From 8757dc970f550dc399f899be0e7a2c00b7e82e8f Mon Sep 17 00:00:00 2001 From: Omar Sandoval Date: Fri, 20 Dec 2019 08:22:49 -0800 Subject: [PATCH 1/3] x86/crash: Define arch_crash_save_vmcoreinfo() if CONFIG_CRASH_CORE=y On x86 kernels configured with CONFIG_PROC_KCORE=y and CONFIG_KEXEC_CORE=n, the vmcoreinfo note in /proc/kcore is incomplete. Specifically, it is missing arch-specific information like the KASLR offset and whether 5-level page tables are enabled. This breaks applications like drgn [1] and crash [2], which need this information for live debugging via /proc/kcore. This happens because: 1. CONFIG_PROC_KCORE selects CONFIG_CRASH_CORE. 2. kernel/crash_core.c (compiled if CONFIG_CRASH_CORE=y) calls arch_crash_save_vmcoreinfo() to get the arch-specific parts of vmcoreinfo. If it is not defined, then it uses a no-op fallback. 3. x86 defines arch_crash_save_vmcoreinfo() in arch/x86/kernel/machine_kexec_*.c, which is only compiled if CONFIG_KEXEC_CORE=y. Therefore, an x86 kernel with CONFIG_CRASH_CORE=y and CONFIG_KEXEC_CORE=n uses the no-op fallback and gets incomplete vmcoreinfo data. This isn't relevant to kdump, which requires CONFIG_KEXEC_CORE. It only affects applications which read vmcoreinfo at runtime, like the ones mentioned above. Fix it by moving arch_crash_save_vmcoreinfo() into two new arch/x86/kernel/crash_core_*.c files, which are gated behind CONFIG_CRASH_CORE. 1: https://github.com/osandov/drgn/blob/73dd7def1217e24cc83d8ca95c995decbd9ba24c/libdrgn/program.c#L385 2: https://github.com/crash-utility/crash/commit/60a42d709280cdf38ab06327a5b4fa9d9208ef86 Signed-off-by: Omar Sandoval Signed-off-by: Borislav Petkov Cc: Andy Lutomirski Cc: Greg Kroah-Hartman Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Kairui Song Cc: Lianbo Jiang Cc: Masahiro Yamada Cc: "Peter Zijlstra (Intel)" Cc: Thomas Gleixner Cc: x86-ml Link: https://lkml.kernel.org/r/0589961254102cca23e3618b96541b89f2b249e2.1576858905.git.osandov@fb.com --- arch/x86/kernel/Makefile | 1 + arch/x86/kernel/crash_core_32.c | 17 +++++++++++++++++ arch/x86/kernel/crash_core_64.c | 24 ++++++++++++++++++++++++ arch/x86/kernel/machine_kexec_32.c | 12 ------------ arch/x86/kernel/machine_kexec_64.c | 19 ------------------- 5 files changed, 42 insertions(+), 31 deletions(-) create mode 100644 arch/x86/kernel/crash_core_32.c create mode 100644 arch/x86/kernel/crash_core_64.c diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile index 6175e370ee4ab..9b294c13809ae 100644 --- a/arch/x86/kernel/Makefile +++ b/arch/x86/kernel/Makefile @@ -94,6 +94,7 @@ obj-$(CONFIG_FUNCTION_TRACER) += ftrace_$(BITS).o obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += ftrace.o obj-$(CONFIG_FTRACE_SYSCALLS) += ftrace.o obj-$(CONFIG_X86_TSC) += trace_clock.o +obj-$(CONFIG_CRASH_CORE) += crash_core_$(BITS).o obj-$(CONFIG_KEXEC_CORE) += machine_kexec_$(BITS).o obj-$(CONFIG_KEXEC_CORE) += relocate_kernel_$(BITS).o crash.o obj-$(CONFIG_KEXEC_FILE) += kexec-bzimage64.o diff --git a/arch/x86/kernel/crash_core_32.c