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path: root/arch/powerpc/kernel/secvar-sysfs.c
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2024-09-05powerpc: Constify struct kobj_typeHuang Xiaojia
'struct kobj_type' is not modified. It is only used in kobject_init_and_add()/kobject_init() which takes a 'const struct kobj_type *ktype' parameter. Constifying this structure moves some data to a read-only section, so increase over all security. On a x86_64, compiled with ppc64 defconfig: Before: ====== text data bss dec hex filename 7145 606 0 7751 1e47 arch/powerpc/kernel/cacheinfo.o 3663 384 16 4063 fdf arch/powerpc/kernel/secvar-sysfs.o After: ====== text data bss dec hex filename 7193 558 0 7751 1e47 arch/powerpc/kernel/cacheinfo.o 3663 384 16 4063 fdf arch/powerpc/kernel/secvar-sysfs.o Signed-off-by: Huang Xiaojia <huangxiaojia2@huawei.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20240826150957.3500237-1-huangxiaojia2@huawei.com
2023-02-12powerpc/secvar: Don't print error on ENOENT when reading variablesAndrew Donnellan
If attempting to read the size or data attributes of a non-existent variable (which will be possible after a later patch to expose the PLPKS via the secvar interface), don't spam the kernel log with error messages. Only print errors for return codes that aren't ENOENT. Reported-by: Sudhakar Kuppusamy <sudhakar@linux.ibm.com> Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com> Reviewed-by: Stefan Berger <stefanb@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20230210080401.345462-14-ajd@linux.ibm.com
2023-02-12powerpc/secvar: Warn when PAGE_SIZE is smaller than max object sizeAndrew Donnellan
Due to sysfs constraints, when writing to a variable, we can only handle writes of up to PAGE_SIZE. It's possible that the maximum object size is larger than PAGE_SIZE, in which case, print a warning on boot so that the user is aware. Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com> Signed-off-by: Russell Currey <ruscur@russell.cc> Reviewed-by: Stefan Berger <stefanb@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20230210080401.345462-13-ajd@linux.ibm.com
2023-02-12powerpc/secvar: Allow backend to populate static list of variable namesAndrew Donnellan
Currently, the list of variables is populated by calling secvar_ops->get_next() repeatedly, which is explicitly modelled on the OPAL API (including the keylen parameter). For the upcoming PLPKS backend, we have a static list of variable names. It is messy to fit that into get_next(), so instead, let the backend put a NULL-terminated array of variable names into secvar_ops->var_names, which will be used if get_next() is undefined. Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com> Signed-off-by: Russell Currey <ruscur@russell.cc> Reviewed-by: Stefan Berger <stefanb@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20230210080401.345462-12-ajd@linux.ibm.com
2023-02-12powerpc/secvar: Extend sysfs to include config varsRussell Currey
The forthcoming pseries consumer of the secvar API wants to expose a number of config variables. Allowing secvar implementations to provide their own sysfs attributes makes it easy for consumers to expose what they need to. This is not being used by the OPAL secvar implementation at present, and the config directory will not be created if no attributes are set. Signed-off-by: Russell Currey <ruscur@russell.cc> Co-developed-by: Andrew Donnellan <ajd@linux.ibm.com> Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com> Reviewed-by: Stefan Berger <stefanb@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20230210080401.345462-11-ajd@linux.ibm.com
2023-02-12powerpc/secvar: Clean up init error messagesAndrew Donnellan
Remove unnecessary prefixes from error messages in secvar_sysfs_init() (the file defines pr_fmt, so putting "secvar:" in every message is unnecessary). Make capitalisation and punctuation more consistent. Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com> Signed-off-by: Russell Currey <ruscur@russell.cc> Reviewed-by: Stefan Berger <stefanb@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20230210080401.345462-10-ajd@linux.ibm.com
2023-02-12powerpc/secvar: Handle max object size in the consumerRussell Currey
Currently the max object size is handled in the core secvar code with an entirely OPAL-specific implementation, so create a new max_size() op and move the existing implementation into the powernv platform. Should be no functional change. Signed-off-by: Russell Currey <ruscur@russell.cc> Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com> Reviewed-by: Stefan Berger <stefanb@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20230210080401.345462-9-ajd@linux.ibm.com
2023-02-12powerpc/secvar: Handle format string in the consumerRussell Currey
The code that handles the format string in secvar-sysfs.c is entirely OPAL specific, so create a new "format" op in secvar_operations to make the secvar code more generic. No functional change. Signed-off-by: Russell Currey <ruscur@russell.cc> Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com> Reviewed-by: Stefan Berger <stefanb@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20230210080401.345462-8-ajd@linux.ibm.com
2023-02-12powerpc/secvar: Use sysfs_emit() instead of sprintf()Russell Currey
The secvar format string and object size sysfs files are both ASCII text, and should use sysfs_emit(). No functional change. Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Russell Currey <ruscur@russell.cc> Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com> Reviewed-by: Stefan Berger <stefanb@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20230210080401.345462-7-ajd@linux.ibm.com
2023-02-12powerpc/secvar: Use u64 in secvar_operationsMichael Ellerman
There's no reason for secvar_operations to use uint64_t vs the more common kernel type u64. The types are compatible, but they require different printk format strings which can lead to confusion. Change all the secvar related routines to use u64. Reviewed-by: Russell Currey <ruscur@russell.cc> Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com> Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20230210080401.345462-5-ajd@linux.ibm.com
2023-02-12powerpc/secvar: Fix incorrect return in secvar_sysfs_load()Russell Currey
secvar_ops->get_next() returns -ENOENT when there are no more variables to return, which is expected behaviour. Fix this by returning 0 if get_next() returns -ENOENT. This fixes an issue introduced in commit bd5d9c743d38 ("powerpc: expose secure variables to userspace via sysfs"), but the return code of secvar_sysfs_load() was never checked so this issue never mattered. Signed-off-by: Russell Currey <ruscur@russell.cc> Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com> Reviewed-by: Stefan Berger <stefanb@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20230210080401.345462-4-ajd@linux.ibm.com
2022-03-08powerpc/secvar: fix refcount leak in format_show()Hangyu Hua
Refcount leak will happen when format_show returns failure in multiple cases. Unified management of of_node_put can fix this problem. Signed-off-by: Hangyu Hua <hbh25y@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220302021959.10959-1-hbh25y@gmail.com
2019-11-13powerpc: expose secure variables to userspace via sysfsNayna Jain
PowerNV secure variables, which store the keys used for OS kernel verification, are managed by the firmware. These secure variables need to be accessed by the userspace for addition/deletion of the certificates. This patch adds the sysfs interface to expose secure variables for PowerNV secureboot. The users shall use this interface for manipulating the keys stored in the secure variables. Signed-off-by: Nayna Jain <nayna@linux.ibm.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Eric Richter <erichte@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1573441836-3632-3-git-send-email-nayna@linux.ibm.com