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[Linux-stable-mirror] [PATCH] drm/ast: Load lut in crtc_commit

by Daniel Vetter

In the past the ast driver relied upon the fbdev emulation helpers to call ->load_lut at boot-up. But since commit b8e2b0199cc377617dc238f5106352c06dcd3fa2 Author: Peter Rosin <peda(a)axentia.se> Date: Tue Jul 4 12:36:57 2017 +0200 drm/fb-helper: factor out pseudo-palette that's cleaned up and drivers are expected to boot into a consistent lut state. This patch fixes that. Fixes: b8e2b0199cc3 ("drm/fb-helper: factor out pseudo-palette") Cc: Peter Rosin <peda(a)axenita.se> Cc: Daniel Vetter <daniel.vetter(a)ffwll.ch> Cc: <stable(a)vger.kernel.org> # v4.14+ Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=198123 Cc: Bill Fraser <bill.fraser(a)gmail.com> Reported-and-Tested-by: Bill Fraser <bill.fraser(a)gmail.com> Signed-off-by: Daniel Vetter <daniel.vetter(a)intel.com> --- drivers/gpu/drm/ast/ast_mode.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/gpu/drm/ast/ast_mode.c b/drivers/gpu/drm/ast/ast_mode.c index 9555a3542022..831b73392d82 100644 --- a/drivers/gpu/drm/ast/ast_mode.c +++ b/drivers/gpu/drm/ast/ast_mode.c @@ -644,6 +644,7 @@ static void ast_crtc_commit(struct drm_crtc *crtc) { struct ast_private *ast = crtc->dev->dev_private; ast_set_index_reg_mask(ast, AST_IO_SEQ_PORT, 0x1, 0xdf, 0); + ast_crtc_load_lut(crtc); } -- 2.15.1

7 years, 5 months

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[Linux-stable-mirror] [PATCH v2] drm/vc4: Fix NULL pointer dereference in vc4_save_hang_state()

by Boris Brezillon

When saving BOs in the hang state we skip one entry of the kernel_state->bo[] array, thus leaving it to NULL. This leads to a NULL pointer dereference when, later in this function, we iterate over all BOs to check their ->madv state. Fixes: ca26d28bbaa3 ("drm/vc4: improve throughput by pipelining binning and rendering jobs") Cc: <stable(a)vger.kernel.org> Signed-off-by: Boris Brezillon <boris.brezillon(a)free-electrons.com> --- Changes in v2: - Get rid of prev_idx an replace it by k which is indepently incremented every time a new object is added to kernel_state->bo[]. - Add a WARN_ON_ONCE() when final value of k is inconsistent --- drivers/gpu/drm/vc4/vc4_gem.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/vc4/vc4_gem.c b/drivers/gpu/drm/vc4/vc4_gem.c index 6c32c89a83a9..3216f12052fe 100644 --- a/drivers/gpu/drm/vc4/vc4_gem.c +++ b/drivers/gpu/drm/vc4/vc4_gem.c @@ -146,7 +146,7 @@ vc4_save_hang_state(struct drm_device *dev) struct vc4_exec_info *exec[2]; struct vc4_bo *bo; unsigned long irqflags; - unsigned int i, j, unref_list_count, prev_idx; + unsigned int i, j, k, unref_list_count; kernel_state = kcalloc(1, sizeof(*kernel_state), GFP_KERNEL); if (!kernel_state) @@ -182,7 +182,7 @@ vc4_save_hang_state(struct drm_device *dev) return; } - prev_idx = 0; + k = 0; for (i = 0; i < 2; i++) { if (!exec[i]) continue; @@ -197,7 +197,7 @@ vc4_save_hang_state(struct drm_device *dev) WARN_ON(!refcount_read(&bo->usecnt)); refcount_inc(&bo->usecnt); drm_gem_object_get(&exec[i]->bo[j]->base); - kernel_state->bo[j + prev_idx] = &exec[i]->bo[j]->base; + kernel_state->bo[k++] = &exec[i]->bo[j]->base; } list_for_each_entry(bo, &exec[i]->unref_list, unref_head) { @@ -205,12 +205,12 @@ vc4_save_hang_state(struct drm_device *dev) * because they are naturally unpurgeable. */ drm_gem_object_get(&bo->base.base); - kernel_state->bo[j + prev_idx] = &bo->base.base; - j++; + kernel_state->bo[k++] = &bo->base.base; } - prev_idx = j + 1; } + WARN_ON_ONCE(k != state->bo_count); + if (exec[0]) state->start_bin = exec[0]->ct0ca; if (exec[1]) -- 2.11.0

7 years, 5 months

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[Linux-stable-mirror] [PATCH] UBI: block: Fix locking for idr_alloc/idr_remove

