From: Denis Mukhin <[email protected]> Introduce CONFIG_PRINTK_RATELIMIT_MS and CONFIG_PRINTK_RATELIMIT_BURST for configuring rate-limiting policy at the compile time.
Use symbols for global rate-limiting initialization in the console driver. Signed-off-by: Denis Mukhin <[email protected]> --- Changes since v3: - added note on security support for non-standard configurations - gated menu with EXPERT I kept both settings for now. --- xen/common/Kconfig | 36 ++++++++++++++++++++++++++++++++++++ xen/drivers/char/console.c | 6 ++++-- 2 files changed, 40 insertions(+), 2 deletions(-) diff --git a/xen/common/Kconfig b/xen/common/Kconfig index da80fdba8469..749d3bfb08e0 100644 --- a/xen/common/Kconfig +++ b/xen/common/Kconfig @@ -672,4 +672,40 @@ config PM_STATS Enable collection of performance management statistics to aid in analyzing and tuning power/performance characteristics of the system +menu "Console rate-limiting" + visible if EXPERT + +config PRINTK_RATELIMIT_MS + int "printk rate-limiting time window (milliseconds)" + default 5000 + help + Specifies the time window, in milliseconds, for rate-limited [*] printk + messages. No more than `CONFIG_PRINTK_RATELIMIT_BURST` messages will be + printed within this window. + + Setting this value to 0 disables rate-limiting entirely. + + Configurations using a value other than the default of 5000 are not + security supported. + + [*] Rate-limited messages are those controlled by the `loglvl` and + `guest_loglvl` command-line parameters. + +config PRINTK_RATELIMIT_BURST + int "printk rate-limited message burst size" + default 10 + help + Defines the maximum number of rate-limited [*] printk messages that may + be printed within each `CONFIG_PRINTK_RATELIMIT_MS` time window. + + Setting this value to 0 disables rate-limiting entirely. + + Configurations using a value other than the default of 10 are not + security supported. + + [*] Rate-limited messages are those controlled by the `loglvl` and + `guest_loglvl` command-line parameters. + +endmenu + endmenu diff --git a/xen/drivers/char/console.c b/xen/drivers/char/console.c index 76a1681670c1..2c7be1e61f3e 100644 --- a/xen/drivers/char/console.c +++ b/xen/drivers/char/console.c @@ -1353,10 +1353,12 @@ bool __printk_ratelimit(unsigned int ratelimit_ms, } /* Minimum time in ms between messages */ -static const unsigned int printk_ratelimit_ms = 5 * 1000; +static const unsigned int printk_ratelimit_ms = + CONFIG_PRINTK_RATELIMIT_MS; /* Number of messages we send before ratelimiting */ -static const unsigned int printk_ratelimit_burst = 10; +static const unsigned int printk_ratelimit_burst = + CONFIG_PRINTK_RATELIMIT_BURST; bool printk_ratelimit(void) { -- 2.54.0
