alpha: Generate dwarf2 unwind info for various kernel entry points.

Having unwind info past the PALcode generated stack frame makes
debugging the kernel significantly easier.

Acked-by: Matt Turner <mattst88@gmail.com>
Signed-off-by: Matt Turner <mattst88@gmail.com>
Signed-off-by: Richard Henderson <rth@twiddle.net>

1 files changed, 288 insertions, 111 deletions

diff --git a/arch/alpha/kernel/entry.S b/arch/alpha/kernel/entry.S
index f62a994ef126..a969b95ee5ac 100644
--- a/arch/alpha/kernel/entry.S
+++ b/arch/alpha/kernel/entry.S
@@ -12,11 +12,32 @@
 
         .text
         .set noat
+        .cfi_sections   .debug_frame
 
 /* Stack offsets.  */
 #define SP_OFF                  184
 #define SWITCH_STACK_SIZE       320
 
+.macro  CFI_START_OSF_FRAME     func
+        .align  4
+        .globl  \func
+        .type   \func,@function
+\func:
+        .cfi_startproc simple
+        .cfi_return_column 64
+        .cfi_def_cfa    $sp, 48
+        .cfi_rel_offset 64, 8
+        .cfi_rel_offset $gp, 16
+        .cfi_rel_offset $16, 24
+        .cfi_rel_offset $17, 32
+        .cfi_rel_offset $18, 40
+.endm
+
+.macro  CFI_END_OSF_FRAME       func
+        .cfi_endproc
+        .size   \func, . - \func
+.endm
+
 /*
  * This defines the normal kernel pt-regs layout.
  *
@@ -27,100 +48,158 @@
  * the palcode-provided values are available to the signal handler.
  */
 
-#define SAVE_ALL                        \
-        subq    $sp, SP_OFF, $sp;       \
-        stq     $0, 0($sp);             \
-        stq     $1, 8($sp);             \
-        stq     $2, 16($sp);            \
-        stq     $3, 24($sp);            \
-        stq     $4, 32($sp);            \
-        stq     $28, 144($sp);          \
-        lda     $2, alpha_mv;           \
-        stq     $5, 40($sp);            \
-        stq     $6, 48($sp);            \
-        stq     $7, 56($sp);            \
-        stq     $8, 64($sp);            \
-        stq     $19, 72($sp);           \
-        stq     $20, 80($sp);           \
-        stq     $21, 88($sp);           \
-        ldq     $2, HAE_CACHE($2);      \
-        stq     $22, 96($sp);           \
-        stq     $23, 104($sp);          \
-        stq     $24, 112($sp);          \
-        stq     $25, 120($sp);          \
-        stq     $26, 128($sp);          \
-        stq     $27, 136($sp);          \
-        stq     $2, 152($sp);           \
-        stq     $16, 160($sp);          \
-        stq     $17, 168($sp);          \
+.macro  SAVE_ALL
+        subq    $sp, SP_OFF, $sp
+        .cfi_adjust_cfa_offset  SP_OFF
+        stq     $0, 0($sp)
+        stq     $1, 8($sp)
+        stq     $2, 16($sp)
+        stq     $3, 24($sp)
+        stq     $4, 32($sp)
+        stq     $28, 144($sp)
+        .cfi_rel_offset $0, 0
+        .cfi_rel_offset $1, 8
+        .cfi_rel_offset $2, 16
+        .cfi_rel_offset $3, 24
+        .cfi_rel_offset $4, 32
+        .cfi_rel_offset $28, 144
+        lda     $2, alpha_mv
+        stq     $5, 40($sp)
+        stq     $6, 48($sp)
+        stq     $7, 56($sp)
+        stq     $8, 64($sp)
+        stq     $19, 72($sp)
+        stq     $20, 80($sp)
+        stq     $21, 88($sp)
+        ldq     $2, HAE_CACHE($2)
+        stq     $22, 96($sp)
+        stq     $23, 104($sp)
+        stq     $24, 112($sp)
+        stq     $25, 120($sp)
+        stq     $26, 128($sp)
+        stq     $27, 136($sp)
+        stq     $2, 152($sp)
+        stq     $16, 160($sp)
+        stq     $17, 168($sp)
         stq     $18, 176($sp)
+        .cfi_rel_offset $5, 40
+        .cfi_rel_offset $6, 48
+        .cfi_rel_offset $7, 56
+        .cfi_rel_offset $8, 64
+        .cfi_rel_offset $19, 72
+        .cfi_rel_offset $20, 80
+        .cfi_rel_offset $21, 88
+        .cfi_rel_offset $22, 96
+        .cfi_rel_offset $23, 104
+        .cfi_rel_offset $24, 112
+        .cfi_rel_offset $25, 120
+        .cfi_rel_offset $26, 128
+        .cfi_rel_offset $27, 136
+.endm
 
