| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <6eb528bd-adc5-983a-3725-ff95cab85a72@loongson.cn> Date: Wed, 31 Dec 2025 09:11:16 +0800 From: lixianglai <lixianglai@...ngson.cn> To: Bibo Mao <maobibo@...ngson.cn>, loongarch@...ts.linux.dev, linux-kernel@...r.kernel.org, kvm@...r.kernel.org Cc: stable@...r.kernel.org, Huacai Chen <chenhuacai@...nel.org>, WANG Xuerui <kernel@...0n.name>, Tianrui Zhao <zhaotianrui@...ngson.cn>, Charlie Jenkins <charlie@...osinc.com>, Thomas Gleixner <tglx@...utronix.de>, Tiezhu Yang <yangtiezhu@...ngson.cn> Subject: Re: [PATCH V3 2/2] LoongArch: KVM: fix "unreliable stack" issue Hi Bibo Mao: > > > On 2025/12/27 上午9:27, Xianglai Li wrote: >> Insert the appropriate UNWIND macro definition into the kvm_exc_entry in >> the assembly function to guide the generation of correct ORC table >> entries, >> thereby solving the timeout problem of loading the livepatch-sample >> module >> on a physical machine running multiple vcpus virtual machines. >> >> While solving the above problems, we have gained an additional benefit, >> that is, we can obtain more call stack information >> >> Stack information that can be obtained before the problem is fixed: >> [<0>] kvm_vcpu_block+0x88/0x120 [kvm] >> [<0>] kvm_vcpu_halt+0x68/0x580 [kvm] >> [<0>] kvm_emu_idle+0xd4/0xf0 [kvm] >> [<0>] kvm_handle_gspr+0x7c/0x700 [kvm] >> [<0>] kvm_handle_exit+0x160/0x270 [kvm] >> [<0>] kvm_exc_entry+0x100/0x1e0 >> >> Stack information that can be obtained after the problem is fixed: >> [<0>] kvm_vcpu_block+0x88/0x120 [kvm] >> [<0>] kvm_vcpu_halt+0x68/0x580 [kvm] >> [<0>] kvm_emu_idle+0xd4/0xf0 [kvm] >> [<0>] kvm_handle_gspr+0x7c/0x700 [kvm] >> [<0>] kvm_handle_exit+0x160/0x270 [kvm] >> [<0>] kvm_exc_entry+0x104/0x1e4 >> [<0>] kvm_enter_guest+0x38/0x11c >> [<0>] kvm_arch_vcpu_ioctl_run+0x26c/0x498 [kvm] >> [<0>] kvm_vcpu_ioctl+0x200/0xcf8 [kvm] >> [<0>] sys_ioctl+0x498/0xf00 >> [<0>] do_syscall+0x98/0x1d0 >> [<0>] handle_syscall+0xb8/0x158 >> >> Cc: stable@...r.kernel.org >> Signed-off-by: Xianglai Li <lixianglai@...ngson.cn> >> --- >> Cc: Huacai Chen <chenhuacai@...nel.org> >> Cc: WANG Xuerui <kernel@...0n.name> >> Cc: Tianrui Zhao <zhaotianrui@...ngson.cn> >> Cc: Bibo Mao <maobibo@...ngson.cn> >> Cc: Charlie Jenkins <charlie@...osinc.com> >> Cc: Xianglai Li <lixianglai@...ngson.cn> >> Cc: Thomas Gleixner <tglx@...utronix.de> >> Cc: Tiezhu Yang <yangtiezhu@...ngson.cn> >> >> arch/loongarch/kvm/switch.S | 28 +++++++++++++++++++--------- >> 1 file changed, 19 insertions(+), 9 deletions(-) >> >> diff --git a/arch/loongarch/kvm/switch.S b/arch/loongarch/kvm/switch.S >> index 93845ce53651..a3ea9567dbe5 100644 >> --- a/arch/loongarch/kvm/switch.S >> +++ b/arch/loongarch/kvm/switch.S >> @@ -10,6 +10,7 @@ >> #include <asm/loongarch.h> >> #include <asm/regdef.h> >> #include <asm/unwind_hints.h> >> +#include <linux/kvm_types.h> >> #define HGPR_OFFSET(x) (PT_R0 + 8*x) >> #define GGPR_OFFSET(x) (KVM_ARCH_GGPR + 8*x) >> @@ -110,9 +111,9 @@ >> * need to copy world switch code to DMW area. >> */ >> .text >> + .p2align PAGE_SHIFT >> .cfi_sections .debug_frame >> SYM_CODE_START(kvm_exc_entry) >> - .p2align PAGE_SHIFT >> UNWIND_HINT_UNDEFINED >> csrwr a2, KVM_TEMP_KS >> csrrd a2, KVM_VCPU_KS >> @@ -170,6 +171,7 @@ SYM_CODE_START(kvm_exc_entry) >> /* restore per cpu register */ >> ld.d u0, a2, KVM_ARCH_HPERCPU >> addi.d sp, sp, -PT_SIZE >> + UNWIND_HINT_REGS >> /* Prepare handle exception */ >> or a0, s0, zero >> @@ -200,7 +202,7 @@ ret_to_host: >> jr ra >> SYM_CODE_END(kvm_exc_entry) >> -EXPORT_SYMBOL(kvm_exc_entry) >> +EXPORT_SYMBOL_FOR_KVM(kvm_exc_entry) >> /* >> * int kvm_enter_guest(struct kvm_run *run, struct kvm_vcpu *vcpu) >> @@ -215,6 +217,14 @@ SYM_FUNC_START(kvm_enter_guest) >> /* Save host GPRs */ >> kvm_save_host_gpr a2 >> + /* >> + * The csr_era member variable of the pt_regs structure is required >> + * for unwinding orc to perform stack traceback, so we need to put >> + * pc into csr_era member variable here. >> + */ >> + pcaddi t0, 0 >> + st.d t0, a2, PT_ERA > maybe PRMD need be set with fake pt_regs also, something like this: > ori t0, zero, CSR_PRMD_PIE > st.d t0, a2, PT_PRMD > Ok, I will fix it in the next version Thanks, Xianglai. > Regards > Bibo Mao >> + >> addi.d a2, a1, KVM_VCPU_ARCH >> st.d sp, a2, KVM_ARCH_HSP >> st.d tp, a2, KVM_ARCH_HTP >> @@ -225,7 +235,7 @@ SYM_FUNC_START(kvm_enter_guest) >> csrwr a1, KVM_VCPU_KS >> kvm_switch_to_guest >> SYM_FUNC_END(kvm_enter_guest) >> -EXPORT_SYMBOL(kvm_enter_guest) >> +EXPORT_SYMBOL_FOR_KVM(kvm_enter_guest) >> SYM_FUNC_START(kvm_save_fpu) >> fpu_save_csr a0 t1 >> @@ -233,7 +243,7 @@ SYM_FUNC_START(kvm_save_fpu) >> fpu_save_cc a0 t1 t2 >> jr ra >> SYM_FUNC_END(kvm_save_fpu) >> -EXPORT_SYMBOL(kvm_save_fpu) >> +EXPORT_SYMBOL_FOR_KVM(kvm_save_fpu) >> SYM_FUNC_START(kvm_restore_fpu) >> fpu_restore_double a0 t1 >> @@ -241,7 +251,7 @@ SYM_FUNC_START(kvm_restore_fpu) >> fpu_restore_cc a0 t1 t2 >> jr ra >> SYM_FUNC_END(kvm_restore_fpu) >> -EXPORT_SYMBOL(kvm_restore_fpu) >> +EXPORT_SYMBOL_FOR_KVM(kvm_restore_fpu) >> #ifdef CONFIG_CPU_HAS_LSX >> SYM_FUNC_START(kvm_save_lsx) >> @@ -250,7 +260,7 @@ SYM_FUNC_START(kvm_save_lsx) >> lsx_save_data a0 t1 >> jr ra >> SYM_FUNC_END(kvm_save_lsx) >> -EXPORT_SYMBOL(kvm_save_lsx) >> +EXPORT_SYMBOL_FOR_KVM(kvm_save_lsx) >> SYM_FUNC_START(kvm_restore_lsx) >> lsx_restore_data a0 t1 >> @@ -258,7 +268,7 @@ SYM_FUNC_START(kvm_restore_lsx) >> fpu_restore_csr a0 t1 t2 >> jr ra >> SYM_FUNC_END(kvm_restore_lsx) >> -EXPORT_SYMBOL(kvm_restore_lsx) >> +EXPORT_SYMBOL_FOR_KVM(kvm_restore_lsx) >> #endif >> #ifdef CONFIG_CPU_HAS_LASX >> @@ -268,7 +278,7 @@ SYM_FUNC_START(kvm_save_lasx) >> lasx_save_data a0 t1 >> jr ra >> SYM_FUNC_END(kvm_save_lasx) >> -EXPORT_SYMBOL(kvm_save_lasx) >> +EXPORT_SYMBOL_FOR_KVM(kvm_save_lasx) >> SYM_FUNC_START(kvm_restore_lasx) >> lasx_restore_data a0 t1 >> @@ -276,7 +286,7 @@ SYM_FUNC_START(kvm_restore_lasx) >> fpu_restore_csr a0 t1 t2 >> jr ra >> SYM_FUNC_END(kvm_restore_lasx) >> -EXPORT_SYMBOL(kvm_restore_lasx) >> +EXPORT_SYMBOL_FOR_KVM(kvm_restore_lasx) >> #endif >> #ifdef CONFIG_CPU_HAS_LBT >>
Powered by blists - more mailing lists