| Message ID | 20200914172750.852684-6-georgepope@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | UBSan Enablement for hyp/nVHE code | expand |
On Mon, Sep 14, 2020 at 05:27:41PM +0000, George-Aurelian Popescu wrote: > From: George Popescu <georgepope@google.com> Just realized that with UBSAN disabled this code won't compile. Sorry for that. Had to add the two lines of code below: > Store data, which is collected from UBSan handlers that lives inside hyp/nVHE, > into the kvm_ubsan_buffer. > This buffer is designed to store only UBSan data because it should not be > preoccupied by other mechanisms data structures and functionalities. > > Map the buffer and the write index before switching the control to > hyp/nVHE. > > Map the kernel .data region to read the compile time generated UBSan struct's > data from hyp/nVHE. > > Signed-off-by: George Popescu <georgepope@google.com> > --- > arch/arm64/include/asm/kvm_asm.h | 3 +++ > arch/arm64/include/asm/kvm_host.h | 6 +++++ > arch/arm64/include/asm/kvm_ubsan.h | 17 +++++++++++++ > arch/arm64/kvm/Makefile | 4 ++++ > arch/arm64/kvm/arm.c | 38 +++++++++++++++++++++++++++++- > arch/arm64/kvm/hyp/hyp-entry.S | 4 ++++ > arch/arm64/kvm/hyp/nvhe/ubsan.c | 24 ++++++++++++++++++- > arch/arm64/kvm/kvm_ubsan_buffer.c | 32 +++++++++++++++++++++++++ > 8 files changed, 126 insertions(+), 2 deletions(-) > create mode 100644 arch/arm64/include/asm/kvm_ubsan.h > create mode 100644 arch/arm64/kvm/kvm_ubsan_buffer.c > > diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h > index 200bb8d0a720..9d4a77f08ffd 100644 > --- a/arch/arm64/include/asm/kvm_asm.h > +++ b/arch/arm64/include/asm/kvm_asm.h > @@ -63,6 +63,9 @@ > #define CHOOSE_VHE_SYM(sym) sym > #define CHOOSE_NVHE_SYM(sym) kvm_nvhe_sym(sym) > > +#define this_cpu_ptr_nvhe(sym) this_cpu_ptr(&kvm_nvhe_sym(sym)) > +#define per_cpu_ptr_nvhe(sym, cpu) per_cpu_ptr(&kvm_nvhe_sym(sym), cpu) > + > #ifndef __KVM_NVHE_HYPERVISOR__ > /* > * BIG FAT WARNINGS: > diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h > index adc8957e9321..337fd2d0f976 100644 > --- a/arch/arm64/include/asm/kvm_host.h > +++ b/arch/arm64/include/asm/kvm_host.h > @@ -494,8 +494,14 @@ u64 __kvm_call_hyp(void *hypfn, ...); > __kvm_call_hyp(kvm_ksym_ref_nvhe(f), ##__VA_ARGS__); \ > }) > > +#ifdef CONFIG_UBSAN > +extern void __kvm_check_ubsan_buffer(void); #else static inline void __kvm_check_ubsan_buffer(void){} > +#endif > + > #define __kvm_arm_check_debug_buffer() \ > { \ > + if (IS_ENABLED(CONFIG_UBSAN)) \ > + __kvm_check_ubsan_buffer(); \ > } > > /* > diff --git a/arch/arm64/include/asm/kvm_ubsan.h b/arch/arm64/include/asm/kvm_ubsan.h > new file mode 100644 > index 000000000000..af607a796376 > --- /dev/null > +++ b/arch/arm64/include/asm/kvm_ubsan.h > @@ -0,0 +1,17 @@ > +/* SPDX-License-Identifier: GPL-2.0-only */ > +/* > + * Copyright 2020 Google LLC > + * Author: George Popescu <georgepope@google.com> > + */ > + > +#ifdef CONFIG_UBSAN > +#include <ubsan.h> > + > + > +#define UBSAN_MAX_TYPE 6 > +#define KVM_UBSAN_BUFFER_SIZE 1000 > + > +struct kvm_ubsan_info { > + int type; > +}; > +#endif > diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile > index 99977c1972cc..92f06cb5b3df 100644 > --- a/arch/arm64/kvm/Makefile > +++ b/arch/arm64/kvm/Makefile > @@ -24,4 +24,8 @@ kvm-y := $(KVM)/kvm_main.o $(KVM)/coalesced_mmio.o $(KVM)/eventfd.o \ > vgic/vgic-mmio-v3.o vgic/vgic-kvm-device.o \ > vgic/vgic-its.o vgic/vgic-debug.o > > +CFLAGS_kvm_ubsan_buffer.o += -I $(srctree)/lib/ > +CFLAGS_arm.o += -I $(srctree)/lib > + > +kvm-$(CONFIG_UBSAN) += kvm_ubsan_buffer.o > kvm-$(CONFIG_KVM_ARM_PMU) += pmu-emul.o > diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c > index b588c3b5c2f0..eff57069e103 100644 > --- a/arch/arm64/kvm/arm.c > +++ b/arch/arm64/kvm/arm.c > @@ -42,10 +42,17 @@ > #include <kvm/arm_pmu.h> > #include <kvm/arm_psci.h> > > +#include <asm/kvm_debug_buffer.h> > +#include <asm/kvm_ubsan.h> > + > #ifdef REQUIRES_VIRT > __asm__(".arch_extension virt"); > #endif > > +#ifdef CONFIG_UBSAN > +DECLARE_KVM_DEBUG_BUFFER(struct kvm_ubsan_info, kvm_ubsan_buff, KVM_UBSAN_BUFFER_SIZE); > +#endif > + > DEFINE_PER_CPU(kvm_host_data_t, kvm_host_data); > static DEFINE_PER_CPU(unsigned long, kvm_arm_hyp_stack_page); > > @@ -1519,7 +1526,15 @@ static int init_hyp_mode(void) > kvm_err("Cannot map bss section\n"); > goto out_err; > } > - > +#ifdef CONFIG_UBSAN > + /* required by ubsan to access the handlers structures fields */ > + err = create_hyp_mappings(kvm_ksym_ref(_data), > + kvm_ksym_ref(__end_once), PAGE_HYP_RO); > + if (err) { > + kvm_err("Cannot map data section\n"); > + goto out_err; > + } > +#endif > err = kvm_map_vectors(); > if (err) { > kvm_err("Cannot map vectors\n"); > @@ -1552,6 +1567,27 @@ static int init_hyp_mode(void) > } > } > > +#ifdef CONFIG_UBSAN > + for_each_possible_cpu(cpu) { > + /* map the write index */ > + struct kvm_ubsan_info *buff; > + unsigned long *wr_ind; > + > + wr_ind = per_cpu_ptr_nvhe(kvm_ubsan_buff_wr_ind, cpu); > + err = create_hyp_mappings(wr_ind, wr_ind + 1, PAGE_HYP); > + if (err) { > + kvm_err("Cannot map the busan buffer write index: %d\n", err); > + goto out_err; > + } > + buff = per_cpu_ptr(kvm_nvhe_sym(kvm_ubsan_buff), cpu); > + err = create_hyp_mappings(buff, buff + KVM_UBSAN_BUFFER_SIZE, PAGE_HYP); > + if (err) { > + kvm_err("Cannot map the ubsan buffer: %d\n", err); > + goto out_err; > + } > + } > +#endif > + > err = hyp_map_aux_data(); > if (err) > kvm_err("Cannot map host auxiliary data: %d\n", err); > diff --git a/arch/arm64/kvm/hyp/hyp-entry.S b/arch/arm64/kvm/hyp/hyp-entry.S > index 8df0082b9ccf..bcdbab4d2e43 100644 > --- a/arch/arm64/kvm/hyp/hyp-entry.S > +++ b/arch/arm64/kvm/hyp/hyp-entry.S > @@ -14,6 +14,7 @@ > #include <asm/kvm_asm.h> > #include <asm/kvm_mmu.h> > #include <asm/mmu.h> > +#include <asm/kvm_debug_buffer.h> > > .macro save_caller_saved_regs_vect > /* x0 and x1 