-#define RESTORE_ALL                     \
-        lda     $19, alpha_mv;          \
-        ldq     $0, 0($sp);             \
-        ldq     $1, 8($sp);             \
-        ldq     $2, 16($sp);            \
-        ldq     $3, 24($sp);            \
-        ldq     $21, 152($sp);          \
-        ldq     $20, HAE_CACHE($19);    \
-        ldq     $4, 32($sp);            \
-        ldq     $5, 40($sp);            \
-        ldq     $6, 48($sp);            \
-        ldq     $7, 56($sp);            \
-        subq    $20, $21, $20;          \
-        ldq     $8, 64($sp);            \
-        beq     $20, 99f;               \
-        ldq     $20, HAE_REG($19);      \
-        stq     $21, HAE_CACHE($19);    \
-        stq     $21, 0($20);            \
-99:;                                    \
-        ldq     $19, 72($sp);           \
-        ldq     $20, 80($sp);           \
-        ldq     $21, 88($sp);           \
-        ldq     $22, 96($sp);           \
-        ldq     $23, 104($sp);          \
-        ldq     $24, 112($sp);          \
-        ldq     $25, 120($sp);          \
-        ldq     $26, 128($sp);          \
-        ldq     $27, 136($sp);          \
-        ldq     $28, 144($sp);          \
+.macro  RESTORE_ALL
+        lda     $19, alpha_mv
+        ldq     $0, 0($sp)
+        ldq     $1, 8($sp)
+        ldq     $2, 16($sp)
+        ldq     $3, 24($sp)
+        ldq     $21, 152($sp)
+        ldq     $20, HAE_CACHE($19)
+        ldq     $4, 32($sp)
+        ldq     $5, 40($sp)
+        ldq     $6, 48($sp)
+        ldq     $7, 56($sp)
+        subq    $20, $21, $20
+        ldq     $8, 64($sp)
+        beq     $20, 99f
+        ldq     $20, HAE_REG($19)
+        stq     $21, HAE_CACHE($19)
+        stq     $21, 0($20)
+99:     ldq     $19, 72($sp)
+        ldq     $20, 80($sp)
+        ldq     $21, 88($sp)
+        ldq     $22, 96($sp)
+        ldq     $23, 104($sp)
+        ldq     $24, 112($sp)
+        ldq     $25, 120($sp)
+        ldq     $26, 128($sp)
+        ldq     $27, 136($sp)
+        ldq     $28, 144($sp)
         addq    $sp, SP_OFF, $sp
+        .cfi_restore    $0
+        .cfi_restore    $1
+        .cfi_restore    $2
+        .cfi_restore    $3
+        .cfi_restore    $4
+        .cfi_restore    $5
+        .cfi_restore    $6
+        .cfi_restore    $7
+        .cfi_restore    $8
+        .cfi_restore    $19
+        .cfi_restore    $20
+        .cfi_restore    $21
+        .cfi_restore    $22
+        .cfi_restore    $23
+        .cfi_restore    $24
+        .cfi_restore    $25
+        .cfi_restore    $26
+        .cfi_restore    $27
+        .cfi_restore    $28
+        .cfi_adjust_cfa_offset  -SP_OFF
+.endm
+
+.macro  DO_SWITCH_STACK
+        bsr     $1, do_switch_stack
+        .cfi_adjust_cfa_offset  SWITCH_STACK_SIZE
+        .cfi_rel_offset $9, 0
+        .cfi_rel_offset $10, 8
+        .cfi_rel_offset $11, 16
+        .cfi_rel_offset $12, 24
+        .cfi_rel_offset $13, 32
+        .cfi_rel_offset $14, 40
+        .cfi_rel_offset $15, 48
+        /* We don't really care about the FP registers for debugging.  */
+.endm
+
+.macro  UNDO_SWITCH_STACK
+        bsr     $1, undo_switch_stack
+        .cfi_restore    $9
+        .cfi_restore    $10
+        .cfi_restore    $11
+        .cfi_restore    $12
+        .cfi_restore    $13
+        .cfi_restore    $14
+        .cfi_restore    $15
+        .cfi_adjust_cfa_offset  -SWITCH_STACK_SIZE
+.endm
 
