[PATCH 5.8 080/177] ARC: show_regs: fix r12 printing and simplify

Greg Kroah-Hartman
2020-09-15T14:58:42Z

From: Vineet Gupta <vgupta@synopsys.com>

[ Upstream commit e5c388b4b967037a0e00b60194b0dbcf94881a9b ]

when working on ARC64, spotted an issue in ARCv2 reg file printing.
print_reg_file() assumes contiguous reg-file whereas in ARCv2 they are
not: r12 comes before r0-r11 due to hardware auto-save. Apparently this
issue has been present since v2 port submission.

To avoid bolting hacks for this discontinuity while looping through
pt_regs, just ditching the loop and print pt_regs directly.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/arc/kernel/troubleshoot.c | 77 +++++++++++++---------------------
1 file changed, 30 insertions(+), 47 deletions(-)

diff --git a/arch/arc/kernel/troubleshoot.c b/arch/arc/kernel/troubleshoot.c
index 28e8bf04b253f..a331bb5d8319f 100644
--- a/arch/arc/kernel/troubleshoot.c
+++ b/arch/arc/kernel/troubleshoot.c
@@ -18,44 +18,37 @@

#define ARC_PATH_MAX 256

-/*
- * Common routine to print scratch regs (r0-r12) or callee regs (r13-r25)
- * -Prints 3 regs per line and a CR.
- * -To continue, callee regs right after scratch, special handling of CR
- */
-static noinline void print_reg_file(long *reg_rev, int start_num)
+static noinline void print_regs_scratch(struct pt_regs *regs)
{
- unsigned int i;
- char buf[512];
- int n = 0, len = sizeof(buf);
-
- for (i = start_num; i < start_num + 13; i++) {
- n += scnprintf(buf + n, len - n, "r%02u: 0x%08lx\t",
- i, (unsigned long)*reg_rev);
-
- if (((i + 1) % 3) == 0)
- n += scnprintf(buf + n, len - n, "\n");
-
- /* because pt_regs has regs reversed: r12..r0, r25..r13 */
- if (is_isa_arcv2() && start_num == 0)
- reg_rev++;
- else
- reg_rev--;
- }
-
- if (start_num != 0)
- n += scnprintf(buf + n, len - n, "\n\n");
+ pr_cont("BTA: 0x%08lx\n SP: 0x%08lx FP: 0x%08lx BLK: %pS\n",
+ regs->bta, regs->sp, regs->fp, (void *)regs->blink);
+ pr_cont("LPS: 0x%08lx\tLPE: 0x%08lx\tLPC: 0x%08lx\n",
+ regs->lp_start, regs->lp_end, regs->lp_count);

- /* To continue printing callee regs on same line as scratch regs */
- if (start_num == 0)
- pr_info("%s", buf);
- else
- pr_cont("%s\n", buf);
+ pr_info("r00: 0x%08lx\tr01: 0x%08lx\tr02: 0x%08lx\n" \
+ "r03: 0x%08lx\tr04: 0x%08lx\tr05: 0x%08lx\n" \
+ "r06: 0x%08lx\tr07: 0x%08lx\tr08: 0x%08lx\n" \
+ "r09: 0x%08lx\tr10: 0x%08lx\tr11: 0x%08lx\n" \
+ "r12: 0x%08lx\t",
+ regs->r0, regs->r1, regs->r2,
+ regs->r3, regs->r4, regs->r5,
+ regs->r6, regs->r7, regs->r8,
+ regs->r9, regs->r10, regs->r11,
+ regs->r12);
}

-static void show_callee_regs(struct callee_regs *cregs)
+static void print_regs_callee(struct callee_regs *regs)
{
- print_reg_file(&(cregs->r13), 13);
+ pr_cont("r13: 0x%08lx\tr14: 0x%08lx\n" \
+ "r15: 0x%08lx\tr16: 0x%08lx\tr17: 0x%08lx\n" \
+ "r18: 0x%08lx\tr19: 0x%08lx\tr20: 0x%08lx\n" \
+ "r21: 0x%08lx\tr22: 0x%08lx\tr23: 0x%08lx\n" \
+ "r24: 0x%08lx\tr25: 0x%08lx\n",
+ regs->r13, regs->r14,
+ regs->r15, regs->r16, regs->r17,
+ regs->r18, regs->r19, regs->r20,
+ regs->r21, regs->r22, regs->r23,
+ regs->r24, regs->r25);
}

static void print_task_path_n_nm(struct task_struct *tsk)
@@ -175,7 +168,7 @@ static void show_ecr_verbose(struct pt_regs *regs)
void show_regs(struct pt_regs *regs)
{
struct task_struct *tsk = current;
- struct callee_regs *cregs;
+ struct callee_regs *cregs = (struct callee_regs *)tsk->thread.callee_reg;

/*
* generic code calls us with preemption disabled, but some calls
@@ -204,25 +197,15 @@ void show_regs(struct pt_regs *regs)
STS_BIT(regs, A2), STS_BIT(regs, A1),
STS_BIT(regs, E2), STS_BIT(regs, E1));
#else
- pr_cont(" [%2s%2s%2s%2s]",
+ pr_cont(" [%2s%2s%2s%2s] ",
STS_BIT(regs, IE),
(regs->status32 & STATUS_U_MASK) ? "U " : "K ",
STS_BIT(regs, DE), STS_BIT(regs, AE));
#endif
- pr_cont(" BTA: 0x%08lx\n SP: 0x%08lx FP: 0x%08lx BLK: %pS\n",
- regs->bta, regs->sp, regs->fp, (void *)regs->blink);
- pr_info("LPS: 0x%08lx\tLPE: 0x%08lx\tLPC: 0x%08lx\n",
- regs->lp_start, regs->lp_end, regs->lp_count);
-
- /* print regs->r0 thru regs->r12
- * Sequential printing was generating horrible code
- */
- print_reg_file(&(regs->r0), 0);

- /* If Callee regs were saved, display them too */
- cregs = (struct callee_regs *)current->thread.callee_reg;
+ print_regs_scratch(regs);
if (cregs)
- show_callee_regs(cregs);
+ print_regs_callee(cregs);

preempt_disable();
}
--
2.25.1