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[Linux-stable-mirror] Patch "powerpc/64s: Wire up cpu_show_meltdown()" has been added to the 4.9-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled powerpc/64s: Wire up cpu_show_meltdown() to the 4.9-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-wire-up-cpu_show_meltdown.patch and it can be found in the queue-4.9 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 fd6e440f20b1a4304553775fc55938848ff617c9 Mon Sep 17 00:00:00 2001 From: Michael Ellerman <mpe(a)ellerman.id.au> Date: Tue, 16 Jan 2018 21:20:05 +1100 Subject: powerpc/64s: Wire up cpu_show_meltdown() From: Michael Ellerman <mpe(a)ellerman.id.au> commit fd6e440f20b1a4304553775fc55938848ff617c9 upstream. The recent commit 87590ce6e373 ("sysfs/cpu: Add vulnerability folder") added a generic folder and set of files for reporting information on CPU vulnerabilities. One of those was for meltdown: /sys/devices/system/cpu/vulnerabilities/meltdown This commit wires up that file for 64-bit Book3S powerpc. For now we default to "Vulnerable" unless the RFI flush is enabled. That may not actually be true on all hardware, further patches will refine the reporting based on the CPU/platform etc. But for now we default to being pessimists. Signed-off-by: Michael Ellerman <mpe(a)ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/powerpc/Kconfig | 1 + arch/powerpc/kernel/setup_64.c | 8 ++++++++ 2 files changed, 9 insertions(+) --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -128,6 +128,7 @@ config PPC select ARCH_HAS_GCOV_PROFILE_ALL select GENERIC_SMP_IDLE_THREAD select GENERIC_CMOS_UPDATE + select GENERIC_CPU_VULNERABILITIES if PPC_BOOK3S_64 select GENERIC_TIME_VSYSCALL_OLD select GENERIC_CLOCKEVENTS select GENERIC_CLOCKEVENTS_BROADCAST if SMP --- a/arch/powerpc/kernel/setup_64.c +++ b/arch/powerpc/kernel/setup_64.c @@ -778,5 +778,13 @@ void __init setup_rfi_flush(enum l1d_flu if (!no_rfi_flush) rfi_flush_enable(enable); } + +ssize_t cpu_show_meltdown(struct device *dev, struct device_attribute *attr, char *buf) +{ + if (rfi_flush) + return sprintf(buf, "Mitigation: RFI Flush\n"); + + return sprintf(buf, "Vulnerable\n"); +} #endif /* CONFIG_PPC_BOOK3S_64 */ #endif Patches currently in stable-queue which might be from mpe(a)ellerman.id.au are queue-4.9/powerpc-64-add-macros-for-annotating-the-destination-of-rfid-hrfid.patch queue-4.9/powerpc-pseries-add-h_get_cpu_characteristics-flags-wrapper.patch queue-4.9/powerpc-64s-allow-control-of-rfi-flush-via-debugfs.patch queue-4.9/powerpc-powernv-check-device-tree-for-rfi-flush-settings.patch queue-4.9/powerpc-64s-convert-slb_miss_common-to-use-rfi_to_user-kernel.patch queue-4.9/powerpc-64s-support-disabling-rfi-flush-with-no_rfi_flush-and-nopti.patch queue-4.9/powerpc-64-convert-the-syscall-exit-path-to-use-rfi_to_user-kernel.patch queue-4.9/powerpc-64s-add-support-for-rfi-flush-of-l1-d-cache.patch queue-4.9/powerpc-pseries-query-hypervisor-for-rfi-flush-settings.patch queue-4.9/powerpc-64-convert-fast_exception_return-to-use-rfi_to_user-kernel.patch queue-4.9/powerpc-64s-wire-up-cpu_show_meltdown.patch

