[PATCH] powerpc/xmon: Change printk() to pr_cont()

From: Christophe Leroy
Date: Fri Dec 04 2020 - 05:36:39 EST


Since some time now, printk() adds carriage return, leading to
unusable xmon output:

[ 54.288722] sysrq: Entering xmon
[ 54.292209] Vector: 0 at [cace3d2c]
[ 54.292274] pc:
[ 54.292331] c0023650
[ 54.292468] : xmon+0x28/0x58
[ 54.292519]
[ 54.292574] lr:
[ 54.292630] c0023724
[ 54.292749] : sysrq_handle_xmon+0xa4/0xfc
[ 54.292801]
[ 54.292867] sp: cace3de8
[ 54.292931] msr: 9032
[ 54.292999] current = 0xc28d0000
[ 54.293072] pid = 377, comm = sh
[ 54.293157] Linux version 5.10.0-rc6-s3k-dev-01364-gedf13f0ccd76-dirty (root@xxxxxxxxxxxxxxxxxxxxxxxxx) (powerpc64-linux-gcc (GCC) 10.1.0, GNU ld (GNU Binutils) 2.34) #4211 PREEMPT Fri Dec 4 09:32:11 UTC 2020
[ 54.293287] enter ? for help
[ 54.293470] [cace3de8]
[ 54.293532] c0023724
[ 54.293654] sysrq_handle_xmon+0xa4/0xfc
[ 54.293711] (unreliable)
[ 54.293859] [cace3e18]
[ 54.293918] c03885a8
[ 54.294056] __handle_sysrq+0xe4/0x1d4
[ 54.294108]
[ 54.294255] [cace3e48]
[ 54.294314] c0388704
[ 54.294441] write_sysrq_trigger+0x34/0x74
[ 54.294493]
[ 54.294641] [cace3e68]
[ 54.294700] c01f65d0
[ 54.294822] proc_reg_write+0xac/0x11c
[ 54.294875]
[ 54.295023] [cace3e88]
[ 54.295082] c0179910
[ 54.295198] vfs_write+0x134/0x46c
[ 54.295250]
[ 54.295396] [cace3f08]
[ 54.295455] c0179de8
[ 54.295567] ksys_write+0x78/0x11c
[ 54.295619]
[ 54.295766] [cace3f38]
[ 54.295825] c00110d0
[ 54.295951] ret_from_syscall+0x0/0x34
[ 54.296002]
[ 54.296159] --- Exception: c01 (System Call) at
[ 54.296217] 0fd4e784
[ 54.296303]
[ 54.296375] SP (7fca6ff0) is in userspace
[ 54.296431] mon>
[ 54.296484] <no input ...>

Use pr_cont() instead.

Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
Fixes: 4bcc595ccd80 ("printk: reinstate KERN_CONT for printing continuation lines")
Cc: stable@xxxxxxxxxxxxxxx
---
arch/powerpc/xmon/nonstdio.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/xmon/nonstdio.c b/arch/powerpc/xmon/nonstdio.c
index 5c1a50912229..9b0d85bff021 100644
--- a/arch/powerpc/xmon/nonstdio.c
+++ b/arch/powerpc/xmon/nonstdio.c
@@ -178,7 +178,7 @@ void xmon_printf(const char *format, ...)

if (n && rc == 0) {
/* No udbg hooks, fallback to printk() - dangerous */
- printk("%s", xmon_outbuf);
+ pr_cont("%s", xmon_outbuf);
}
}

--
2.25.0