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authorVasily Gorbik <gor@linux.ibm.com>2019-08-11 20:55:18 +0200
committerVasily Gorbik <gor@linux.ibm.com>2019-08-21 12:58:52 +0200
commit2e83e0eb85ca62985406920f97ece36d822d421f (patch)
treeb4d13c99106c0f44bb7c1e9b8465a00386e489ff /arch/s390/kernel/early.c
parent19413fe04f49b32c63b470079afef8d1c7995cc1 (diff)
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s390: clean .bss before running uncompressed kernel
Clean uncompressed kernel .bss section in the startup code before the uncompressed kernel is executed. At this point of time initrd and certificates have been already rescued. Uncompressed kernel .bss size is known from vmlinux_info. It is also taken into consideration during uncompressed kernel positioning by kaslr (so it is safe to clean it). With that uncompressed kernel is starting with .bss section zeroed and no .bss section usage restrictions apply. Which makes chkbss checks for uncompressed kernel objects obsolete and they can be removed. early_nobss.c is also not needed anymore. Parts of it which are still relevant are moved to early.c. Kasan initialization code is now called directly from head64 (early.c is instrumented and should not be executed before kasan shadow memory is set up). Reviewed-by: Philipp Rudo <prudo@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Diffstat (limited to 'arch/s390/kernel/early.c')
-rw-r--r--arch/s390/kernel/early.c16
1 files changed, 16 insertions, 0 deletions
diff --git a/arch/s390/kernel/early.c b/arch/s390/kernel/early.c
index 6312fed48530..b432d63d0b37 100644
--- a/arch/s390/kernel/early.c
+++ b/arch/s390/kernel/early.c
@@ -32,6 +32,21 @@
#include <asm/boot_data.h>
#include "entry.h"
+static void __init reset_tod_clock(void)
+{
+ u64 time;
+
+ if (store_tod_clock(&time) == 0)
+ return;
+ /* TOD clock not running. Set the clock to Unix Epoch. */
+ if (set_tod_clock(TOD_UNIX_EPOCH) != 0 || store_tod_clock(&time) != 0)
+ disabled_wait();
+
+ memset(tod_clock_base, 0, 16);
+ *(__u64 *) &tod_clock_base[1] = TOD_UNIX_EPOCH;
+ S390_lowcore.last_update_clock = TOD_UNIX_EPOCH;
+}
+
/*
* Initialize storage key for kernel pages
*/
@@ -301,6 +316,7 @@ static void __init check_image_bootable(void)
void __init startup_init(void)
{
+ reset_tod_clock();
check_image_bootable();
time_early_init();
init_kernel_storage_key();