[PATCH v1 2/2] kexec: Support -S paramter to return whether the kexec payload is loaded.
Konrad Rzeszutek Wilk
konrad.wilk at oracle.com
Mon Nov 14 14:12:53 PST 2016
Instead of the scripts having to poke at various fields we can
provide that functionality via the -S parameter.
Returns 0 if the payload is loaded. Can be used in combination
with -l or -p to get the state of the proper kexec image.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk at oracle.com>
---
v0: First version (internal product).
v1: Posted on kexec mailing list. Changed -s to -S
CC: kexec at lists.infradead.org
CC: xen-devel at lists.xenproject.org
CC: Daniel Kiper <daniel.kiper at oracle.com>
---
kexec/kexec-xen.c | 20 ++++++++++++++++++
kexec/kexec.8 | 5 +++++
kexec/kexec.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++++++-----
kexec/kexec.h | 5 ++++-
4 files changed, 85 insertions(+), 6 deletions(-)
diff --git a/kexec/kexec-xen.c b/kexec/kexec-xen.c
index 24a4191..5a1e9d2 100644
--- a/kexec/kexec-xen.c
+++ b/kexec/kexec-xen.c
@@ -105,6 +105,26 @@ int xen_kexec_unload(uint64_t kexec_flags)
return ret;
}
+int xen_kexec_status(uint64_t kexec_flags)
+{
+ xc_interface *xch;
+ uint8_t type;
+ int ret;
+
+ xch = xc_interface_open(NULL, NULL, 0);
+ if (!xch)
+ return -1;
+
+ type = (kexec_flags & KEXEC_ON_CRASH) ? KEXEC_TYPE_CRASH
+ : KEXEC_TYPE_DEFAULT;
+
+ ret = xc_kexec_status(xch, type);
+
+ xc_interface_close(xch);
+
+ return ret;
+}
+
void xen_kexec_exec(void)
{
xc_interface *xch;
diff --git a/kexec/kexec.8 b/kexec/kexec.8
index 4d0c1d1..02f4ccf 100644
--- a/kexec/kexec.8
+++ b/kexec/kexec.8
@@ -107,6 +107,11 @@ command:
.B \-d\ (\-\-debug)
Enable debugging messages.
.TP
+.B \-D\ (\-\-status)
+Return 0 if the type (by default crash) is loaded. Can be used in conjuction
+with -l or -p to toggle the type. Note it will
+.BR not\ load\ the\ kernel.
+.TP
.B \-e\ (\-\-exec)
Run the currently loaded kernel. Note that it will reboot into the loaded kernel without calling shutdown(8).
.TP
diff --git a/kexec/kexec.c b/kexec/kexec.c
index 500e5a9..bc72688 100644
--- a/kexec/kexec.c
+++ b/kexec/kexec.c
@@ -855,6 +855,32 @@ static int k_unload (unsigned long kexec_flags)
return result;
}
+static int kexec_loaded(void);
+static int __kexec_loaded(const char *f);
+
+static int k_status(unsigned long kexec_flags)
+{
+ int result;
+ long native_arch;
+
+ /* set the arch */
+ native_arch = physical_arch();
+ if (native_arch < 0) {
+ return -1;
+ }
+ kexec_flags |= native_arch;
+
+ if (xen_present())
+ result = xen_kexec_status(kexec_flags);
+ else {
+ if (kexec_flags & KEXEC_ON_CRASH)
+ result = __kexec_loaded("/sys/kernel/kexec_crash_loaded");
+ else
+ result = kexec_loaded();
+ }
+ return result;
+}
+
/*
* Start a reboot.
