diff options
Diffstat (limited to 'arch/arm64/kernel')
| -rw-r--r-- | arch/arm64/kernel/entry.S | 22 | ||||
| -rw-r--r-- | arch/arm64/kernel/fpsimd.c | 29 | ||||
| -rw-r--r-- | arch/arm64/kernel/perf_callchain.c | 7 | ||||
| -rw-r--r-- | arch/arm64/kernel/process.c | 36 | ||||
| -rw-r--r-- | arch/arm64/kernel/return_address.c | 9 | ||||
| -rw-r--r-- | arch/arm64/kernel/stacktrace.c | 59 | ||||
| -rw-r--r-- | arch/arm64/kernel/time.c | 7 | ||||
| -rw-r--r-- | arch/arm64/kernel/traps.c | 13 | ||||
| -rw-r--r-- | arch/arm64/kernel/vdso/Makefile | 13 | ||||
| -rw-r--r-- | arch/arm64/kernel/vdso32/Makefile | 14 |
10 files changed, 129 insertions, 80 deletions
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index 9cdc4592da3e..320a30dbe35e 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -586,10 +586,8 @@ el1_sync: b.eq el1_ia cmp x24, #ESR_ELx_EC_SYS64 // configurable trap b.eq el1_undef - cmp x24, #ESR_ELx_EC_SP_ALIGN // stack alignment exception - b.eq el1_sp_pc cmp x24, #ESR_ELx_EC_PC_ALIGN // pc alignment exception - b.eq el1_sp_pc + b.eq el1_pc cmp x24, #ESR_ELx_EC_UNKNOWN // unknown exception in EL1 b.eq el1_undef cmp x24, #ESR_ELx_EC_BREAKPT_CUR // debug exception in EL1 @@ -611,9 +609,11 @@ el1_da: bl do_mem_abort kernel_exit 1 -el1_sp_pc: +el1_pc: /* - * Stack or PC alignment exception handling + * PC alignment exception handling. We don't handle SP alignment faults, + * since we will have hit a recursive exception when trying to push the + * initial pt_regs. */ mrs x0, far_el1 inherit_daif pstate=x23, tmp=x2 @@ -732,9 +732,9 @@ el0_sync: ccmp x24, #ESR_ELx_EC_WFx, #4, ne b.eq el0_sys cmp x24, #ESR_ELx_EC_SP_ALIGN // stack alignment exception - b.eq el0_sp_pc + b.eq el0_sp cmp x24, #ESR_ELx_EC_PC_ALIGN // pc alignment exception - b.eq el0_sp_pc + b.eq el0_pc cmp x24, #ESR_ELx_EC_UNKNOWN // unknown exception in EL0 b.eq el0_undef cmp x24, #ESR_ELx_EC_BREAKPT_LOW // debug exception in EL0 @@ -758,7 +758,7 @@ el0_sync_compat: cmp x24, #ESR_ELx_EC_FP_EXC32 // FP/ASIMD exception b.eq el0_fpsimd_exc cmp x24, #ESR_ELx_EC_PC_ALIGN // pc alignment exception - b.eq el0_sp_pc + b.eq el0_pc cmp x24, #ESR_ELx_EC_UNKNOWN // unknown exception in EL0 b.eq el0_undef cmp x24, #ESR_ELx_EC_CP15_32 // CP15 MRC/MCR trap @@ -858,11 +858,15 @@ el0_fpsimd_exc: mov x1, sp bl do_fpsimd_exc b ret_to_user +el0_sp: + ldr x26, [sp, #S_SP] + b el0_sp_pc +el0_pc: + mrs x26, far_el1 el0_sp_pc: /* * Stack or PC alignment exception handling */ - mrs x26, far_el1 gic_prio_kentry_setup tmp=x0 enable_da_f #ifdef CONFIG_TRACE_IRQFLAGS diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c index eec4776ae5f0..37d3912cfe06 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -406,6 +406,18 @@ static __uint128_t arm64_cpu_to_le128(__uint128_t x) #define arm64_le128_to_cpu(x) arm64_cpu_to_le128(x) +static void __fpsimd_to_sve(void *sst, struct user_fpsimd_state const *fst, + unsigned int vq) +{ + unsigned int i; + __uint128_t *p; + + for (i = 0; i < SVE_NUM_ZREGS; ++i) { + p = (__uint128_t *)ZREG(sst, vq, i); + *p = arm64_cpu_to_le128(fst->vregs[i]); + } +} + /* * Transfer the FPSIMD state in task->thread.uw.fpsimd_state to * task->thread.sve_state. @@ -423,17 +435,12 @@ static void fpsimd_to_sve(struct task_struct *task) unsigned int vq; void *sst = task->thread.sve_state; struct user_fpsimd_state const *fst = &task->thread.uw.fpsimd_state; - unsigned int i; - __uint128_t *p; if (!system_supports_sve()) return; vq = sve_vq_from_vl(task->thread.sve_vl); - for (i = 0; i < 32; ++i) { - p = (__uint128_t *)ZREG(sst, vq, i); - *p = arm64_cpu_to_le128(fst->vregs[i]); - } + __fpsimd_to_sve(sst, fst, vq); } /* @@ -459,7 +466,7 @@ static void sve_to_fpsimd(struct task_struct *task) return; vq = sve_vq_from_vl(task->thread.sve_vl); - for (i = 0; i < 32; ++i) { + for (i = 0; i < SVE_NUM_ZREGS; ++i) { p = (__uint128_t const *)ZREG(sst, vq, i); fst->vregs[i] = arm64_le128_to_cpu(*p); } @@ -550,8 +557,6 @@ void sve_sync_from_fpsimd_zeropad(struct task_struct *task) unsigned int vq; void *sst = task->thread.sve_state; struct user_fpsimd_state const *fst = &task->thread.uw.fpsimd_state; - unsigned int i; - __uint128_t *p; if (!test_tsk_thread_flag(task, TIF_SVE)) return; @@ -559,11 +564,7 @@ void sve_sync_from_fpsimd_zeropad(struct task_struct *task) vq = sve_vq_from_vl(task->thread.sve_vl); memset(sst, 0, SVE_SIG_REGS_SIZE(vq)); - - for (i = 0; i < 32; ++i) { - p = (__uint128_t *)ZREG(sst, vq, i); - *p = arm64_cpu_to_le128(fst->vregs[i]); - } + __fpsimd_to_sve(sst, fst, vq); } int sve_set_vector_length(struct task_struct *task, diff --git a/arch/arm64/kernel/perf_callchain.c b/arch/arm64/kernel/perf_callchain.c index 9d63514b9836..b0e03e052dd1 100644 --- a/arch/arm64/kernel/perf_callchain.c +++ b/arch/arm64/kernel/perf_callchain.c @@ -154,12 +154,7 @@ void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, return; } - frame.fp = regs->regs[29]; - frame.pc = regs->pc; -#ifdef CONFIG_FUNCTION_GRAPH_TRACER - frame.graph = 0; -#endif - + start_backtrace(&frame, regs->regs[29], regs->pc); walk_stackframe(current, &frame, callchain_trace, entry); } diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index 6a869d9f304f..f674f28df663 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -398,7 +398,7 @@ int copy_thread(unsigned long clone_flags, unsigned long stack_start, childregs->pstate |= PSR_UAO_BIT; if (arm64_get_ssbd_state() == ARM64_SSBD_FORCE_DISABLE) - childregs->pstate |= PSR_SSBS_BIT; + set_ssbs_bit(childregs); if (system_uses_irq_prio_masking()) childregs->pmr_save = GIC_PRIO_IRQON; @@ -443,6 +443,32 @@ void uao_thread_switch(struct task_struct *next) } /* + * Force SSBS state on context-switch, since it may be lost after migrating + * from a CPU which treats the bit as RES0 in a heterogeneous system. + */ +static void ssbs_thread_switch(struct task_struct *next) +{ + struct pt_regs *regs = task_pt_regs(next); + + /* + * Nothing to do for kernel threads, but 'regs' may