[PATCH v3] kexec: implemented XEN KEXEC STATUS to determine if an image is loaded

[PATCH v3] kexec: implemented XEN KEXEC STATUS to determine if an image is loaded

[Eric DeVolder]

Instead of the scripts having to poke at various fields we can
provide that functionality via the -S parameter.

kexec_loaded/kexec_crash_loaded exposes Linux kernel kexec/crash
state. It does not say anything about Xen kexec/crash state. So,
we need a special approach to get the latter. Though for
compatibility we provide similar functionality in kexec-tools
for the former.

This change enables the --status or -S option to work either
with or without Xen.

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@oracle.com>
Signed-off-by: Eric DeVolder <eric.devolder@oracle.com>
---
Note: The corresponding Xen changes have been committed
to the Xen staging branch. Follow this thread:
https://lists.xenproject.org/archives/html/xen-devel/2017-01/msg01570.html

CC: Andrew Cooper <andrew.cooper3@citrix.com>
CC: kexec@lists.infradead.org
CC: xen-devel@lists.xenproject.org
CC: Daniel Kiper <daniel.kiper@oracle.com>

v0: First version (internal product).
v1: Posted on kexec mailing list. Changed -s to -S
v2: Incorporated feedback from kexec mailing list, posted on kexec mailing list
v3: Incorporated feedback from kexec mailing list
---
 configure.ac      |  8 ++++++-
 kexec/kexec-xen.c | 26 +++++++++++++++++++++++
 kexec/kexec.8     |  6 ++++++
 kexec/kexec.c     | 62 ++++++++++++++++++++++++++++++++++++++++++++++++-------
 kexec/kexec.h     |  5 ++++-
 5 files changed, 98 insertions(+), 9 deletions(-)

diff --git a/configure.ac b/configure.ac
index 3044185..c6e864b 100644
--- a/configure.ac
+++ b/configure.ac
@@ -165,8 +165,14 @@ fi
 dnl find Xen control stack libraries
 if test "$with_xen" = yes ; then
 	AC_CHECK_HEADER(xenctrl.h,
-		[AC_CHECK_LIB(xenctrl, xc_kexec_load, ,
+		[AC_CHECK_LIB(xenctrl, xc_kexec_load, [ have_xenctrl_h=yes ],
 		AC_MSG_NOTICE([Xen support disabled]))])
+if test "$have_xenctrl_h" = yes ; then
+	AC_CHECK_LIB(xenctrl, xc_kexec_status,
+		AC_DEFINE(HAVE_KEXEC_CMD_STATUS, 1,
+			[The kexec_status call is available]),
+		AC_MSG_NOTICE([The kexec_status call is not available]))
+fi
 fi
 
 dnl ---Sanity checks
diff --git a/kexec/kexec-xen.c b/kexec/kexec-xen.c
index 24a4191..2b448d3 100644
--- a/kexec/kexec-xen.c
+++ b/kexec/kexec-xen.c
@@ -105,6 +105,27 @@ 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 = -1;
+
+#ifdef HAVE_KEXEC_CMD_STATUS
+	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);
+#endif
+
+	return ret;
+}
+
 void xen_kexec_exec(void)
 {
 	xc_interface *xch;
@@ -130,6 +151,11 @@ int xen_kexec_unload(uint64_t kexec_flags)
 	return -1;
 }
 
+int xen_kexec_status(uint64_t kexec_flags)
+{
+	return -1;
+}
+
 void xen_kexec_exec(void)
 {
 }
diff --git a/kexec/kexec.8 b/kexec/kexec.8
index 4d0c1d1..f4b39a6 100644
--- a/kexec/kexec.8
+++ b/kexec/kexec.8
@@ -107,6 +107,12 @@ command:
 .B \-d\ (\-\-debug)
 Enable debugging messages.
 .TP
+.B \-S\ (\-\-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 this option supersedes other options
+and it will
+.BR not\ load\ or\ unload\ 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..defbbe3 100644
--- a/kexec/kexec.c
+++ b/kexec/kexec.c
@@ -51,6 +51,9 @@
 #include "kexec-lzma.h"
 #include <arch/options.h>
 