7 years, 3 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 4.9-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 4.9-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-4.9 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 @@ -682,8 +682,29 @@ 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) { /* @@ -754,7 +775,8 @@ 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 */ #endif Patches currently in stable-queue which might be from mpe(a)ellerman.id.au are queue-4.9/powerpc-64-add-macros-for-annotating-the-destination-of-rfid-hrfid.patch queue-4.9/powerpc-pseries-add-h_get_cpu_characteristics-flags-wrapper.patch queue-4.9/powerpc-64s-allow-control-of-rfi-flush-via-debugfs.patch queue-4.9/powerpc-powernv-check-device-tree-for-rfi-flush-settings.patch queue-4.9/powerpc-64s-convert-slb_miss_common-to-use-rfi_to_user-kernel.patch queue-4.9/powerpc-64s-support-disabling-rfi-flush-with-no_rfi_flush-and-nopti.patch queue-4.9/powerpc-64-convert-the-syscall-exit-path-to-use-rfi_to_user-kernel.patch queue-4.9/powerpc-64s-add-support-for-rfi-flush-of-l1-d-cache.patch queue-4.9/powerpc-pseries-query-hypervisor-for-rfi-flush-settings.patch queue-4.9/powerpc-64-convert-fast_exception_return-to-use-rfi_to_user-kernel.patch queue-4.9/powerpc-64s-wire-up-cpu_show_meltdown.patch

7 years, 3 months

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[Linux-stable-mirror] Patch "powerpc/64s: Allow control of RFI flush via debugfs" has been added to the 4.9-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled powerpc/64s: Allow control of RFI flush via debugfs to the 4.9-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-allow-control-of-rfi-flush-via-debugfs.patch and it can be found in the queue-4.9 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 236003e6b5443c45c18e613d2b0d776a9f87540e Mon Sep 17 00:00:00 2001 From: Michael Ellerman <mpe(a)ellerman.id.au> Date: Tue, 16 Jan 2018 22:17:18 +1100 Subject: powerpc/64s: Allow control of RFI flush via debugfs From: Michael Ellerman <mpe(a)ellerman.id.au> commit 236003e6b5443c45c18e613d2b0d776a9f87540e upstream. Expose the state of the RFI flush (enabled/disabled) via debugfs, and allow it to be enabled/disabled at runtime. eg: $ cat /sys/kernel/debug/powerpc/rfi_flush 1 $ echo 0 > /sys/kernel/debug/powerpc/rfi_flush $ cat /sys/kernel/debug/powerpc/rfi_flush 0 Signed-off-by: Michael Ellerman <mpe(a)ellerman.id.au> Reviewed-by: Nicholas Piggin <npiggin(a)gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/powerpc/kernel/setup_64.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) --- a/arch/powerpc/kernel/setup_64.c +++ b/arch/powerpc/kernel/setup_64.c @@ -38,6 +38,7 @@ #include <linux/memory.h> #include <linux/nmi.h> +#include <asm/debugfs.h> #include <asm/io.h> #include <asm/kdump.h> #include <asm/prom.h> @@ -779,6 +780,35 @@ void __init setup_rfi_flush(enum l1d_flu rfi_flush_enable(enable); } +#ifdef CONFIG_DEBUG_FS +static int rfi_flush_set(void *data, u64 val) +{ + if (val == 1) + rfi_flush_enable(true); + else if (val == 0) + rfi_flush_enable(false); + else + return -EINVAL; + + return 0; +} + +static int rfi_flush_get(void *data, u64 *val) +{ + *val = rfi_flush ? 1 : 0; + return 0; +} + +DEFINE_SIMPLE_ATTRIBUTE(fops_rfi_flush, rfi_flush_get, rfi_flush_set, "%llu\n"); + +static __init int rfi_flush_debugfs_init(void) +{ + debugfs_create_file("rfi_flush", 0600, powerpc_debugfs_root, NULL, &fops_rfi_flush); + return 0; +} +device_initcall(rfi_flush_debugfs_init); +#endif + ssize_t cpu_show_meltdown(struct device *dev, struct device_attribute *attr, char *buf) { if (rfi_flush) Patches currently in stable-queue which might be from mpe(a)ellerman.id.au are queue-4.9/powerpc-64-add-macros-for-annotating-the-destination-of-rfid-hrfid.patch queue-4.9/powerpc-pseries-add-h_get_cpu_characteristics-flags-wrapper.patch queue-4.9/powerpc-64s-allow-control-of-rfi-flush-via-debugfs.patch queue-4.9/powerpc-powernv-check-device-tree-for-rfi-flush-settings.patch queue-4.9/powerpc-64s-convert-slb_miss_common-to-use-rfi_to_user-kernel.patch queue-4.9/powerpc-64s-support-disabling-rfi-flush-with-no_rfi_flush-and-nopti.patch queue-4.9/powerpc-64-convert-the-syscall-exit-path-to-use-rfi_to_user-kernel.patch queue-4.9/powerpc-64s-add-support-for-rfi-flush-of-l1-d-cache.patch queue-4.9/powerpc-pseries-query-hypervisor-for-rfi-flush-settings.patch queue-4.9/powerpc-64-convert-fast_exception_return-to-use-rfi_to_user-kernel.patch queue-4.9/powerpc-64s-wire-up-cpu_show_meltdown.patch

