- 07 Mar, 2022 15 commits
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Heiko Carstens authored
This is more or less a combination of commit 2e77a62c ("arm64: extable: add a dedicated uaccess handler") and commit 4b5305de ("x86/extable: Extend extable functionality"). To describe the problem that needs to solved let's cite the full arm64 commit message: ------ For inline assembly, we place exception fixups out-of-line in the `.fixup` section such that these are out of the way of the fast path. This has a few drawbacks: * Since the fixup code is anonymous, backtraces will symbolize fixups as offsets from the nearest prior symbol, currently `__entry_tramp_text_end`. This is confusing, and painful to debug without access to the relevant vmlinux. * Since the exception handler adjusts the PC to execute the fixup, and the fixup uses a direct branch back into the function it fixes, backtraces of fixups miss the original function. This is confusing, and violates requirements for RELIABLE_STACKTRACE (and therefore LIVEPATCH). * Inline assembly and associated fixups are generated from templates, and we have many copies of logically identical fixups which only differ in which specific registers are written to and which address is branched to at the end of the fixup. This is potentially wasteful of I-cache resources, and makes it hard to add additional logic to fixups without significant bloat. This patch address all three concerns for inline uaccess fixups by adding a dedicated exception handler which updates registers in exception context and subsequent returns back into the function which faulted, removing the need for fixups specialized to each faulting instruction. Other than backtracing, there should be no functional change as a result of this patch. ------ Acked-by:
Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by:
Heiko Carstens <hca@linux.ibm.com> Signed-off-by:
Vasily Gorbik <gor@linux.ibm.com>
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Heiko Carstens authored
Follow arm64, riscv, and x86 and change extable layout to common "relative table with data". This allows to get rid of s390 specific code in sorttable.c. The main difference to before is that extable entries do not contain a relative function pointer anymore. Instead data and type fields are added. The type field is used to indicate which exception handler needs to be called, while the data field is currently unused. Acked-by:
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Heiko Carstens authored
Add and use fixup_exception helper function in order to remove the duplicated exception handler fixup code at several places. Reviewed-by:
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Heiko Carstens authored
Pass pt_regs to early program check handler like it is done for every other interrupt and exception handler. Also the passed pt_regs can be changed by the called function and the changes register contents and psw contents will be taken into account when returning. In addition the return psw will not be copied to the program check old psw in lowcore, but to the usual return psw location, like it is also done by the regular program check handler. This allows also to get rid of the code that disabled lowcore protection when changing the return address. Reviewed-by:
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Heiko Carstens authored
Just like arm64, riscv, and x86 move extable related functions to mm/extable.c. This is currently only one function, but this will change with subsequent changes. Reviewed-by:
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Heiko Carstens authored
Follow arm64 and riscv and move the EX_TABLE define to asm-extable.h which is a lot less generic than the current linkage.h. Also make sure that all files which contain EX_TABLE usages actually include the new header file. This should make sure that the files always compile and there won't be any random compile breakage due to other header file dependencies. Reviewed-by:
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Heiko Carstens authored
It is very unlikely that an exception happens within the amode31 text section, therefore safe a couple of cycles for the common case, and search the amode31 extable last. Reviewed-by:
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Heiko Carstens authored
The early program check handler is active before the amode31 extable is sorted. Therefore in case a program check happens early within the amode31 code the extable entry might not be found. Fix this by sorting the amode31 extable early. Signed-off-by:
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Halil Pasic authored
Protected virtualization guests have to use shared pages for airq notifier bit vectors and summary bytes or bits, thus these need to be allocated as DMA coherent memory. Commit b50623e5 ("s390/airq: use DMA memory for adapter interrupts") took care of the notifier bit vectors, but omitted to take care of the summary bytes/bits. In practice this omission is not a big deal, because the summary ain't necessarily allocated here, but can be supplied by the driver. Currently all the I/O we have for SE guests is virtio-ccw, and virtio-ccw uses a self-allocated array of summary indicators. Let us cover all our bases nevertheless! Signed-off-by:
Halil Pasic <pasic@linux.ibm.com> Reviewed-by:
Harald Freudenberger <freude@linux.ibm.com> Signed-off-by:
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Jürgen Christ authored