+#define KEXEC_LOADED_PATH "/sys/kernel/kexec_loaded"
+#define KEXEC_CRASH_LOADED_PATH "/sys/kernel/kexec_crash_loaded"
+
 unsigned long long mem_min = 0;
 unsigned long long mem_max = ULONG_MAX;
 static unsigned long kexec_flags = 0;
@@ -58,6 +61,8 @@ static unsigned long kexec_flags = 0;
 static unsigned long kexec_file_flags = 0;
 int kexec_debug = 0;
 
+static int kexec_loaded(const char *file);
+
 void dbgprint_mem_range(const char *prefix, struct memory_range *mr, int nr_mr)
 {
 	int i;
@@ -890,8 +895,6 @@ 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;
@@ -909,7 +912,7 @@ static int my_load_jump_back_helper(unsigned long kexec_flags, void *entry)
 {
 	int result;
 
-	if (kexec_loaded()) {
+	if (kexec_loaded(KEXEC_LOADED_PATH)) {
 		fprintf(stderr, "There is kexec kernel loaded, make sure "
 			"you are in kexeced kernel.\n");
 		return -1;
@@ -970,6 +973,7 @@ 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 +985,7 @@ void usage(void)
 	printf("\n");
 }
 
-static int kexec_loaded(void)
+static int kexec_loaded(const char *file)
 {
 	long ret = -1;
 	FILE *fp;
@@ -992,7 +996,7 @@ 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 +1019,30 @@ static int kexec_loaded(void)
 	return (int)ret;
 }
 
+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(KEXEC_CRASH_LOADED_PATH);
+		else
+			result = kexec_loaded(KEXEC_LOADED_PATH);
+	}
+	return result;
+}
+
+
 /*
  * Remove parameter from a kernel command line. Helper function by get_command_line().
  */
@@ -1204,6 +1232,7 @@ 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 +1374,9 @@ 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 +1387,20 @@ 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 +1438,9 @@ 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);
@@ -1408,7 +1456,7 @@ int main(int argc, char *argv[])
 						kexec_flags, entry);
 	}
 	/* Don't shutdown unless there is something to reboot to! */
-	if ((result == 0) && (do_shutdown || do_exec) && !kexec_loaded()) {
+	if ((result == 0) && (do_shutdown || do_exec) && !kexec_loaded(KEXEC_LOADED_PATH)) {
 		die("Nothing has been loaded!\n");
 	}
 	if ((result == 0) && do_shutdown) {
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 */
-- 
2.7.4


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Re: [PATCH v3] kexec: implemented XEN KEXEC STATUS to determine if an image is loaded

[Daniel Kiper]

On Tue, Jan 24, 2017 at 12:55:35PM -0600, Eric DeVolder wrote:
> Instead of the scripts having to poke at various fields we can
> provide that functionality via the -S parameter.
>
> kexec_loaded/kexec_crash_loaded exposes Linux kernel kexec/crash
> state. It does not say anything about Xen kexec/crash state. So,
> we need a special approach to get the latter. Though for
> compatibility we provide similar functionality in kexec-tools
> for the former.
>
> This change enables the --status or -S option to work either
> with or without Xen.
>
> 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@oracle.com>
> Signed-off-by: Eric DeVolder <eric.devolder@oracle.com>
> ---
> Note: The corresponding Xen changes have been committed
> to the Xen staging branch. Follow this thread:
> https://lists.xenproject.org/archives/html/xen-devel/2017-01/msg01570.html
>
> CC: Andrew Cooper <andrew.cooper3@citrix.com>
> CC: kexec@lists.infradead.org
> CC: xen-devel@lists.xenproject.org
> CC: Daniel Kiper <daniel.kiper@oracle.com>
>
> v0: First version (internal product).
> v1: Posted on kexec mailing list. Changed -s to -S
> v2: Incorporated feedback from kexec mailing list, posted on kexec mailing list
> v3: Incorporated feedback from kexec mailing list
> ---
>  configure.ac      |  8 ++++++-
>  kexec/kexec-xen.c | 26 +++++++++++++++++++++++
>  kexec/kexec.8     |  6 ++++++
>  kexec/kexec.c     | 62 ++++++++++++++++++++++++++++++++++++++++++++++++-------
>  kexec/kexec.h     |  5 ++++-
>  5 files changed, 98 insertions(+), 9 deletions(-)
>
> diff --git a/configure.ac b/configure.ac
> index 3044185..c6e864b 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -165,8 +165,14 @@ fi
>  dnl find Xen control stack libraries
>  if test "$with_xen" = yes ; then
>  	AC_CHECK_HEADER(xenctrl.h,
> -		[AC_CHECK_LIB(xenctrl, xc_kexec_load, ,
> +		[AC_CHECK_LIB(xenctrl, xc_kexec_load, [ have_xenctrl_h=yes ],
>  		AC_MSG_NOTICE([Xen support disabled]))])
> +if test "$have_xenctrl_h" = yes ; then
> +	AC_CHECK_LIB(xenctrl, xc_kexec_status,
> +		AC_DEFINE(HAVE_KEXEC_CMD_STATUS, 1,
> +			[The kexec_status call is available]),
> +		AC_MSG_NOTICE([The kexec_status call is not available]))
> +fi