 /*
  * Non-syscall kernel entry points.
  */
 
-        .align  4
-        .globl  entInt
-        .ent    entInt
-entInt:
+CFI_START_OSF_FRAME entInt
         SAVE_ALL
         lda     $8, 0x3fff
         lda     $26, ret_from_sys_call
         bic     $sp, $8, $8
         mov     $sp, $19
         jsr     $31, do_entInt
-.end entInt
+CFI_END_OSF_FRAME entInt
 
-        .align  4
-        .globl  entArith
-        .ent    entArith
-entArith:
+CFI_START_OSF_FRAME entArith
         SAVE_ALL
         lda     $8, 0x3fff
         lda     $26, ret_from_sys_call
         bic     $sp, $8, $8
         mov     $sp, $18
         jsr     $31, do_entArith
-.end entArith
+CFI_END_OSF_FRAME entArith
 
-        .align  4
-        .globl  entMM
-        .ent    entMM
-entMM:
+CFI_START_OSF_FRAME entMM
         SAVE_ALL
 /* save $9 - $15 so the inline exception code can manipulate them.  */
         subq    $sp, 56, $sp
+        .cfi_adjust_cfa_offset  56
         stq     $9, 0($sp)
         stq     $10, 8($sp)
         stq     $11, 16($sp)
@@ -128,6 +207,13 @@ entMM:
         stq     $13, 32($sp)
         stq     $14, 40($sp)
         stq     $15, 48($sp)
+        .cfi_rel_offset $9, 0
+        .cfi_rel_offset $10, 8
+        .cfi_rel_offset $11, 16
+        .cfi_rel_offset $12, 24
+        .cfi_rel_offset $13, 32
+        .cfi_rel_offset $14, 40
+        .cfi_rel_offset $15, 48
         addq    $sp, 56, $19
 /* handle the fault */
         lda     $8, 0x3fff
@@ -142,28 +228,33 @@ entMM:
         ldq     $14, 40($sp)
         ldq     $15, 48($sp)
         addq    $sp, 56, $sp
+        .cfi_restore    $9
+        .cfi_restore    $10
+        .cfi_restore    $11
+        .cfi_restore    $12
+        .cfi_restore    $13
+        .cfi_restore    $14
+        .cfi_restore    $15
+        .cfi_adjust_cfa_offset  -56
 /* finish up the syscall as normal.  */
         br      ret_from_sys_call
-.end entMM
+CFI_END_OSF_FRAME entMM
 
-        .align  4
-        .globl  entIF
-        .ent    entIF
-entIF:
+CFI_START_OSF_FRAME entIF
         SAVE_ALL
         lda     $8, 0x3fff
         lda     $26, ret_from_sys_call
         bic     $sp, $8, $8
         mov     $sp, $17
         jsr     $31, do_entIF
-.end entIF
+CFI_END_OSF_FRAME entIF
 