by Bradley Bolen

From: Bradley Bolen <bradleybolen(a)gmail.com> This fixes a race with idr_alloc where gd->first_minor can be set to the same value for two simultaneous calls to ubiblock_create. Each instance calls device_add_disk with the same first_minor. device_add_disk calls bdi_register_owner which generates several warnings. WARNING: CPU: 1 PID: 179 at kernel-source/fs/sysfs/dir.c:31 sysfs_warn_dup+0x68/0x88 sysfs: cannot create duplicate filename '/devices/virtual/bdi/252:2' WARNING: CPU: 1 PID: 179 at kernel-source/lib/kobject.c:240 kobject_add_internal+0x1ec/0x2f8 kobject_add_internal failed for 252:2 with -EEXIST, don't try to register things with the same name in the same directory WARNING: CPU: 1 PID: 179 at kernel-source/fs/sysfs/dir.c:31 sysfs_warn_dup+0x68/0x88 sysfs: cannot create duplicate filename '/dev/block/252:2' However, device_add_disk does not error out when bdi_register_owner returns an error. Control continues until reaching blk_register_queue. It then BUGs. kernel BUG at kernel-source/fs/sysfs/group.c:113! [<c01e26cc>] (internal_create_group) from [<c01e2950>] (sysfs_create_group+0x20/0x24) [<c01e2950>] (sysfs_create_group) from [<c00e3d38>] (blk_trace_init_sysfs+0x18/0x20) [<c00e3d38>] (blk_trace_init_sysfs) from [<c02bdfbc>] (blk_register_queue+0xd8/0x154) [<c02bdfbc>] (blk_register_queue) from [<c02cec84>] (device_add_disk+0x194/0x44c) [<c02cec84>] (device_add_disk) from [<c0436ec8>] (ubiblock_create+0x284/0x2e0) [<c0436ec8>] (ubiblock_create) from [<c0427bb8>] (vol_cdev_ioctl+0x450/0x554) [<c0427bb8>] (vol_cdev_ioctl) from [<c0189110>] (vfs_ioctl+0x30/0x44) [<c0189110>] (vfs_ioctl) from [<c01892e0>] (do_vfs_ioctl+0xa0/0x790) [<c01892e0>] (do_vfs_ioctl) from [<c0189a14>] (SyS_ioctl+0x44/0x68) [<c0189a14>] (SyS_ioctl) from [<c0010640>] (ret_fast_syscall+0x0/0x34) Locking idr_alloc/idr_remove removes the race and keeps gd->first_minor unique. Fixes: 2bf50d42f3a4 ("UBI: block: Dynamically allocate minor numbers") Cc: stable(a)vger.kernel.org Signed-off-by: Bradley Bolen <bradleybolen(a)gmail.com> --- drivers/mtd/ubi/block.c | 42 ++++++++++++++++++++++++++---------------- 1 file changed, 26 insertions(+), 16 deletions(-) diff --git a/drivers/mtd/ubi/block.c b/drivers/mtd/ubi/block.c index b210fdb..b1fc28f 100644 --- a/drivers/mtd/ubi/block.c +++ b/drivers/mtd/ubi/block.c @@ -99,6 +99,8 @@ struct ubiblock { /* Linked list of all ubiblock instances */ static LIST_HEAD(ubiblock_devices); +static DEFINE_IDR(ubiblock_minor_idr); +/* Protects ubiblock_devices and ubiblock_minor_idr */ static DEFINE_MUTEX(devices_mutex); static int ubiblock_major; @@ -351,8 +353,6 @@ static int ubiblock_init_request(struct blk_mq_tag_set *set, .init_request = ubiblock_init_request, }; -static DEFINE_IDR(ubiblock_minor_idr); - int ubiblock_create(struct ubi_volume_info *vi) { struct ubiblock *dev; @@ -365,14 +365,15 @@ int ubiblock_create(struct ubi_volume_info *vi) /* Check that the volume isn't already handled */ mutex_lock(&devices_mutex); if (find_dev_nolock(vi->ubi_num, vi->vol_id)) { - mutex_unlock(&devices_mutex); - return -EEXIST; + ret = -EEXIST; + goto out_unlock; } - mutex_unlock(&devices_mutex); dev = kzalloc(sizeof(struct ubiblock), GFP_KERNEL); - if (!dev) - return -ENOMEM; + if (!dev) { + ret = -ENOMEM; + goto out_unlock; + } mutex_init(&dev->dev_mutex); @@ -437,14 +438,13 @@ int ubiblock_create(struct ubi_volume_info *vi) goto out_free_queue; } - mutex_lock(&devices_mutex); list_add_tail(&dev->list, &ubiblock_devices); - mutex_unlock(&devices_mutex); /* Must be the last step: anyone can call file ops from now on */ add_disk(dev->gd); dev_info(disk_to_dev(dev->gd), "created from ubi%d:%d(%s)", dev->ubi_num, dev->vol_id, vi->name); + mutex_unlock(&devices_mutex); return 0; out_free_queue: @@ -457,6 +457,8 @@ int ubiblock_create(struct ubi_volume_info *vi) put_disk(dev->gd); out_free_dev: kfree(dev); +out_unlock: + mutex_unlock(&devices_mutex); return ret; } @@ -478,30 +480,36 @@ static void ubiblock_cleanup(struct ubiblock *dev) int ubiblock_remove(struct ubi_volume_info *vi) { struct ubiblock *dev; + int ret; mutex_lock(&devices_mutex); dev = find_dev_nolock(vi->ubi_num, vi->vol_id); if (!dev) { - mutex_unlock(&devices_mutex); - return -ENODEV; + ret = -ENODEV; + goto out_unlock; } /* Found a device, let's lock it so we can check if it's busy */ mutex_lock(&dev->dev_mutex); if (dev->refcnt > 0) { - mutex_unlock(&dev->dev_mutex); - mutex_unlock(&devices_mutex); - return -EBUSY; + ret = -EBUSY; + goto out_unlock_dev; } /* Remove from device list */ list_del(&dev->list); - mutex_unlock(&devices_mutex); - ubiblock_cleanup(dev); mutex_unlock(&dev->dev_mutex); + mutex_unlock(&devices_mutex); + kfree(dev); return 0; + +out_unlock_dev: + mutex_unlock(&dev->dev_mutex); +out_unlock: + mutex_unlock(&devices_mutex); + return ret; } static int ubiblock_resize(struct ubi_volume_info *vi) @@ -630,6 +638,7 @@ static void ubiblock_remove_all(void) struct ubiblock *next; struct ubiblock *dev; + mutex_lock(&devices_mutex); list_for_each_entry_safe(dev, next, &ubiblock_devices, list) { /* The module is being forcefully removed */ WARN_ON(dev->desc); @@ -638,6 +647,7 @@ static void ubiblock_remove_all(void) ubiblock_cleanup(dev); kfree(dev); } + mutex_unlock(&devices_mutex); } int __init ubiblock_init(void) -- 1.9.3

7 years, 5 months

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[Linux-stable-mirror] Patch "powerpc/pseries: Query hypervisor for RFI flush settings" has been added to the 4.14-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled powerpc/pseries: Query hypervisor for RFI flush settings to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: powerpc-pseries-query-hypervisor-for-rfi-flush-settings.patch and it can be found in the queue-4.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From 8989d56878a7735dfdb234707a2fee6faf631085 Mon Sep 17 00:00:00 2001 From: Michael Neuling <mikey(a)neuling.org> Date: Wed, 10 Jan 2018 03:07:15 +1100 Subject: powerpc/pseries: Query hypervisor for RFI flush settings From: Michael Neuling <mikey(a)neuling.org> commit 8989d56878a7735dfdb234707a2fee6faf631085 upstream. A new hypervisor call is available which tells the guest settings related to the RFI flush. Use it to query the appropriate flush instruction(s), and whether the flush is required. Signed-off-by: Michael Neuling <mikey(a)neuling.org> Signed-off-by: Michael Ellerman <mpe(a)ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/powerpc/platforms/pseries/setup.c | 35 +++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) --- a/arch/powerpc/platforms/pseries/setup.c +++ b/arch/powerpc/platforms/pseries/setup.c @@ -459,6 +459,39 @@ static void __init find_and_init_phbs(vo of_pci_check_probe_only(); } +static void pseries_setup_rfi_flush(void) +{ + struct h_cpu_char_result result; + enum l1d_flush_type types; + bool enable; + long rc; + + /* Enable by default */ + enable = true; + + rc = plpar_get_cpu_characteristics(&result); + if (rc == H_SUCCESS) { + types = L1D_FLUSH_NONE; + + if (result.character & H_CPU_CHAR_L1D_FLUSH_TRIG2) + types |= L1D_FLUSH_MTTRIG; + if (result.character & H_CPU_CHAR_L1D_FLUSH_ORI30) + types |= L1D_FLUSH_ORI; + + /* Use fallback if nothing set in hcall */ + if (types == L1D_FLUSH_NONE) + types = L1D_FLUSH_FALLBACK; + + if (!(result.behaviour & H_CPU_BEHAV_L1D_FLUSH_PR)) + enable = false; + } else { + /* Default to fallback if case hcall is not available */ + types = L1D_FLUSH_FALLBACK; + } + + setup_rfi_flush(types, enable); +} + static void __init pSeries_setup_arch(void) { set_arch_panic_timeout(10, ARCH_PANIC_TIMEOUT); @@ -476,6 +509,8 @@ static void __init pSeries_setup_arch(vo fwnmi_init(); + pseries_setup_rfi_flush(); + /* By default, only probe PCI (can be overridden by rtas_pci) */ pci_add_flags(PCI_PROBE_ONLY); Patches currently in stable-queue which might be from mikey(a)neuling.org are queue-4.14/powerpc-pseries-add-h_get_cpu_characteristics-flags-wrapper.patch queue-4.14/powerpc-pseries-query-hypervisor-for-rfi-flush-settings.patch

