- 07 Aug, 2018 40 commits
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Murilo Opsfelder Araujo authored
Replace printk_ratelimited() by printk() and a default rate limit burst to limit displaying unhandled signals messages. This will allow us to call print_vma_addr() in a future patch, which does not work with printk_ratelimited(). Signed-off-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Murilo Opsfelder Araujo authored
Isolate the logic of printing unhandled signals out of _exception_pkey(). No functional change, only code rearrangement. Signed-off-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Michael Ellerman authored
The alignment_handler is documented to only work on Power8/Power9, but we can make it run on older CPUs by guarding more of the tests with feature checks. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
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Michael Ellerman authored
Currently the alignment_handler test prints "Can't open /dev/fb0" about 80 times per run, which is a little annoying. Refactor it to check earlier if it can open /dev/fb0 and skip if not, this results in each test printing something like: test: test_alignment_handler_vsx_206 tags: git_version:v4.18-rc3-134-gfb21a48904aa [SKIP] Test skipped on line 291 skip: test_alignment_handler_vsx_206 Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
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Michael Ellerman authored
Because rfi_flush_fallback runs immediately before the return to userspace it currently runs with the user r1 (stack pointer). This means if we oops in there we will report a bad kernel stack pointer in the exception entry path, eg: Bad kernel stack pointer 7ffff7150e40 at c0000000000023b4 Oops: Bad kernel stack pointer, sig: 6 [#1] LE SMP NR_CPUS=32 NUMA PowerNV Modules linked in: CPU: 0 PID: 1246 Comm: klogd Not tainted 4.18.0-rc2-gcc-7.3.1-00175-g0443f8a69ba3 #7 NIP: c0000000000023b4 LR: 0000000010053e00 CTR: 0000000000000040 REGS: c0000000fffe7d40 TRAP: 4100 Not tainted (4.18.0-rc2-gcc-7.3.1-00175-g0443f8a69ba3) MSR: 9000000002803031 <SF,HV,VEC,VSX,FP,ME,IR,DR,LE> CR: 44000442 XER: 20000000 CFAR: c00000000000bac8 IRQMASK: c0000000f1e66a80 GPR00: 0000000002000000 00007ffff7150e40 00007fff93a99900 0000000000000020 ... NIP [c0000000000023b4] rfi_flush_fallback+0x34/0x80 LR [0000000010053e00] 0x10053e00 Although the NIP tells us where we were, and the TRAP number tells us what happened, it would still be nicer if we could report the actual exception rather than barfing about the stack pointer. We an do that fairly simply by loading the kernel stack pointer on entry and restoring the user value before returning. That way we see a regular oops such as: Unrecoverable exception 4100 at c00000000000239c Oops: Unrecoverable exception, sig: 6 [#1] LE SMP NR_CPUS=32 NUMA PowerNV Modules linked in: CPU: 0 PID: 1251 Comm: klogd Not tainted 4.18.0-rc3-gcc-7.3.1-00097-g4ebfcac65acd-dirty #40 NIP: c00000000000239c LR: 0000000010053e00 CTR: 0000000000000040 REGS: c0000000f1e17bb0 TRAP: 4100 Not tainted (4.18.0-rc3-gcc-7.3.1-00097-g4ebfcac65acd-dirty) MSR: 9000000002803031 <SF,HV,VEC,VSX,FP,ME,IR,DR,LE> CR: 44000442 XER: 20000000 CFAR: c00000000000bac8 IRQMASK: 0 ... NIP [c00000000000239c] rfi_flush_fallback+0x3c/0x80 LR [0000000010053e00] 0x10053e00 Call Trace: [c0000000f1e17e30] [c00000000000b9e4] system_call+0x5c/0x70 (unreliable) Note this shouldn't make the kernel stack pointer vulnerable to a meltdown attack, because it should be flushed from the cache before we return to userspace. The user r1 value will be in the cache, because we load it in the return path, but that is harmless. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
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Michael Ellerman authored
Look for fw-features properties to determine the appropriate settings for the count cache flush, and then call the generic powerpc code to set it up based on the security feature flags. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Michael Ellerman authored
Use the existing hypercall to determine the appropriate settings for the count cache flush, and then call the generic powerpc code to set it up based on the security feature flags. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Michael Ellerman authored
Some CPU revisions support a mode where the count cache needs to be flushed by software on context switch. Additionally some revisions may have a hardware accelerated flush, in which case the software flush sequence can be shortened. If we detect the appropriate flag from firmware we patch a branch into _switch() which takes us to a count cache flush sequence. That sequence in turn may be patched to return early if we detect that the CPU supports accelerating the flush sequence in hardware. Add debugfs support for reporting the state of the flush, as well as runtime disabling it. And modify the spectre_v2 sysfs file to report the state of the software flush. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Michael Ellerman authored
