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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/arm26/lib/backtrace.S
downloadlinux-stericsson-2.6.12-rc2.tar.gz
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'arch/arm26/lib/backtrace.S')
-rw-r--r--arch/arm26/lib/backtrace.S145
1 files changed, 145 insertions, 0 deletions
diff --git a/arch/arm26/lib/backtrace.S b/arch/arm26/lib/backtrace.S
new file mode 100644
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+++ b/arch/arm26/lib/backtrace.S
@@ -0,0 +1,145 @@
+/*
+ * linux/arch/arm26/lib/backtrace.S
+ *
+ * Copyright (C) 1995, 1996 Russell King
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/config.h>
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+ .text
+
+@ fp is 0 or stack frame
+
+#define frame r4
+#define next r5
+#define save r6
+#define mask r7
+#define offset r8
+
+ENTRY(__backtrace)
+ mov r1, #0x10
+ mov r0, fp
+
+ENTRY(c_backtrace)
+
+#ifdef CONFIG_NO_FRAME_POINTER
+ mov pc, lr
+#else
+
+ stmfd sp!, {r4 - r8, lr} @ Save an extra register so we have a location...
+ mov mask, #0xfc000003
+ tst mask, r0
+ movne r0, #0
+ movs frame, r0
+1: moveq r0, #-2
+ LOADREGS(eqfd, sp!, {r4 - r8, pc})
+
+2: stmfd sp!, {pc} @ calculate offset of PC in STMIA instruction
+ ldr r0, [sp], #4
+ adr r1, 2b - 4
+ sub offset, r0, r1
+
+3: tst frame, mask @ Check for address exceptions...
+ bne 1b
+
+1001: ldr next, [frame, #-12] @ get fp
+1002: ldr r2, [frame, #-4] @ get lr
+1003: ldr r3, [frame, #0] @ get pc
+ sub save, r3, offset @ Correct PC for prefetching
+ bic save, save, mask
+1004: ldr r1, [save, #0] @ get instruction at function
+ mov r1, r1, lsr #10
+ ldr r3, .Ldsi+4
+ teq r1, r3
+ subeq save, save, #4
+ adr r0, .Lfe
+ mov r1, save
+ bic r2, r2, mask
+ bl printk @ print pc and link register
+
+ ldr r0, [frame, #-8] @ get sp
+ sub r0, r0, #4
+1005: ldr r1, [save, #4] @ get instruction at function+4
+ mov r3, r1, lsr #10
+ ldr r2, .Ldsi+4
+ teq r3, r2 @ Check for stmia sp!, {args}
+ addeq save, save, #4 @ next instruction
+ bleq .Ldumpstm
+
+ sub r0, frame, #16
+1006: ldr r1, [save, #4] @ Get 'stmia sp!, {rlist, fp, ip, lr, pc}' instruction
+ mov r3, r1, lsr #10
+ ldr r2, .Ldsi
+ teq r3, r2
+ bleq .Ldumpstm
+
+ teq frame, next
+ movne frame, next
+ teqne frame, #0
+ bne 3b
+ LOADREGS(fd, sp!, {r4 - r8, pc})
+
+/*
+ * Fixup for LDMDB
+ */
+ .section .fixup,"ax"
+ .align 0
+1007: ldr r0, =.Lbad
+ mov r1, frame
+ bl printk
+ LOADREGS(fd, sp!, {r4 - r8, pc})
+ .ltorg
+ .previous
+
+ .section __ex_table,"a"
+ .align 3
+ .long 1001b, 1007b
+ .long 1002b, 1007b
+ .long 1003b, 1007b
+ .long 1004b, 1007b
+ .long 1005b, 1007b
+ .long 1006b, 1007b
+ .previous
+
+#define instr r4
+#define reg r5
+#define stack r6
+
+.Ldumpstm: stmfd sp!, {instr, reg, stack, r7, lr}
+ mov stack, r0
+ mov instr, r1
+ mov reg, #9
+ mov r7, #0
+1: mov r3, #1
+ tst instr, r3, lsl reg
+ beq 2f
+ add r7, r7, #1
+ teq r7, #4
+ moveq r7, #0
+ moveq r3, #'\n'
+ movne r3, #' '
+ ldr r2, [stack], #-4
+ mov r1, reg
+ adr r0, .Lfp
+ bl printk
+2: subs reg, reg, #1
+ bpl 1b
+ teq r7, #0
+ adrne r0, .Lcr
+ blne printk
+ mov r0, stack
+ LOADREGS(fd, sp!, {instr, reg, stack, r7, pc})
+
+.Lfe: .asciz "Function entered at [<%p>] from [<%p>]\n"
+.Lfp: .asciz " r%d = %08X%c"
+.Lcr: .asciz "\n"
+.Lbad: .asciz "Backtrace aborted due to bad frame pointer <%p>\n"
+ .align
+.Ldsi: .word 0x00e92dd8 >> 2
+ .word 0x00e92d00 >> 2
+
+#endif