7 years, 5 months

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[Linux-stable-mirror] Patch "powerpc/powernv: Check device-tree for RFI flush settings" has been added to the 4.14-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled powerpc/powernv: Check device-tree for RFI flush settings to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: powerpc-powernv-check-device-tree-for-rfi-flush-settings.patch and it can be found in the queue-4.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From 6e032b350cd1fdb830f18f8320ef0e13b4e24094 Mon Sep 17 00:00:00 2001 From: Oliver O'Halloran <oohall(a)gmail.com> Date: Wed, 10 Jan 2018 03:07:15 +1100 Subject: powerpc/powernv: Check device-tree for RFI flush settings From: Oliver O'Halloran <oohall(a)gmail.com> commit 6e032b350cd1fdb830f18f8320ef0e13b4e24094 upstream. New device-tree properties are available which tell the hypervisor settings related to the RFI flush. Use them to determine the appropriate flush instruction to use, and whether the flush is required. Signed-off-by: Oliver O'Halloran <oohall(a)gmail.com> Signed-off-by: Michael Ellerman <mpe(a)ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/powerpc/platforms/powernv/setup.c | 49 +++++++++++++++++++++++++++++++++ 1 file changed, 49 insertions(+) --- a/arch/powerpc/platforms/powernv/setup.c +++ b/arch/powerpc/platforms/powernv/setup.c @@ -36,13 +36,62 @@ #include <asm/opal.h> #include <asm/kexec.h> #include <asm/smp.h> +#include <asm/setup.h> #include "powernv.h" +static void pnv_setup_rfi_flush(void) +{ + struct device_node *np, *fw_features; + enum l1d_flush_type type; + int enable; + + /* Default to fallback in case fw-features are not available */ + type = L1D_FLUSH_FALLBACK; + enable = 1; + + np = of_find_node_by_name(NULL, "ibm,opal"); + fw_features = of_get_child_by_name(np, "fw-features"); + of_node_put(np); + + if (fw_features) { + np = of_get_child_by_name(fw_features, "inst-l1d-flush-trig2"); + if (np && of_property_read_bool(np, "enabled")) + type = L1D_FLUSH_MTTRIG; + + of_node_put(np); + + np = of_get_child_by_name(fw_features, "inst-l1d-flush-ori30,30,0"); + if (np && of_property_read_bool(np, "enabled")) + type = L1D_FLUSH_ORI; + + of_node_put(np); + + /* Enable unless firmware says NOT to */ + enable = 2; + np = of_get_child_by_name(fw_features, "needs-l1d-flush-msr-hv-1-to-0"); + if (np && of_property_read_bool(np, "disabled")) + enable--; + + of_node_put(np); + + np = of_get_child_by_name(fw_features, "needs-l1d-flush-msr-pr-0-to-1"); + if (np && of_property_read_bool(np, "disabled")) + enable--; + + of_node_put(np); + of_node_put(fw_features); + } + + setup_rfi_flush(type, enable > 0); +} + static void __init pnv_setup_arch(void) { set_arch_panic_timeout(10, ARCH_PANIC_TIMEOUT); + pnv_setup_rfi_flush(); + /* Initialize SMP */ pnv_smp_init(); Patches currently in stable-queue which might be from oohall(a)gmail.com are queue-4.14/powerpc-powernv-check-device-tree-for-rfi-flush-settings.patch