-        .align  4
-        .globl  entUna
-        .ent    entUna
-entUna:
+CFI_START_OSF_FRAME entUna
         lda     $sp, -256($sp)
+        .cfi_adjust_cfa_offset  256
         stq     $0, 0($sp)
+        .cfi_rel_offset $0, 0
+        .cfi_remember_state
         ldq     $0, 256($sp)    /* get PS */
         stq     $1, 8($sp)
         stq     $2, 16($sp)
@@ -195,6 +286,32 @@ entUna:
         stq     $28, 224($sp)
         mov     $sp, $19
         stq     $gp, 232($sp)
+        .cfi_rel_offset $1, 1*8
+        .cfi_rel_offset $2, 2*8
+        .cfi_rel_offset $3, 3*8
+        .cfi_rel_offset $4, 4*8
+        .cfi_rel_offset $5, 5*8
+        .cfi_rel_offset $6, 6*8
+        .cfi_rel_offset $7, 7*8
+        .cfi_rel_offset $8, 8*8
+        .cfi_rel_offset $9, 9*8
+        .cfi_rel_offset $10, 10*8
+        .cfi_rel_offset $11, 11*8
+        .cfi_rel_offset $12, 12*8
+        .cfi_rel_offset $13, 13*8
+        .cfi_rel_offset $14, 14*8
+        .cfi_rel_offset $15, 15*8
+        .cfi_rel_offset $19, 19*8
+        .cfi_rel_offset $20, 20*8
+        .cfi_rel_offset $21, 21*8
+        .cfi_rel_offset $22, 22*8
+        .cfi_rel_offset $23, 23*8
+        .cfi_rel_offset $24, 24*8
+        .cfi_rel_offset $25, 25*8
+        .cfi_rel_offset $26, 26*8
+        .cfi_rel_offset $27, 27*8
+        .cfi_rel_offset $28, 28*8
+        .cfi_rel_offset $29, 29*8
         lda     $8, 0x3fff
         stq     $31, 248($sp)
         bic     $sp, $8, $8
@@ -228,16 +345,45 @@ entUna:
         ldq     $28, 224($sp)
         ldq     $gp, 232($sp)
         lda     $sp, 256($sp)
+        .cfi_restore    $1
+        .cfi_restore    $2
+        .cfi_restore    $3
+        .cfi_restore    $4
+        .cfi_restore    $5
+        .cfi_restore    $6
+        .cfi_restore    $7
+        .cfi_restore    $8
+        .cfi_restore    $9
+        .cfi_restore    $10
+        .cfi_restore    $11
+        .cfi_restore    $12
+        .cfi_restore    $13
+        .cfi_restore    $14
+        .cfi_restore    $15
+        .cfi_restore    $19
+        .cfi_restore    $20
+        .cfi_restore    $21
+        .cfi_restore    $22
+        .cfi_restore    $23
+        .cfi_restore    $24
+        .cfi_restore    $25
+        .cfi_restore    $26
+        .cfi_restore    $27
+        .cfi_restore    $28
+        .cfi_restore    $29
+        .cfi_adjust_cfa_offset  -256
         call_pal PAL_rti
-.end entUna
 
         .align  4
-        .ent    entUnaUser
 entUnaUser:
+        .cfi_restore_state
         ldq     $0, 0($sp)      /* restore original $0 */
         lda     $sp, 256($sp)   /* pop entUna's stack frame */
+        .cfi_restore    $0
+        .cfi_adjust_cfa_offset  -256
         SAVE_ALL                /* setup normal kernel stack */
         lda     $sp, -56($sp)
+        .cfi_adjust_cfa_offset  56
         stq     $9, 0($sp)
         stq     $10, 8($sp)
         stq     $11, 16($sp)
@@ -245,6 +391,13 @@ entUnaUser:
         stq     $13, 32($sp)
         stq     $14, 40($sp)
         stq     $15, 48($sp)
+        .cfi_rel_offset $9, 0
+        .cfi_rel_offset $10, 8
+        .cfi_rel_offset $11, 16
+        .cfi_rel_offset $12, 24
+        .cfi_rel_offset $13, 32
+        .cfi_rel_offset $14, 40
+        .cfi_rel_offset $15, 48
         lda     $8, 0x3fff
         addq    $sp, 56, $19
         bic     $sp, $8, $8
@@ -257,20 +410,25 @@ entUnaUser:
         ldq     $14, 40($sp)
         ldq     $15, 48($sp)
         lda     $sp, 56($sp)
+        .cfi_restore    $9
+        .cfi_restore    $10
+        .cfi_restore    $11
+        .cfi_restore    $12
+        .cfi_restore    $13
+        .cfi_restore    $14
+        .cfi_restore    $15
+        .cfi_adjust_cfa_offset  -56
         br      ret_from_sys_call
-.end entUnaUser
+CFI_END_OSF_FRAME entUna
 
