result
in the top bits of an int argument being non-zero.
This issue was originally raised and detailed in the following thread:
https://lore.kernel.org/linux-api/Y1%2FDS6uoWP7OSkmd@arm.com/
And was discovered during the porting of Linux to Morello [1].
This series modifies the interested commands so that they explicitly
take an int argument. It also propagates this change down to helper and
related functions as necessary.
This series is also available on my fork at:
https://git.morello-project.org/Sevenarth/linux/-/commits/fcntl-int-handlin…
Best regards,
Luca Vizzarro
[1] https://git.morello-project.org/morello/kernel/linux
Luca Vizzarro (5):
fcntl: Cast commands with int args explicitly
fs: Pass argument to fcntl_setlease as int
pipe: Pass argument of pipe_fcntl as int
memfd: Pass argument of memfd_fcntl as int
dnotify: Pass argument of fcntl_dirnotify as int
fs/cifs/cifsfs.c | 2 +-
fs/fcntl.c | 29 +++++++++++++++--------------
fs/libfs.c | 2 +-
fs/locks.c | 20 ++++++++++----------
fs/nfs/nfs4_fs.h | 2 +-
fs/nfs/nfs4file.c | 2 +-
fs/nfs/nfs4proc.c | 4 ++--
fs/notify/dnotify/dnotify.c | 4 ++--
fs/pipe.c | 6 +++---
include/linux/dnotify.h | 4 ++--
include/linux/filelock.h | 12 ++++++------
include/linux/fs.h | 6 +++---
include/linux/memfd.h | 4 ++--
include/linux/pipe_fs_i.h | 4 ++--
mm/memfd.c | 6 +-----
15 files changed, 52 insertions(+), 55 deletions(-)
--
2.34.1
Hi All,
I am Menna, a Linux kernel intern- Outreahy internship. I worked on a
project related to the Morello kernel. I checked the user guides and
followed this: https://git.morello-project.org/morello/morello-linux, but I
have a problem I couldn't create my own FVP kernel image and run it, I want
to develop the kernel and update the FVP image and run it but I don't know
how to do that.
Could you please help me?
Thanks in advance,
Menna
Syscalls provided by CONFIG_COMPAT_32BIT_TIME are not required in
64-bit compat. Only enable this option by default if CONFIG_COMPAT32
is selected.
Note that this is a non-functional change on arm64 as since commit
"arm64: compat: handle time in compat64 syscalls", syscall handlers
provided by CONFIG_COMPAT_32BIT_TIME are unused in compat64.
Signed-off-by: Kevin Brodsky <kevin.brodsky(a)arm.com>
---
I discovered this by chance when looking at Tudor's AIO patches, as
some AIO syscalls have such 32-bit time variants. This patch makes
things slightly more consistent and avoids including syscall
handlers that end up completely unused in compat64.
Kevin
arch/Kconfig | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/Kconfig b/arch/Kconfig
index 143825c4d3af..e0b819abd16c 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -1137,7 +1137,7 @@ config COMPAT_OLD_SIGACTION
config COMPAT_32BIT_TIME
bool "Provide system calls for 32-bit time_t"
- default !64BIT || COMPAT
+ default !64BIT || COMPAT32
help
This enables 32 bit time_t support in addition to 64 bit time_t support.
This is relevant on all 32-bit architectures, and 64-bit architectures
--
2.38.1
Hi,
This is a small update to the series, for more info see the original
cover letter [1].
Following various discussions, the interface remains broadly unchanged,
with a separate function for each permission set (read/write/RW). Luca's
work on explicit checking however exposed that check_user_ptr_read()
should clearly take a pointer to const. The write/RW variants still take
a non-const pointer; accordingly fault_in_safe_writeable() will be
changed to take a non-const pointer too [2], which feels more logical.
For symmetry, make_user_ptr_for_read_uaccess() now returns a pointer to
const. A few patches are modified accordingly; the additional changes
are minimal. A nice side-effect is that this reduces the risks of misuse
at compile time, since copy_to_user(uptr, ...) will trigger a warning if
uptr is a pointer to const.
v1..v2:
- Patch 1: made check_user_ptr_read() and
make_user_ptr_for_read_uaccess() take/return a pointer to const.