7 years, 5 months

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[Linux-stable-mirror] Patch "powerpc/64s: Simple RFI macro conversions" has been added to the 4.14-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled powerpc/64s: Simple RFI macro conversions to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: powerpc-64s-simple-rfi-macro-conversions.patch and it can be found in the queue-4.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From 222f20f140623ef6033491d0103ee0875fe87d35 Mon Sep 17 00:00:00 2001 From: Nicholas Piggin <npiggin(a)gmail.com> Date: Wed, 10 Jan 2018 03:07:15 +1100 Subject: powerpc/64s: Simple RFI macro conversions From: Nicholas Piggin <npiggin(a)gmail.com> commit 222f20f140623ef6033491d0103ee0875fe87d35 upstream. This commit does simple conversions of rfi/rfid to the new macros that include the expected destination context. By simple we mean cases where there is a single well known destination context, and it's simply a matter of substituting the instruction for the appropriate macro. Signed-off-by: Nicholas Piggin <npiggin(a)gmail.com> Signed-off-by: Michael Ellerman <mpe(a)ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/powerpc/include/asm/exception-64s.h | 4 ++-- arch/powerpc/kernel/entry_64.S | 14 +++++++++----- arch/powerpc/kernel/exceptions-64s.S | 22 +++++++++++----------- arch/powerpc/kvm/book3s_hv_rmhandlers.S | 7 +++---- arch/powerpc/kvm/book3s_rmhandlers.S | 7 +++++-- arch/powerpc/kvm/book3s_segment.S | 4 ++-- 6 files changed, 32 insertions(+), 26 deletions(-) --- a/arch/powerpc/include/asm/exception-64s.h +++ b/arch/powerpc/include/asm/exception-64s.h @@ -242,7 +242,7 @@ END_FTR_SECTION_NESTED(ftr,ftr,943) mtspr SPRN_##h##SRR0,r12; \ mfspr r12,SPRN_##h##SRR1; /* and SRR1 */ \ mtspr SPRN_##h##SRR1,r10; \ - h##rfid; \ + h##RFI_TO_KERNEL; \ b . /* prevent speculative execution */ #define EXCEPTION_PROLOG_PSERIES_1(label, h) \ __EXCEPTION_PROLOG_PSERIES_1(label, h) @@ -256,7 +256,7 @@ END_FTR_SECTION_NESTED(ftr,ftr,943) mtspr SPRN_##h##SRR0,r12; \ mfspr r12,SPRN_##h##SRR1; /* and SRR1 */ \ mtspr SPRN_##h##SRR1,r10; \ - h##rfid; \ + h##RFI_TO_KERNEL; \ b . /* prevent speculative execution */ #define EXCEPTION_PROLOG_PSERIES_1_NORI(label, h) \ --- a/arch/powerpc/kernel/entry_64.S +++ b/arch/powerpc/kernel/entry_64.S @@ -37,6 +37,11 @@ #include <asm/tm.h> #include <asm/ppc-opcode.h> #include <asm/export.h> +#ifdef CONFIG_PPC_BOOK3S +#include <asm/exception-64s.h> +#else +#include <asm/exception-64e.h> +#endif /* * System calls. @@ -397,8 +402,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR) mtmsrd r10, 1 mtspr SPRN_SRR0, r11 mtspr SPRN_SRR1, r12 - - rfid + RFI_TO_USER b . /* prevent speculative execution */ #endif _ASM_NOKPROBE_SYMBOL(system_call_common); @@ -1073,7 +1077,7 @@ __enter_rtas: mtspr SPRN_SRR0,r5 mtspr SPRN_SRR1,r6 - rfid + RFI_TO_KERNEL b . /* prevent speculative execution */ rtas_return_loc: @@ -1098,7 +1102,7 @@ rtas_return_loc: mtspr SPRN_SRR0,r3 mtspr SPRN_SRR1,r4 - rfid + RFI_TO_KERNEL b . /* prevent speculative execution */ _ASM_NOKPROBE_SYMBOL(__enter_rtas) _ASM_NOKPROBE_SYMBOL(rtas_return_loc) @@ -1171,7 +1175,7 @@ _GLOBAL(enter_prom) LOAD_REG_IMMEDIATE(r12, MSR_SF | MSR_ISF | MSR_LE) andc r11,r11,r12 mtsrr1 r11 - rfid + RFI_TO_KERNEL #endif /* CONFIG_PPC_BOOK3E */ 1: /* Return from OF */ --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -254,7 +254,7 @@ BEGIN_FTR_SECTION LOAD_HANDLER(r12, machine_check_handle_early) 1: mtspr SPRN_SRR0,r12 mtspr SPRN_SRR1,r11 - rfid + RFI_TO_KERNEL b . /* prevent speculative execution */ 2: /* Stack overflow. Stay on emergency stack and panic. @@ -443,7 +443,7 @@ EXC_COMMON_BEGIN(machine_check_handle_ea li r3,MSR_ME andc r10,r10,r3 /* Turn off MSR_ME */ mtspr SPRN_SRR1,r10 - rfid + RFI_TO_KERNEL b . 2: /* @@ -461,7 +461,7 @@ EXC_COMMON_BEGIN(machine_check_handle_ea */ bl machine_check_queue_event MACHINE_CHECK_HANDLER_WINDUP - rfid + RFI_TO_USER_OR_KERNEL 9: /* Deliver the machine check to host kernel in V mode. */ MACHINE_CHECK_HANDLER_WINDUP @@ -649,7 +649,7 @@ END_MMU_FTR_SECTION_IFCLR(MMU_FTR_TYPE_R mtspr SPRN_SRR0,r10 ld r10,PACAKMSR(r13) mtspr SPRN_SRR1,r10 - rfid + RFI_TO_KERNEL b . 8: std r3,PACA_EXSLB+EX_DAR(r13) @@ -660,7 +660,7 @@ END_MMU_FTR_SECTION_IFCLR(MMU_FTR_TYPE_R mtspr SPRN_SRR0,r10 ld r10,PACAKMSR(r13) mtspr SPRN_SRR1,r10 - rfid + RFI_TO_KERNEL b . EXC_COMMON_BEGIN(unrecov_slb) @@ -905,7 +905,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_REAL_LE) mtspr SPRN_SRR0,r10 ; \ ld r10,PACAKMSR(r13) ; \ mtspr SPRN_SRR1,r10 ; \ - rfid ; \ + RFI_TO_KERNEL ; \ b . ; /* prevent speculative execution */ #define SYSCALL_FASTENDIAN \ @@ -914,7 +914,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_REAL_LE) xori r12,r12,MSR_LE ; \ mtspr SPRN_SRR1,r12 ; \ mr r13,r9 ; \ - rfid ; /* return to userspace */ \ + RFI_TO_USER ; /* return to userspace */ \ b . ; /* prevent speculative execution */ #if defined(CONFIG_RELOCATABLE) @@ -1299,7 +1299,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_CFAR) ld r11,PACA_EXGEN+EX_R11(r13) ld r12,PACA_EXGEN+EX_R12(r13) ld r13,PACA_EXGEN+EX_R13(r13) - HRFID + HRFI_TO_UNKNOWN b . #endif @@ -1403,7 +1403,7 @@ masked_##_H##interrupt: \ ld r10,PACA_EXGEN+EX_R10(r13); \ ld r11,PACA_EXGEN+EX_R11(r13); \ /* returns to kernel where r13 must be set up, so don't restore it */ \ - ##_H##rfid; \ + ##_H##RFI_TO_KERNEL; \ b .; \ MASKED_DEC_HANDLER(_H) @@ -1426,7 +1426,7 @@ TRAMP_REAL_BEGIN(kvmppc_skip_interrupt) addi r13, r13, 4 mtspr SPRN_SRR0, r13 GET_SCRATCH0(r13) - rfid + RFI_TO_KERNEL b . TRAMP_REAL_BEGIN(kvmppc_skip_Hinterrupt) @@ -1438,7 +1438,7 @@ TRAMP_REAL_BEGIN(kvmppc_skip_Hinterrupt) addi r13, r13, 4 mtspr SPRN_HSRR0, r13 GET_SCRATCH0(r13) - hrfid + HRFI_TO_KERNEL b . #endif --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S @@ -78,7 +78,7 @@ _GLOBAL_TOC(kvmppc_hv_entry_trampoline) mtmsrd r0,1 /* clear RI in MSR */ mtsrr0 r5 mtsrr1 r6 - RFI + RFI_TO_KERNEL kvmppc_call_hv_entry: ld r4, HSTATE_KVM_VCPU(r13) @@ -187,7 +187,7 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300) mtmsrd r6, 1 /* Clear RI in MSR */ mtsrr0 r8 mtsrr1 r7 - RFI + RFI_TO_KERNEL /* Virtual-mode return */ .Lvirt_return: @@ -1131,8 +1131,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300) ld r0, VCPU_GPR(R0)(r4) ld r4, VCPU_GPR(R4)(r4) - - hrfid + HRFI_TO_GUEST b . secondary_too_late: --- a/arch/powerpc/kvm/book3s_rmhandlers.S +++ b/arch/powerpc/kvm/book3s_rmhandlers.S @@ -46,6 +46,9 @@ #define FUNC(name) name +#define RFI_TO_KERNEL RFI +#define RFI_TO_GUEST RFI + .macro INTERRUPT_TRAMPOLINE intno .global kvmppc_trampoline_\intno @@ -141,7 +144,7 @@ kvmppc_handler_skip_ins: GET_SCRATCH0(r13) /* And get back into the code */ - RFI + RFI_TO_KERNEL #endif /* @@ -164,6 +167,6 @@ _GLOBAL_TOC(kvmppc_entry_trampoline) ori r5, r5, MSR_EE mtsrr0 r7 mtsrr1 r6 - RFI + RFI_TO_KERNEL #include "book3s_segment.S" --- a/arch/powerpc/kvm/book3s_segment.S +++ b/arch/powerpc/kvm/book3s_segment.S @@ -156,7 +156,7 @@ no_dcbz32_on: PPC_LL r9, SVCPU_R9(r3) PPC_LL r3, (SVCPU_R3)(r3) - RFI + RFI_TO_GUEST kvmppc_handler_trampoline_enter_end: @@ -407,5 +407,5 @@ END_FTR_SECTION_IFSET(CPU_FTR_HVMODE) cmpwi r12, BOOK3S_INTERRUPT_DOORBELL beqa BOOK3S_INTERRUPT_DOORBELL - RFI + RFI_TO_KERNEL kvmppc_handler_trampoline_exit_end: Patches currently in stable-queue which might be from npiggin(a)gmail.com are queue-4.14/powerpc-64s-simple-rfi-macro-conversions.patch queue-4.14/powerpc-64-add-macros-for-annotating-the-destination-of-rfid-hrfid.patch queue-4.14/powerpc-64s-convert-slb_miss_common-to-use-rfi_to_user-kernel.patch queue-4.14/powerpc-64-convert-the-syscall-exit-path-to-use-rfi_to_user-kernel.patch queue-4.14/powerpc-64s-add-support-for-rfi-flush-of-l1-d-cache.patch queue-4.14/powerpc-64-convert-fast_exception_return-to-use-rfi_to_user-kernel.patch