The scheduling function will get an extension which will process the target_id value from an EP11 cprb. This patch extracts the value during preparation of the ap message. Signed-off-by:
Jürgen Christ <jchrist@linux.ibm.com> Signed-off-by:
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Harald Freudenberger authored
Instead of offering the user space given receive buffer size to the crypto card firmware as limit for the reply message offer the internal per queue reply buffer size. As the queue's reply buffer is always adjusted to the max message size possible for this card this may offer more buffer space. However, now it is important to check the user space reply buffer on pushing back the reply. If the reply does not fit into the user space provided buffer the ioctl will fail with errno EMSGSIZE. Signed-off-by:
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Harald Freudenberger authored
There is a new CPRB minor version T7 to be supported with this patch. Together with this the functions which extract the CPRB data from userspace and prepare the AP message do now check the CPRB minor version and provide some info in the flag field of the ap message struct for further processing. The 3 functions doing this job have been renamed to prep_cca_ap_msg, prep_ep11_ap_msg and prep_rng_ap_msg to reflect their job better (old was get..fc). This patch also introduces two new flags to be used internal with the flag field of the struct ap_message: AP_MSG_FLAG_USAGE is set when prep_cca_ap_msg or prep_ep11_ap_msg come to the conclusion that this is a ordinary crypto load CPRB (which means T2 for CCA CPRBs and no admin bit for EP11 CPRBs). AP_MSG_FLAG_ADMIN is set when prep_cca_ap_msg or prep_ep11_ap_msg think, this is an administrative (control) crypto load CPRB (which means T3, T5, T6 or T7 for CCA CPRBs and admin bit set for EP11 CPRBs). Signed-off-by:
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Harald Freudenberger authored
A crypto card may be in checkstopped state. With this patch this is handled as a new state in the ap card and ap queue structs. There is also a new card sysfs attribute /sys/devices/ap/cardxx/chkstop and a new queue sysfs attribute /sys/devices/ap/cardxx/xx.yyyy/chkstop displaying the checkstop state of the card or queue. Please note that the queue's checkstop state is only a copy of the card's checkstop state but makes maintenance much easier. The checkstop state expressed here is the result of an RC 0x04 (CHECKSTOP) during an AP command, mostly the PQAP(TAPQ) command which is 'testing' the queue. Signed-off-by:
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Harald Freudenberger authored
This patch adds CEX8 exploitation support for the AP bus code, the zcrypt device driver zoo and the vfio device driver. Signed-off-by:
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Harald Freudenberger authored
This patch adds some debug feature improvements related to some failures happened in the past. With CEX8 the max request and response sizes have been extended but the user space applications did not rework their code and thus ran into receive buffer issues. This ffdc patch here helps with additional checks and debug feature messages in debugging and pointing to the root cause of some failures related to wrong buffer sizes. Signed-off-by:
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- 01 Mar, 2022 25 commits
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Heiko Carstens authored
Disallow constructs like this: pte_val(*pte) = __pa(addr) | prot; which would directly write into a page table. Users are supposed to use the set_pte()/set_pXd() primitives, which guarantee block concurrent (aka atomic) writes. Reviewed-by:Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by:
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Heiko Carstens authored
Convert pgtable code so pte_val()/pXd_val() aren't used as lvalue anymore. This allows in later step to convert pte_val()/pXd_val() to functions, which in turn makes it impossible to use these macros to modify page table entries like they have been used before. Therefore a construct like this: pte_val(*pte) = __pa(addr) | prot; which would directly write into a page table, isn't possible anymore with the last step of this series. Reviewed-by: -
Heiko Carstens authored
Convert pgtable code so pte_val()/pXd_val() aren't used as lvalue anymore. This allows in later step to convert pte_val()/pXd_val() to functions, which in turn makes it impossible to use these macros to modify page table entries like they have been used before. Therefore a construct like this: pte_val(*pte) = __pa(addr) | prot; which would directly write into a page table, isn't possible anymore with the last step of this series. Reviewed-by: -
Heiko Carstens authored
Convert pgtable code so pte_val()/pXd_val() aren't used as lvalue anymore. This allows in later step to convert pte_val()/pXd_val() to functions, which in turn makes it impossible to use these macros to modify page table entries like they have been used before. Therefore a construct like this: pte_val(*pte) = __pa(addr) | prot; which would directly write into a page table, isn't possible anymore with the last step of this series. Reviewed-by: -
Heiko Carstens authored
Convert pgtable code so pte_val()/pXd_val() aren't used as lvalue anymore. This allows in later step to convert pte_val()/pXd_val() to functions, which in turn makes it impossible to use these macros to modify page table entries like they have been used before. Therefore a construct like this: pte_val(*pte) = __pa(addr) | prot; which would directly write into a page table, isn't possible anymore with the last step of this series. Reviewed-by: -