I have a feeling that you have missed my comment. Please add two TABs
starting from "+if test "$have_xenctrl_h" = yes ; then" up to "+fi".
So, it should look more or less like this:

		AC_MSG_NOTICE([Xen support disabled]))])
+		if test "$have_xenctrl_h" = yes ; then
+			AC_CHECK_LIB(xenctrl, xc_kexec_status,
...

If it is not needed or something like that please drop me a line.

>  fi
>
>  dnl ---Sanity checks
> diff --git a/kexec/kexec-xen.c b/kexec/kexec-xen.c
> index 24a4191..2b448d3 100644
> --- a/kexec/kexec-xen.c
> +++ b/kexec/kexec-xen.c
> @@ -105,6 +105,27 @@ 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 = -1;
> +
> +#ifdef HAVE_KEXEC_CMD_STATUS
> +	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);
> +#endif
> +
> +	return ret;
> +}
> +
>  void xen_kexec_exec(void)
>  {
>  	xc_interface *xch;
> @@ -130,6 +151,11 @@ int xen_kexec_unload(uint64_t kexec_flags)
>  	return -1;
>  }
>
> +int xen_kexec_status(uint64_t kexec_flags)
> +{
> +	return -1;
> +}
> +
>  void xen_kexec_exec(void)
>  {
>  }
> diff --git a/kexec/kexec.8 b/kexec/kexec.8
> index 4d0c1d1..f4b39a6 100644
> --- a/kexec/kexec.8
> +++ b/kexec/kexec.8
> @@ -107,6 +107,12 @@ command:
>  .B \-d\ (\-\-debug)
>  Enable debugging messages.
>  .TP
> +.B \-S\ (\-\-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 this option supersedes other options
> +and it will
> +.BR not\ load\ or\ unload\ the\ kernel.

Same as above. I think that you have missed my earlier comments.
I suppose that you can join "+and it will" and "+.BR not\ load\ or\
unload\ the\ kernel." into one line.

> +.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..defbbe3 100644
> --- a/kexec/kexec.c
> +++ b/kexec/kexec.c
> @@ -51,6 +51,9 @@
>  #include "kexec-lzma.h"
>  #include <arch/options.h>
>
> +#define KEXEC_LOADED_PATH "/sys/kernel/kexec_loaded"
> +#define KEXEC_CRASH_LOADED_PATH "/sys/kernel/kexec_crash_loaded"
> +
>  unsigned long long mem_min = 0;
>  unsigned long long mem_max = ULONG_MAX;
>  static unsigned long kexec_flags = 0;
> @@ -58,6 +61,8 @@ static unsigned long kexec_flags = 0;
>  static unsigned long kexec_file_flags = 0;
>  int kexec_debug = 0;
>
> +static int kexec_loaded(const char *file);
> +

Why are you shuffling this...

