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Groups > linux.kernel > #1242898
| From | Ben Hutchings <ben@decadent.org.uk> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH 3.2 029/107] sparc64: Fix userspace FPU register corruptions. |
| Date | 2015-10-09 02:40 +0200 |
| Message-ID | <qhtT4-2Qh-25@gated-at.bofh.it> (permalink) |
| References | <qhtzH-2tg-3@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
3.2.72-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: "David S. Miller" <davem@davemloft.net> commit 44922150d87cef616fd183220d43d8fde4d41390 upstream. If we have a series of events from userpsace, with %fprs=FPRS_FEF, like follows: ETRAP ETRAP VIS_ENTRY(fprs=0x4) VIS_EXIT RTRAP (kernel FPU restore with fpu_saved=0x4) RTRAP We will not restore the user registers that were clobbered by the FPU using kernel code in the inner-most trap. Traps allocate FPU save slots in the thread struct, and FPU using sequences save the "dirty" FPU registers only. This works at the initial trap level because all of the registers get recorded into the top-level FPU save area, and we'll return to userspace with the FPU disabled so that any FPU use by the user will take an FPU disabled trap wherein we'll load the registers back up properly. But this is not how trap returns from kernel to kernel operate. The simplest fix for this bug is to always save all FPU register state for anything other than the top-most FPU save area. Getting rid of the optimized inner-slot FPU saving code ends up making VISEntryHalf degenerate into plain VISEntry. Longer term we need to do something smarter to reinstate the partial save optimizations. Perhaps the fundament error is having trap entry and exit allocate FPU save slots and restore register state. Instead, the VISEntry et al. calls should be doing that work. This bug is about two decades old. Reported-by: James Y Knight <jyknight@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> [bwh: Backported to 3.2: - Adjust context - Drop changes to NG4memcpy.S and ksyms.c] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> --- --- a/arch/sparc/include/asm/visasm.h +++ b/arch/sparc/include/asm/visasm.h @@ -28,18 +28,12 @@ * Must preserve %o5 between VISEntryHalf and VISExitHalf */ #define VISEntryHalf \ - rd %fprs, %o5; \ - andcc %o5, FPRS_FEF, %g0; \ - be,pt %icc, 297f; \ - sethi %hi(298f), %g7; \ - sethi %hi(VISenterhalf), %g1; \ - jmpl %g1 + %lo(VISenterhalf), %g0; \ - or %g7, %lo(298f), %g7; \ - clr %o5; \ -297: wr %o5, FPRS_FEF, %fprs; \ -298: + VISEntry #define VISExitHalf \ + VISExit + +#define VISExitHalfFast \ wr %o5, 0, %fprs; #ifndef __ASSEMBLY__ --- a/arch/sparc/lib/VISsave.S +++ b/arch/sparc/lib/VISsave.S @@ -44,9 +44,8 @@ vis1: ldub [%g6 + TI_FPSAVED], %g3 stx %g3, [%g6 + TI_GSR] 2: add %g6, %g1, %g3 - cmp %o5, FPRS_DU - be,pn %icc, 6f - sll %g1, 3, %g1 + mov FPRS_DU | FPRS_DL | FPRS_FEF, %o5 + sll %g1, 3, %g1 stb %o5, [%g3 + TI_FPSAVED] rd %gsr, %g2 add %g6, %g1, %g3 @@ -80,65 +79,3 @@ vis1: ldub [%g6 + TI_FPSAVED], %g3 .align 32 80: jmpl %g7 + %g0, %g0 nop - -6: ldub [%g3 + TI_FPSAVED], %o5 - or %o5, FPRS_DU, %o5 - add %g6, TI_FPREGS+0x80, %g2 - stb %o5, [%g3 + TI_FPSAVED] - - sll %g1, 5, %g1 - add %g6, TI_FPREGS+0xc0, %g3 - wr %g0, FPRS_FEF, %fprs - membar #Sync - stda %f32, [%g2 + %g1] ASI_BLK_P - stda %f48, [%g3 + %g1] ASI_BLK_P - membar #Sync - ba,pt %xcc, 80f - nop - - .align 32 -80: jmpl %g7 + %g0, %g0 - nop - - .align 32 -VISenterhalf: - ldub [%g6 + TI_FPDEPTH], %g1 - brnz,a,pn %g1, 1f - cmp %g1, 1 - stb %g0, [%g6 + TI_FPSAVED] - stx %fsr, [%g6 + TI_XFSR] - clr %o5 - jmpl %g7 + %g0, %g0 - wr %g0, FPRS_FEF, %fprs - -1: bne,pn %icc, 2f - srl %g1, 1, %g1 - ba,pt %xcc, vis1 - sub %g7, 8, %g7 -2: addcc %g6, %g1, %g3 - sll %g1, 3, %g1 - andn %o5, FPRS_DU, %g2 - stb %g2, [%g3 + TI_FPSAVED] - - rd %gsr, %g2 - add %g6, %g1, %g3 - stx %g2, [%g3 + TI_GSR] - add %g6, %g1, %g2 - stx %fsr, [%g2 + TI_XFSR] - sll %g1, 5, %g1 -3: andcc %o5, FPRS_DL, %g0 - be,pn %icc, 4f - add %g6, TI_FPREGS, %g2 - - add %g6, TI_FPREGS+0x40, %g3 - membar #Sync - stda %f0, [%g2 + %g1] ASI_BLK_P - stda %f16, [%g3 + %g1] ASI_BLK_P - membar #Sync - ba,pt %xcc, 4f - nop - - .align 32 -4: and %o5, FPRS_DU, %o5 - jmpl %g7 + %g0, %g0 - wr %o5, FPRS_FEF, %fprs -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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[PATCH 3.2 000/107] 3.2.72-rc1 review Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:30 +0200
[PATCH 3.2 072/107] USB: option: add ZTE PIDs Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:30 +0200
[PATCH 3.2 069/107] hfs,hfsplus: cache pages correctly between bnode_create and bnode_free Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:30 +0200
[PATCH 3.2 015/107] ocfs2: fix BUG in ocfs2_downconvert_thread_do_work() Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:30 +0200
[PATCH 3.2 049/107] DRM - radeon: Don't link train DisplayPort on HPD until we get the dpcd Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:30 +0200