be junk + * (e.g. idle task) so check the flags and bail early. + */ + if (unlikely(next->flags & PF_KTHREAD)) + return; + + /* If the mitigation is enabled, then we leave SSBS clear. */ + if ((arm64_get_ssbd_state() == ARM64_SSBD_FORCE_ENABLE) || + test_tsk_thread_flag(next, TIF_SSBD)) + return; + + if (compat_user_mode(regs)) + set_compat_ssbs_bit(regs); + else if (user_mode(regs)) + set_ssbs_bit(regs); +} + +/* * We store our current task in sp_el0, which is clobbered by userspace. Keep a * shadow copy so that we can restore this upon entry from userspace. * @@ -471,6 +497,7 @@ __notrace_funcgraph struct task_struct *__switch_to(struct task_struct *prev, entry_task_switch(next); uao_thread_switch(next); ptrauth_thread_switch(next); + ssbs_thread_switch(next); /* * Complete any pending TLB or cache maintenance on this CPU in case @@ -498,11 +525,8 @@ unsigned long get_wchan(struct task_struct *p) if (!stack_page) return 0; - frame.fp = thread_saved_fp(p); - frame.pc = thread_saved_pc(p); -#ifdef CONFIG_FUNCTION_GRAPH_TRACER - frame.graph = 0; -#endif + start_backtrace(&frame, thread_saved_fp(p), thread_saved_pc(p)); + do { if (unwind_frame(p, &frame)) goto out; diff --git a/arch/arm64/kernel/return_address.c b/arch/arm64/kernel/return_address.c index b21cba90f82d..c4ae647d2306 100644 --- a/arch/arm64/kernel/return_address.c +++ b/arch/arm64/kernel/return_address.c @@ -38,12 +38,9 @@ void *return_address(unsigned int level) data.level = level + 2; data.addr = NULL; - frame.fp = (unsigned long)__builtin_frame_address(0); - frame.pc = (unsigned long)return_address; /* dummy */ -#ifdef CONFIG_FUNCTION_GRAPH_TRACER - frame.graph = 0; -#endif - + start_backtrace(&frame, + (unsigned long)__builtin_frame_address(0), + (unsigned long)return_address); walk_stackframe(current, &frame, save_return_addr, &data); if (!data.level) diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c index 62d395151abe..2b160ae594eb 100644 --- a/arch/arm64/kernel/stacktrace.c +++ b/arch/arm64/kernel/stacktrace.c @@ -29,9 +29,18 @@ * ldp x29, x30, [sp] * add sp, sp, #0x10 */ + +/* + * Unwind from one frame record (A) to the next frame record (B). + * + * We terminate early if the location of B indicates a malformed chain of frame + * records (e.g. a cycle), determined based on the location and fp value of A + * and the location (but not the fp value) of B. + */ int notrace unwind_frame(struct task_struct *tsk, struct stackframe *frame) { unsigned long fp = frame->fp; + struct stack_info info; if (fp & 0xf) return -EINVAL; @@ -39,11 +48,40 @@ int notrace unwind_frame(struct task_struct *tsk, struct stackframe *frame) if (!tsk) tsk = current; - if (!on_accessible_stack(tsk, fp, NULL)) + if (!on_accessible_stack(tsk, fp, &info)) + return -EINVAL; + + if (test_bit(info.type, frame->stacks_done)) return -EINVAL; + /* + * As stacks grow downward, any valid record on the same stack must be + * at a strictly higher address than the prior record. + * + * Stacks