7 years, 3 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 4.9-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 4.9-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-4.9 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: Nicholas Piggin <npiggin(a)gmail.com> [mpe: Backport to 4.4 based on patch from Balbir] 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 | 22 ++++++++++++++++++++-- 1 file changed, 20 insertions(+), 2 deletions(-) --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -655,6 +655,8 @@ END_MMU_FTR_SECTION_IFCLR(MMU_FTR_TYPE_R andi. r10,r12,MSR_RI /* check for unrecoverable exception */ beq- 2f + andi. r10,r12,MSR_PR /* check for user mode (PR != 0) */ + bne 1f /* All done -- return from exception. */ @@ -671,7 +673,23 @@ 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 */ + +1: +.machine push +.machine "power4" + mtcrf 0x80,r9 + mtcrf 0x01,r9 /* slb_allocate uses cr0 and cr7 */ +.machine pop + + RESTORE_PPR_PACA(PACA_EXSLB, r9) + 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 */ 2: mfspr r11,SPRN_SRR0 @@ -679,7 +697,7 @@ 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: mfspr r11,SPRN_SRR0 Patches currently in stable-queue which might be from npiggin(a)gmail.com are queue-4.9/powerpc-64-add-macros-for-annotating-the-destination-of-rfid-hrfid.patch queue-4.9/powerpc-64s-allow-control-of-rfi-flush-via-debugfs.patch queue-4.9/powerpc-64s-convert-slb_miss_common-to-use-rfi_to_user-kernel.patch queue-4.9/powerpc-64-convert-the-syscall-exit-path-to-use-rfi_to_user-kernel.patch queue-4.9/powerpc-64s-add-support-for-rfi-flush-of-l1-d-cache.patch queue-4.9/powerpc-64-convert-fast_exception_return-to-use-rfi_to_user-kernel.patch

