[PATCH 1/4] ARM: unwind: don't allocate while printing stack trace

[Ahmad Fatoum <a.fatoum@pengutronix.de>]

Calling dump_stack() in response to failing assertions can be useful to
pinpoint where things started going awry. This is also done in TLSF
code, but dump_stack actually calls malloc, because it uses the logging
functions instead of printing directly to console.

To avoid circular dependencies and dump_stack() falsifying debugging
results, let's use eprintf instead of pr_*: That way, the output still
makes it to stderr, but it's no longer logged. This also removes the
orange WARNING: prefix, but that can be added back if needed.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
---
 arch/arm/lib32/unwind.c | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/arch/arm/lib32/unwind.c b/arch/arm/lib32/unwind.c
index 6f73cb1b7300..c355bba1b7a4 100644
--- a/arch/arm/lib32/unwind.c
+++ b/arch/arm/lib32/unwind.c
@@ -65,9 +65,9 @@ static void dump_backtrace_entry(unsigned long where, unsigned long from,
 				 unsigned long frame)
 {
 #ifdef CONFIG_KALLSYMS
-	pr_warning("[<%08lx>] (%pS) from [<%08lx>] (%pS)\n", where, (void *)where, from, (void *)from);
+	eprintf("[<%08lx>] (%pS) from [<%08lx>] (%pS)\n", where, (void *)where, from, (void *)from);
 #else
-	pr_warning("Function entered at [<%08lx>] from [<%08lx>]\n", where, from);
+	eprintf("Function entered at [<%08lx>] from [<%08lx>]\n", where, from);
 #endif
 }
 
@@ -124,7 +124,7 @@ static const struct unwind_idx *search_index(unsigned long addr,
 	if (likely(start->addr_offset <= addr_prel31))
 		return start;
 	else {
-		pr_warning("unwind: Unknown symbol address %08lx\n", addr);
+		eprintf("unwind: Unknown symbol address %08lx\n", addr);
 		return NULL;
 	}
 }
@@ -177,7 +177,7 @@ static unsigned long unwind_get_byte(struct unwind_ctrl_block *ctrl)
 	unsigned long ret;
 
 	if (ctrl->entries <= 0) {
-		pr_warning("unwind: Corrupt unwind table\n");
+		eprintf("unwind: Corrupt unwind table\n");
 		return 0;
 	}
 
@@ -214,7 +214,7 @@ static int unwind_exec_insn(struct unwind_ctrl_block *ctrl)
 		insn = (insn << 8) | unwind_get_byte(ctrl);
 		mask = insn & 0x0fff;
 		if (mask == 0) {
-			pr_warning("unwind: 'Refuse to unwind' instruction %04lx\n",
+			eprintf("unwind: 'Refuse to unwind' instruction %04lx\n",
 				   insn);
 			return -URC_FAILURE;
 		}
@@ -253,7 +253,7 @@ static int unwind_exec_insn(struct unwind_ctrl_block *ctrl)
 		int reg = 0;
 
 		if (mask == 0 || mask & 0xf0) {
-			pr_warning("unwind: Spare encoding %04lx\n",
+			eprintf("unwind: Spare encoding %04lx\n",
 			       (insn << 8) | mask);
 			return -URC_FAILURE;
 		}
@@ -271,7 +271,7 @@ static int unwind_exec_insn(struct unwind_ctrl_block *ctrl)
 
 		ctrl->vrs[SP] += 0x204 + (uleb128 << 2);
 	} else {
-		pr_warning("unwind: Unhandled instruction %02lx\n", insn);
+		eprintf("unwind: Unhandled instruction %02lx\n", insn);
 		return -URC_FAILURE;
 	}
 
@@ -303,7 +303,7 @@ int unwind_frame(struct stackframe *frame)
 
 	idx = unwind_find_idx(frame->pc);
 	if (!idx) {
-		pr_warning("unwind: Index not found %08lx\n", frame->pc);
+		eprintf("unwind: Index not found %08lx\n", frame->pc);
 		return -URC_FAILURE;
 	}
 
@@ -322,7 +322,7 @@ int unwind_frame(struct stackframe *frame)
 		/* only personality routine 0 supported in the index */
 		ctrl.insn = &idx->insn;
 	else {
-		pr_warning("unwind: Unsupported personality routine %08lx in the index at %p\n",
+		eprintf("unwind: Unsupported personality routine %08lx in the index at %p\n",
 			   idx->insn, idx);
 		return -URC_FAILURE;
 	}
@@ -335,7 +335,7 @@ int unwind_frame(struct stackframe *frame)
 		ctrl.byte = 1;
 		ctrl.entries = 1 + ((*ctrl.insn & 0x00ff0000) >> 16);
 	} else {
-		pr_warning("unwind: Unsupported personality routine %08lx at %p\n",
+		eprintf("unwind: Unsupported personality routine %08lx at %p\n",
 			   *ctrl.insn, ctrl.insn);
 		return -URC_FAILURE;
 	}
-- 
2.39.2