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authorVasily Gorbik <gor@linux.ibm.com>2020-11-10 17:05:35 +0100
committerHeiko Carstens <hca@linux.ibm.com>2020-11-20 19:19:11 +0100
commit8977ab65b894d889c3919581bf545ed106a9a1a5 (patch)
treeefa9ed3c411a6323f15a546ea00914e7248b65ef
parent246218962e2175cd1dfa1e5467e9bffae5cc7b5e (diff)
s390/decompressor: add stacktrace support
Decompressor works on a single statically allocated stack. Stacktrace implementation with -mbackchain just takes few lines of code. Linux version 5.10.0-rc3-22793-g0f84a355b776-dirty (gor@tuxmaker) #27 SMP PREEMPT Mon Nov 9 17:30:18 CET 2020 Kernel fault: interruption code 0005 ilc:2 PSW : 0000000180000000 0000000000012f92 (parse_boot_command_line+0x27a/0x46c) R:0 T:0 IO:0 EX:0 Key:0 M:0 W:0 P:0 AS:0 CC:0 PM:0 RI:0 EA:3 GPRS: 0000000000000000 00ffffffffffffff 0000000000000000 000000000001a62c 000000000000bf60 0000000000000000 00000000000003c0 0000000000000000 0000000000000080 000000000002322d 000000007f29ef20 0000000000efd018 000000000311c000 0000000000010070 0000000000012f82 000000000000bea8 Call Trace: (sp:000000000000bea8 [<000000000002016e>] 000000000002016e) sp:000000000000bf18 [<0000000000012408>] startup_kernel+0x88/0x2fc sp:000000000000bf60 [<00000000000100c4>] startup_normal+0xb0/0xb0 Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
-rw-r--r--arch/s390/Makefile2
-rw-r--r--arch/s390/boot/boot.h5
-rw-r--r--arch/s390/boot/head.S3
-rw-r--r--arch/s390/boot/pgm_check_info.c23
-rw-r--r--arch/s390/include/asm/thread_info.h2
5 files changed, 32 insertions, 3 deletions
diff --git a/arch/s390/Makefile b/arch/s390/Makefile
index ba94b03c8b2f..8db267d2a543 100644
--- a/arch/s390/Makefile
+++ b/arch/s390/Makefile
@@ -25,7 +25,7 @@ KBUILD_AFLAGS_DECOMPRESSOR := $(CLANG_FLAGS) -m64 -D__ASSEMBLY__
KBUILD_AFLAGS_DECOMPRESSOR += $(if $(CONFIG_DEBUG_INFO),$(aflags_dwarf))
KBUILD_CFLAGS_DECOMPRESSOR := $(CLANG_FLAGS) -m64 -O2
KBUILD_CFLAGS_DECOMPRESSOR += -DDISABLE_BRANCH_PROFILING -D__NO_FORTIFY
-KBUILD_CFLAGS_DECOMPRESSOR += -fno-delete-null-pointer-checks -msoft-float
+KBUILD_CFLAGS_DECOMPRESSOR += -fno-delete-null-pointer-checks -msoft-float -mbackchain
KBUILD_CFLAGS_DECOMPRESSOR += -fno-asynchronous-unwind-tables
KBUILD_CFLAGS_DECOMPRESSOR += -ffreestanding
KBUILD_CFLAGS_DECOMPRESSOR += $(call cc-disable-warning, address-of-packed-member)
diff --git a/arch/s390/boot/boot.h b/arch/s390/boot/boot.h
index ca485bfa4e50..8b50967f5804 100644
--- a/arch/s390/boot/boot.h
+++ b/arch/s390/boot/boot.h
@@ -4,6 +4,10 @@
#include <linux/types.h>
+#define BOOT_STACK_OFFSET 0x8000
+
+#ifndef __ASSEMBLY__
+
#include <linux/compiler.h>
void startup_kernel(void);
@@ -25,4 +29,5 @@ extern int kaslr_enabled;
unsigned long read_ipl_report(unsigned long safe_offset);
+#endif /* __ASSEMBLY__ */
#endif /* BOOT_BOOT_H */
diff --git a/arch/s390/boot/head.S b/arch/s390/boot/head.S
index cf70917f98e8..dacb7813f982 100644
--- a/arch/s390/boot/head.S
+++ b/arch/s390/boot/head.S
@@ -28,6 +28,7 @@
#include <asm/thread_info.h>
#include <asm/page.h>
#include <asm/ptrace.h>
+#include "boot.h"
#define ARCH_OFFSET 4
@@ -325,7 +326,7 @@ SYM_CODE_START_LOCAL(startup_normal)
SYM_CODE_END(startup_normal)
.Lstack:
- .long 0x8000 + (1<<(PAGE_SHIFT+BOOT_STACK_ORDER)) - STACK_FRAME_OVERHEAD
+ .long BOOT_STACK_OFFSET + BOOT_STACK_SIZE - STACK_FRAME_OVERHEAD
.align 8
6: .long 0x7fffffff,0xffffffff
.Lext_new_psw:
diff --git a/arch/s390/boot/pgm_check_info.c b/arch/s390/boot/pgm_check_info.c
index 8ba8136adb4d..d8bfc5673956 100644
--- a/arch/s390/boot/pgm_check_info.c
+++ b/arch/s390/boot/pgm_check_info.c
@@ -2,6 +2,7 @@
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/ctype.h>
+#include <asm/stacktrace.h>
#include <asm/lowcore.h>
#include <asm/setup.h>
#include <asm/sclp.h>
@@ -121,6 +122,27 @@ out:
sclp_early_printk(buf);
}
+static noinline void print_stacktrace(void)
+{
+ struct stack_info boot_stack = { STACK_TYPE_TASK, BOOT_STACK_OFFSET,
+ BOOT_STACK_OFFSET + BOOT_STACK_SIZE };
+ unsigned long sp = S390_lowcore.gpregs_save_area[15];
+ bool first = true;
+
+ decompressor_printk("Call Trace:\n");
+ while (!(sp & 0x7) && on_stack(&boot_stack, sp, sizeof(struct stack_frame))) {
+ struct stack_frame *sf = (struct stack_frame *)sp;
+
+ decompressor_printk(first ? "(sp:%016lx [<%016lx>] %pS)\n" :
+ " sp:%016lx [<%016lx>] %pS\n",
+ sp, sf->gprs[8], (void *)sf->gprs[8]);
+ if (sf->back_chain <= sp)
+ break;
+ sp = sf->back_chain;
+ first = false;
+ }
+}
+
void print_pgm_check_info(void)
{
unsigned long *gpregs = (unsigned long *)S390_lowcore.gpregs_save_area;
@@ -148,4 +170,5 @@ void print_pgm_check_info(void)
gpregs[8], gpregs[9], gpregs[10], gpregs[11]);
decompressor_printk(" %016lx %016lx %016lx %016lx\n",
gpregs[12], gpregs[13], gpregs[14], gpregs[15]);
+ print_stacktrace();
}
diff --git a/arch/s390/include/asm/thread_info.h b/arch/s390/include/asm/thread_info.h
index 13a04fcf7762..ce788f3e534d 100644
--- a/arch/s390/include/asm/thread_info.h
+++ b/arch/s390/include/asm/thread_info.h
@@ -18,7 +18,7 @@
#else
#define THREAD_SIZE_ORDER 2
#endif
-#define BOOT_STACK_ORDER 2
+#define BOOT_STACK_SIZE (PAGE_SIZE << 2)
#define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER)
#ifndef __ASSEMBLY__