7 years, 3 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 4.9-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 4.9-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-4.9 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> [Balbir - back ported to stable with changes] Signed-off-by: Balbir Singh <bsingharora(a)gmail.com> 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 | 15 +++++ arch/powerpc/include/asm/paca.h | 10 +++ arch/powerpc/include/asm/setup.h | 13 ++++ arch/powerpc/kernel/asm-offsets.c | 4 + arch/powerpc/kernel/exceptions-64s.S | 86 ++++++++++++++++++++++++++++++ arch/powerpc/kernel/setup_64.c | 79 +++++++++++++++++++++++++++ arch/powerpc/kernel/vmlinux.lds.S | 9 +++ arch/powerpc/lib/feature-fixups.c | 42 ++++++++++++++ 9 files changed, 290 insertions(+), 8 deletions(-) --- a/arch/powerpc/include/asm/exception-64s.h +++ b/arch/powerpc/include/asm/exception-64s.h @@ -51,34 +51,58 @@ #define EX_PPR 88 /* SMT thread status register (priority) */ #define EX_CTR 96 -/* 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 @@ -189,4 +189,19 @@ void apply_feature_fixups(void); void setup_feature_keys(void); #endif +#define RFI_FLUSH_FIXUP_SECTION \ +951: \ + .pushsection __rfi_flush_fixup,"a"; \ + .align 2; \ +952: \ + FTR_ENTRY_OFFSET 951b-952b; \ + .popsection; + + +#ifndef __ASSEMBLY__ + +extern long __start___rfi_flush_fixup, __stop___rfi_flush_fixup; + +#endif + #endif /* __ASM_POWERPC_FEATURE_FIXUPS_H */ --- a/arch/powerpc/include/asm/paca.h +++ b/arch/powerpc/include/asm/paca.h @@ -205,6 +205,16 @@ 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[13] __aligned(0x80); + void *rfi_flush_fallback_area; + u64 l1d_flush_congruence; + u64 l1d_flush_sets; +#endif }; #ifdef CONFIG_PPC_BOOK3S --- a/arch/powerpc/include/asm/setup.h +++ b/arch/powerpc/include/asm/setup.h @@ -38,6 +38,19 @@ 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 @@ -240,6 +240,10 @@ int main(void) #ifdef CONFIG_PPC_BOOK3S_64 DEFINE(PACAMCEMERGSP, offsetof(struct paca_struct, mc_emergency_sp)); DEFINE(PACA_IN_MCE, offsetof(struct paca_struct, in_mce)); + DEFINE(PACA_RFI_FLUSH_FALLBACK_AREA, offsetof(struct paca_struct, rfi_flush_fallback_area)); + DEFINE(PACA_EXRFI, offsetof(struct paca_struct, exrfi)); + DEFINE(PACA_L1D_FLUSH_CONGRUENCE, offsetof(struct paca_struct, l1d_flush_congruence)); + DEFINE(PACA_L1D_FLUSH_SETS, offsetof(struct paca_struct, l1d_flush_sets)); #endif DEFINE(PACAHWCPUID, offsetof(struct paca_struct, hw_cpu_id)); DEFINE(PACAKEXECSTATE, offsetof(struct paca_struct, kexec_state)); --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -1594,6 +1594,92 @@ END_FTR_SECTION_IFSET(CPU_FTR_CFAR) bl kernel_bad_stack b 1b + .globl rfi_flush_fallback +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 + + .globl hrfi_flush_fallback +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 + /* * Called from arch_local_irq_enable when an interrupt needs * to be resent. r3 contains 0x500, 0x900, 0xa00 or 0xe80 to indicate --- a/arch/powerpc/kernel/setup_64.c +++ b/arch/powerpc/kernel/setup_64.c @@ -678,4 +678,83 @@ 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.dsize; + 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 */ #endif --- a/arch/powerpc/kernel/vmlinux.lds.S +++ b/arch/powerpc/kernel/vmlinux.lds.S @@ -132,6 +132,15 @@ SECTIONS /* Read-only data */ RODATA +#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 @@ -23,6 +23,7 @@ #include <asm/sections.h> #include <asm/setup.h> #include <asm/firmware.h> +#include <asm/setup.h> struct fixup_entry { unsigned long mask; @@ -115,6 +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-4.9/powerpc-64-add-macros-for-annotating-the-destination-of-rfid-hrfid.patch queue-4.9/powerpc-pseries-add-h_get_cpu_characteristics-flags-wrapper.patch queue-4.9/powerpc-64s-allow-control-of-rfi-flush-via-debugfs.patch queue-4.9/powerpc-powernv-check-device-tree-for-rfi-flush-settings.patch queue-4.9/powerpc-64s-convert-slb_miss_common-to-use-rfi_to_user-kernel.patch queue-4.9/powerpc-64s-support-disabling-rfi-flush-with-no_rfi_flush-and-nopti.patch queue-4.9/powerpc-64-convert-the-syscall-exit-path-to-use-rfi_to_user-kernel.patch queue-4.9/powerpc-64s-add-support-for-rfi-flush-of-l1-d-cache.patch queue-4.9/powerpc-pseries-query-hypervisor-for-rfi-flush-settings.patch queue-4.9/powerpc-64-convert-fast_exception_return-to-use-rfi_to_user-kernel.patch queue-4.9/powerpc-64s-wire-up-cpu_show_meltdown.patch

7 years, 3 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 4.9-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 4.9-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-4.9 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 @@ -251,13 +251,23 @@ 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 */ syscall_error: Patches currently in stable-queue which might be from npiggin(a)gmail.com are queue-4.9/powerpc-64-add-macros-for-annotating-the-destination-of-rfid-hrfid.patch queue-4.9/powerpc-64s-allow-control-of-rfi-flush-via-debugfs.patch queue-4.9/powerpc-64s-convert-slb_miss_common-to-use-rfi_to_user-kernel.patch queue-4.9/powerpc-64-convert-the-syscall-exit-path-to-use-rfi_to_user-kernel.patch queue-4.9/powerpc-64s-add-support-for-rfi-flush-of-l1-d-cache.patch queue-4.9/powerpc-64-convert-fast_exception_return-to-use-rfi_to_user-kernel.patch