- Patch 3, 4, 9: made variables pointers to const when using
make_user_ptr_for_read_uaccess().
Review branch:
https://git.morello-project.org/kbrodsky-arm/linux/-/commits/morello/user_p…
Thanks,
Kevin
[1] https://op-lists.linaro.org/archives/list/linux-morello@op-lists.linaro.org…
[2] https://op-lists.linaro.org/archives/list/linux-morello@op-lists.linaro.org…
Kevin Brodsky (9):
linux/user_ptr.h: Introduce uaccess-related helpers
fs/binfmt_elf: Create appropriate user pointer for uaccess
coredump: Create appropriate user pointer for uaccess
mm/memory: Create appropriate user pointer for uaccess
Revert "mm/hugetlb: Use appropriate user pointer conversions"
Revert "mm/shmem: Use appropriate user pointer conversions"
audit: Create appropriate user pointer for uaccess
perf: Avoid uaddr_to_user_ptr_safe() for arbitrary user address
arm64: Create appropriate user pointer for uaccess
Documentation/core-api/user_ptr.rst | 100 ++++++++++++++++++----------
arch/arm64/kernel/debug-monitors.c | 3 +-
arch/arm64/kernel/traps.c | 3 +-
fs/binfmt_elf.c | 14 ++--
fs/coredump.c | 4 +-
include/linux/user_ptr.h | 86 ++++++++++++++++++++++--
kernel/auditsc.c | 3 +-
kernel/events/internal.h | 2 +-
lib/user_ptr.c | 46 +++++++++++++
mm/hugetlb.c | 2 +-
mm/memory.c | 4 +-
mm/shmem.c | 2 +-
12 files changed, 218 insertions(+), 51 deletions(-)
--
2.38.1
This series makes it possible for purecap apps to use the aio_ring
shared memory region to bypass the io_getevents syscall's overhead.
This functionality is also used in libaio.
With these patches, all io_* LTP tests pass in both Purecap and
plain AArch64 modes. Note that the LTP tests only address the basic
functionality of the aio system and a significant portion of the
functionality is untested in LTP.
For a more comprehensive testing, libaio has been updated with the new
uAPI and ported. All the tests in libaio pass accordingly, in both
Purecap and plain AArch64 modes.
v3..v2:
- Improve the commit messages
- Revert a few unrelated changes
- Change compat_aio_context_t to compat_uptr_t
- Remove io_events_compat union member
- Improve code formatting
- Add copy_to_user_with_ptr in copy_io_events_to_user
- Split copy_from_user_with_ptr for struct __aio_sigset into a
different patch
v2..v1:
- Add Patch 1 that fixes a parameter type for the compat handler
- Split the change the types to user pointers into two patches: one
for aio_context_t, and the other for io_event struct fields.
- vmap all the ring pages at the beginning and cache them in the ctx
- Don't remap the pages while allowing tag access to the shared
memory. Setting the VM flags is enough.
- Change aio_context_t to a void __user *.
- Improve commit messages.
- Refactor some of the functions for compat handling.
- Create valid user pointers ctx_id when received from a compat task
Gitlab issue:
https://git.morello-project.org/morello/kernel/linux/-/issues/49
Review branch:
https://git.morello-project.org/tudcre01/linux/-/commits/morello/aio_v3
Tudor Cretu (7):
aio: Fix type of nr parameter in compat handler of io_submit
aio: Use copy_from_user_with_ptr for struct __aio_sigset
aio: vmap entire aio_ring instead of kmapping each page
aio: Implement compat handling for the io_event struct
aio: Allow capability tag access on the shared memory
aio: Change aio_context_t to a user pointer
aio: Use user pointer type in the io_event struct
fs/aio.c | 284 +++++++++++++++++++++--------------
include/asm-generic/compat.h | 3 +-
include/uapi/linux/aio_abi.h | 12 +-
3 files changed, 180 insertions(+), 119 deletions(-)
--
2.34.1
This series makes it possible for purecap apps to use the aio_ring
shared memory region to bypass the io_getevents syscall's overhead.
This functionality is also used in libaio.
With these patches, all io_* LTP tests pass in both Purecap and
plain AArch64 modes. Note that the LTP tests only address the basic
functionality of the aio system and a significant portion of the
functionality is untested in LTP.