Heiko Carstens authored
Use the new set_pXd()/set_pte() helper functions at all places where page table entries are modified. Reviewed-by:
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Heiko Carstens authored
Add set_pte_bit()/clear_pte_bit() and set_pXd_bit()/clear_pXd_bit helper functions which are supposed to be used if bits within ptes/pXds are set/cleared. The only point of these helper functions is to get more readable code. This is quite similar to what arm64 has. Reviewed-by:
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Heiko Carstens authored
Add set_pXd()/set_pte() helper functions which must be used to update page table entries. The new helpers use WRITE_ONCE() to make sure that a page table entry is written to only once. Without this the compiler could otherwise generate code which writes several times to a page table entry when updating its contents from invalid to valid, which could lead to surprising results especially for multithreaded processes... Reviewed-by:
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Vasily Gorbik authored
Remove __s390_indirect_jump_r13use_r14 expoline thunk unused since commit fbbdfca5 ("s390/entry.S: factor out SIEEXIT macro"). Signed-off-by:
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Heiko Carstens authored
Finally use epsw to create a complete psw mask within pt_regs. Without this only some bits are correct, while other bits are (incorrectly) always zero. The epsw instruction is quite heavy weight, however given that this only effects ftrace_regs_caller this seems to be the right thing, so we finally get a complete psw mask for ftrace kprobed functions. Reviewed-by:
Sven Schnelle <svens@linux.ibm.com> Acked-by:
Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by:
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Heiko Carstens authored
Remove opencoded offsetof and use offsetof instead. The generated code is identical before/after this change. Reviewed-by:
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Alexander Gordeev authored
With commit 57892847 ("s390/smp: reallocate IPL CPU lowcore") virtual addresses are wrongly passed to memblock_free_late() and SPX instructions on IPL CPU reinitialization. Note: this does not fix a bug currently, since virtual and physical addresses are identical. Fixes: 57892847 ("s390/smp: reallocate IPL CPU lowcore") Reviewed-by:
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Harald Freudenberger authored
This patch switches the sysfs attribute /sys/bus/ap/scans from read-only to read-write. If there is something written to this attribute, an AP bus rescan is forced. If an AP bus scan is triggered this way a debug feature entry line reports this in /sys/kernel/debug/s390dbf/ap/sprintf. Signed-off-by:
Jakob Naucke <naucke@linux.ibm.com> Reviewed-by:
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Tony Krowiak authored
This patch introduces an extension to the ap bus to notify device drivers when the host AP configuration changes - i.e., adapters, domains or control domains are added or removed. When an adapter or domain is added to the host's AP configuration, the AP bus will create the associated queue devices in the linux sysfs device model. Each new type 10 (i.e., CEX4) or newer queue device with an APQN that is not reserved for the default device driver will get bound to the vfio_ap device driver. Likewise, whan an adapter or domain is removed from the host's AP configuration, the AP bus will remove the associated queue devices from the sysfs device model. Each of the queues that is bound to the vfio_ap device driver will get unbound. With the introduction of hot plug support, binding or unbinding of a queue device will result in plugging or unplugging one or more queues from a guest that is using the queue. If there are multiple changes to the host's AP configuration, it could result in the probe and remove callbacks getting invoked multiple times. Each time queues are plugged into or unplugged from a guest, the guest's VCPUs must be taken out of SIE. If this occurs multiple times due to changes in the host's AP configuration, that can have an undesirable negative affect on the guest's performance. To alleviate this problem, this patch introduces two new callbacks: one to notify the vfio_ap device driver when the AP bus scan routine detects a change to the host's AP configuration; and, one to notify the driver when the AP bus is done scanning. This will allow the vfio_ap driver to do bulk processing of all affected adapters, domains and control domains for affected guests rather than plugging or unplugging them one at a time when the probe or remove callback is invoked. The two new callbacks are: void (*on_config_changed)(struct ap_config_info *new_config_info, struct ap_config_info *old_config_info); This callback is invoked at the start of the AP bus scan function when it determines that the host AP configuration information has changed since the previous scan. This is done by storing an old and current QCI info struct and comparing them. If there is any difference, the callback is invoked. void (*on_scan_complete)(struct ap_config_info *new_config_info, struct ap_config_info *old_config_info); The on_scan_complete callback is invoked after the ap bus scan is completed if the host AP configuration data has changed. Signed-off-by:Tony Krowiak <akrowiak@linux.ibm.com> Signed-off-by:
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Tony Krowiak authored