b/arch/x86/kernel/crash_core_32.c new file mode 100644 index 0000000000000..c0159a7bca6df --- /dev/null +++ b/arch/x86/kernel/crash_core_32.c @@ -0,0 +1,17 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include + +#include +#include + +void arch_crash_save_vmcoreinfo(void) +{ +#ifdef CONFIG_NUMA + VMCOREINFO_SYMBOL(node_data); + VMCOREINFO_LENGTH(node_data, MAX_NUMNODES); +#endif +#ifdef CONFIG_X86_PAE + VMCOREINFO_CONFIG(X86_PAE); +#endif +} diff --git a/arch/x86/kernel/crash_core_64.c b/arch/x86/kernel/crash_core_64.c new file mode 100644 index 0000000000000..845a57eb4eb70 --- /dev/null +++ b/arch/x86/kernel/crash_core_64.c @@ -0,0 +1,24 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include + +#include +#include + +void arch_crash_save_vmcoreinfo(void) +{ + u64 sme_mask = sme_me_mask; + + VMCOREINFO_NUMBER(phys_base); + VMCOREINFO_SYMBOL(init_top_pgt); + vmcoreinfo_append_str("NUMBER(pgtable_l5_enabled)=%d\n", + pgtable_l5_enabled()); + +#ifdef CONFIG_NUMA + VMCOREINFO_SYMBOL(node_data); + VMCOREINFO_LENGTH(node_data, MAX_NUMNODES); +#endif + vmcoreinfo_append_str("KERNELOFFSET=%lx\n", kaslr_offset()); + VMCOREINFO_NUMBER(KERNEL_IMAGE_SIZE); + VMCOREINFO_NUMBER(sme_mask); +} diff --git a/arch/x86/kernel/machine_kexec_32.c b/arch/x86/kernel/machine_kexec_32.c index 7b45e8daad22e..02bddfc122a4d 100644 --- a/arch/x86/kernel/machine_kexec_32.c +++ b/arch/x86/kernel/machine_kexec_32.c @@ -250,15 +250,3 @@ void machine_kexec(struct kimage *image) __ftrace_enabled_restore(save_ftrace_enabled); } - -void arch_crash_save_vmcoreinfo(void) -{ -#ifdef CONFIG_NUMA - VMCOREINFO_SYMBOL(node_data); - VMCOREINFO_LENGTH(node_data, MAX_NUMNODES); -#endif -#ifdef CONFIG_X86_PAE - VMCOREINFO_CONFIG(X86_PAE); -#endif -} - diff --git a/arch/x86/kernel/machine_kexec_64.c b/arch/x86/kernel/machine_kexec_64.c index 16e125a50b333..ad5cdd6a5f238 100644 --- a/arch/x86/kernel/machine_kexec_64.c +++ b/arch/x86/kernel/machine_kexec_64.c @@ -398,25 +398,6 @@ void machine_kexec(struct kimage *image) __ftrace_enabled_restore(save_ftrace_enabled); } -void arch_crash_save_vmcoreinfo(void) -{ - u64 sme_mask = sme_me_mask; - - VMCOREINFO_NUMBER(phys_base); - VMCOREINFO_SYMBOL(init_top_pgt); - vmcoreinfo_append_str("NUMBER(pgtable_l5_enabled)=%d\n", - pgtable_l5_enabled()); - -#ifdef CONFIG_NUMA - VMCOREINFO_SYMBOL(node_data); - VMCOREINFO_LENGTH(node_data, MAX_NUMNODES); -#endif - vmcoreinfo_append_str("KERNELOFFSET=%lx\n", - kaslr_offset()); - VMCOREINFO_NUMBER(KERNEL_IMAGE_SIZE); - VMCOREINFO_NUMBER(sme_mask); -} - /* arch-dependent functionality related to kexec file-based syscall */ #ifdef CONFIG_KEXEC_FILE From 538f127cd3bcf76071139f4bfe9cc3b2a46f3b3d Mon Sep 17 00:00:00 2001 From: Wei Liu Date: Sun, 22 Dec 2019 23:34:04 +0000 Subject: [PATCH 2/3] x86/hyper-v: Add "polling" bit to hv_synic_sint That bit is documented in TLFS 5.0c as follows: Setting the polling bit will have the effect of unmasking an interrupt source, except that an actual interrupt is not generated. Signed-off-by: Wei Liu Signed-off-by: Thomas Gleixner Reviewed-by: Michael Kelley Link: https://lore.kernel.org/r/20191222233404.1629-1-wei.liu@kernel.org --- arch/x86/include/asm/hyperv-tlfs.