[PATCH 3.2 098/107] ipv6: lock socket in ip6_datagram_connect() Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:30 +0200
[PATCH 3.2 024/107] libfc: Fix fc_fcp_cleanup_each_cmd() Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:30 +0200
[PATCH 3.2 094/107] Initialize msg/shm IPC objects before doing ipc_addid() Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:40 +0200
[PATCH 3.2 060/107] drm/i915: Always mark the object as dirty when used by the GPU Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:40 +0200
[PATCH 3.2 047/107] eCryptfs: Invalidate dcache entries when lower i_nlink is zero Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:40 +0200
[PATCH 3.2 009/107] target: REPORT LUNS should return LUN 0 even for dynamic ACLs Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:40 +0200
[PATCH 3.2 095/107] net/tipc: initialize security state for new connection socket Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:40 +0200
[PATCH 3.2 018/107] x86/ldt: Make modify_ldt synchronous Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:40 +0200
[PATCH 3.2 036/107] PCI: Add VPD function 0 quirk for Intel Ethernet devices Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:40 +0200
[PATCH 3.2 016/107] net: Clone skb before setting peeked flag Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:40 +0200
[PATCH 3.2 026/107] x86/ldt: Further fix FPU emulation Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:40 +0200
[PATCH 3.2 029/107] sparc64: Fix userspace FPU register corruptions. Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:40 +0200
[PATCH 3.2 023/107] libiscsi: Fix host busy blocking during connection teardown Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:40 +0200
[PATCH 3.2 019/107] x86/ldt: Correct LDT access in single stepping logic Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:40 +0200
[PATCH 3.2 017/107] net: Fix skb_set_peeked use-after-free bug Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:40 +0200
[PATCH 3.2 005/107] crypto: ixp4xx - Remove bogus BUG_ON on scattered dst buffer Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:40 +0200
[PATCH 3.2 033/107] PCI: Fix TI816X class code quirk Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:40 +0200
[PATCH 3.2 051/107] rtlwifi: rtl8192cu: Add new device ID Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:40 +0200
[PATCH 3.2 032/107] [media] rc-core: fix remove uevent generation Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:40 +0200
[PATCH 3.2 068/107] powerpc/MSI: Fix race condition in tearing down MSI interrupts Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:40 +0200
[PATCH 3.2 037/107] usb: gadget: m66592-udc: forever loop in set_feature() Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:40 +0200
[PATCH 3.2 054/107] xfs: return errors from partial I/O failures to files Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:40 +0200
[PATCH 3.2 103/107] ipv6: prevent fib6_run_gc() contention Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:40 +0200
[PATCH 3.2 044/107] serial: 8250: bind to ALi Fast Infrared Controller (ALI5123) Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:40 +0200
[PATCH 3.2 070/107] hfs: fix B-tree corruption after insertion at position 0 Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:40 +0200
[PATCH 3.2 050/107] rtlwifi: rtl8192cu: Add new device ID Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:40 +0200
[PATCH 3.2 048/107] xfs: Fix xfs_attr_leafblock definition Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:40 +0200
[PATCH 3.2 025/107] ipc,sem: fix use after free on IPC_RMID after a task using same semaphore set exits Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:40 +0200
[PATCH 3.2 007/107] target/iscsi: Fix double free of a TUR followed by a solicited NOPOUT Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:40 +0200
[PATCH 3.2 081/107] usb: Use the USB_SS_MULT() macro to get the burst multiplier. Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:50 +0200
[PATCH 3.2 079/107] s390/compat: correct uc_sigmask of the compat signal frame Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:50 +0200
[PATCH 3.2 091/107] virtio-net: drop NETIF_F_FRAGLIST Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:50 +0200
[PATCH 3.2 053/107] drivercore: Fix unregistration path of platform devices Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:50 +0200
[PATCH 3.2 006/107] USB: sierra: add 1199:68AB device ID Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:50 +0200
[PATCH 3.2 059/107] spi: spi-pxa2xx: Check status register to determine if SSSR_TINT is disabled Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:50 +0200
[PATCH 3.2 002/107] pktgen: Require CONFIG_INET due to use of IPv4 checksum function Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:50 +0200
[PATCH 3.2 085/107] cifs: use server timestamp for ntlmv2 authentication Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:50 +0200