Introduces a new driver callback to prevent a root user from re-assigning the APQN of a queue that is in use by a non-default host device driver to a default host device driver and vice versa. The callback will be invoked whenever a change to the AP bus's sysfs apmask or aqmask attributes would result in one or more APQNs being re-assigned. If the callback responds in the affirmative for any driver queried, the change to the apmask or aqmask will be rejected with a device busy error. For this patch, only non-default drivers will be queried. Currently, there is only one non-default driver, the vfio_ap device driver. The vfio_ap device driver facilitates pass-through of an AP queue to a guest. The idea here is that a guest may be administered by a different sysadmin than the host and we don't want AP resources to unexpectedly disappear from a guest's AP configuration (i.e., adapters and domains assigned to the matrix mdev). This will enforce the proper procedure for removing AP resources intended for guest usage which is to first unassign them from the matrix mdev, then unbind them from the vfio_ap device driver. Signed-off-by:
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Vasily Gorbik authored
Running kprobe test on a kernel built with clang 14 didn't actually trigger pgm_pre_handler() and no unwinder code was called. Even though do_report_trap() is a global symbol, clang inlined it in several local functions including illegal_op() handler, so that kprobbing a global symbol didn't have a desired effect. To achieve the same test result (unwinding from a program check handler) introduce a local function and probe an instruction in the middle, so that kprobe doesn't take KPROBE_ON_FTRACE path. While at it, add another test for KPROBE_ON_FTRACE. Signed-off-by: -
Vasily Gorbik authored
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Vasily Gorbik authored
By default no backtraces are printed when a test succeeds, but sometimes it is useful to spot issues automated test doesn't cover. Add "backtrace" module parameter to force it. Signed-off-by: -
Vasily Gorbik authored
- make current_test static - use current_test consistently - add TEST_WITH_FLAGS macro to contract parametrized tests definition Signed-off-by: -
Vasily Gorbik authored
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Vasily Gorbik authored
-mpacked-stack option has been supported by both minimum gcc and clang versions for a while. With commit e2bc3e91 ("scripts/min-tool-version.sh: Raise minimum clang version to 13.0.0 for s390") minimum clang version now also supports a combination of flags -mpacked-stack -mbackchain -pg -mfentry and fulfills all requirements to always enable the packed stack layout. Reviewed-by:
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Vasily Gorbik authored
This helps to avoid several merge conflicts later. * fixes: s390/extable: fix exception table sorting s390/ftrace: fix arch_ftrace_get_regs implementation s390/ftrace: fix ftrace_caller/ftrace_regs_caller generation s390/setup: preserve memory at OLDMEM_BASE and OLDMEM_SIZE s390/cio: verify the driver availability for path_event call s390/module: fix building test_modules_helpers.o with clang MAINTAINERS: downgrade myself to Reviewer for s390 MAINTAINERS: add Alexander Gordeev as maintainer for s390 Signed-off-by: -
Heiko Carstens authored
s390 has a swap_ex_entry_fixup function, however it is not being used since common code expects a swap_ex_entry_fixup define. If it is not defined the default implementation will be used. So fix this by adding a proper define. However also the implementation of the function must be fixed, since a NULL value for handler has a special meaning and must not be adjusted. Luckily all of this doesn't fix a real bug currently: the main extable is correctly sorted during build time, and for runtime sorting there is currently no case where the handler field is not NULL. Fixes: 05a68e89 ("s390/kernel: expand exception table logic to allow new handling options") Acked-by:
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Heiko Carstens authored
arch_ftrace_get_regs is supposed to return a struct pt_regs pointer only if the pt_regs structure contains all register contents, which means it must have been populated when created via ftrace_regs_caller. If it was populated via ftrace_caller the contents are not complete (the psw mask part is missing), and therefore a NULL pointer needs be returned. The current code incorrectly always returns a struct pt_regs pointer. Fix this by adding another pt_regs flag which indicates if the contents are complete, and fix arch_ftrace_get_regs accordingly. Fixes: 89497968 ("s390/ftrace: provide separate ftrace_caller/ftrace_regs_caller implementations") Reported-by:
Christophe Leroy <christophe.leroy@csgroup.eu> Reported-by:
Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Reviewed-by:
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Heiko Carstens authored
ftrace_caller was used for both ftrace_caller and ftrace_regs_caller, which means that the target address of the hotpatch trampoline was never updated. With commit 89497968 ("s390/ftrace: provide separate ftrace_caller/ftrace_regs_caller implementations") a separate ftrace_regs_caller entry point was implemeted, however it was forgotten to implement the necessary changes for ftrace_modify_call and ftrace_make_call, where the branch target has to be modified accordingly. Therefore add the missing code now. Fixes: 89497968 ("s390/ftrace: provide separate ftrace_caller/ftrace_regs_caller implementations") Reviewed-by:
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