x86/entry: Convert General protection exception to IDTENTRY

Convert #GP to IDTENTRY_ERRORCODE:
  - Implement the C entry point with DEFINE_IDTENTRY
  - Emit the ASM stub with DECLARE_IDTENTRY
  - Remove the ASM idtentry in 64bit
  - Remove the open coded ASM entry code in 32bit
  - Fixup the XEN/PV code
  - Remove the old prototypes
  - Remove the RCU warning as the new entry macro ensures correctness

No functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Andy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20200505134905.637269946@linutronix.de

diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S
index ffe43d2..9d94a03 100644 (file)
--- a/arch/x86/entry/entry_32.S
+++ b/arch/x86/entry/entry_32.S
@@ -1302,7 +1302,7 @@ SYM_CODE_START(simd_coprocessor_error)
        pushl   $0
 #ifdef CONFIG_X86_INVD_BUG
        /* AMD 486 bug: invd from userspace calls exception 19 instead of #GP */
-       ALTERNATIVE "pushl      $do_general_protection",        \
+       ALTERNATIVE "pushl      $exc_general_protection",       \
                    "pushl      $do_simd_coprocessor_error",    \
                    X86_FEATURE_XMM
 #else
@@ -1690,12 +1690,6 @@ SYM_CODE_START(int3)
        jmp     common_exception
 SYM_CODE_END(int3)
 
-SYM_CODE_START(general_protection)
-       ASM_CLAC
-       pushl   $do_general_protection
-       jmp     common_exception
-SYM_CODE_END(general_protection)
-
 .pushsection .text, "ax"
 SYM_CODE_START(rewind_stack_do_exit)
        /* Prevent any naive code from trying to unwind to our caller. */

diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index c92592d..5cecdd1 100644 (file)
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -1073,7 +1073,6 @@ apicinterrupt IRQ_WORK_VECTOR                     irq_work_interrupt              smp_irq_work_interrupt
  */
 
 idtentry       X86_TRAP_BP             int3                    do_int3                         has_error_code=0
-idtentry       X86_TRAP_GP             general_protection      do_general_protection           has_error_code=1
 idtentry       X86_TRAP_SPURIOUS       spurious_interrupt_bug  do_spurious_interrupt_bug       has_error_code=0
 idtentry       X86_TRAP_MF             coprocessor_error       do_coprocessor_error            has_error_code=0
 idtentry       X86_TRAP_AC             alignment_check         do_alignment_check              has_error_code=1
@@ -1209,7 +1208,7 @@ SYM_CODE_START(xen_failsafe_callback)
        addq    $0x30, %rsp
        pushq   $0                              /* RIP */
        UNWIND_HINT_IRET_REGS offset=8
-       jmp     general_protection
+       jmp     asm_exc_general_protection
 1:     /* Segment mismatch => Category 1 (Bad segment). Retry the IRET. */
        movq    (%rsp), %rcx
        movq    8(%rsp), %r11

diff --git a/arch/x86/include/asm/idtentry.h b/arch/x86/include/asm/idtentry.h
index 4c0abd3..986fc65 100644 (file)
--- a/arch/x86/include/asm/idtentry.h
+++ b/arch/x86/include/asm/idtentry.h
@@ -134,5 +134,6 @@ DECLARE_IDTENTRY(X86_TRAP_OLD_MF,   exc_coproc_segment_overrun);
 DECLARE_IDTENTRY_ERRORCODE(X86_TRAP_TS,        exc_invalid_tss);
 DECLARE_IDTENTRY_ERRORCODE(X86_TRAP_NP,        exc_segment_not_present);
 DECLARE_IDTENTRY_ERRORCODE(X86_TRAP_SS,        exc_stack_segment);
+DECLARE_IDTENTRY_ERRORCODE(X86_TRAP_GP,        exc_general_protection);
 
 #endif

diff --git a/arch/x86/include/asm/traps.h b/arch/x86/include/asm/traps.h
index 5e580ff..3a096a4 100644 (file)
--- a/arch/x86/include/asm/traps.h
+++ b/arch/x86/include/asm/traps.h
@@ -17,7 +17,6 @@ asmlinkage void int3(void);
 #ifdef CONFIG_X86_64
 asmlinkage void double_fault(void);
 #endif
-asmlinkage void general_protection(void);
 asmlinkage void page_fault(void);
 asmlinkage void async_page_fault(void);
 asmlinkage void spurious_interrupt_bug(void);
@@ -33,7 +32,6 @@ asmlinkage void xen_xennmi(void);
 asmlinkage void xen_xendebug(void);
 asmlinkage void xen_int3(void);
 asmlinkage void xen_double_fault(void);
-asmlinkage void xen_general_protection(void);
 asmlinkage void xen_page_fault(void);
 asmlinkage void xen_spurious_interrupt_bug(void);
 asmlinkage void xen_coprocessor_error(void);
@@ -48,7 +46,6 @@ dotraplinkage void do_debug(struct pt_regs *regs, long error_code);
 dotraplinkage void do_nmi(struct pt_regs *regs, long error_code);
 dotraplinkage void do_int3(struct pt_regs *regs, long error_code);
 dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code, unsigned long cr2);
-dotraplinkage void do_general_protection(struct pt_regs *regs, long error_code);
 dotraplinkage void do_page_fault(struct pt_regs *regs, unsigned long error_code, unsigned long address);
 dotraplinkage void do_spurious_interrupt_bug(struct pt_regs *regs, long error_code);
 dotraplinkage void do_coprocessor_error(struct pt_regs *regs, long error_code);

