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path: root/drivers/char/hw_random/via-rng.c
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2013-09-02hwrng: via - Add MODULE_DEVICE_TABLEBen Hutchings
via-rng currently isn't auto-loaded if built as a module. Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2011-01-07hwrng: via_rng - Fix memory scribbling on some CPUsHerbert Xu
It has been reported that on at least one Nano CPU the xstore instruction will write as many as 16 bytes of data to the output buffer. This causes memory corruption as we use rng->priv which is only 4-8 bytes long. This patch fixes this by using an intermediate buffer on the stack with at least 16 bytes and aligned to a 16-byte boundary. The problem was observed on the following processor: processor : 0 vendor_id : CentaurHauls cpu family : 6 model : 15 model name : VIA Nano processor U2250 (1.6GHz Capable) stepping : 3 cpu MHz : 1600.000 cache size : 1024 KB fdiv_bug : no hlt_bug : no f00f_bug : no coma_bug : no fpu : yes fpu_exception : yes cpuid level : 10 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat clflush acpi mmx fxsr sse sse2 ss tm syscall nx lm constant_tsc up rep_good pni monitor vmx est tm2 ssse3 cx16 xtpr rng rng_en ace ace_en ace2 phe phe_en lahf_lm bogomips : 3192.08 clflush size : 64 cache_alignment : 128 address sizes : 36 bits physical, 48 bits virtual power management: Tested-by: Mario 'BitKoenig' Holbe <Mario.Holbe@TU-Ilmenau.DE> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2011-01-07hwrng: via_rng - Fix asm constraintsHerbert Xu
The inline asm to invoke xstore did not specify the constraints correctly. In particular, dx/di should have been marked as output registers as well as input as they're modified by xstore. Thanks to Mario Holbe for creating this patch and testing it. Tested-by: Mario 'BitKoenig' Holbe <Mario.Holbe@TU-Ilmenau.DE> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-06-02hwrng: via_rng - Support VIA Nano hardware RNGHarald Welte
The VIA Nano CPU supports the same XSTORE instruction based RNG, but it lacks the MSR present in earlier CPUs. Signed-off-by: Harald Welte <HaraldWelte@viatech.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-06-02hwrng: via_rng - The VIA Hardware RNG driver is for the CPU, not ChipsetHarald Welte
This is a cosmetic change, fixing the MODULE_DESCRIPTION() of via-rng.c Signed-off-by: Harald Welte <HaraldWelte@viatech.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-10-27Tidy up addresses in random driversAlan Cox
Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-13crypto: padlock - fix VIA PadLock instruction usage with irq_ts_save/restore()Suresh Siddha
Wolfgang Walter reported this oops on his via C3 using padlock for AES-encryption: ################################################################## BUG: unable to handle kernel NULL pointer dereference at 000001f0 IP: [<c01028c5>] __switch_to+0x30/0x117 *pde = 00000000 Oops: 0002 [#1] PREEMPT Modules linked in: Pid: 2071, comm: sleep Not tainted (2.6.26 #11) EIP: 0060:[<c01028c5>] EFLAGS: 00010002 CPU: 0 EIP is at __switch_to+0x30/0x117 EAX: 00000000 EBX: c0493300 ECX: dc48dd00 EDX: c0493300 ESI: dc48dd00 EDI: c0493530 EBP: c04cff8c ESP: c04cff7c DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 0068 Process sleep (pid: 2071, ti=c04ce000 task=dc48dd00 task.ti=d2fe6000) Stack: dc48df30 c0493300 00000000 00000000 d2fe7f44 c03b5b43 c04cffc8 00000046 c0131856 0000005a dc472d3c c0493300 c0493470 d983ae00 00002696 00000000 c0239f54 00000000 c04c4000 c04cffd8 c01025fe c04f3740 00049800 c04cffe0 Call Trace: [<c03b5b43>] ? schedule+0x285/0x2ff [<c0131856>] ? pm_qos_requirement+0x3c/0x53 [<c0239f54>] ? acpi_processor_idle+0x0/0x434 [<c01025fe>] ? cpu_idle+0x73/0x7f [<c03a4dcd>] ? rest_init+0x61/0x63 ======================= Wolfgang also found out that adding kernel_fpu_begin() and kernel_fpu_end() around the padlock instructions fix the oops. Suresh wrote: These padlock instructions though don't use/touch SSE registers, but it behaves similar to other SSE instructions. For example, it might cause DNA faults when cr0.ts is set. While this is a spurious DNA trap, it might cause oops with the recent fpu code changes. This is the code sequence that is probably causing this problem: a) new app is getting exec'd and it is somewhere in between start_thread() and flush_old_exec() in the load_xyz_binary() b) At pont "a", task's fpu state (like TS_USEDFPU, used_math() etc) is cleared. c) Now we get an interrupt/softirq which starts using these encrypt/decrypt routines in the network stack. This generates a math fault (as cr0.ts is '1') which sets TS_USEDFPU and restores the math that is in the task's xstate. d) Return to exec code path, which does start_thread() which does free_thread_xstate() and sets xstate pointer to NULL while the TS_USEDFPU is still set. e) At the next context switch from the new exec'd task to another task, we have a scenarios where TS_USEDFPU is set but xstate pointer is null. This can cause an oops during unlazy_fpu() in __switch_to() Now: 1) This should happen with or with out pre-emption. Viro also encountered similar problem with out CONFIG_PREEMPT. 2) kernel_fpu_begin() and kernel_fpu_end() will fix this problem, because kernel_fpu_begin() will manually do a clts() and won't run in to the situation of setting TS_USEDFPU in step "c" above. 3) This was working before the fpu changes, because its a spurious math fault which doesn't corrupt any fpu/sse registers and the task's math state was always in an allocated state. With out the recent lazy fpu allocation changes, while we don't see oops, there is a possible race still present in older kernels(for example, while kernel is using kernel_fpu_begin() in some optimized clear/copy page and an interrupt/softirq happens which uses these padlock instructions generating DNA fault). This is the failing scenario that existed even before the lazy fpu allocation changes: 0. CPU's TS flag is set 1. kernel using FPU in some optimized copy routine and while doing kernel_fpu_begin() takes an interrupt just before doing clts() 2. Takes an interrupt and ipsec uses padlock instruction. And we take a DNA fault as TS flag is still set. 3. We handle the DNA fault and set TS_USEDFPU and clear cr0.ts 4. We complete the padlock routine 5. Go back to step-1, which resumes clts() in kernel_fpu_begin(), finishes the optimized copy routine and does kernel_fpu_end(). At this point, we have cr0.ts again set to '1' but the task's TS_USEFPU is stilll set and not cleared. 6. Now kernel resumes its user operation. And at the next context switch, kernel sees it has do a FP save as TS_USEDFPU is still set and then will do a unlazy_fpu() in __switch_to(). unlazy_fpu() will take a DNA fault, as cr0.ts is '1' and now, because we are in __switch_to(), math_state_restore() will get confused and will restore the next task's FP state and will save it in prev tasks's FP state. Remember, in __switch_to() we are already on the stack of the next task but take a DNA fault for the prev task. This causes the fpu leakage. Fix the padlock instruction usage by calling them inside the context of new routines irq_ts_save/restore(), which clear/restore cr0.ts manually in the interrupt context. This will not generate spurious DNA in the context of the interrupt which will fix the oops encountered and the possible FPU leakage issue. Reported-and-bisected-by: Wolfgang Walter <wolfgang.walter@stwm.de> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-02-06via-rng: enable secondary noise source on CPUs where it is presentDave Jones