7 years, 3 months

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[Linux-stable-mirror] Patch "powerpc/64: Convert fast_exception_return to use RFI_TO_USER/KERNEL" has been added to the 4.9-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 fast_exception_return to use RFI_TO_USER/KERNEL to the 4.9-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-fast_exception_return-to-use-rfi_to_user-kernel.patch and it can be found in the queue-4.9 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 a08f828cf47e6c605af21d2cdec68f84e799c318 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 fast_exception_return to use RFI_TO_USER/KERNEL From: Nicholas Piggin <npiggin(a)gmail.com> commit a08f828cf47e6c605af21d2cdec68f84e799c318 upstream. Similar to the syscall return path, in fast_exception_return 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 | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) --- a/arch/powerpc/kernel/entry_64.S +++ b/arch/powerpc/kernel/entry_64.S @@ -859,7 +859,7 @@ BEGIN_FTR_SECTION END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR) ACCOUNT_CPU_USER_EXIT(r13, r2, r4) REST_GPR(13, r1) -1: + mtspr SPRN_SRR1,r3 ld r2,_CCR(r1) @@ -872,8 +872,22 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR) ld r3,GPR3(r1) ld r4,GPR4(r1) ld r1,GPR1(r1) + RFI_TO_USER + b . /* prevent speculative execution */ - rfid +1: mtspr SPRN_SRR1,r3 + + ld r2,_CCR(r1) + mtcrf 0xFF,r2 + ld r2,_NIP(r1) + mtspr SPRN_SRR0,r2 + + ld r0,GPR0(r1) + ld r2,GPR2(r1) + ld r3,GPR3(r1) + ld r4,GPR4(r1) + ld r1,GPR1(r1) + RFI_TO_KERNEL b . /* prevent speculative execution */ #endif /* CONFIG_PPC_BOOK3E */ Patches currently in stable-queue which might be from npiggin(a)gmail.com are queue-4.9/powerpc-64-add-macros-for-annotating-the-destination-of-rfid-hrfid.patch queue-4.9/powerpc-64s-allow-control-of-rfi-flush-via-debugfs.patch queue-4.9/powerpc-64s-convert-slb_miss_common-to-use-rfi_to_user-kernel.patch queue-4.9/powerpc-64-convert-the-syscall-exit-path-to-use-rfi_to_user-kernel.patch queue-4.9/powerpc-64s-add-support-for-rfi-flush-of-l1-d-cache.patch queue-4.9/powerpc-64-convert-fast_exception_return-to-use-rfi_to_user-kernel.patch