Add security feature flags to indicate the need for software to flush the count cache on context switch, and for the presence of a hardware assisted count cache flush. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Michael Ellerman authored
Add a macro and some helper C functions for patching single asm instructions. The gas macro means we can do something like: 1: nop patch_site 1b, patch__foo Which is less visually distracting than defining a GLOBAL symbol at 1, and also doesn't pollute the symbol table which can confuse eg. perf. These are obviously similar to our existing feature sections, but are not automatically patched based on CPU/MMU features, rather they are designed to be manually patched by C code at some arbitrary point. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Diana Craciun authored
Currently only supported on powerpc. Signed-off-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Diana Craciun authored
Used barrier_nospec to sanitize the syscall table. Signed-off-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Diana Craciun authored
Implement the barrier_nospec as a isync;sync instruction sequence. The implementation uses the infrastructure built for BOOK3S 64. Signed-off-by: Diana Craciun <diana.craciun@nxp.com> [mpe: Split out of larger patch] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Diana Craciun authored
In a subsequent patch we will enable building security.c for Book3E. However the NXP platforms are not vulnerable to Meltdown, so make the Meltdown vulnerability reporting PPC_BOOK3S_64 specific. Signed-off-by: Diana Craciun <diana.craciun@nxp.com> [mpe: Split out of larger patch] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Michael Ellerman authored
Currently we require platform code to call setup_barrier_nospec(). But if we add an empty definition for the !CONFIG_PPC_BARRIER_NOSPEC case then we can call it in setup_arch(). Signed-off-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Michael Ellerman authored
Add a config symbol to encode which platforms support the barrier_nospec speculation barrier. Currently this is just Book3S 64 but we will add Book3E in a future patch. Signed-off-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Diana Craciun authored
NXP Book3E platforms are not vulnerable to speculative store bypass, so make the mitigations PPC_BOOK3S_64 specific. Signed-off-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Diana Craciun authored
The speculation barrier can be disabled from the command line with the parameter: "nospectre_v1". Signed-off-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Michael Ellerman authored
We only need to use __MASKABLE_EXCEPTION in one of the four cases for hardware interrupt, so use the helper macros in the other cases. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Michael Ellerman authored
We pass the "loc" (location) parameter to MASKABLE_EXCEPTION and friends, but it's not used, so drop it. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Michael Ellerman authored
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Michael Ellerman authored
_MASKABLE_RELON_EXCEPTION_PSERIES() does nothing useful, update all callers to use __MASKABLE_RELON_EXCEPTION_PSERIES() directly. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Michael Ellerman authored
_MASKABLE_EXCEPTION_PSERIES() does nothing useful, update all callers to use __MASKABLE_EXCEPTION_PSERIES() directly. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Michael Ellerman authored
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Michael Ellerman authored
To just EXCEPTION_RELON_PROLOG(). Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Michael Ellerman authored
The EXCEPTION_RELON_PROLOG_PSERIES_1() macro does the same job as EXCEPTION_PROLOG_2 (which we just recently created), except for "RELON" (relocation on) exceptions. So rename it as such. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Michael Ellerman authored
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Michael Ellerman authored
As with the other patches in this series, we are removing the "PSERIES" from the name as it's no longer meaningful. In this case it's not simply a case of removing the "PSERIES" as that would result in a clash with the existing EXCEPTION_PROLOG_1. Instead we name this one EXCEPTION_PROLOG_2, as it's usually used in sequence after 0 and 1. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Michael Ellerman authored
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Michael Ellerman authored
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Michael Ellerman authored
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Michael Ellerman authored