For a more comprehensive testing, libaio has been updated with the new
uAPI and ported. All the tests in libaio pass accordingly, in both
Purecap and plain AArch64 modes.
v2..v1:
- Add Patch 1 that fixes a parameter type for the compat handler
- Split the change the types to user pointers into two patches: one
for aio_context_t, and the other for io_event struct fields.
- vmap all the ring pages at the beginning and cache them in the ctx
- Don't remap the pages while allowing tag access to the shared
memory. Setting the VM flags is enough.
- Change aio_context_t to a void __user *.
- Improve commit messages.
- Refactor some of the functions for compat handling.
- Create valid user pointers ctx_id when received from a compat task
Gitlab issue:
https://git.morello-project.org/morello/kernel/linux/-/issues/49
Review branch:
https://git.morello-project.org/tudcre01/linux/-/commits/morello/aio_v2
Tudor Cretu (6):
aio: Fix type of nr parameter in compat handler of io_submit
aio: vmap entire aio_ring instead of kmapping each page
aio: Implement compat handling for the io_event struct
aio: Allow capability tag access on the shared memory
aio: Change aio_context_t to a user pointer
aio: Use user pointer type in the io_event struct
fs/aio.c | 306 ++++++++++++++++++++++-------------
include/uapi/linux/aio_abi.h | 12 +-
2 files changed, 198 insertions(+), 120 deletions(-)
--
2.34.1
This series makes it possible for purecap apps to use the aio_ring
shared memory region to bypass the io_getevents syscall's overhead.
This functionality is also used in libaio.
With these patches, all io_* LTP tests pass in both Purecap and
plain AArch64 modes. Note that the LTP tests only address the basic
functionality of the aio system and a significant portion of the
functionality is untested in LTP.
For a more comprehensive testing, libaio has been updated with the new
uAPI and ported. All the tests in libaio pass accordingly, in both
Purecap and plain AArch64 modes.
Gitlab issue:
https://git.morello-project.org/morello/kernel/linux/-/issues/49
Review branch:
https://git.morello-project.org/tudcre01/linux/-/commits/morello/aio_v1
Tudor Cretu (4):
aio: Fix the relationship between ctx pages and io_events array
aio: Implement compat handling for the io_event struct
aio: Allow capability tag access on the shared memory
aio: Use user pointer type in the io_event struct and aio_context_t
fs/aio.c | 197 ++++++++++++++++++++++++++---------
include/uapi/linux/aio_abi.h | 12 +--
2 files changed, 153 insertions(+), 56 deletions(-)
--
2.34.1
Hi,
Here are a few small patches to fix kernel module loading in the PCuABI kernel [1].
(Sorry about the delay!) There are some notes on testing in the third patch.
Thanks,
Kristina
[1] https://git.morello-project.org/morello/kernel/linux/-/issues/41
Kristina Martsenko (3):
module: Allow arch overrides for ELF arch check
arm64: elf: Enable module loading for PCuABI kernels
arm64: morello: Add test modules to defconfig
.../configs/morello_transitional_pcuabi_defconfig | 6 ++++++
arch/arm64/include/asm/elf.h | 10 ++--------
include/linux/moduleloader.h | 4 ++++
kernel/module/main.c | 2 +-
4 files changed, 13 insertions(+), 9 deletions(-)
base-commit: 7f84d159d4eb989bf2f42d2e3b27a204cb3c1ec4
--
2.25.1
Hi,
This series introduces new user_ptr helpers to help in certain
uaccess-related situations. This is a follow-up to my previous series
"New CHERI API and separation of root capabilities"; the CHERI helpers
it introduced are used to implement the new generic user_ptr helpers in
PCuABI.
The new helpers are (see patch 1 for details):
* make_user_ptr_for_<perms>_uaccess(), to create user pointers in order
to perform uaccess, with appropriate bounds and permissions.
* check_user_ptr_<perms>(), to perform explicit checking of user
pointers.
This series does not actually make use of check_user_ptr_<perms>(),
rather it prepares the ground for implementing explicit checking when
user memory is accessed via kernel mappings [1].
The rest of the series (patch 2-9) is about converting existing uses of
uaddr_to_user_ptr_safe(), as it should now only be used for *providing*
user pointers to userspace, and not for uaccess.