7 years, 5 months

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[Linux-stable-mirror] Patch "powerpc/64s: Support disabling RFI flush with no_rfi_flush and nopti" has been added to the 4.14-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled powerpc/64s: Support disabling RFI flush with no_rfi_flush and nopti to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: powerpc-64s-support-disabling-rfi-flush-with-no_rfi_flush-and-nopti.patch and it can be found in the queue-4.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From bc9c9304a45480797e13a8e1df96ffcf44fb62fe Mon Sep 17 00:00:00 2001 From: Michael Ellerman <mpe(a)ellerman.id.au> Date: Wed, 10 Jan 2018 03:07:15 +1100 Subject: powerpc/64s: Support disabling RFI flush with no_rfi_flush and nopti From: Michael Ellerman <mpe(a)ellerman.id.au> commit bc9c9304a45480797e13a8e1df96ffcf44fb62fe upstream. Because there may be some performance overhead of the RFI flush, add kernel command line options to disable it. We add a sensibly named 'no_rfi_flush' option, but we also hijack the x86 option 'nopti'. The RFI flush is not the same as KPTI, but if we see 'nopti' we can guess that the user is trying to avoid any overhead of Meltdown mitigations, and it means we don't have to educate every one about a different command line option. Signed-off-by: Michael Ellerman <mpe(a)ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/powerpc/kernel/setup_64.c | 24 +++++++++++++++++++++++- 1 file changed, 23 insertions(+), 1 deletion(-) --- a/arch/powerpc/kernel/setup_64.c +++ b/arch/powerpc/kernel/setup_64.c @@ -788,8 +788,29 @@ early_initcall(disable_hardlockup_detect #ifdef CONFIG_PPC_BOOK3S_64 static enum l1d_flush_type enabled_flush_types; static void *l1d_flush_fallback_area; +static bool no_rfi_flush; bool rfi_flush; +static int __init handle_no_rfi_flush(char *p) +{ + pr_info("rfi-flush: disabled on command line."); + no_rfi_flush = true; + return 0; +} +early_param("no_rfi_flush", handle_no_rfi_flush); + +/* + * The RFI flush is not KPTI, but because users will see doco that says to use + * nopti we hijack that option here to also disable the RFI flush. + */ +static int __init handle_no_pti(char *p) +{ + pr_info("rfi-flush: disabling due to 'nopti' on command line.\n"); + handle_no_rfi_flush(NULL); + return 0; +} +early_param("nopti", handle_no_pti); + static void do_nothing(void *unused) { /* @@ -860,6 +881,7 @@ void __init setup_rfi_flush(enum l1d_flu enabled_flush_types = types; - rfi_flush_enable(enable); + if (!no_rfi_flush) + rfi_flush_enable(enable); } #endif /* CONFIG_PPC_BOOK3S_64 */ Patches currently in stable-queue which might be from mpe(a)ellerman.id.au are queue-4.14/powerpc-64s-simple-rfi-macro-conversions.patch queue-4.14/powerpc-64-add-macros-for-annotating-the-destination-of-rfid-hrfid.patch queue-4.14/powerpc-pseries-add-h_get_cpu_characteristics-flags-wrapper.patch queue-4.14/powerpc-powernv-check-device-tree-for-rfi-flush-settings.patch queue-4.14/powerpc-64s-convert-slb_miss_common-to-use-rfi_to_user-kernel.patch queue-4.14/powerpc-64s-support-disabling-rfi-flush-with-no_rfi_flush-and-nopti.patch queue-4.14/powerpc-64-convert-the-syscall-exit-path-to-use-rfi_to_user-kernel.patch queue-4.14/powerpc-64s-add-support-for-rfi-flush-of-l1-d-cache.patch queue-4.14/powerpc-pseries-query-hypervisor-for-rfi-flush-settings.patch queue-4.14/powerpc-64-convert-fast_exception_return-to-use-rfi_to_user-kernel.patch

7 years, 5 months

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[Linux-stable-mirror] Patch "powerpc/64s: Convert slb_miss_common to use RFI_TO_USER/KERNEL" has been added to the 4.14-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled powerpc/64s: Convert slb_miss_common to use RFI_TO_USER/KERNEL to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: powerpc-64s-convert-slb_miss_common-to-use-rfi_to_user-kernel.patch and it can be found in the queue-4.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From c7305645eb0c1621351cfc104038831ae87c0053 Mon Sep 17 00:00:00 2001 From: Nicholas Piggin <npiggin(a)gmail.com> Date: Wed, 10 Jan 2018 03:07:15 +1100 Subject: powerpc/64s: Convert slb_miss_common to use RFI_TO_USER/KERNEL From: Nicholas Piggin <npiggin(a)gmail.com> commit c7305645eb0c1621351cfc104038831ae87c0053 upstream. In the SLB miss handler we may be returning to user or kernel. We need to add a check early on and save the result in the cr4 register, and then we bifurcate the return path based on that. Signed-off-by: Nicholas Piggin <npiggin(a)gmail.com> Signed-off-by: Michael Ellerman <mpe(a)ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/powerpc/kernel/exceptions-64s.S | 29 ++++++++++++++++++++++++++++- 1 file changed, 28 insertions(+), 1 deletion(-) --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -596,6 +596,9 @@ EXC_COMMON_BEGIN(slb_miss_common) stw r9,PACA_EXSLB+EX_CCR(r13) /* save CR in exc. frame */ std r10,PACA_EXSLB+EX_LR(r13) /* save LR */ + andi. r9,r11,MSR_PR // Check for exception from userspace + cmpdi cr4,r9,MSR_PR // And save the result in CR4 for later + /* * Test MSR_RI before calling slb_allocate_realmode, because the * MSR in r11 gets clobbered. However we still want to allocate @@ -622,9 +625,32 @@ END_MMU_FTR_SECTION_IFCLR(MMU_FTR_TYPE_R /* All done -- return from exception. */ + bne cr4,1f /* returning to kernel */ + +.machine push +.machine "power4" + mtcrf 0x80,r9 + mtcrf 0x08,r9 /* MSR[PR] indication is in cr4 */ + mtcrf 0x04,r9 /* MSR[RI] indication is in cr5 */ + mtcrf 0x02,r9 /* I/D indication is in cr6 */ + mtcrf 0x01,r9 /* slb_allocate uses cr0 and cr7 */ +.machine pop + + RESTORE_CTR(r9, PACA_EXSLB) + RESTORE_PPR_PACA(PACA_EXSLB, r9) + mr r3,r12 + ld r9,PACA_EXSLB+EX_R9(r13) + ld r10,PACA_EXSLB+EX_R10(r13) + ld r11,PACA_EXSLB+EX_R11(r13) + ld r12,PACA_EXSLB+EX_R12(r13) + ld r13,PACA_EXSLB+EX_R13(r13) + RFI_TO_USER + b . /* prevent speculative execution */ +1: .machine push .machine "power4" mtcrf 0x80,r9 + mtcrf 0x08,r9 /* MSR[PR] indication is in cr4 */ mtcrf 0x04,r9 /* MSR[RI] indication is in cr5 */ mtcrf 0x02,r9 /* I/D indication is in cr6 */ mtcrf 0x01,r9 /* slb_allocate uses cr0 and cr7 */ @@ -638,9 +664,10 @@ END_MMU_FTR_SECTION_IFCLR(MMU_FTR_TYPE_R ld r11,PACA_EXSLB+EX_R11(r13) ld r12,PACA_EXSLB+EX_R12(r13) ld r13,PACA_EXSLB+EX_R13(r13) - rfid + RFI_TO_KERNEL b . /* prevent speculative execution */ + 2: std r3,PACA_EXSLB+EX_DAR(r13) mr r3,r12 mfspr r11,SPRN_SRR0 Patches currently in stable-queue which might be from npiggin(a)gmail.com are queue-4.14/powerpc-64s-simple-rfi-macro-conversions.patch queue-4.14/powerpc-64-add-macros-for-annotating-the-destination-of-rfid-hrfid.patch queue-4.14/powerpc-64s-convert-slb_miss_common-to-use-rfi_to_user-kernel.patch queue-4.14/powerpc-64-convert-the-syscall-exit-path-to-use-rfi_to_user-kernel.patch queue-4.14/powerpc-64s-add-support-for-rfi-flush-of-l1-d-cache.patch queue-4.14/powerpc-64-convert-fast_exception_return-to-use-rfi_to_user-kernel.patch