were saved in the vector entry */ > @@ -74,6 +75,9 @@ el1_sync: // Guest trapped into EL2 > cmp x0, #HVC_STUB_HCALL_NR > b.hs 1f > > +#ifdef CONFIG_UBSAN > + clear_kvm_debug_buffer kvm_ubsan_buff_wr_ind, x4, x5, x6 > +#endif > /* > * Compute the idmap address of __kvm_handle_stub_hvc and > * jump there. Since we use kimage_voffset, do not use the > diff --git a/arch/arm64/kvm/hyp/nvhe/ubsan.c b/arch/arm64/kvm/hyp/nvhe/ubsan.c > index a5db6b61ceb2..a43c9646e1e8 100644 > --- a/arch/arm64/kvm/hyp/nvhe/ubsan.c > +++ b/arch/arm64/kvm/hyp/nvhe/ubsan.c > @@ -3,9 +3,31 @@ > * Copyright 2020 Google LLC > * Author: George Popescu <georgepope@google.com> > */ > +#include <linux/bitops.h> > #include <linux/ctype.h> > #include <linux/types.h> > -#include <ubsan.h> > +#include <linux/percpu-defs.h> > +#include <linux/kvm_host.h> > +#include <asm/kvm_arm.h> > +#include <asm/kvm_asm.h> > +#include <asm/kvm_ubsan.h> > +#include <asm/kvm_debug_buffer.h> > +#include <kvm/arm_pmu.h> > + > +DEFINE_KVM_DEBUG_BUFFER(struct kvm_ubsan_info, kvm_ubsan_buff, KVM_UBSAN_BUFFER_SIZE); > + > +static inline struct kvm_ubsan_info *kvm_ubsan_buffer_next_slot(void) > +{ > + struct kvm_ubsan_info *res; > + struct kvm_ubsan_info *buff; > + unsigned long *buff_ind; > + unsigned long buff_size = KVM_UBSAN_BUFFER_SIZE; > + unsigned int struct_size = sizeof(struct kvm_ubsan_info); > + > + init_kvm_debug_buffer(kvm_ubsan_buff, struct kvm_ubsan_info, buff, buff_ind); > + res = kvm_debug_buffer_next_slot(buff, buff_ind, struct_size, buff_size); > + return res; > +} > > void __ubsan_handle_add_overflow(void *_data, void *lhs, void *rhs) {} > > diff --git a/arch/arm64/kvm/kvm_ubsan_buffer.c b/arch/arm64/kvm/kvm_ubsan_buffer.c > new file mode 100644 > index 000000000000..28dcf19b5706 > --- /dev/null > +++ b/arch/arm64/kvm/kvm_ubsan_buffer.c > @@ -0,0 +1,32 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * Copyright 2020 Google LLC > + * Author: George Popescu <georgepope@google.com> > + */ > + > +#include <linux/ctype.h> > +#include <linux/types.h> > +#include <asm/kvm_debug_buffer.h> > +#include <asm/kvm_arm.h> > +#include <asm/kvm_asm.h> > +#include <kvm/arm_pmu.h> > + > +#include <ubsan.h> > +#include <asm/kvm_ubsan.h> > + > +DECLARE_KVM_DEBUG_BUFFER(struct kvm_ubsan_info, kvm_ubsan_buff, KVM_UBSAN_BUFFER_SIZE); > + > + > +void __kvm_check_ubsan_buffer(void) > +{ > + unsigned long *write_ind; > + unsigned long it; > + struct kvm_ubsan_info *slot; > + > + init_kvm_debug_buffer(kvm_ubsan_buff, struct kvm_ubsan_info, slot, write_ind); > + for_each_kvm_debug_buffer_slot(slot, write_ind, it) { > + /* check ubsan data */ > + slot->type = 0; > + } > +} > + > -- > 2.28.0.618.gf4bc123cb7-goog >