>  void dbgprint_mem_range(const char *prefix, struct memory_range *mr, int nr_mr)
>  {
>  	int i;
> @@ -890,8 +895,6 @@ static int my_exec(void)
>  	return -1;
>  }
>
> -static int kexec_loaded(void);
> -

...and this. Could not you leave this forward declaration here (of
course with arg change)? Or is it possible to drop it at all?

Daniel

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Re: [PATCH v3] kexec: implemented XEN KEXEC STATUS to determine if an image is loaded

[Eric DeVolder]

On 01/24/2017 01:16 PM, Daniel Kiper wrote:
> On Tue, Jan 24, 2017 at 12:55:35PM -0600, Eric DeVolder wrote:
>> Instead of the scripts having to poke at various fields we can
>> provide that functionality via the -S parameter.
>>
>> kexec_loaded/kexec_crash_loaded exposes Linux kernel kexec/crash
>> state. It does not say anything about Xen kexec/crash state. So,
>> we need a special approach to get the latter. Though for
>> compatibility we provide similar functionality in kexec-tools
>> for the former.
>>
>> This change enables the --status or -S option to work either
>> with or without Xen.
>>
>> 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@oracle.com>
>> Signed-off-by: Eric DeVolder <eric.devolder@oracle.com>
>> ---
>> Note: The corresponding Xen changes have been committed
>> to the Xen staging branch. Follow this thread:
>> https://lists.xenproject.org/archives/html/xen-devel/2017-01/msg01570.html
>>
>> CC: Andrew Cooper <andrew.cooper3@citrix.com>
>> CC: kexec@lists.infradead.org
>> CC: xen-devel@lists.xenproject.org
>> CC: Daniel Kiper <daniel.kiper@oracle.com>
>>
>> v0: First version (internal product).
>> v1: Posted on kexec mailing list. Changed -s to -S
>> v2: Incorporated feedback from kexec mailing list, posted on kexec mailing list
>> v3: Incorporated feedback from kexec mailing list
>> ---
>>  configure.ac      |  8 ++++++-
>>  kexec/kexec-xen.c | 26 +++++++++++++++++++++++
>>  kexec/kexec.8     |  6 ++++++
>>  kexec/kexec.c     | 62 ++++++++++++++++++++++++++++++++++++++++++++++++-------
>>  kexec/kexec.h     |  5 ++++-
>>  5 files changed, 98 insertions(+), 9 deletions(-)
>>
>> diff --git a/configure.ac b/configure.ac
>> index 3044185..c6e864b 100644
>> --- a/configure.ac
>> +++ b/configure.ac
>> @@ -165,8 +165,14 @@ fi
>>  dnl find Xen control stack libraries
>>  if test "$with_xen" = yes ; then
>>  	AC_CHECK_HEADER(xenctrl.h,
>> -		[AC_CHECK_LIB(xenctrl, xc_kexec_load, ,
>> +		[AC_CHECK_LIB(xenctrl, xc_kexec_load, [ have_xenctrl_h=yes ],
>>  		AC_MSG_NOTICE([Xen support disabled]))])
>> +if test "$have_xenctrl_h" = yes ; then
>> +	AC_CHECK_LIB(xenctrl, xc_kexec_status,
>> +		AC_DEFINE(HAVE_KEXEC_CMD_STATUS, 1,
>> +			[The kexec_status call is available]),
>> +		AC_MSG_NOTICE([The kexec_status call is not available]))
>> +fi
>
> I have a feeling that you have missed my comment. Please add two TABs
> starting from "+if test "$have_xenctrl_h" = yes ; then" up to "+fi".
> So, it should look more or less like this:
>
> 		AC_MSG_NOTICE([Xen support disabled]))])
> +		if test "$have_xenctrl_h" = yes ; then
> +			AC_CHECK_LIB(xenctrl, xc_kexec_status,
> ...
>
> If it is not needed or something like that please drop me a line.

The tabs are not needed for the configure to work properly.

If tabs are needed for readability/style purposes, I will
add them in. There is not any precedent of nesting in
the configure.ac file, so I am unsure what convention is
for this package.