In the padlock spec: "SRC Bits[9:8] Noise source select (I): These bits control the two noise sources on the processor that input bits to the accumulation buffers. On Nehemiah processors prior to stepping 8, these bits are reserved and undefined. The default RESET state is both bits = 0." Signed-off-by: Dave Jones <davej@redhat.com> Tested-by: Udo van den Heuvel <udovdh@xs4all.nl> Cc: Michael Buesch <mb@bu3sch.de> Cc: folkert van Heusden <folkert@vanheusden.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-01-11[HWRNG]: move status polling loop to data_present callbacksPatrick McHardy
Handle waiting for new random within the drivers themselves, this allows to use better suited timeouts for the individual rngs. Signed-off-by: Patrick McHardy <kaber@trash.net> Acked-by: Michael Buesch <mb@bu3sch.de> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2007-05-02PCI: Cleanup the includes of <linux/pci.h>Jean Delvare
I noticed that many source files include <linux/pci.h> while they do not appear to need it. Here is an attempt to clean it all up. In order to find all possibly affected files, I searched for all files including <linux/pci.h> but without any other occurence of "pci" or "PCI". I removed the include statement from all of these, then I compiled an allmodconfig kernel on both i386 and x86_64 and fixed the false positives manually. My tests covered 66% of the affected files, so there could be false positives remaining. Untested files are: arch/alpha/kernel/err_common.c arch/alpha/kernel/err_ev6.c arch/alpha/kernel/err_ev7.c arch/ia64/sn/kernel/huberror.c arch/ia64/sn/kernel/xpnet.c arch/m68knommu/kernel/dma.c arch/mips/lib/iomap.c arch/powerpc/platforms/pseries/ras.c arch/ppc/8260_io/enet.c arch/ppc/8260_io/fcc_enet.c arch/ppc/8xx_io/enet.c arch/ppc/syslib/ppc4xx_sgdma.c arch/sh64/mach-cayman/iomap.c arch/xtensa/kernel/xtensa_ksyms.c arch/xtensa/platform-iss/setup.c drivers/i2c/busses/i2c-at91.c drivers/i2c/busses/i2c-mpc.c drivers/media/video/saa711x.c drivers/misc/hdpuftrs/hdpu_cpustate.c drivers/misc/hdpuftrs/hdpu_nexus.c drivers/net/au1000_eth.c drivers/net/fec_8xx/fec_main.c drivers/net/fec_8xx/fec_mii.c drivers/net/fs_enet/fs_enet-main.c drivers/net/fs_enet/mac-fcc.c drivers/net/fs_enet/mac-fec.c drivers/net/fs_enet/mac-scc.c drivers/net/fs_enet/mii-bitbang.c drivers/net/fs_enet/mii-fec.c drivers/net/ibm_emac/ibm_emac_core.c drivers/net/lasi_82596.c drivers/parisc/hppb.c drivers/sbus/sbus.c drivers/video/g364fb.c drivers/video/platinumfb.c drivers/video/stifb.c drivers/video/valkyriefb.c include/asm-arm/arch-ixp4xx/dma.h sound/oss/au1550_ac97.c I would welcome test reports for these files. I am fine with removing the untested files from the patch if the general opinion is that these changes aren't safe. The tested part would still be nice to have. Note that this patch depends on another header fixup patch I submitted to LKML yesterday: [PATCH] scatterlist.h needs types.h http://lkml.org/lkml/2007/3/01/141 Signed-off-by: Jean Delvare <khali@linux-fr.org> Cc: Badari Pulavarty <pbadari@us.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-01-11[PATCH] Fix HWRNG built-in initcalls priorityMichael Buesch
This changes all HWRNG driver initcalls to module_init(). We must probe the RNGs after the major kernel subsystems are already up and running (like PCI). This fixes Bug 7730. http://bugzilla.kernel.org/show_bug.cgi?id=7730 Signed-off-by: Michael Buesch <mb@bu3sch.de> Cc: Jan Beulich <jbeulich@novell.com> Cc: Jeff Garzik <jeff@garzik.org> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] Add VIA HW RNG driverMichael Buesch
Signed-off-by: Michael Buesch <mb@bu3sch.de> Cc: Jeff Garzik <jeff@garzik.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>