-        .align  4
-        .globl  entDbg
-        .ent    entDbg
-entDbg:
+CFI_START_OSF_FRAME entDbg
         SAVE_ALL
         lda     $8, 0x3fff
         lda     $26, ret_from_sys_call
         bic     $sp, $8, $8
         mov     $sp, $16
         jsr     $31, do_entDbg
-.end entDbg
+CFI_END_OSF_FRAME entDbg
 
 /*
  * The system call entry point is special.  Most importantly, it looks
@@ -285,8 +443,12 @@ entDbg:
 
         .align  4
         .globl  entSys
-        .globl  ret_from_sys_call
-        .ent    entSys
+        .type   entSys, @function
+        .cfi_startproc simple
+        .cfi_return_column 64
+        .cfi_def_cfa    $sp, 48
+        .cfi_rel_offset 64, 8
+        .cfi_rel_offset $gp, 16
 entSys:
         SAVE_ALL
         lda     $8, 0x3fff
@@ -300,6 +462,9 @@ entSys:
         stq     $17, SP_OFF+32($sp)
         s8addq  $0, $5, $5
         stq     $18, SP_OFF+40($sp)
+        .cfi_rel_offset $16, SP_OFF+24
+        .cfi_rel_offset $17, SP_OFF+32
+        .cfi_rel_offset $18, SP_OFF+40
         blbs    $3, strace
         beq     $4, 1f
         ldq     $27, 0($5)
@@ -310,6 +475,7 @@ entSys:
         stq     $31, 72($sp)            /* a3=0 => no error */
 
         .align  4
+        .globl  ret_from_sys_call
 ret_from_sys_call:
         cmovne  $26, 0, $18             /* $18 = 0 => non-restartable */
         ldq     $0, SP_OFF($sp)
@@ -324,10 +490,12 @@ ret_to_user:
         and     $17, _TIF_WORK_MASK, $2
         bne     $2, work_pending
 restore_all:
+        .cfi_remember_state
         RESTORE_ALL
         call_pal PAL_rti
 
 ret_to_kernel:
+        .cfi_restore_state
         lda     $16, 7
         call_pal PAL_swpipl
         br restore_all
@@ -356,7 +524,6 @@ $ret_success:
         stq     $0, 0($sp)
         stq     $31, 72($sp)    /* a3=0 => no error */
         br      ret_from_sys_call
-.end entSys
 
 /*
  * Do all cleanup when returning from all interrupts and system calls.
@@ -370,7 +537,7 @@ $ret_success:
  */
 
         .align  4
-        .ent    work_pending
+        .type   work_pending, @function
 work_pending:
         and     $17, _TIF_NOTIFY_RESUME | _TIF_SIGPENDING, $2
         bne     $2, $work_notifysig
@@ -387,23 +554,22 @@ $work_resched:
 
 $work_notifysig:
         mov     $sp, $16
-        bsr     $1, do_switch_stack
+        DO_SWITCH_STACK
         jsr     $26, do_work_pending
-        bsr     $1, undo_switch_stack
+        UNDO_SWITCH_STACK
         br      restore_all
-.end work_pending
 