>
>>  fi
>>
>>  dnl ---Sanity checks
>> diff --git a/kexec/kexec-xen.c b/kexec/kexec-xen.c
>> index 24a4191..2b448d3 100644
>> --- a/kexec/kexec-xen.c
>> +++ b/kexec/kexec-xen.c
>> @@ -105,6 +105,27 @@ 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 = -1;
>> +
>> +#ifdef HAVE_KEXEC_CMD_STATUS
>> +	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);
>> +#endif
>> +
>> +	return ret;
>> +}
>> +
>>  void xen_kexec_exec(void)
>>  {
>>  	xc_interface *xch;
>> @@ -130,6 +151,11 @@ int xen_kexec_unload(uint64_t kexec_flags)
>>  	return -1;
>>  }
>>
>> +int xen_kexec_status(uint64_t kexec_flags)
>> +{
>> +	return -1;
>> +}
>> +
>>  void xen_kexec_exec(void)
>>  {
>>  }
>> diff --git a/kexec/kexec.8 b/kexec/kexec.8
>> index 4d0c1d1..f4b39a6 100644
>> --- a/kexec/kexec.8
>> +++ b/kexec/kexec.8
>> @@ -107,6 +107,12 @@ command:
>>  .B \-d\ (\-\-debug)
>>  Enable debugging messages.
>>  .TP
>> +.B \-S\ (\-\-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 this option supersedes other options
>> +and it will
>> +.BR not\ load\ or\ unload\ the\ kernel.
>
> Same as above. I think that you have missed my earlier comments.
> I suppose that you can join "+and it will" and "+.BR not\ load\ or\
> unload\ the\ kernel." into one line.

In that file, all dot directives start with the dot in the
first column. I did the same for the .BR in this statement.

>
>> +.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..defbbe3 100644
>> --- a/kexec/kexec.c
>> +++ b/kexec/kexec.c
>> @@ -51,6 +51,9 @@
>>  #include "kexec-lzma.h"
>>  #include <arch/options.h>
>>
>> +#define KEXEC_LOADED_PATH "/sys/kernel/kexec_loaded"
>> +#define KEXEC_CRASH_LOADED_PATH "/sys/kernel/kexec_crash_loaded"
>> +
>>  unsigned long long mem_min = 0;
>>  unsigned long long mem_max = ULONG_MAX;
>>  static unsigned long kexec_flags = 0;
>> @@ -58,6 +61,8 @@ static unsigned long kexec_flags = 0;
>>  static unsigned long kexec_file_flags = 0;
>>  int kexec_debug = 0;
>>
>> +static int kexec_loaded(const char *file);
>> +
>
> Why are you shuffling this...
>
>>  void dbgprint_mem_range(const char *prefix, struct memory_range *mr, int nr_mr)
>>  {
>>  	int i;
>> @@ -890,8 +895,6 @@ static int my_exec(void)
>>  	return -1;
>>  }
>>
>> -static int kexec_loaded(void);
>> -
>
> ...and this. Could not you leave this forward declaration here (of
> course with arg change)? Or is it possible to drop it at all?
>
> Daniel
>


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Re: [PATCH v3] kexec: implemented XEN KEXEC STATUS to determine if an image is loaded

[Eric DeVolder]