7 years, 5 months

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[Linux-stable-mirror] Patch "powerpc/64s: Add support for RFI flush of L1-D cache" has been added to the 4.14-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled powerpc/64s: Add support for RFI flush of L1-D cache to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: powerpc-64s-add-support-for-rfi-flush-of-l1-d-cache.patch and it can be found in the queue-4.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From aa8a5e0062ac940f7659394f4817c948dc8c0667 Mon Sep 17 00:00:00 2001 From: Michael Ellerman <mpe(a)ellerman.id.au> Date: Wed, 10 Jan 2018 03:07:15 +1100 Subject: powerpc/64s: Add support for RFI flush of L1-D cache From: Michael Ellerman <mpe(a)ellerman.id.au> commit aa8a5e0062ac940f7659394f4817c948dc8c0667 upstream. On some CPUs we can prevent the Meltdown vulnerability by flushing the L1-D cache on exit from kernel to user mode, and from hypervisor to guest. This is known to be the case on at least Power7, Power8 and Power9. At this time we do not know the status of the vulnerability on other CPUs such as the 970 (Apple G5), pasemi CPUs (AmigaOne X1000) or Freescale CPUs. As more information comes to light we can enable this, or other mechanisms on those CPUs. The vulnerability occurs when the load of an architecturally inaccessible memory region (eg. userspace load of kernel memory) is speculatively executed to the point where its result can influence the address of a subsequent speculatively executed load. In order for that to happen, the first load must hit in the L1, because before the load is sent to the L2 the permission check is performed. Therefore if no kernel addresses hit in the L1 the vulnerability can not occur. We can ensure that is the case by flushing the L1 whenever we return to userspace. Similarly for hypervisor vs guest. In order to flush the L1-D cache on exit, we add a section of nops at each (h)rfi location that returns to a lower privileged context, and patch that with some sequence. Newer firmwares are able to advertise to us that there is a special nop instruction that flushes the L1-D. If we do not see that advertised, we fall back to doing a displacement flush in software. For guest kernels we support migration between some CPU versions, and different CPUs may use different flush instructions. So that we are prepared to migrate to a machine with a different flush instruction activated, we may have to patch more than one flush instruction at boot if the hypervisor tells us to. In the end this patch is mostly the work of Nicholas Piggin and Michael Ellerman. However a cast of thousands contributed to analysis of the issue, earlier versions of the patch, back ports testing etc. Many thanks to all of them. Tested-by: Jon Masters <jcm(a)redhat.com> Signed-off-by: Nicholas Piggin <npiggin(a)gmail.com> Signed-off-by: Michael Ellerman <mpe(a)ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/powerpc/include/asm/exception-64s.h | 40 +++++++++++--- arch/powerpc/include/asm/feature-fixups.h | 13 ++++ arch/powerpc/include/asm/paca.h | 10 +++ arch/powerpc/include/asm/setup.h | 13 ++++ arch/powerpc/kernel/asm-offsets.c | 5 + arch/powerpc/kernel/exceptions-64s.S | 84 ++++++++++++++++++++++++++++++ arch/powerpc/kernel/setup_64.c | 79 ++++++++++++++++++++++++++++ arch/powerpc/kernel/vmlinux.lds.S | 9 +++ arch/powerpc/lib/feature-fixups.c | 41 ++++++++++++++ 9 files changed, 286 insertions(+), 8 deletions(-) --- a/arch/powerpc/include/asm/exception-64s.h +++ b/arch/powerpc/include/asm/exception-64s.h @@ -69,34 +69,58 @@ */ #define EX_R3 EX_DAR -/* Macros for annotating the expected destination of (h)rfid */ +/* + * Macros for annotating the expected destination of (h)rfid + * + * The nop instructions allow us to insert one or more instructions to flush the + * L1-D cache when returning to userspace or a guest. + */ +#define RFI_FLUSH_SLOT \ + RFI_FLUSH_FIXUP_SECTION; \ + nop; \ + nop; \ + nop #define RFI_TO_KERNEL \ rfid #define RFI_TO_USER \ - rfid + RFI_FLUSH_SLOT; \ + rfid; \ + b rfi_flush_fallback #define RFI_TO_USER_OR_KERNEL \ - rfid + RFI_FLUSH_SLOT; \ + rfid; \ + b rfi_flush_fallback #define RFI_TO_GUEST \ - rfid + RFI_FLUSH_SLOT; \ + rfid; \ + b rfi_flush_fallback #define HRFI_TO_KERNEL \ hrfid #define HRFI_TO_USER \ - hrfid + RFI_FLUSH_SLOT; \ + hrfid; \ + b hrfi_flush_fallback #define HRFI_TO_USER_OR_KERNEL \ - hrfid + RFI_FLUSH_SLOT; \ + hrfid; \ + b hrfi_flush_fallback #define HRFI_TO_GUEST \ - hrfid + RFI_FLUSH_SLOT; \ + hrfid; \ + b hrfi_flush_fallback #define HRFI_TO_UNKNOWN \ - hrfid + RFI_FLUSH_SLOT; \ + hrfid; \ + b hrfi_flush_fallback #ifdef CONFIG_RELOCATABLE #define __EXCEPTION_RELON_PROLOG_PSERIES_1(label, h) \ --- a/arch/powerpc/include/asm/feature-fixups.h +++ b/arch/powerpc/include/asm/feature-fixups.h @@ -187,7 +187,20 @@ label##3: \ FTR_ENTRY_OFFSET label##1b-label##3b; \ .popsection; +#define RFI_FLUSH_FIXUP_SECTION \ +951: \ + .pushsection __rfi_flush_fixup,"a"; \ + .align 2; \ +952: \ + FTR_ENTRY_OFFSET 951b-952b; \ + .popsection; + + #ifndef __ASSEMBLY__ +#include <linux/types.h> + +extern long __start___rfi_flush_fixup, __stop___rfi_flush_fixup; + void apply_feature_fixups(void); void setup_feature_keys(void); #endif --- a/arch/powerpc/include/asm/paca.h +++ b/arch/powerpc/include/asm/paca.h @@ -231,6 +231,16 @@ struct paca_struct { struct sibling_subcore_state *sibling_subcore_state; #endif #endif +#ifdef CONFIG_PPC_BOOK3S_64 + /* + * rfi fallback flush must be in its own cacheline to prevent + * other paca data leaking into the L1d + */ + u64 exrfi[EX_SIZE] __aligned(0x80); + void *rfi_flush_fallback_area; + u64 l1d_flush_congruence; + u64 l1d_flush_sets; +#endif }; extern void copy_mm_to_paca(struct mm_struct *mm); --- a/arch/powerpc/include/asm/setup.h +++ b/arch/powerpc/include/asm/setup.h @@ -39,6 +39,19 @@ static inline void pseries_big_endian_ex static inline void pseries_little_endian_exceptions(void) {} #endif /* CONFIG_PPC_PSERIES */ +void rfi_flush_enable(bool enable); + +/* These are bit flags */ +enum l1d_flush_type { + L1D_FLUSH_NONE = 0x1, + L1D_FLUSH_FALLBACK = 0x2, + L1D_FLUSH_ORI = 0x4, + L1D_FLUSH_MTTRIG = 0x8, +}; + +void __init setup_rfi_flush(enum l1d_flush_type, bool enable); +void do_rfi_flush_fixups(enum l1d_flush_type types); + #endif /* !