Unverified Commit b19aa282 authored by Palmer Dabbelt's avatar Palmer Dabbelt
Browse files

Merge patch series "riscv: Dump faulting instructions in oops handler" 

Björn Töpel <bjorn@kernel.org> says:

From: Björn Töpel <bjorn@rivosinc.com>

RISC-V does not dump faulting instructions in the oops handler. This
series adds "Code:" dumps to the oops output together with
scripts/decodecode support.

* b4-shazam-merge:
  scripts/decodecode: Add support for RISC-V
  riscv: Add instruction dump to RISC-V splats

Link: https://lore.kernel.org/r/20230119074738.708301-1-bjorn@kernel.org


Signed-off-by: default avatarPalmer Dabbelt <palmer@rivosinc.com>
parents 91612cfb 00b24250

arch/riscv/kernel/traps.c

+24 −1
Original line number Diff line number Diff line
@@ -29,6 +29,27 @@ int show_unhandled_signals = 1; 


static DEFINE_SPINLOCK(die_lock);



static void dump_kernel_instr(const char *loglvl, struct pt_regs *regs)

{

	char str[sizeof("0000 ") * 12 + 2 + 1], *p = str;

	const u16 *insns = (u16 *)instruction_pointer(regs);

	long bad;

	u16 val;

	int i;



	for (i = -10; i < 2; i++) {

		bad = get_kernel_nofault(val, &insns[i]);

		if (!bad) {

			p += sprintf(p, i == 0 ? "(%04hx) " : "%04hx ", val);

		} else {

			printk("%sCode: Unable to access instruction at 0x%px.\n",

			       loglvl, &insns[i]);

			return;

		}

	}

	printk("%sCode: %s\n", loglvl, str);

}



void die(struct pt_regs *regs, const char *str)

{

	static int die_counter;
@@ -44,8 +65,10 @@ void die(struct pt_regs *regs, const char *str) 


	pr_emerg("%s [#%d]\n", str, ++die_counter);

	print_modules();

	if (regs)

	if (regs) {

		show_regs(regs);

		dump_kernel_instr(KERN_EMERG, regs);

	}



	cause = regs ? regs->cause : -1;

	ret = notify_die(DIE_OOPS, str, regs, 0, cause, SIGSEGV);

scripts/decodecode

+11 −1
Original line number Diff line number Diff line
@@ -93,6 +93,11 @@ disas() { 
		${CROSS_COMPILE}strip $t.o

	fi



	if [ "$ARCH" = "riscv" ]; then

		OBJDUMPFLAGS="-M no-aliases --section=.text -D"

		${CROSS_COMPILE}strip $t.o

	fi



	if [ $pc_sub -ne 0 ]; then

		if [ $PC ]; then

			adj_vma=$(( $PC - $pc_sub ))
@@ -126,8 +131,13 @@ get_substr_opcode_bytes_num() 
	do

		substr+="$opc"



		opcode="$substr"

		if [ "$ARCH" = "riscv" ]; then

			opcode=$(echo $opcode | tr ' ' '\n' | tac | tr -d '\n')

		fi



		# return if opcode bytes do not match @opline anymore

		if ! echo $opline | grep -q "$substr";

		if ! echo $opline | grep -q "$opcode";

		then

			break

		fi