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/hyperv-tlfs.h b/arch/x86/include/asm/hyperv-tlfs.h index 5f10f7f2098db..92abc1e42bfc1 100644 --- a/arch/x86/include/asm/hyperv-tlfs.h +++ b/arch/x86/include/asm/hyperv-tlfs.h @@ -809,7 +809,8 @@ union hv_synic_sint { u64 reserved1:8; u64 masked:1; u64 auto_eoi:1; - u64 reserved2:46; + u64 polling:1; + u64 reserved2:45; } __packed; }; From 8b7e20a7ba54836076ff35a28349dabea4cec48f Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Wed, 22 Jan 2020 13:11:54 +0900 Subject: [PATCH 3/3] x86/decoder: Add TEST opcode to Group3-2 Add TEST opcode to Group3-2 reg=001b as same as Group3-1 does. Commit 12a78d43de76 ("x86/decoder: Add new TEST instruction pattern") added a TEST opcode assignment to f6 XX/001/XXX (Group 3-1), but did not add f7 XX/001/XXX (Group 3-2). Actually, this TEST opcode variant (ModRM.reg /1) is not described in the Intel SDM Vol2 but in AMD64 Architecture Programmer's Manual Vol.3, Appendix A.2 Table A-6. ModRM.reg Extensions for the Primary Opcode Map. Without this fix, Randy found a warning by insn_decoder_test related to this issue as below. HOSTCC arch/x86/tools/insn_decoder_test HOSTCC arch/x86/tools/insn_sanity TEST posttest arch/x86/tools/insn_decoder_test: warning: Found an x86 instruction decoder bug, please report this. arch/x86/tools/insn_decoder_test: warning: ffffffff81000bf1: f7 0b 00 01 08 00 testl $0x80100,(%rbx) arch/x86/tools/insn_decoder_test: warning: objdump says 6 bytes, but insn_get_length() says 2 arch/x86/tools/insn_decoder_test: warning: Decoded and checked 11913894 instructions with 1 failures TEST posttest arch/x86/tools/insn_sanity: Success: decoded and checked 1000000 random instructions with 0 errors (seed:0x871ce29c) To fix this error, add the TEST opcode according to AMD64 APM Vol.3. [ bp: Massage commit message. ] Reported-by: Randy Dunlap Signed-off-by: Masami Hiramatsu Signed-off-by: Borislav Petkov Acked-by: Randy Dunlap Tested-by: Randy Dunlap Link: https://lkml.kernel.org/r/157966631413.9580.10311036595431878351.stgit@devnote2 --- arch/x86/lib/x86-opcode-map.txt | 2 +- tools/arch/x86/lib/x86-opcode-map.txt | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/lib/x86-opcode-map.txt b/arch/x86/lib/x86-opcode-map.txt index 8908c58bd6cd2..53adc1762ec08 100644 --- a/arch/x86/lib/x86-opcode-map.txt +++ b/arch/x86/lib/x86-opcode-map.txt @@ -929,7 +929,7 @@ EndTable GrpTable: Grp3_2 0: TEST Ev,Iz -1: +1: TEST Ev,Iz 2: NOT Ev 3: NEG Ev 4: MUL rAX,Ev diff --git a/tools/arch/x86/lib/x86-opcode-map.txt b/tools/arch/x86/lib/x86-opcode-map.txt index 8908c58bd6cd2..53adc1762ec08 100644 --- a/tools/arch/x86/lib/x86-opcode-map.txt +++ b/tools/arch/x86/lib/x86-opcode-map.txt @@ -929,7 +929,7 @@ EndTable GrpTable: Grp3_2 0: TEST Ev,Iz -1: +1: TEST Ev,Iz 2: NOT Ev 3: NEG Ev 4: MUL rAX,Ev