 /*
  * PTRACE syscall handler
  */
 
         .align  4
-        .ent    strace
+        .type   strace, @function
 strace:
         /* set up signal stack, call syscall_trace */
-        bsr     $1, do_switch_stack
+        DO_SWITCH_STACK
         jsr     $26, syscall_trace_enter /* returns the syscall number */
-        bsr     $1, undo_switch_stack
+        UNDO_SWITCH_STACK
 
         /* get the arguments back.. */
         ldq     $16, SP_OFF+24($sp)
@@ -431,9 +597,9 @@ ret_from_straced:
 $strace_success:
         stq     $0, 0($sp)              /* save return value */
 
-        bsr     $1, do_switch_stack
+        DO_SWITCH_STACK
         jsr     $26, syscall_trace_leave
-        bsr     $1, undo_switch_stack
+        UNDO_SWITCH_STACK
         br      $31, ret_from_sys_call
 
         .align  3
@@ -447,26 +613,31 @@ $strace_error:
         stq     $0, 0($sp)
         stq     $1, 72($sp)     /* a3 for return */
 
-        bsr     $1, do_switch_stack
+        DO_SWITCH_STACK
         mov     $18, $9         /* save old syscall number */
         mov     $19, $10        /* save old a3 */
         jsr     $26, syscall_trace_leave
         mov     $9, $18
         mov     $10, $19
-        bsr     $1, undo_switch_stack
+        UNDO_SWITCH_STACK
 
         mov     $31, $26        /* tell "ret_from_sys_call" we can restart */
         br      ret_from_sys_call
-.end strace
+CFI_END_OSF_FRAME entSys
 
 /*
  * Save and restore the switch stack -- aka the balance of the user context.
  */
 
         .align  4
-        .ent    do_switch_stack
+        .type   do_switch_stack, @function
+        .cfi_startproc simple
+        .cfi_return_column 64
+        .cfi_def_cfa $sp, 0
+        .cfi_register 64, $1
 do_switch_stack:
         lda     $sp, -SWITCH_STACK_SIZE($sp)
+        .cfi_adjust_cfa_offset  SWITCH_STACK_SIZE
         stq     $9, 0($sp)
         stq     $10, 8($sp)
         stq     $11, 16($sp)
@@ -510,10 +681,14 @@ do_switch_stack:
         stt     $f0, 312($sp)   # save fpcr in slot of $f31
         ldt     $f0, 64($sp)    # dont let "do_switch_stack" change fp state.
         ret     $31, ($1), 1
-.end do_switch_stack
+        .cfi_endproc
+        .size   do_switch_stack, .-do_switch_stack
 
         .align  4
-        .ent    undo_switch_stack
+        .type   undo_switch_stack, @function
+        .cfi_startproc simple
+        .cfi_def_cfa $sp, 0
+        .cfi_register 64, $1
 undo_switch_stack:
         ldq     $9, 0($sp)
         ldq     $10, 8($sp)
@@ -558,7 +733,8 @@ undo_switch_stack:
         ldt     $f30, 304($sp)
         lda     $sp, SWITCH_STACK_SIZE($sp)
         ret     $31, ($1), 1
-.end undo_switch_stack
+        .cfi_endproc
+        .size   undo_switch_stack, .-undo_switch_stack
 
 /*
  * The meat of the context switch code.
@@ -566,17 +742,18 @@ undo_switch_stack:
 
         .align  4
         .globl  alpha_switch_to
-        .ent    alpha_switch_to
+        .type   alpha_switch_to, @function
+        .cfi_startproc
 alpha_switch_to:
-        .prologue 0
-        bsr     $1, do_switch_stack
+        DO_SWITCH_STACK
         call_pal PAL_swpctx
         lda     $8, 0x3fff
-        bsr     $1, undo_switch_stack
+        UNDO_SWITCH_STACK
         bic     $sp, $8, $8
         mov     $17, $0
         ret
-.end alpha_switch_to
+        .cfi_endproc
+        .size   alpha_switch_to, .-alpha_switch_to
 
 /*
  * New processes begin life here.