On 01/24/2017 01:16 PM, Daniel Kiper wrote:
> On Tue, Jan 24, 2017 at 12:55:35PM -0600, Eric DeVolder wrote:
>> Instead of the scripts having to poke at various fields we can
>> provide that functionality via the -S parameter.
>>
>> kexec_loaded/kexec_crash_loaded exposes Linux kernel kexec/crash
>> state. It does not say anything about Xen kexec/crash state. So,
>> we need a special approach to get the latter. Though for
>> compatibility we provide similar functionality in kexec-tools
>> for the former.
>>
>> This change enables the --status or -S option to work either
>> with or without Xen.
>>
>> 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@oracle.com>
>> Signed-off-by: Eric DeVolder <eric.devolder@oracle.com>
>> ---
>> Note: The corresponding Xen changes have been committed
>> to the Xen staging branch. Follow this thread:
>> https://lists.xenproject.org/archives/html/xen-devel/2017-01/msg01570.html
>>
>> CC: Andrew Cooper <andrew.cooper3@citrix.com>
>> CC: kexec@lists.infradead.org
>> CC: xen-devel@lists.xenproject.org
>> CC: Daniel Kiper <daniel.kiper@oracle.com>
>>
>> v0: First version (internal product).
>> v1: Posted on kexec mailing list. Changed -s to -S
>> v2: Incorporated feedback from kexec mailing list, posted on kexec mailing list
>> v3: Incorporated feedback from kexec mailing list
>> ---
>>  configure.ac      |  8 ++++++-
>>  kexec/kexec-xen.c | 26 +++++++++++++++++++++++
>>  kexec/kexec.8     |  6 ++++++
>>  kexec/kexec.c     | 62 ++++++++++++++++++++++++++++++++++++++++++++++++-------
>>  kexec/kexec.h     |  5 ++++-
>>  5 files changed, 98 insertions(+), 9 deletions(-)
>>
>> diff --git a/configure.ac b/configure.ac
>> index 3044185..c6e864b 100644
>> --- a/configure.ac
>> +++ b/configure.ac
>> @@ -165,8 +165,14 @@ fi
>>  dnl find Xen control stack libraries
>>  if test "$with_xen" = yes ; then
>>  	AC_CHECK_HEADER(xenctrl.h,
>> -		[AC_CHECK_LIB(xenctrl, xc_kexec_load, ,
>> +		[AC_CHECK_LIB(xenctrl, xc_kexec_load, [ have_xenctrl_h=yes ],
>>  		AC_MSG_NOTICE([Xen support disabled]))])
>> +if test "$have_xenctrl_h" = yes ; then
>> +	AC_CHECK_LIB(xenctrl, xc_kexec_status,
>> +		AC_DEFINE(HAVE_KEXEC_CMD_STATUS, 1,
>> +			[The kexec_status call is available]),
>> +		AC_MSG_NOTICE([The kexec_status call is not available]))
>> +fi
>
> I have a feeling that you have missed my comment. Please add two TABs
> starting from "+if test "$have_xenctrl_h" = yes ; then" up to "+fi".
> So, it should look more or less like this:
>
> 		AC_MSG_NOTICE([Xen support disabled]))])
> +		if test "$have_xenctrl_h" = yes ; then
> +			AC_CHECK_LIB(xenctrl, xc_kexec_status,
> ...
>
> If it is not needed or something like that please drop me a line.
>
>>  fi
>>
>>  dnl ---Sanity checks
>> diff --git a/kexec/kexec-xen.c b/kexec/kexec-xen.c
>> index 24a4191..2b448d3 100644
>> --- a/kexec/kexec-xen.c
>> +++ b/kexec/kexec-xen.c
>> @@ -105,6 +105,27 @@ 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 = -1;
>> +
>> +#ifdef HAVE_KEXEC_CMD_STATUS
>> +	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);
>> +#endif
>> +
>> +	return ret;
>> +}
>> +
>>  void xen_kexec_exec(void)
>>  {
>>  	xc_interface *xch;
>> @@ -130,6 +151,11 @@ int xen_kexec_unload(uint64_t kexec_flags)
>>  	return -1;
>>  }
>>
>> +int xen_kexec_status(uint64_t kexec_flags)
>> +{
>> +	return -1;
>> +}
>> +
>>  void xen_kexec_exec(void)
>>  {
>>  }
>> diff --git a/kexec/kexec.8 b/kexec/kexec.8
>> index 4d0c1d1..f4b39a6 100644
>> --- a/kexec/kexec.8
>> +++ b/kexec/kexec.8
>> @@ -107,6 +107,12 @@ command:
>>  .B \-d\ (\-\-debug)
>>  Enable debugging messages.
>>  .TP
>> +.B \-S\ (\-\-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 this option supersedes other options
>> +and it will
>> +.BR not\ load\ or\ unload\ the\ kernel.
>
> Same as above. I think that you have missed my earlier comments.
> I suppose that you can join "+and it will" and "+.BR not\ load\ or\
> unload\ the\ kernel." into one line.
>
>> +.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..defbbe3 100644
>> --- a/kexec/kexec.c
>> +++ b/kexec/kexec.c
>> @@ -51,6 +51,9 @@
>>  #include "kexec-lzma.h"
>>  #include <arch/options.h>
>>
>> +#define KEXEC_LOADED_PATH "/sys/kernel/kexec_loaded"
>> +#define KEXEC_CRASH_LOADED_PATH "/sys/kernel/kexec_crash_loaded"
>> +
>>  unsigned long long mem_min = 0;
>>  unsigned long long mem_max = ULONG_MAX;
>>  static unsigned long kexec_flags = 0;
>> @@ -58,6 +61,8 @@ static unsigned long kexec_flags = 0;
>>  static unsigned long kexec_file_flags = 0;
>>  int kexec_debug = 0;
>>
>> +static int kexec_loaded(const char *file);
>> +
>
> Why are you shuffling this...
>
>>  void dbgprint_mem_range(const char *prefix, struct memory_range *mr, int nr_mr)
>>  {
>>  	int i;
>> @@ -890,8 +895,6 @@ static int my_exec(void)
>>  	return -1;
>>  }
>>
>> -static int kexec_loaded(void);
>> -
>
> ...and this. Could not you leave this forward declaration here (of
> course with arg change)? Or is it possible to drop it at all?

