From 2cec178e35baf57d307c0982fd2e53055bd1e9bb Mon Sep 17 00:00:00 2001 From: Nathan Lynch Date: Fri, 14 May 2021 11:24:20 -0500 Subject: powerpc/xmon: make dumping log buffer contents more reliable Log buffer entries that are too long for dump_log_buf()'s small local buffer are: * silently discarded when a single-line entry is too long; kmsg_dump_get_line() returns true but sets &len to 0. * silently truncated to the last fitting new line when a multi-line entry is too long, e.g. register dumps from __show_regs(); this seems undetectable via the kmsg_dump API. xmon_printf()'s internal buffer is already 1KB; enlarge dump_log_buf()'s own buffer to match and make it statically allocated. Verified that this allows complete printing of register dumps on ppc64le with both CONFIG_PRINTK_TIME=y and CONFIG_PRINTK_CALLER=y. Signed-off-by: Nathan Lynch Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210514162420.2911458-1-nathanl@linux.ibm.com --- arch/powerpc/xmon/xmon.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/powerpc/xmon') diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c index c8173e92f19d..f73c10869e64 100644 --- a/arch/powerpc/xmon/xmon.c +++ b/arch/powerpc/xmon/xmon.c @@ -2975,7 +2975,7 @@ static void dump_log_buf(void) { struct kmsg_dump_iter iter; - unsigned char buf[128]; + static unsigned char buf[1024]; size_t len; if (setjmp(bus_error_jmp) != 0) { -- cgit v1.2.3