__ASSEMBLY__ */ #endif /* _ASM_POWERPC_SETUP_H */ --- a/arch/powerpc/kernel/asm-offsets.c +++ b/arch/powerpc/kernel/asm-offsets.c @@ -237,6 +237,11 @@ int main(void) OFFSET(PACA_NMI_EMERG_SP, paca_struct, nmi_emergency_sp); OFFSET(PACA_IN_MCE, paca_struct, in_mce); OFFSET(PACA_IN_NMI, paca_struct, in_nmi); + OFFSET(PACA_RFI_FLUSH_FALLBACK_AREA, paca_struct, rfi_flush_fallback_area); + OFFSET(PACA_EXRFI, paca_struct, exrfi); + OFFSET(PACA_L1D_FLUSH_CONGRUENCE, paca_struct, l1d_flush_congruence); + OFFSET(PACA_L1D_FLUSH_SETS, paca_struct, l1d_flush_sets); + #endif OFFSET(PACAHWCPUID, paca_struct, hw_cpu_id); OFFSET(PACAKEXECSTATE, paca_struct, kexec_state); --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -1434,6 +1434,90 @@ masked_##_H##interrupt: \ b .; \ MASKED_DEC_HANDLER(_H) +TRAMP_REAL_BEGIN(rfi_flush_fallback) + SET_SCRATCH0(r13); + GET_PACA(r13); + std r9,PACA_EXRFI+EX_R9(r13) + std r10,PACA_EXRFI+EX_R10(r13) + std r11,PACA_EXRFI+EX_R11(r13) + std r12,PACA_EXRFI+EX_R12(r13) + std r8,PACA_EXRFI+EX_R13(r13) + mfctr r9 + ld r10,PACA_RFI_FLUSH_FALLBACK_AREA(r13) + ld r11,PACA_L1D_FLUSH_SETS(r13) + ld r12,PACA_L1D_FLUSH_CONGRUENCE(r13) + /* + * The load adresses are at staggered offsets within cachelines, + * which suits some pipelines better (on others it should not + * hurt). + */ + addi r12,r12,8 + mtctr r11 + DCBT_STOP_ALL_STREAM_IDS(r11) /* Stop prefetch streams */ + + /* order ld/st prior to dcbt stop all streams with flushing */ + sync +1: li r8,0 + .rept 8 /* 8-way set associative */ + ldx r11,r10,r8 + add r8,r8,r12 + xor r11,r11,r11 // Ensure r11 is 0 even if fallback area is not + add r8,r8,r11 // Add 0, this creates a dependency on the ldx + .endr + addi r10,r10,128 /* 128 byte cache line */ + bdnz 1b + + mtctr r9 + ld r9,PACA_EXRFI+EX_R9(r13) + ld r10,PACA_EXRFI+EX_R10(r13) + ld r11,PACA_EXRFI+EX_R11(r13) + ld r12,PACA_EXRFI+EX_R12(r13) + ld r8,PACA_EXRFI+EX_R13(r13) + GET_SCRATCH0(r13); + rfid + +TRAMP_REAL_BEGIN(hrfi_flush_fallback) + SET_SCRATCH0(r13); + GET_PACA(r13); + std r9,PACA_EXRFI+EX_R9(r13) + std r10,PACA_EXRFI+EX_R10(r13) + std r11,PACA_EXRFI+EX_R11(r13) + std r12,PACA_EXRFI+EX_R12(r13) + std r8,PACA_EXRFI+EX_R13(r13) + mfctr r9 + ld r10,PACA_RFI_FLUSH_FALLBACK_AREA(r13) + ld r11,PACA_L1D_FLUSH_SETS(r13) + ld r12,PACA_L1D_FLUSH_CONGRUENCE(r13) + /* + * The load adresses are at staggered offsets within cachelines, + * which suits some pipelines better (on others it should not + * hurt). + */ + addi r12,r12,8 + mtctr r11 + DCBT_STOP_ALL_STREAM_IDS(r11) /* Stop prefetch streams */ + + /* order ld/st prior to dcbt stop all streams with flushing */ + sync +1: li r8,0 + .rept 8 /* 8-way set associative */ + ldx r11,r10,r8 + add r8,r8,r12 + xor r11,r11,r11 // Ensure r11 is 0 even if fallback area is not + add r8,r8,r11 // Add 0, this creates a dependency on the ldx + .endr + addi r10,r10,128 /* 128 byte cache line */ + bdnz 1b + + mtctr r9 + ld r9,PACA_EXRFI+EX_R9(r13) + ld r10,PACA_EXRFI+EX_R10(r13) + ld r11,PACA_EXRFI+EX_R11(r13) + ld r12,PACA_EXRFI+EX_R12(r13) + ld r8,PACA_EXRFI+EX_R13(r13) + GET_SCRATCH0(r13); + hrfid + /* * Real mode exceptions actually use this too, but alternate * instruction code patches (which end up in the common .text area) --- a/arch/powerpc/kernel/setup_64.c +++ b/arch/powerpc/kernel/setup_64.c @@ -784,3 +784,82 @@ static int __init disable_hardlockup_det return 0; } early_initcall(disable_hardlockup_detector); + +#ifdef CONFIG_PPC_BOOK3S_64 +static enum l1d_flush_type enabled_flush_types; +static void *l1d_flush_fallback_area; +bool rfi_flush; + +static void do_nothing(void *unused) +{ + /* + * We don't need to do the flush explicitly, just enter+exit kernel is + * sufficient, the RFI exit handlers will do the right thing. + */ +} + +void rfi_flush_enable(bool enable) +{ + if (rfi_flush == enable) + return; + + if (enable) { + do_rfi_flush_fixups(enabled_flush_types); + on_each_cpu(do_nothing, NULL, 1); + } else + do_rfi_flush_fixups(L1D_FLUSH_NONE); + + rfi_flush = enable; +} + +static void init_fallback_flush(void) +{ + u64 l1d_size, limit; + int cpu; + + l1d_size = ppc64_caches.l1d.size; + limit = min(safe_stack_limit(), ppc64_rma_size); + + /* + * Align to L1d size, and size it at 2x L1d size, to catch possible + * hardware prefetch runoff. We don't have a recipe for load patterns to + * reliably avoid the prefetcher. + */ + l1d_flush_fallback_area = __va(memblock_alloc_base(l1d_size * 2, l1d_size, limit)); + memset(l1d_flush_fallback_area, 0, l1d_size * 2); + + for_each_possible_cpu(cpu) { + /* + * The fallback flush is currently coded for 8-way + * associativity. Different associativity is possible, but it + * will be treated as 8-way and may not evict the lines as + * effectively. + * + * 128 byte lines are mandatory. + */ + u64 c = l1d_size / 8; + + paca[cpu].rfi_flush_fallback_area = l1d_flush_fallback_area; + paca[cpu].l1d_flush_congruence = c; + paca[cpu].l1d_flush_sets = c / 128; + } +} + +void __init setup_rfi_flush(enum l1d_flush_type types, bool enable) +{ + if (types & L1D_FLUSH_FALLBACK) { + pr_info("rfi-flush: Using fallback displacement flush\n"); + init_fallback_flush(); + } + + if (types & L1D_FLUSH_ORI) + pr_info("rfi-flush: Using ori type flush\n"); + + if (types & L1D_FLUSH_MTTRIG) + pr_info("rfi-flush: Using mttrig type flush\n"); + + enabled_flush_types = types; + + rfi_flush_enable(enable); +} +#endif /* CONFIG_PPC_BOOK3S_64 */ --- a/arch/powerpc/kernel/vmlinux.lds.S +++ b/arch/powerpc/kernel/vmlinux.lds.S @@ -132,6 +132,15 @@ SECTIONS /* Read-only data */ RO_DATA(PAGE_SIZE) +#ifdef CONFIG_PPC64 + . = ALIGN(8); + __rfi_flush_fixup : AT(ADDR(__rfi_flush_fixup) - LOAD_OFFSET) { + __start___rfi_flush_fixup = .; + *(__rfi_flush_fixup) + __stop___rfi_flush_fixup = .; + } +#endif + EXCEPTION_TABLE(0) NOTES :kernel :notes --- a/arch/powerpc/lib/feature-fixups.c +++ b/arch/powerpc/lib/feature-fixups.c @@ -116,6 +116,47 @@ void do_feature_fixups(unsigned long val } } +#ifdef CONFIG_PPC_BOOK3S_64 +void do_rfi_flush_fixups(enum l1d_flush_type types) +{ + unsigned int instrs[3], *dest; + long *start, *end; + int i; + + start = PTRRELOC(&__start___rfi_flush_fixup), + end = PTRRELOC(&__stop___rfi_flush_fixup); + + instrs[0] = 0x60000000; /* nop */ + instrs[1] = 0x60000000; /* nop */ + instrs[2] = 0x60000000; /* nop */ + + if (types & L1D_FLUSH_FALLBACK) + /* b .+16 to fallback flush */ + instrs[0] = 0x48000010; + + i = 0; + if (types & L1D_FLUSH_ORI) { + instrs[i++] = 0x63ff0000; /* ori 31,31,0 speculation barrier */ + instrs[i++] = 0x63de0000; /* ori 30,30,0 L1d flush*/ + } + + if (types & L1D_FLUSH_MTTRIG) + instrs[i++] = 0x7c12dba6; /* mtspr TRIG2,r0 (SPR #882) */ + + for (i = 0; start < end; start++, i++) { + dest = (void *)start + *start; + + pr_devel("patching dest %lx\n", (unsigned long)dest); + + patch_instruction(dest, instrs[0]); + patch_instruction(dest + 1, instrs[1]); + patch_instruction(dest + 2, instrs[2]); + } + + printk(KERN_DEBUG "rfi-flush: patched %d locations\n", i); +} +#endif /* CONFIG_PPC_BOOK3S_64 */ + void do_lwsync_fixups(unsigned long value, void *fixup_start, void *fixup_end) { long *start, *end; Patches currently in stable-queue which might be from mpe(a)ellerman.id.au are queue-4.14/powerpc-64s-simple-rfi-macro-conversions.patch queue-4.14/powerpc-64-add-macros-for-annotating-the-destination-of-rfid-hrfid.patch queue-4.14/powerpc-pseries-add-h_get_cpu_characteristics-flags-wrapper.patch queue-4.14/powerpc-powernv-check-device-tree-for-rfi-flush-settings.patch queue-4.14/powerpc-64s-convert-slb_miss_common-to-use-rfi_to_user-kernel.patch queue-4.14/powerpc-64s-support-disabling-rfi-flush-with-no_rfi_flush-and-nopti.patch queue-4.14/powerpc-64-convert-the-syscall-exit-path-to-use-rfi_to_user-kernel.patch queue-4.14/powerpc-64s-add-support-for-rfi-flush-of-l1-d-cache.patch queue-4.14/powerpc-pseries-query-hypervisor-for-rfi-flush-settings.patch queue-4.14/powerpc-64-convert-fast_exception_return-to-use-rfi_to_user-kernel.patch