7 years, 3 months

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[Linux-stable-mirror] Patch "powerpc/64: Add macros for annotating the destination of rfid/hrfid" has been added to the 4.9-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled powerpc/64: Add macros for annotating the destination of rfid/hrfid to the 4.9-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-add-macros-for-annotating-the-destination-of-rfid-hrfid.patch and it can be found in the queue-4.9 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 50e51c13b3822d14ff6df4279423e4b7b2269bc3 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: Add macros for annotating the destination of rfid/hrfid From: Nicholas Piggin <npiggin(a)gmail.com> commit 50e51c13b3822d14ff6df4279423e4b7b2269bc3 upstream. The rfid/hrfid ((Hypervisor) Return From Interrupt) instruction is used for switching from the kernel to userspace, and from the hypervisor to the guest kernel. However it can and is also used for other transitions, eg. from real mode kernel code to virtual mode kernel code, and it's not always clear from the code what the destination context is. To make it clearer when reading the code, add macros which encode the expected destination context. 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-64e.h | 6 ++++++ arch/powerpc/include/asm/exception-64s.h | 29 +++++++++++++++++++++++++++++ 2 files changed, 35 insertions(+) --- a/arch/powerpc/include/asm/exception-64e.h +++ b/arch/powerpc/include/asm/exception-64e.h @@ -209,5 +209,11 @@ exc_##label##_book3e: ori r3,r3,vector_offset@l; \ mtspr SPRN_IVOR##vector_number,r3; +#define RFI_TO_KERNEL \ + rfi + +#define RFI_TO_USER \ + rfi + #endif /* _ASM_POWERPC_EXCEPTION_64E_H */ --- a/arch/powerpc/include/asm/exception-64s.h +++ b/arch/powerpc/include/asm/exception-64s.h @@ -51,6 +51,35 @@ #define EX_PPR 88 /* SMT thread status register (priority) */ #define EX_CTR 96 +/* Macros for annotating the expected destination of (h)rfid */ + +#define RFI_TO_KERNEL \ + rfid + +#define RFI_TO_USER \ + rfid + +#define RFI_TO_USER_OR_KERNEL \ + rfid + +#define RFI_TO_GUEST \ + rfid + +#define HRFI_TO_KERNEL \ + hrfid + +#define HRFI_TO_USER \ + hrfid + +#define HRFI_TO_USER_OR_KERNEL \ + hrfid + +#define HRFI_TO_GUEST \ + hrfid + +#define HRFI_TO_UNKNOWN \ + hrfid + #ifdef CONFIG_RELOCATABLE #define __EXCEPTION_RELON_PROLOG_PSERIES_1(label, h) \ mfspr r11,SPRN_##h##SRR0; /* save SRR0 */ \ Patches currently in stable-queue which might be from npiggin(a)gmail.com are queue-4.9/powerpc-64-add-macros-for-annotating-the-destination-of-rfid-hrfid.patch queue-4.9/powerpc-64s-allow-control-of-rfi-flush-via-debugfs.patch queue-4.9/powerpc-64s-convert-slb_miss_common-to-use-rfi_to_user-kernel.patch queue-4.9/powerpc-64-convert-the-syscall-exit-path-to-use-rfi_to_user-kernel.patch queue-4.9/powerpc-64s-add-support-for-rfi-flush-of-l1-d-cache.patch queue-4.9/powerpc-64-convert-fast_exception_return-to-use-rfi_to_user-kernel.patch