[PATCH 3.2 066/107] ARM: 8429/1: disable GCC SRA optimization Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:50 +0200
[PATCH 3.2 061/107] Add radeon suspend/resume quirk for HP Compaq dc5750. Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:50 +0200
[PATCH 3.2 046/107] USB: ftdi_sio: Added custom PID for CustomWare products Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:50 +0200
[PATCH 3.2 013/107] perf: Fix fasync handling on inherited events Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:50 +0200
[PATCH 3.2 074/107] btrfs: skip waiting on ordered range for special files Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:50 +0200
[PATCH 3.2 052/107] of/address: Don't loop forever in of_find_matching_node_by_address(). Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:50 +0200
[PATCH 3.2 042/107] NFSv4: don't set SETATTR for O_RDONLY|O_EXCL Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:50 +0200
[PATCH 3.2 093/107] ipc/sem.c: fully initialize sem_array before making it visible Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:50 +0200
[PATCH 3.2 039/107] auxdisplay: ks0108: fix refcount Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:50 +0200
[PATCH 3.2 083/107] usb: xhci: Clear XHCI_STATE_DYING on start Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:50 +0200
[PATCH 3.2 062/107] IB/uverbs: reject invalid or unknown opcodes Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:50 +0200
[PATCH 3.2 058/107] IB/uverbs: Fix race between ib_uverbs_open and remove_one Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:50 +0200
[PATCH 3.2 102/107] perf tools: Fix build with perl 5.18 Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:50 +0200
[PATCH 3.2 075/107] ARM: 7880/1: Clear the IT state independent of the Thumb-2 mode Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:50 +0200
[PATCH 3.2 105/107] parisc: Filter out spurious interrupts in PA-RISC irq handler Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:50 +0200
[PATCH 3.2 100/107] net/ipv6: Correct PIM6 mrt_lock handling Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:50 +0200
[PATCH 3.2 030/107] dcache: Handle escaped paths in prepend_path Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:50 +0200
[PATCH 3.2 041/107] windfarm: decrement client count when unregistering Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:50 +0200
[PATCH 3.2 076/107] ARM: fix Thumb2 signal handling when ARMv6 is enabled Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:50 +0200
[PATCH 3.2 057/107] IB/mlx4: Use correct SL on AH query under RoCE Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:50 +0200
[PATCH 3.2 090/107] ipv6: addrconf: validate new MTU before applying it Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:50 +0200
[PATCH 3.2 010/107] MIPS: Fix sched_getaffinity with MT FPAFF enabled Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 02:50 +0200
[PATCH 3.2 063/107] Input: evdev - do not report errors form flush() Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 03:00 +0200
[PATCH 3.2 078/107] ASoC: fix broken pxa SoC support Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 03:00 +0200
[PATCH 3.2 064/107] crypto: ghash-clmulni: specify context size for ghash async algorithm Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 03:00 +0200
[PATCH 3.2 065/107] fs: create and use seq_show_option for escaping Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 03:00 +0200
[PATCH 3.2 084/107] xhci: change xhci 1.0 only restrictions to support xhci 1.1 Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 03:00 +0200
[PATCH 3.2 071/107] perf header: Fixup reading of HEADER_NRCPUS feature Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 03:00 +0200
[PATCH 3.2 104/107] ipv6: update ip6_rt_last_gc every time GC is run Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 03:00 +0200
[PATCH 3.2 055/107] IB/qib: Change lkey table allocation to support more MRs Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 03:00 +0200
[PATCH 3.2 073/107] Btrfs: fix read corruption of compressed and shared extents Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 03:00 +0200
Re: [PATCH 3.2 000/107] 3.2.72-rc1 review Guenter Roeck <linux@roeck-us.net> - 2015-10-09 03:00 +0200
Re: [PATCH 3.2 000/107] 3.2.72-rc1 review Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 03:20 +0200
[PATCH 3.2 077/107] x86/platform: Fix Geode LX timekeeping in the generic x86 build Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 03:00 +0200
[PATCH 3.2 087/107] ocfs2/dlm: fix deadlock when dispatch assert master Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 03:00 +0200
[PATCH 3.2 056/107] SUNRPC: xs_reset_transport must mark the connection as disconnected Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 03:00 +0200
[PATCH 3.2 082/107] xhci: give command abortion one more chance before killing xhci Ben Hutchings <ben@decadent.org.uk> - 2015-10-09 03:00 +0200
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