After this series, the only remaining users of uaddr_to_user_ptr_safe()
are:
- fs/binfmt_elf.c to provide all the initial capabilities (stack,
AT_CHERI_*_CAP, etc.). uaddr_to_user_ptr_safe() is still used to write
the initial data on the stack too; it didn't seem worthwhile to
refactor this code as it is going to change anyway as part of [2]
and [3].
- mmap / mremap / shmat to return a valid capability.
To clarify which helper should be used in which situation, here are two
tables specifying the helper to use depending on whether the address is
specified by userspace or the kernel itself, and whether the pointer is
provided to userspace or used by the kernel itself.
*Before* this series:
+-----------------------------------+---------------------+--------------------------+
| Pointer for \ Address provided by | User | Kernel |
+===================================+=====================+==========================+
| User | - | uaddr_to_user_ptr_safe() |
+-----------------------------------+---------------------+--------------------------+
| Kernel (uaccess) | uaddr_to_user_ptr() | uaddr_to_user_ptr_safe() |
+-----------------------------------+---------------------+--------------------------+
*After* this series:
+-----------------------------------+---------------------+-------------------------------+
| Pointer for \ Address provided by | User | Kernel |
+===================================+=====================+===============================+
| User | - | uaddr_to_user_ptr_safe() |
+-----------------------------------+---------------------+-------------------------------+
| Kernel (uaccess) | uaddr_to_user_ptr() | make_user_ptr_*_for_uaccess() |
+-----------------------------------+---------------------+-------------------------------+
Eventually both uaddr_to_user_ptr() and uaddr_to_user_ptr_safe() should
disappear, the first thanks to userspace always providing full pointers
and the second being replaced by handcrafted code creating capabilities
in line with the PCuABI spec (whose bounds give access to only the
intended object and potentially padding).
Note that patch 1 and 4 were included in the first RFC of the CHERI API
series [4]. They remain broadly the same, but:
- make_privileged_user_ptr and check_user_ptr() have been renamed, and the
permissions are now specified by calling the right variant of the function
instead of passing a bitfield. They are now called respectively
make_user_ptr_for_<perms>_uaccess() and check_user_ptr_<perms>().
- The user_ptr documentation has been updated accordingly.
- The commit messages have been improved to reflect the overall
intention better.
Review branch:
https://git.morello-project.org/kbrodsky-arm/linux/-/commits/morello/user_p…
Rendered doc:
https://git.morello-project.org/kbrodsky-arm/linux/-/blob/morello/user_ptr_…
Thanks,
Kevin
[1] https://git.morello-project.org/morello/kernel/linux/-/issues/7
[2] https://git.morello-project.org/morello/kernel/linux/-/issues/19
[3] https://git.morello-project.org/morello/kernel/linux/-/issues/22
[4] https://op-lists.linaro.org/archives/list/linux-morello@op-lists.linaro.org…
Kevin Brodsky (9):
linux/user_ptr.h: Introduce uaccess-related helpers
fs/binfmt_elf: Create appropriate user pointer for uaccess
coredump: Create appropriate user pointer for uaccess
mm/memory: Create appropriate user pointer for uaccess
Revert "mm/hugetlb: Use appropriate user pointer conversions"
Revert "mm/shmem: Use appropriate user pointer conversions"
audit: Create appropriate user pointer for uaccess
perf: Avoid uaddr_to_user_ptr_safe() for arbitrary user address
arm64: Create appropriate user pointer for uaccess
Documentation/core-api/user_ptr.rst | 100 ++++++++++++++++++----------
arch/arm64/kernel/debug-monitors.c | 3 +-
arch/arm64/kernel/traps.c | 2 +-
fs/binfmt_elf.c | 14 ++--
fs/coredump.c | 4 +-
include/linux/user_ptr.h | 86 ++++++++++++++++++++++--
kernel/auditsc.c | 3 +-
kernel/events/internal.h | 2 +-
lib/user_ptr.c | 46 +++++++++++++
mm/hugetlb.c | 2 +-
mm/memory.c | 2 +-
mm/shmem.c | 2 +-
12 files changed, 216 insertions(+), 50 deletions(-)
--
2.38.1