The "PSERIES" in STD_EXCEPTION_PSERIES is to differentiate the macros from the legacy iSeries versions, which are called STD_EXCEPTION_ISERIES. It is not anything to do with pseries vs powernv or powermac etc. We removed the legacy iSeries code in 2012, in commit 8ee3e0d6x ("powerpc: Remove the main legacy iSerie platform code"). So remove "PSERIES" from the macros. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Michael Ellerman authored
EXCEPTION_RELON_PROLOG_PSERIES() only has two users, STD_RELON_EXCEPTION_PSERIES() and STD_RELON_EXCEPTION_HV() both of which "call" SET_SCRATCH0(), so just move SET_SCRATCH0() into EXCEPTION_RELON_PROLOG_PSERIES(). Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Michael Ellerman authored
EXCEPTION_PROLOG_PSERIES() only has two users, STD_EXCEPTION_PSERIES() and STD_EXCEPTION_HV() both of which "call" SET_SCRATCH0(), so just move SET_SCRATCH0() into EXCEPTION_PROLOG_PSERIES(). Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Darren Stevens authored
Pasemi arch code finds the root of the PCI-e bus by searching the device-tree for a node called 'pxp'. But the root bus has a compatible property of 'pasemi,rootbus' so search for that instead. Signed-off-by: Darren Stevens <darren@stevens-zone.net> Acked-by: Olof Johansson <olof@lixom.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Christophe Leroy authored
This patch adds a test for testing the new assembly strlen() for PPC32 Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> [mpe: Fix 64-bit build] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Christophe Leroy authored
The generic implementation of strlen() reads strings byte per byte. This patch implements strlen() in assembly based on a read of entire words, in the same spirit as what some other arches and glibc do. On a 8xx the time spent in strlen is reduced by 3/4 for long strings. strlen() selftest on an 8xx provides the following values: Before the patch (ie with the generic strlen() in lib/string.c): len 256 : time = 1.195055 len 016 : time = 0.083745 len 008 : time = 0.046828 len 004 : time = 0.028390 After the patch: len 256 : time = 0.272185 ==> 78% improvment len 016 : time = 0.040632 ==> 51% improvment len 008 : time = 0.033060 ==> 29% improvment len 004 : time = 0.029149 ==> 2% degradation On a 832x: Before the patch: len 256 : time = 0.236125 len 016 : time = 0.018136 len 008 : time = 0.011000 len 004 : time = 0.007229 After the patch: len 256 : time = 0.094950 ==> 60% improvment len 016 : time = 0.013357 ==> 26% improvment len 008 : time = 0.010586 ==> 4% improvment len 004 : time = 0.008784 Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Christophe Leroy authored
This patch adds a test for strlen() string.c contains a copy of strlen() from lib/string.c The test first tests the correctness of strlen() by comparing the result with libc strlen(). It tests all cases of alignment. It them tests the duration of an aligned strlen() on a 4 bytes string, on a 16 bytes string and on a 256 bytes string. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> [mpe: Drop change log from copy of string.c] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Christophe Leroy authored
This patch renames memcmp test to memcmp_64 and adds a memcmp_32 test for testing the 32 bits version of memcmp() Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> [mpe: Fix 64-bit build by adding build_32bit test] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Mahesh Salgaonkar authored
rtas_log_buf is a buffer to hold RTAS event data that are communicated to kernel by hypervisor. This buffer is then used to pass RTAS event data to user through proc fs. This buffer is allocated from vmalloc (non-linear mapping) area. On Machine check interrupt, register r3 points to RTAS extended event log passed by hypervisor that contains the MCE event. The pseries machine check handler then logs this error into rtas_log_buf. The rtas_log_buf is a vmalloc-ed (non-linear) buffer we end up taking up a page fault (vector 0x300) while accessing it. Since machine check interrupt handler runs in NMI context we can not afford to take any page fault. Page faults are not honored in NMI context and causes kernel panic. Apart from that, as Nick pointed out, pSeries_log_error() also takes a spin_lock while logging error which is not safe in NMI context. It may endup in deadlock if we get another MCE before releasing the lock. Fix this by deferring the logging of rtas error to irq work queue. Current implementation uses two different buffers to hold rtas error log depending on whether extended log is provided or not. This makes bit difficult to identify which buffer has valid data that needs to logged later in irq work. Simplify this using single buffer, one per paca, and copy rtas log to it irrespective of whether extended log is provided or not. Allocate this buffer below RMA region so that it can be accessed in real mode mce handler. Fixes: b96672dd ("powerpc: Machine check interrupt is a non-maskable interrupt") Cc: stable@vger.kernel.org # v4.14+ Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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