can nest in several valid orders, e.g. + * + * TASK -> IRQ -> OVERFLOW -> SDEI_NORMAL + * TASK -> SDEI_NORMAL -> SDEI_CRITICAL -> OVERFLOW + * + * ... but the nesting itself is strict. Once we transition from one + * stack to another, it's never valid to unwind back to that first + * stack. + */ + if (info.type == frame->prev_type) { + if (fp <= frame->prev_fp) + return -EINVAL; + } else { + set_bit(frame->prev_type, frame->stacks_done); + } + + /* + * Record this frame record's values and location. The prev_fp and + * prev_type are only meaningful to the next unwind_frame() invocation. + */ frame->fp = READ_ONCE_NOCHECK(*(unsigned long *)(fp)); frame->pc = READ_ONCE_NOCHECK(*(unsigned long *)(fp + 8)); + frame->prev_fp = fp; + frame->prev_type = info.type; #ifdef CONFIG_FUNCTION_GRAPH_TRACER if (tsk->ret_stack && @@ -122,12 +160,7 @@ void save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace) data.skip = trace->skip; data.no_sched_functions = 0; - frame.fp = regs->regs[29]; - frame.pc = regs->pc; -#ifdef CONFIG_FUNCTION_GRAPH_TRACER - frame.graph = 0; -#endif - + start_backtrace(&frame, regs->regs[29], regs->pc); walk_stackframe(current, &frame, save_trace, &data); } EXPORT_SYMBOL_GPL(save_stack_trace_regs); @@ -146,17 +179,15 @@ static noinline void __save_stack_trace(struct task_struct *tsk, data.no_sched_functions = nosched; if (tsk != current) { - frame.fp = thread_saved_fp(tsk); - frame.pc = thread_saved_pc(tsk); + start_backtrace(&frame, thread_saved_fp(tsk), + thread_saved_pc(tsk)); } else { /* We don't want this function nor the caller */ data.skip += 2; - frame.fp = (unsigned long)__builtin_frame_address(0); - frame.pc = (unsigned long)__save_stack_trace; + start_backtrace(&frame, + (unsigned long)__builtin_frame_address(0), + (unsigned long)__save_stack_trace); } -#ifdef CONFIG_FUNCTION_GRAPH_TRACER - frame.graph = 0; -#endif walk_stackframe(tsk, &frame, save_trace, &data); diff --git a/arch/arm64/kernel/time.c b/arch/arm64/kernel/time.c index 9f25aedeac9d..0b2946414dc9 100644 --- a/arch/arm64/kernel/time.c +++ b/arch/arm64/kernel/time.c @@ -38,11 +38,8 @@ unsigned long profile_pc(struct pt_regs *regs) if (!in_lock_functions(regs->pc)) return regs->pc; - frame.fp = regs->regs[29]; - frame.pc = regs->pc; -#ifdef CONFIG_FUNCTION_GRAPH_TRACER - frame.graph = 0; -#endif + start_backtrace(&frame, regs->regs[29], regs->pc); + do { int ret = unwind_frame(NULL, &frame); if (ret < 0) diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c index 969e1565152b..32893b3d9164 100644 --- a/arch/arm64/kernel/traps.c +++ b/arch/arm64/kernel/traps.c @@ -100,18 +100,17 @@ void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk) return; if (tsk == current) { - frame.fp = (unsigned long)__builtin_frame_address(0); - frame.pc = (unsigned long)dump_backtrace; + start_backtrace(&frame, + (unsigned long)__builtin_frame_address(0), + (unsigned long)dump_backtrace); } else { /* * task blocked in __switch_to */ - frame.fp = thread_saved_fp(tsk); - frame.pc = thread_saved_pc(tsk); + start_backtrace(&frame, + thread_saved_fp(tsk), + thread_saved_pc(tsk)); } -#ifdef CONFIG_FUNCTION_GRAPH_TRACER - frame.graph = 0; -#endif printk("Call trace:\n"); do { diff --git a/arch/arm64/kernel/vdso/Makefile b/arch/arm64/kernel/vdso/Makefile index 4ab863045188..dd2514bb1511 100644 --- a/arch/arm64/kernel/vdso/Makefile +++ b/arch/arm64/kernel/vdso/Makefile @@ -32,10 +32,10 @@ UBSAN_SANITIZE := n OBJECT_FILES_NON_STANDARD := y KCOV_INSTRUMENT := n -ifeq ($(c-gettimeofday-y),) CFLAGS_vgettimeofday.o = -O2 -mcmodel=tiny -else -CFLAGS_vgettimeofday.o = -O2 -mcmodel=tiny -include $(c-gettimeofday-y) + +ifneq ($(c-gettimeofday-y),) + CFLAGS_vgettimeofday.o += -include $(c-gettimeofday-y) endif # Clang versions less than 8 do not support -mcmodel=tiny @@ -57,8 +57,7 @@ $(obj)/vdso.o : $(obj)/vdso.so # Link rule for the .so file, .lds has to be first $(obj)/vdso.so.dbg: $(obj)/vdso.lds $(obj-vdso) FORCE - $(call if_changed,ld) - $(call if_changed,vdso_check) + $(call if_changed,vdsold_and_vdso_check) # Strip rule for the .so file $(obj)/%.so: OBJCOPYFLAGS := -S @@ -74,8 +73,8 @@ include/generated/vdso-offsets.h: $(obj)/vdso.so.dbg FORCE $(call if_changed,vdsosym) # Actual build commands -quiet_cmd_vdsocc = VDSOCC $@ - cmd_vdsocc = $(CC) $(a_flags) $(c_flags) -c -o $@ $< +quiet_cmd_vdsold_and_vdso_check = LD $@ + cmd_vdsold_and_vdso_check = $(cmd_ld); $(cmd_vdso_check) # Install commands for the unstripped file quiet_cmd_vdso_install = INSTALL $@ diff --git a/arch/arm64/kernel/vdso32/Makefile b/arch/arm64/kernel/vdso32/Makefile index 60a4c6239712..1fba0776ed40 100644 --- a/arch/arm64/kernel/vdso32/Makefile +++ b/arch/arm64/kernel/vdso32/Makefile @@ -144,8 +144,7 @@ $(obj)/vdso.so.dbg: $(obj)/vdso.so.raw $(obj)/$(munge) FORCE # Link rule for the .so file, .lds has to be first $(obj)/vdso.so.raw: $(src)/vdso.lds $(obj-vdso) FORCE - $(call if_changed,vdsold) - $(call if_changed,vdso_check) + $(call if_changed,vdsold_and_vdso_check) # Compilation rules for the vDSO sources $(c-obj-vdso): %.o: %.c FORCE @@ -156,14 +155,17 @@ $(asm-obj-vdso): %.o: %.S FORCE $(call if_changed_dep,vdsoas) # Actual build commands -quiet_cmd_vdsold = VDSOL $@ +quiet_cmd_vdsold_and_vdso_check = LD32 $@ + cmd_vdsold_and_vdso_check = $(cmd_vdsold); $(cmd_vdso_check) + +quiet_cmd_vdsold = LD32 $@ cmd_vdsold = $(COMPATCC) -Wp,-MD,$(depfile) $(VDSO_LDFLAGS) \ -Wl,-T $(filter %.lds,$^) $(filter %.o,$^) -o $@ -quiet_cmd_vdsocc = VDSOC $@ +quiet_cmd_vdsocc = CC32 $@ cmd_vdsocc = $(COMPATCC) -Wp,-MD,$(depfile) $(VDSO_CFLAGS) -c -o $@ $< -quiet_cmd_vdsocc_gettimeofday = VDSOC_GTD $@ +quiet_cmd_vdsocc_gettimeofday = CC32 $@ cmd_vdsocc_gettimeofday = $(COMPATCC) -Wp,-MD,$(depfile) $(VDSO_CFLAGS) $(VDSO_CFLAGS_gettimeofday_o) -c -o $@ $< -quiet_cmd_vdsoas = VDSOA $@ +quiet_cmd_vdsoas = AS32 $@ cmd_vdsoas = $(COMPATCC) -Wp,-MD,$(depfile) $(VDSO_AFLAGS) -c -o $@ $< quiet_cmd_vdsomunge = MUNGE $@ |