From d20d8e51338fc39aedf98786a4e9b71d4af4bda7 Mon Sep 17 00:00:00 2001 From: Vasily Gorbik Date: Wed, 20 Nov 2024 22:23:48 +0100 Subject: [PATCH] s390/boot: Add bootdebug option to control debug messages Suppress decompressor debug messages by default, similar to regular kernel debug messages that require 'DEBUG' or 'dyndbg' to be enabled (depending on CONFIG_DYNAMIC_DEBUG). Introduce a 'bootdebug' option to enable printing these messages when needed. All messages are still stored in the boot ring buffer regardless. To enable boot debug messages: bootdebug debug Or combine with 'earlyprintk' to print them without delay: bootdebug debug earlyprintk Signed-off-by: Vasily Gorbik Acked-by: Heiko Carstens Signed-off-by: Alexander Gordeev --- arch/s390/boot/ipl_parm.c | 2 ++ arch/s390/boot/printk.c | 4 ++++ arch/s390/include/asm/boot_data.h | 1 + arch/s390/kernel/early.c | 1 + arch/s390/kernel/setup.c | 10 ++++++++-- 5 files changed, 16 insertions(+), 2 deletions(-) diff --git a/arch/s390/boot/ipl_parm.c b/arch/s390/boot/ipl_parm.c index fd4874ab30cb7..397046f0c1dfe 100644 --- a/arch/s390/boot/ipl_parm.c +++ b/arch/s390/boot/ipl_parm.c @@ -317,6 +317,8 @@ void parse_boot_command_line(void) boot_earlyprintk = true; if (!strcmp(param, "debug")) boot_console_loglevel = CONSOLE_LOGLEVEL_DEBUG; + if (!strcmp(param, "bootdebug")) + bootdebug = true; if (!strcmp(param, "quiet")) boot_console_loglevel = CONSOLE_LOGLEVEL_QUIET; if (!strcmp(param, "ignore_loglevel")) diff --git a/arch/s390/boot/printk.c b/arch/s390/boot/printk.c index 7b7203f078c80..4c60245697ab0 100644 --- a/arch/s390/boot/printk.c +++ b/arch/s390/boot/printk.c @@ -17,6 +17,7 @@ bool boot_ignore_loglevel; char __bootdata(boot_rb)[PAGE_SIZE * 2]; bool __bootdata(boot_earlyprintk); size_t __bootdata(boot_rb_off); +bool __bootdata(bootdebug); static void boot_rb_add(const char *str, size_t len) { @@ -168,6 +169,9 @@ static void boot_console_earlyprintk(const char *buf) /* always print emergency messages */ if (level > LOGLEVEL_EMERG && !boot_earlyprintk) return; + /* print debug messages only when bootdebug is enabled */ + if (level == LOGLEVEL_DEBUG && !bootdebug) + return; if (boot_ignore_loglevel || level < boot_console_loglevel) sclp_early_printk(printk_skip_level(buf)); } diff --git a/arch/s390/include/asm/boot_data.h b/arch/s390/include/asm/boot_data.h index e7ef7524b847e..da5527c50738e 100644 --- a/arch/s390/include/asm/boot_data.h +++ b/arch/s390/include/asm/boot_data.h @@ -18,6 +18,7 @@ extern unsigned long early_ipl_comp_list_size; extern char boot_rb[PAGE_SIZE * 2]; extern bool boot_earlyprintk; extern size_t boot_rb_off; +extern bool bootdebug; #define boot_rb_foreach(cb) \ do { \ diff --git a/arch/s390/kernel/early.c b/arch/s390/kernel/early.c index 62f8f5a750a30..4cdf3bf33052e 100644 --- a/arch/s390/kernel/early.c +++ b/arch/s390/kernel/early.c @@ -50,6 +50,7 @@ decompressor_handled_param(facilities); decompressor_handled_param(nokaslr); decompressor_handled_param(cmma); decompressor_handled_param(relocate_lowcore); +decompressor_handled_param(bootdebug); #if IS_ENABLED(CONFIG_KVM) decompressor_handled_param(prot_virt); #endif diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c index feff1bb9ac2da..dd0979182890e 100644 --- a/arch/s390/kernel/setup.c +++ b/arch/s390/kernel/setup.c @@ -160,6 +160,7 @@ struct oldmem_data __bootdata_preserved(oldmem_data); char __bootdata(boot_rb)[PAGE_SIZE * 2]; bool __bootdata(boot_earlyprintk); size_t __bootdata(boot_rb_off); +bool __bootdata(bootdebug); unsigned long __bootdata_preserved(VMALLOC_START); EXPORT_SYMBOL(VMALLOC_START); @@ -882,13 +883,18 @@ static void __init log_component_list(void) } /* - * Print avoiding interpretation of % in buf + * Print avoiding interpretation of % in buf and taking bootdebug option + * into consideration. */ static void __init print_rb_entry(char *buf) { char fmt[] = KERN_SOH "0boot: %s"; + int level = printk_get_level(buf); - fmt[1] = printk_get_level(buf); + if (level == KERN_DEBUG[1] && !bootdebug) + return; + + fmt[1] = level; printk(fmt, printk_skip_level(buf)); }