On Mon, Sep 14, 2020 at 05:27:41PM +0000, George-Aurelian Popescu wrote: > From: George Popescu <georgepope@google.com> > > Store data, which is collected from UBSan handlers that lives inside hyp/nVHE, > into the kvm_ubsan_buffer. > This buffer is designed to store only UBSan data because it should not be > preoccupied by other mechanisms data structures and functionalities. > > Map the buffer and the write iqndex before switching the control to > hyp/nVHE. > > Map the kernel .data region to read the compile time generated UBSan struct's > data from hyp/nVHE. > > Signed-off-by: George Popescu <georgepope@google.com> > --- > arch/arm64/include/asm/kvm_asm.h | 3 +++ > arch/arm64/include/asm/kvm_host.h | 6 +++++ > arch/arm64/include/asm/kvm_ubsan.h | 17 +++++++++++++ > arch/arm64/kvm/Makefile | 4 ++++ > arch/arm64/kvm/arm.c | 38 +++++++++++++++++++++++++++++- > arch/arm64/kvm/hyp/hyp-entry.S | 4 ++++ > arch/arm64/kvm/hyp/nvhe/ubsan.c | 24 ++++++++++++++++++- > arch/arm64/kvm/kvm_ubsan_buffer.c | 32 +++++++++++++++++++++++++ > 8 files changed, 126 insertions(+), 2 deletions(-) > create mode 100644 arch/arm64/include/asm/kvm_ubsan.h > create mode 100644 arch/arm64/kvm/kvm_ubsan_buffer.c > > diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h > index 200bb8d0a720..9d4a77f08ffd 100644 > --- a/arch/arm64/include/asm/kvm_asm.h > +++ b/arch/arm64/include/asm/kvm_asm.h > @@ -63,6 +63,9 @@ > #define CHOOSE_VHE_SYM(sym) sym > #define CHOOSE_NVHE_SYM(sym) kvm_nvhe_sym(sym) > > +#define this_cpu_ptr_nvhe(sym) this_cpu_ptr(&kvm_nvhe_sym(sym)) > +#define per_cpu_ptr_nvhe(sym, cpu) per_cpu_ptr(&kvm_nvhe_sym(sym), cpu) > + > #ifndef __KVM_NVHE_HYPERVISOR__ > /* > * BIG FAT WARNINGS: > diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h > index adc8957e9321..337fd2d0f976 100644 > --- a/arch/arm64/include/asm/kvm_host.h > +++ b/arch/arm64/include/asm/kvm_host.h > @@ -494,8 +494,14 @@ u64 __kvm_call_hyp(void *hypfn, ...); > __kvm_call_hyp(kvm_ksym_ref_nvhe(f), ##__VA_ARGS__); \ > }) > > +#ifdef CONFIG_UBSAN > +extern void __kvm_check_ubsan_buffer(void); > +#endif > + > #define __kvm_arm_check_debug_buffer() \ > { \ > + if (IS_ENABLED(CONFIG_UBSAN)) \ > + __kvm_check_ubsan_buffer(); \ > } > > /* > diff --git a/arch/arm64/include/asm/kvm_ubsan.h b/arch/arm64/include/asm/kvm_ubsan.h > new file mode 100644 > index 000000000000..af607a796376 > --- /dev/null > +++ b/arch/arm64/include/asm/kvm_ubsan.h > @@ -0,0 +1,17 @@ > +/* SPDX-License-Identifier: GPL-2.0-only */ > +/* > + * Copyright 2020 Google LLC > + * Author: George Popescu <georgepope@google.com> > + */ > + > +#ifdef CONFIG_UBSAN The header should have an inclusion guard as well. > +#include <ubsan.h> Is it possible to only include this from within kvm_ubsan_buffer.c similar to how lib/ubsan.c keeps it self contained? Then export function for things like mapping it up to hyp? > + > + > +#define UBSAN_MAX_TYPE 6 > +#define KVM_UBSAN_BUFFER_SIZE 1000 > + > +struct kvm_ubsan_info { > + int type; > +}; > +#endif > diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile > index 99977c1972cc..92f06cb5b3df 100644 > --- a/arch/arm64/kvm/Makefile > +++ b/arch/arm64/kvm/Makefile > @@ -24,4 +24,8 @@ kvm-y := $(KVM)/kvm_main.o $(KVM)/coalesced_mmio.o $(KVM)/eventfd.o \ > vgic/vgic-mmio-v3.o vgic/vgic-kvm-device.o \ > vgic/vgic-its.o vgic/vgic-debug.o > > +CFLAGS_kvm_ubsan_buffer.o += -I $(srctree)/lib/ > +CFLAGS_arm.o += -I $(srctree)/lib > + > +kvm-$(CONFIG_UBSAN) += kvm_ubsan_buffer.o > kvm-$(CONFIG_KVM_ARM_PMU) += pmu-emul.o > diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c > index b588c3b5c2f0..eff57069e103 100644 > --- a/arch/arm64/kvm/arm.c > +++ b/arch/arm64/kvm/arm.c > @@ -42,10 +42,17 @@ > #include <kvm/arm_pmu.h> > #include <kvm/arm_psci.h> > > +#include <asm/kvm_debug_buffer.h> > +#include <asm/kvm_ubsan.h> > + > #ifdef REQUIRES_VIRT > __asm__(".arch_extension virt"); > #endif > > +#ifdef CONFIG_UBSAN > +DECLARE_KVM_DEBUG_BUFFER(struct kvm_ubsan_info, kvm_ubsan_buff, KVM_UBSAN_BUFFER_SIZE); > +#endif > + > DEFINE_PER_CPU(kvm_host_data_t, kvm_host_data); > static DEFINE_PER_CPU(unsigned long, kvm_arm_hyp_stack_page); > > @@ -1519,7 +1526,15 @@ static int init_hyp_mode(void) > kvm_err("Cannot map bss section\n"); > goto out_err; > } > - > +#ifdef CONFIG_UBSAN > + /* required by ubsan to access the handlers structures fields */ > + err = create_hyp_mappings(kvm_ksym_ref(_data), > + kvm_ksym_ref(__end_once), PAGE_HYP_RO); > + if (err) { > + kvm_err("Cannot map data section\n"); > + goto out_err; > + } > +#endif > err = kvm_map_vectors(); > if (err) { > kvm_err("Cannot map vectors\n"); > @@ -1552,6 +1567,27 @@ static int init_hyp_mode(void) > } > } > > +#ifdef CONFIG_UBSAN > + for_each_possible_cpu(cpu) { > + /* map the write index */ > + struct kvm_ubsan_info *buff; > + unsigned long *wr_ind; > + > + wr_ind = per_cpu_ptr_nvhe(kvm_ubsan_buff_wr_ind, cpu); > + err = create_hyp_mappings(wr_ind, wr_ind + 1, PAGE_HYP); > + if (err) { > + kvm_err("Cannot map the busan buffer write index: %d\n", err); > + goto out_err; > + } > + buff = per_cpu_ptr(kvm_nvhe_sym(kvm_ubsan_buff), cpu); > + err = create_hyp_mappings(buff, buff + KVM_UBSAN_BUFFER_SIZE, PAGE_HYP); > + if (err) { > + kvm_err("Cannot map the ubsan buffer: %d\n", err); > + goto out_err; > + } > + } > +#endif > + > err = hyp_map_aux_data(); > if (err) > kvm_err("Cannot map host auxiliary data: %d\n", err); > diff --git a/arch/arm64/kvm/hyp/hyp-entry.S b/arch/arm64/kvm/hyp/hyp-entry.S > index 8df0082b9ccf..bcdbab4d2e43 100644 > --- a/arch/arm64/kvm/hyp/hyp-entry.S > +++ b/arch/arm64/kvm/hyp/hyp-entry.S > @@ -14,6 +14,7 @@ > #include <asm/kvm_asm.h> > #include <asm/kvm_mmu.h> > #include <asm/mmu.h> > +#include <asm/kvm_debug_buffer.h> > > .macro save_caller_saved_regs_vect > /* x0 and x1 were saved in the vector entry */ > @@ -74,6 +75,9 @@ el1_sync: // Guest trapped into EL2 > cmp x0, #HVC_STUB_HCALL_NR > b.hs 1f > > +#ifdef CONFIG_UBSAN > + clear_kvm_debug_buffer kvm_ubsan_buff_wr_ind, x4, x5, x6 > +#endif > /* > * Compute the idmap address of __kvm_handle_stub_hvc and > * jump there. Since we use kimage_voffset, do not use the > diff --git a/arch/arm64/kvm/hyp/nvhe/ubsan.c b/arch/arm64/kvm/hyp/nvhe/ubsan.c > index a5db6b61ceb2..a43c9646e1e8 100644 > --- a/arch/arm64/kvm/hyp/nvhe/ubsan.c > +++ b/arch/arm64/kvm/hyp/nvhe/ubsan.c > @@ -3,9 +3,31 @@ > * Copyright 2020 Google LLC > * Author: George Popescu <georgepope@google.com> > */ > +#include <linux/bitops.h> > #include <linux/ctype.h> > #include <linux/types.h> > -#include <ubsan.h> > +#include <linux/percpu-defs.h> > +#include <linux/kvm_host.h> > +#include <asm/kvm_arm.h> > +#include <asm/kvm_asm.h> > +#include <asm/kvm_ubsan.h> > +#include <asm/kvm_debug_buffer.h> > +#include <kvm/arm_pmu.h> > + > +DEFINE_KVM_DEBUG_BUFFER(struct kvm_ubsan_info, kvm_ubsan_buff, KVM_UBSAN_BUFFER_SIZE); > + > +static inline struct kvm_ubsan_info *kvm_ubsan_buffer_next_slot(void) > +{ > + struct kvm_ubsan_info *res; > + struct kvm_ubsan_info *buff; > + unsigned long *buff_ind; > + unsigned long buff_size = KVM_UBSAN_BUFFER_SIZE; > + unsigned int struct_size = sizeof(struct kvm_ubsan_info); > + > + init_kvm_debug_buffer(kvm_ubsan_buff, struct kvm_ubsan_info, buff, buff_ind); > + res = kvm_debug_buffer_next_slot(buff, buff_ind, struct_size, buff_size); > + return res; > +} > > void __ubsan_handle_add_overflow(void *_data, void *lhs, void *rhs) {} > > diff --git a/arch/arm64/kvm/kvm_ubsan_buffer.c b/arch/arm64/kvm/kvm_ubsan_buffer.c > new file mode 100644 > index 000000000000..28dcf19b5706 > --- /dev/null > +++ b/arch/arm64/kvm/kvm_ubsan_buffer.c > @@ -0,0 +1,32 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * Copyright 2020 Google LLC > + * Author: George Popescu <georgepope@google.com> > + */ > + > +#include <linux/ctype.h> > +#include <linux/types.h> > +#include <asm/kvm_debug_buffer.h> > +#include <asm/kvm_arm.h> > +#include <asm/kvm_asm.h> > +#include <kvm/arm_pmu.h> > + > +#include <ubsan.h> > +#include <asm/kvm_ubsan.h> > + > +DECLARE_KVM_DEBUG_BUFFER(struct kvm_ubsan_info, kvm_ubsan_buff, KVM_UBSAN_BUFFER_SIZE); > + > + > +void __kvm_check_ubsan_buffer(void) > +{ > + unsigned long *write_ind; > + unsigned long it; > + struct kvm_ubsan_info *slot; > + > + init_kvm_debug_buffer(kvm_ubsan_buff, struct kvm_ubsan_info, slot, write_ind); > + for_each_kvm_debug_buffer_slot(slot, write_ind, it) { > + /* check ubsan data */ > + slot->type = 0; > + } > +} > + > -- > 2.28.0.618.gf4bc123cb7-goog >
diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h index 200bb8d0a720..9d4a77f08ffd 100644 --- a/arch/arm64/include/asm/kvm_asm.h +++ b/arch/arm64/include/asm/kvm_asm.h @@ -63,6 +63,9 @@ #define CHOOSE_VHE_SYM(sym) sym #define CHOOSE_NVHE_SYM(sym) kvm_nvhe_sym(sym) +#define this_cpu_ptr_nvhe(sym) this_cpu_ptr(&kvm_nvhe_sym(sym)) +#define per_cpu_ptr_nvhe(sym, cpu) per_cpu_ptr(&kvm_nvhe_sym(sym), cpu) + #ifndef __KVM_NVHE_HYPERVISOR__ /* * BIG FAT WARNINGS: diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index adc8957e9321..337fd2d0f976 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -494,8 +494,14 @@ u64 __kvm_call_hyp(void *hypfn, ...); __kvm_call_hyp(kvm_ksym_ref_nvhe(f), ##__VA_ARGS__); \ }) +#ifdef CONFIG_UBSAN +extern void __kvm_check_ubsan_buffer(void); +#endif + #define __kvm_arm_check_debug_buffer() \ { \ + if (IS_ENABLED(CONFIG_UBSAN)) \ + __kvm_check_ubsan_buffer(); \ } /* diff --git a/arch/arm64/include/asm/kvm_ubsan.h b/arch/arm64/include/asm/kvm_ubsan.h new file mode 100644 index 000000000000..af607a796376 --- /dev/null +++ b/arch/arm64/include/asm/kvm_ubsan.h @@ -0,0 +1,17 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright 2020 Google LLC + * Author: George Popescu <georgepope@google.com> + */ + +#ifdef CONFIG_UBSAN +#include <ubsan.h> + + +#define UBSAN_MAX_TYPE 6 +#define KVM_UBSAN_BUFFER_SIZE 1000 + +struct kvm_ubsan_info { + int type; +}; +#endif diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile index 99977c1972cc..92f06cb5b3df 100644 --- a/arch/arm64/kvm/Makefile +++ b/arch/arm64/kvm/Makefile @@ -24,4 +24,8 @@ kvm-y := $(KVM)/kvm_main.o $(KVM)/coalesced_mmio.o $(KVM)/eventfd.o \ vgic/vgic-mmio-v3.o vgic/vgic-kvm-device.o \ vgic/vgic-its.o vgic/vgic-debug.o +CFLAGS_kvm_ubsan_buffer.o += -I $(srctree)/lib/ +CFLAGS_arm.o += -I $(srctree)/lib + +kvm-$(CONFIG_UBSAN) += kvm_ubsan_buffer.o kvm-$(CONFIG_KVM_ARM_PMU) += pmu-emul.o diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index b588c3b5c2f0..eff57069e103 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -42,10 +42,17 @@ #include <kvm/arm_pmu.h> #include <kvm/arm_psci.h> +#include <asm/kvm_debug_buffer.h> +#include <asm/kvm_ubsan.h> + #ifdef REQUIRES_VIRT __asm__(".arch_extension virt"); #endif +#ifdef CONFIG_UBSAN +DECLARE_KVM_DEBUG_BUFFER(struct kvm_ubsan_info, kvm_ubsan_buff, KVM_UBSAN_BUFFER_SIZE); +#endif + DEFINE_PER_CPU(kvm_host_data_t, kvm_host_data); static DEFINE_PER_CPU(unsigned long, kvm_arm_hyp_stack_page); @@ -1519,7 +1526,15 @@ static int init_hyp_mode(void) kvm_err("Cannot map bss section\n"); goto out_err; } - +#ifdef CONFIG_UBSAN + /* required by ubsan to access the handlers structures fields */ + err = create_hyp_mappings(kvm_ksym_ref(_data), + kvm_ksym_ref(__end_once), PAGE_HYP_RO); + if (err) { + kvm_err("Cannot map data section\n"); + goto out_err; + } +#endif err = kvm_map_vectors(); if (err) { kvm_err("Cannot map vectors\n"); @@ -1552,6 +1567,27 @@ static int init_hyp_mode(void) } } +#ifdef CONFIG_UBSAN + for_each_possible_cpu(cpu) { + /* map the write index */ + struct kvm_ubsan_info *buff; + unsigned long *wr_ind; + + wr_ind = per_cpu_ptr_nvhe(kvm_ubsan_buff_wr_ind, cpu); + err = create_hyp_mappings(wr_ind, wr_ind + 1, PAGE_HYP); + if (err) { + kvm_err("Cannot map the busan buffer write index: %d\n", err); + goto out_err; + } + buff = per_cpu_ptr(kvm_nvhe_sym(kvm_ubsan_buff), cpu); + err = create_hyp_mappings(buff, buff + KVM_UBSAN_BUFFER_SIZE, PAGE_HYP); + if (err) { + kvm_err("Cannot map the ubsan buffer: %d\n", err); + goto out_err; + } + } +#endif + err = hyp_map_aux_data(); if (err) kvm_err("Cannot map host auxiliary data: %d\n", err); diff --git a/arch/arm64/kvm/hyp/hyp-entry.S b/arch/arm64/kvm/hyp/hyp-entry.S index 8df0082b9ccf..bcdbab4d2e43 100644 --- a/arch/arm64/kvm/hyp/hyp-entry.S +++ b/arch/arm64/kvm/hyp/hyp-entry.S @@ -14,6 +14,7 @@ #include <asm/kvm_asm.h> #include <asm/kvm_mmu.h> #include <asm/mmu.h> +#include <asm/kvm_debug_buffer.h> .macro save_caller_saved_regs_vect /* x0 and x1 were saved in the vector entry */ @@ -74,6 +75,9 @@ el1_sync: // Guest trapped into EL2 cmp x0, #HVC_STUB_HCALL_NR b.hs 1f +#ifdef CONFIG_UBSAN + clear_kvm_debug_buffer kvm_ubsan_buff_wr_ind, x4, x5, x6 +#endif /* * Compute the idmap address of __kvm_handle_stub_hvc and * jump there. Since we use kimage_voffset, do not use the diff --git a/arch/arm64/kvm/hyp/nvhe/ubsan.c b/arch/arm64/kvm/hyp/nvhe/ubsan.c index a5db6b61ceb2..a43c9646e1e8 100644 --- a/arch/arm64/kvm/hyp/nvhe/ubsan.c +++ b/arch/arm64/kvm/hyp/nvhe/ubsan.c @@ -3,9 +3,31 @@ * Copyright 2020 Google LLC * Author: George Popescu <georgepope@google.com> */ +#include <linux/bitops.h> #include <linux/ctype.h> #include <linux/types.h> -#include <ubsan.h> +#include <linux/percpu-defs.h> +#include <linux/kvm_host.h> +#include <asm/kvm_arm.h> +#include <asm/kvm_asm.h> +#include <asm/kvm_ubsan.h> +#include <asm/kvm_debug_buffer.h> +#include <kvm/arm_pmu.h> + +DEFINE_KVM_DEBUG_BUFFER(struct kvm_ubsan_info, kvm_ubsan_buff, KVM_UBSAN_BUFFER_SIZE); + +static inline struct kvm_ubsan_info *kvm_ubsan_buffer_next_slot(void) +{ + struct kvm_ubsan_info *res; + struct kvm_ubsan_info *buff; + unsigned long *buff_ind; + unsigned long buff_size = KVM_UBSAN_BUFFER_SIZE; + unsigned int struct_size = sizeof(struct kvm_ubsan_info); + + init_kvm_debug_buffer(kvm_ubsan_buff, struct kvm_ubsan_info, buff, buff_ind); + res = kvm_debug_buffer_next_slot(buff, buff_ind, struct_size, buff_size); + return res; +} void __ubsan_handle_add_overflow(void *_data, void *lhs, void *rhs) {} diff --git a/arch/arm64/kvm/kvm_ubsan_buffer.c b/arch/arm64/kvm/kvm_ubsan_buffer.c new file mode 100644 index 000000000000..28dcf19b5706 --- /dev/null +++ b/arch/arm64/kvm/kvm_ubsan_buffer.c @@ -0,0 +1,32 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright 2020 Google LLC + * Author: George Popescu <georgepope@google.com> + */ + +#include <linux/ctype.h> +#include <linux/types.h> +#include <asm/kvm_debug_buffer.h> +#include <asm/kvm_arm.h> +#include <asm/kvm_asm.h> +#include <kvm/arm_pmu.h> + +#include <ubsan.h> +#include <asm/kvm_ubsan.h> + +DECLARE_KVM_DEBUG_BUFFER(struct kvm_ubsan_info, kvm_ubsan_buff, KVM_UBSAN_BUFFER_SIZE); + + +void __kvm_check_ubsan_buffer(void) +{ + unsigned long *write_ind; + unsigned long it; + struct kvm_ubsan_info *slot; + + init_kvm_debug_buffer(kvm_ubsan_buff, struct kvm_ubsan_info, slot, write_ind); + for_each_kvm_debug_buffer_slot(slot, write_ind, it) { + /* check ubsan data */ + slot->type = 0; + } +} +