7 years, 5 months

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[Linux-stable-mirror] Patch "powerpc/64: Convert the syscall exit path to use RFI_TO_USER/KERNEL" has been added to the 4.14-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled powerpc/64: Convert the syscall exit path to use RFI_TO_USER/KERNEL to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: powerpc-64-convert-the-syscall-exit-path-to-use-rfi_to_user-kernel.patch and it can be found in the queue-4.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From b8e90cb7bc04a509e821e82ab6ed7a8ef11ba333 Mon Sep 17 00:00:00 2001 From: Nicholas Piggin <npiggin(a)gmail.com> Date: Wed, 10 Jan 2018 03:07:15 +1100 Subject: powerpc/64: Convert the syscall exit path to use RFI_TO_USER/KERNEL From: Nicholas Piggin <npiggin(a)gmail.com> commit b8e90cb7bc04a509e821e82ab6ed7a8ef11ba333 upstream. In the syscall exit path we may be returning to user or kernel context. We already have a test for that, because we conditionally restore r13. So use that existing test and branch, and bifurcate the return based on that. Signed-off-by: Nicholas Piggin <npiggin(a)gmail.com> Signed-off-by: Michael Ellerman <mpe(a)ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/powerpc/kernel/entry_64.S | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) --- a/arch/powerpc/kernel/entry_64.S +++ b/arch/powerpc/kernel/entry_64.S @@ -267,13 +267,23 @@ BEGIN_FTR_SECTION END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR) ld r13,GPR13(r1) /* only restore r13 if returning to usermode */ + ld r2,GPR2(r1) + ld r1,GPR1(r1) + mtlr r4 + mtcr r5 + mtspr SPRN_SRR0,r7 + mtspr SPRN_SRR1,r8 + RFI_TO_USER + b . /* prevent speculative execution */ + + /* exit to kernel */ 1: ld r2,GPR2(r1) ld r1,GPR1(r1) mtlr r4 mtcr r5 mtspr SPRN_SRR0,r7 mtspr SPRN_SRR1,r8 - RFI + RFI_TO_KERNEL b . /* prevent speculative execution */ .Lsyscall_error: Patches currently in stable-queue which might be from npiggin(a)gmail.com are queue-4.14/powerpc-64s-simple-rfi-macro-conversions.patch queue-4.14/powerpc-64-add-macros-for-annotating-the-destination-of-rfid-hrfid.patch queue-4.14/powerpc-64s-convert-slb_miss_common-to-use-rfi_to_user-kernel.patch queue-4.14/powerpc-64-convert-the-syscall-exit-path-to-use-rfi_to_user-kernel.patch queue-4.14/powerpc-64s-add-support-for-rfi-flush-of-l1-d-cache.patch queue-4.14/powerpc-64-convert-fast_exception_return-to-use-rfi_to_user-kernel.patch

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