From 9f744abb4639e793689570fc9dcdf5f2f028bc9a Mon Sep 17 00:00:00 2001 From: Alexander Egorenkov Date: Thu, 25 Mar 2021 12:10:56 +0100 Subject: [PATCH] s390/boot: replace magic string check with a bootdata flag The magic string "S390EP" at offset 0x10008 indicated to the decompressed kernel that it was booted by the decompressor. Introduce a new bootdata flag instead which conveys the same information in an explicit and a cleaner way. But keep the magic string because it is a kernel ABI. Signed-off-by: Alexander Egorenkov Reviewed-by: Vasily Gorbik Signed-off-by: Vasily Gorbik --- arch/s390/boot/startup.c | 1 + arch/s390/include/asm/setup.h | 2 ++ arch/s390/kernel/early.c | 4 +++- 3 files changed, 6 insertions(+), 1 deletion(-) diff --git a/arch/s390/boot/startup.c b/arch/s390/boot/startup.c index bbe4df6c2f8b..d0cf21641e3a 100644 --- a/arch/s390/boot/startup.c +++ b/arch/s390/boot/startup.c @@ -23,6 +23,7 @@ unsigned long __bootdata_preserved(vmemmap_size); unsigned long __bootdata_preserved(MODULES_VADDR); unsigned long __bootdata_preserved(MODULES_END); unsigned long __bootdata(ident_map_size); +int __bootdata(is_full_image) = 1; u64 __bootdata_preserved(stfle_fac_list[16]); u64 __bootdata_preserved(alt_stfle_fac_list[16]); diff --git a/arch/s390/include/asm/setup.h b/arch/s390/include/asm/setup.h index a8b75da3c1b8..3a77aa96d092 100644 --- a/arch/s390/include/asm/setup.h +++ b/arch/s390/include/asm/setup.h @@ -159,6 +159,8 @@ static inline unsigned long kaslr_offset(void) return __kaslr_offset; } +extern int is_full_image; + static inline u32 gen_lpswe(unsigned long addr) { BUILD_BUG_ON(addr > 0xfff); diff --git a/arch/s390/kernel/early.c b/arch/s390/kernel/early.c index c2cf79d353cf..fb84e3fc1686 100644 --- a/arch/s390/kernel/early.c +++ b/arch/s390/kernel/early.c @@ -33,6 +33,8 @@ #include #include "entry.h" +int __bootdata(is_full_image); + static void __init reset_tod_clock(void) { union tod_clock clk; @@ -279,7 +281,7 @@ static void __init setup_boot_command_line(void) static void __init check_image_bootable(void) { - if (!memcmp(EP_STRING, (void *)EP_OFFSET, strlen(EP_STRING))) + if (is_full_image) return; sclp_early_printk("Linux kernel boot failure: An attempt to boot a vmlinux ELF image failed.\n"); -- GitLab