7 years, 3 months

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[Linux-stable-mirror] Patch "powerpc: Simplify module TOC handling" has been added to the 4.4-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled powerpc: Simplify module TOC handling to the 4.4-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-simplify-module-toc-handling.patch and it can be found in the queue-4.4 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 c153693d7eb9eeb28478aa2deaaf0b4e7b5ff5e9 Mon Sep 17 00:00:00 2001 From: Alan Modra <amodra(a)gmail.com> Date: Fri, 15 Jan 2016 20:52:22 +1100 Subject: powerpc: Simplify module TOC handling From: Alan Modra <amodra(a)gmail.com> commit c153693d7eb9eeb28478aa2deaaf0b4e7b5ff5e9 upstream. PowerPC64 uses the symbol .TOC. much as other targets use _GLOBAL_OFFSET_TABLE_. It identifies the value of the GOT pointer (or in powerpc parlance, the TOC pointer). Global offset tables are generally local to an executable or shared library, or in the kernel, module. Thus it does not make sense for a module to resolve a relocation against .TOC. to the kernel's .TOC. value. A module has its own .TOC., and indeed the powerpc64 module relocation processing ignores the kernel value of .TOC. and instead calculates a module-local value. This patch removes code involved in exporting the kernel .TOC., tweaks modpost to ignore an undefined .TOC., and the module loader to twiddle the section symbol so that .TOC. isn't seen as undefined. Note that if the kernel was compiled with -msingle-pic-base then ELFv2 would not have function global entry code setting up r2. In that case the module call stubs would need to be modified to set up r2 using the kernel .TOC. value, requiring some of this code to be reinstated. mpe: Furthermore a change in binutils master (not yet released) causes the current way we handle the TOC to no longer work when building with MODVERSIONS=y and RELOCATABLE=n. The symptom is that modules can not be loaded due to there being no version found for TOC. Signed-off-by: Alan Modra <amodra(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/misc_64.S | 28 ---------------------------- arch/powerpc/kernel/module_64.c | 12 +++++++++--- scripts/mod/modpost.c | 3 ++- 3 files changed, 11 insertions(+), 32 deletions(-) --- a/arch/powerpc/kernel/misc_64.S +++ b/arch/powerpc/kernel/misc_64.S @@ -701,31 +701,3 @@ _GLOBAL(kexec_sequence) li r5,0 blr /* image->start(physid, image->start, 0); */ #endif /* CONFIG_KEXEC */ - -#ifdef CONFIG_MODULES -#if defined(_CALL_ELF) && _CALL_ELF == 2 - -#ifdef CONFIG_MODVERSIONS -.weak __crc_TOC. -.section "___kcrctab+TOC.","a" -.globl __kcrctab_TOC. -__kcrctab_TOC.: - .llong __crc_TOC. -#endif - -/* - * Export a fake .TOC. since both modpost and depmod will complain otherwise. - * Both modpost and depmod strip the leading . so we do the same here. - */ -.section "__ksymtab_strings","a" -__kstrtab_TOC.: - .asciz "TOC." - -.section "___ksymtab+TOC.","a" -/* This symbol name is important: it's used by modpost to find exported syms */ -.globl __ksymtab_TOC. -__ksymtab_TOC.: - .llong 0 /* .value */ - .llong __kstrtab_TOC. -#endif /* ELFv2 */ -#endif /* MODULES */ --- a/arch/powerpc/kernel/module_64.c +++ b/arch/powerpc/kernel/module_64.c @@ -326,7 +326,10 @@ static void dedotify_versions(struct mod } } -/* Undefined symbols which refer to .funcname, hack to funcname (or .TOC.) */ +/* + * Undefined symbols which refer to .funcname, hack to funcname. Make .TOC. + * seem to be defined (value set later). + */ static void dedotify(Elf64_Sym *syms, unsigned int numsyms, char *strtab) { unsigned int i; @@ -334,8 +337,11 @@ static void dedotify(Elf64_Sym *syms, un for (i = 1; i < numsyms; i++) { if (syms[i].st_shndx == SHN_UNDEF) { char *name = strtab + syms[i].st_name; - if (name[0] == '.') + if (name[0] == '.') { + if (strcmp(name+1, "TOC.") == 0) + syms[i].st_shndx = SHN_ABS; syms[i].st_name++; + } } } } @@ -351,7 +357,7 @@ static Elf64_Sym *find_dot_toc(Elf64_Shd numsyms = sechdrs[symindex].sh_size / sizeof(Elf64_Sym); for (i = 1; i < numsyms; i++) { - if (syms[i].st_shndx == SHN_UNDEF + if (syms[i].st_shndx == SHN_ABS && strcmp(strtab + syms[i].st_name, "TOC.") == 0) return &syms[i]; } --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -594,7 +594,8 @@ static int ignore_undef_symbol(struct el if (strncmp(symname, "_restgpr0_", sizeof("_restgpr0_") - 1) == 0 || strncmp(symname, "_savegpr0_", sizeof("_savegpr0_") - 1) == 0 || strncmp(symname, "_restvr_", sizeof("_restvr_") - 1) == 0 || - strncmp(symname, "_savevr_", sizeof("_savevr_") - 1) == 0) + strncmp(symname, "_savevr_", sizeof("_savevr_") - 1) == 0 || + strcmp(symname, ".TOC.") == 0) return 1; /* Do not ignore this symbol */ return 0; Patches currently in stable-queue which might be from amodra(a)gmail.com are queue-4.4/powerpc-simplify-module-toc-handling.patch

7 years, 3 months

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[Linux-stable-mirror] Patch "powerpc/pseries: Query hypervisor for RFI flush settings" has been added to the 4.4-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 4.4-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-4.4 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 | 37 ++++++++++++++++++++++++++++++++- 1 file changed, 36 insertions(+), 1 deletion(-) --- a/arch/powerpc/platforms/pseries/setup.c +++ b/arch/powerpc/platforms/pseries/setup.c @@ -499,6 +499,39 @@ 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); @@ -515,7 +548,9 @@ static void __init pSeries_setup_arch(vo fwnmi_init(); - /* By default, only probe PCI (can be overriden by rtas_pci) */ + pseries_setup_rfi_flush(); + + /* By default, only probe PCI (can be overridden by rtas_pci) */ pci_add_flags(PCI_PROBE_ONLY); /* Find and initialize PCI host bridges */ Patches currently in stable-queue which might be from mikey(a)neuling.org are queue-4.4/powerpc-pseries-add-h_get_cpu_characteristics-flags-wrapper.patch queue-4.4/powerpc-pseries-query-hypervisor-for-rfi-flush-settings.patch

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