*/
@@ -890,8 +916,6 @@ static int my_exec(void)
return -1;
}
-static int kexec_loaded(void);
-
static int load_jump_back_helper_image(unsigned long kexec_flags, void *entry)
{
int result;
@@ -970,6 +994,7 @@ void usage(void)
" to original kernel.\n"
" -s, --kexec-file-syscall Use file based syscall for kexec operation\n"
" -d, --debug Enable debugging to help spot a failure.\n"
+ " -S, --status Return 0 if the type (by default crash) is loaded.\n"
"\n"
"Supported kernel file types and options: \n");
for (i = 0; i < file_types; i++) {
@@ -981,7 +1006,7 @@ void usage(void)
printf("\n");
}
-static int kexec_loaded(void)
+static int __kexec_loaded(const char *file)
{
long ret = -1;
FILE *fp;
@@ -992,7 +1017,7 @@ static int kexec_loaded(void)
if (xen_present())
return 1;
- fp = fopen("/sys/kernel/kexec_loaded", "r");
+ fp = fopen(file, "r");
if (fp == NULL)
return -1;
@@ -1015,6 +1040,12 @@ static int kexec_loaded(void)
return (int)ret;
}
+static int kexec_loaded(void)
+{
+ return __kexec_loaded("/sys/kernel/kexec_loaded");
+}
+
+
/*
* Remove parameter from a kernel command line. Helper function by get_command_line().
*/
@@ -1204,6 +1235,7 @@ int main(int argc, char *argv[])
int do_unload = 0;
int do_reuse_initrd = 0;
int do_kexec_file_syscall = 0;
+ int do_status = 0;
void *entry = 0;
char *type = 0;
char *endptr;
@@ -1345,6 +1377,9 @@ int main(int argc, char *argv[])
case OPT_KEXEC_FILE_SYSCALL:
/* We already parsed it. Nothing to do. */
break;
+ case OPT_STATUS:
+ do_status = 1;
+ break;
default:
break;
}
@@ -1355,6 +1390,20 @@ int main(int argc, char *argv[])
if (skip_sync)
do_sync = 0;
+ if (do_status) {
+ if (kexec_flags == 0)
+ kexec_flags = KEXEC_ON_CRASH;
+ do_load = 0;
+ do_reuse_initrd = 0;
+ do_unload = 0;
+ do_load = 0;
+ do_shutdown = 0;
+ do_sync = 0;
+ do_ifdown = 0;
+ do_exec = 0;
+ do_load_jump_back_helper = 0;
+ }
+
if (do_load && (kexec_flags & KEXEC_ON_CRASH) &&
!is_crashkernel_mem_reserved()) {
die("Memory for crashkernel is not reserved\n"
@@ -1392,7 +1441,9 @@ int main(int argc, char *argv[])
check_reuse_initrd();
arch_reuse_initrd();
}
-
+ if (do_status) {
+ result = k_status(kexec_flags);
+ }
if (do_unload) {
if (do_kexec_file_syscall)
result = kexec_file_unload(kexec_file_flags);
diff --git a/kexec/kexec.h b/kexec/kexec.h
index 9194f1c..2b06f59 100644
--- a/kexec/kexec.h
+++ b/kexec/kexec.h
@@ -219,6 +219,7 @@ extern int file_types;
#define OPT_TYPE 't'
#define OPT_PANIC 'p'
#define OPT_KEXEC_FILE_SYSCALL 's'
+#define OPT_STATUS 'S'
#define OPT_MEM_MIN 256
#define OPT_MEM_MAX 257
#define OPT_REUSE_INITRD 258
@@ -245,8 +246,9 @@ extern int file_types;
{ "reuseinitrd", 0, 0, OPT_REUSE_INITRD }, \
{ "kexec-file-syscall", 0, 0, OPT_KEXEC_FILE_SYSCALL }, \
{ "debug", 0, 0, OPT_DEBUG }, \
+ { "status", 0, 0, OPT_STATUS }, \
-#define KEXEC_OPT_STR "h?vdfxyluet:ps"
+#define KEXEC_OPT_STR "h?vdfxyluet:psS"
extern void dbgprint_mem_range(const char *prefix, struct memory_range *mr, int nr_mr);
extern void die(const char *fmt, ...)
@@ -311,5 +313,6 @@ int xen_present(void);
int xen_kexec_load(struct kexec_info *info);
int xen_kexec_unload(uint64_t kexec_flags);
void xen_kexec_exec(void);
+int xen_kexec_status(uint64_t kexec_flags);
#endif /* KEXEC_H */
--
2.5.5
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