diff --git a/arch/x86/kernel/idt.c b/arch/x86/kernel/idt.c
index 8d95cbf..6f0af12 100644 (file)
--- a/arch/x86/kernel/idt.c
+++ b/arch/x86/kernel/idt.c
@@ -82,7 +82,7 @@ static const __initconst struct idt_data def_idts[] = {
        INTG(X86_TRAP_TS,               asm_exc_invalid_tss),
        INTG(X86_TRAP_NP,               asm_exc_segment_not_present),
        INTG(X86_TRAP_SS,               asm_exc_stack_segment),
-       INTG(X86_TRAP_GP,               general_protection),
+       INTG(X86_TRAP_GP,               asm_exc_general_protection),
        INTG(X86_TRAP_SPURIOUS,         spurious_interrupt_bug),
        INTG(X86_TRAP_MF,               coprocessor_error),
        INTG(X86_TRAP_AC,               alignment_check),

diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 3dfdc4d..e65c761 100644 (file)
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -145,7 +145,7 @@ do_trap_no_signal(struct task_struct *tsk, int trapnr, const char *str,
         * process no chance to handle the signal and notice the
         * kernel fault information, so that won't result in polluting
         * the information about previously queued, but not yet
-        * delivered, faults.  See also do_general_protection below.
+        * delivered, faults.  See also exc_general_protection below.
         */
        tsk->thread.error_code = error_code;
        tsk->thread.trap_nr = trapnr;
@@ -375,7 +375,7 @@ dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code, unsign
                 * which is what the stub expects, given that the faulting
                 * RIP will be the IRET instruction.
                 */
-               regs->ip = (unsigned long)general_protection;
+               regs->ip = (unsigned long)asm_exc_general_protection;
                regs->sp = (unsigned long)&gpregs->orig_ax;
 
                return;
@@ -494,7 +494,7 @@ static enum kernel_gp_hint get_kernel_gp_address(struct pt_regs *regs,
 
 #define GPFSTR "general protection fault"
 
-dotraplinkage void do_general_protection(struct pt_regs *regs, long error_code)
+DEFINE_IDTENTRY_ERRORCODE(exc_general_protection)
 {
        char desc[sizeof(GPFSTR) + 50 + 2*sizeof(unsigned long) + 1] = GPFSTR;
        enum kernel_gp_hint hint = GP_NO_HINT;
@@ -502,7 +502,6 @@ dotraplinkage void do_general_protection(struct pt_regs *regs, long error_code)
        unsigned long gp_addr;
        int ret;
 
-       RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU");
        cond_local_irq_enable(regs);
 
        if (static_cpu_has(X86_FEATURE_UMIP)) {
@@ -570,7 +569,6 @@ dotraplinkage void do_general_protection(struct pt_regs *regs, long error_code)
 exit:
        cond_local_irq_disable(regs);
 }
-NOKPROBE_SYMBOL(do_general_protection);
 
 dotraplinkage void notrace do_int3(struct pt_regs *regs, long error_code)
 {

diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
index 8290f39..ca441c7 100644 (file)
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -630,7 +630,7 @@ static struct trap_array_entry trap_array[] = {
        TRAP_ENTRY(exc_invalid_tss,                     false ),
        TRAP_ENTRY(exc_segment_not_present,             false ),
        TRAP_ENTRY(exc_stack_segment,                   false ),
-       { general_protection,          xen_general_protection,          false },
+       TRAP_ENTRY(exc_general_protection,              false ),
        { spurious_interrupt_bug,      xen_spurious_interrupt_bug,      false },
        { coprocessor_error,           xen_coprocessor_error,           false },
        { alignment_check,             xen_alignment_check,             false },

diff --git a/arch/x86/xen/xen-asm_64.S b/arch/x86/xen/xen-asm_64.S
index 0ecc055..802ec00 100644 (file)
--- a/arch/x86/xen/xen-asm_64.S
+++ b/arch/x86/xen/xen-asm_64.S
@@ -42,7 +42,7 @@ xen_pv_trap asm_exc_coproc_segment_overrun
 xen_pv_trap asm_exc_invalid_tss
 xen_pv_trap asm_exc_segment_not_present
 xen_pv_trap asm_exc_stack_segment
-xen_pv_trap general_protection
+xen_pv_trap asm_exc_general_protection
 xen_pv_trap page_fault
 xen_pv_trap spurious_interrupt_bug
 xen_pv_trap coprocessor_error