diff options
Diffstat (limited to 'arch/x86/kernel/traps.c')
| -rw-r--r-- | arch/x86/kernel/traps.c | 55 |
1 files changed, 32 insertions, 23 deletions
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index 9f88b8a78e50..36354b470590 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -68,6 +68,7 @@ #include <asm/vdso.h> #include <asm/tdx.h> #include <asm/cfi.h> +#include <asm/msr.h> #ifdef CONFIG_X86_64 #include <asm/x86_init.h> @@ -351,7 +352,7 @@ static noinstr bool handle_bug(struct pt_regs *regs) case BUG_UD1_UBSAN: if (IS_ENABLED(CONFIG_UBSAN_TRAP)) { pr_crit("%s at %pS\n", - report_ubsan_failure(regs, ud_imm), + report_ubsan_failure(ud_imm), (void *)regs->ip); } break; @@ -749,7 +750,7 @@ static bool try_fixup_enqcmd_gp(void) if (current->pasid_activated) return false; - wrmsrl(MSR_IA32_PASID, pasid | MSR_IA32_PASID_VALID); + wrmsrq(MSR_IA32_PASID, pasid | MSR_IA32_PASID_VALID); current->pasid_activated = 1; return true; @@ -882,16 +883,16 @@ static void do_int3_user(struct pt_regs *regs) DEFINE_IDTENTRY_RAW(exc_int3) { /* - * poke_int3_handler() is completely self contained code; it does (and + * smp_text_poke_int3_handler() is completely self contained code; it does (and * must) *NOT* call out to anything, lest it hits upon yet another * INT3. */ - if (poke_int3_handler(regs)) + if (smp_text_poke_int3_handler(regs)) return; /* * irqentry_enter_from_user_mode() uses static_branch_{,un}likely() - * and therefore can trigger INT3, hence poke_int3_handler() must + * and therefore can trigger INT3, hence smp_text_poke_int3_handler() must * be done before. If the entry came from kernel mode, then use * nmi_enter() because the INT3 could have been hit in any context * including NMI. @@ -1021,24 +1022,32 @@ static bool is_sysenter_singlestep(struct pt_regs *regs) #endif } -static __always_inline unsigned long debug_read_clear_dr6(void) +static __always_inline unsigned long debug_read_reset_dr6(void) { unsigned long dr6; + get_debugreg(dr6, 6); + dr6 ^= DR6_RESERVED; /* Flip to positive polarity */ + /* * The Intel SDM says: * - * Certain debug exceptions may clear bits 0-3. The remaining - * contents of the DR6 register are never cleared by the - * processor. To avoid confusion in identifying debug - * exceptions, debug handlers should clear the register before - * returning to the interrupted task. + * Certain debug exceptions may clear bits 0-3 of DR6. + * + * BLD induced #DB clears DR6.BLD and any other debug + * exception doesn't modify DR6.BLD. * - * Keep it simple: clear DR6 immediately. + * RTM induced #DB clears DR6.RTM and any other debug + * exception sets DR6.RTM. + * + * To avoid confusion in identifying debug exceptions, + * debug handlers should set DR6.BLD and DR6.RTM, and + * clear other DR6 bits before returning. + * + * Keep it simple: write DR6 with its architectural reset + * value 0xFFFF0FF0, defined as DR6_RESERVED, immediately. */ - get_debugreg(dr6, 6); set_debugreg(DR6_RESERVED, 6); - dr6 ^= DR6_RESERVED; /* Flip to positive polarity */ return dr6; } @@ -1120,9 +1129,9 @@ static noinstr void exc_debug_kernel(struct pt_regs *regs, unsigned long dr6) */ unsigned long debugctl; - rdmsrl(MSR_IA32_DEBUGCTLMSR, debugctl); + rdmsrq(MSR_IA32_DEBUGCTLMSR, debugctl); debugctl |= DEBUGCTLMSR_BTF; - wrmsrl(MSR_IA32_DEBUGCTLMSR, debugctl); + wrmsrq(MSR_IA32_DEBUGCTLMSR, debugctl); } /* @@ -1238,13 +1247,13 @@ out: /* IST stack entry */ DEFINE_IDTENTRY_DEBUG(exc_debug) { - exc_debug_kernel(regs, debug_read_clear_dr6()); + exc_debug_kernel(regs, debug_read_reset_dr6()); } /* User entry, runs on regular task stack */ DEFINE_IDTENTRY_DEBUG_USER(exc_debug) { - exc_debug_user(regs, debug_read_clear_dr6()); + exc_debug_user(regs, debug_read_reset_dr6()); } #ifdef CONFIG_X86_FRED @@ -1263,7 +1272,7 @@ DEFINE_FREDENTRY_DEBUG(exc_debug) { /* * FRED #DB stores DR6 on the stack in the format which - * debug_read_clear_dr6() returns for the IDT entry points. + * debug_read_reset_dr6() returns for the IDT entry points. */ unsigned long dr6 = fred_event_data(regs); @@ -1278,7 +1287,7 @@ DEFINE_FREDENTRY_DEBUG(exc_debug) /* 32 bit does not have separate entry points. */ DEFINE_IDTENTRY_RAW(exc_debug) { - unsigned long dr6 = debug_read_clear_dr6(); + unsigned long dr6 = debug_read_reset_dr6(); if (user_mode(regs)) exc_debug_user(regs, dr6); @@ -1295,7 +1304,7 @@ DEFINE_IDTENTRY_RAW(exc_debug) static void math_error(struct pt_regs *regs, int trapnr) { struct task_struct *task = current; - struct fpu *fpu = &task->thread.fpu; + struct fpu *fpu = x86_task_fpu(task); int si_code; char *str = (trapnr == X86_TRAP_MF) ? "fpu exception" : "simd exception"; @@ -1386,11 +1395,11 @@ static bool handle_xfd_event(struct pt_regs *regs) if (!IS_ENABLED(CONFIG_X86_64) || !cpu_feature_enabled(X86_FEATURE_XFD)) return false; - rdmsrl(MSR_IA32_XFD_ERR, xfd_err); + rdmsrq(MSR_IA32_XFD_ERR, xfd_err); if (!xfd_err) return false; - wrmsrl(MSR_IA32_XFD_ERR, 0); + wrmsrq(MSR_IA32_XFD_ERR, 0); /* Die if that happens in kernel space */ if (WARN_ON(!user_mode(regs))) |