It is possible to relocate kexec_loaded() so that the forward 
declaration is not needed. I will do so.

eric


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Re: [PATCH v3] kexec: implemented XEN KEXEC STATUS to determine if an image is loaded

[Daniel Kiper]

On Tue, Jan 24, 2017 at 04:37:27PM -0600, Eric DeVolder wrote:
> On 01/24/2017 01:16 PM, Daniel Kiper wrote:
> >On Tue, Jan 24, 2017 at 12:55:35PM -0600, Eric DeVolder wrote:

[...]

> >>diff --git a/configure.ac b/configure.ac
> >>index 3044185..c6e864b 100644
> >>--- a/configure.ac
> >>+++ b/configure.ac
> >>@@ -165,8 +165,14 @@ fi
> >> dnl find Xen control stack libraries
> >> if test "$with_xen" = yes ; then
> >> 	AC_CHECK_HEADER(xenctrl.h,
> >>-		[AC_CHECK_LIB(xenctrl, xc_kexec_load, ,
> >>+		[AC_CHECK_LIB(xenctrl, xc_kexec_load, [ have_xenctrl_h=yes ],
> >> 		AC_MSG_NOTICE([Xen support disabled]))])
> >>+if test "$have_xenctrl_h" = yes ; then
> >>+	AC_CHECK_LIB(xenctrl, xc_kexec_status,
> >>+		AC_DEFINE(HAVE_KEXEC_CMD_STATUS, 1,
> >>+			[The kexec_status call is available]),
> >>+		AC_MSG_NOTICE([The kexec_status call is not available]))
> >>+fi
> >
> >I have a feeling that you have missed my comment. Please add two TABs
> >starting from "+if test "$have_xenctrl_h" = yes ; then" up to "+fi".
> >So, it should look more or less like this:
> >
> >		AC_MSG_NOTICE([Xen support disabled]))])
> >+		if test "$have_xenctrl_h" = yes ; then
> >+			AC_CHECK_LIB(xenctrl, xc_kexec_status,
> >...
> >
> >If it is not needed or something like that please drop me a line.
>
> The tabs are not needed for the configure to work properly.

Yep.

> If tabs are needed for readability/style purposes, I will
> add them in. There is not any precedent of nesting in

Please do as above.

> the configure.ac file, so I am unsure what convention is
> for this package.

OK, no problem.

> >> fi
> >>
> >> dnl ---Sanity checks
> >>diff --git a/kexec/kexec-xen.c b/kexec/kexec-xen.c
> >>index 24a4191..2b448d3 100644
> >>--- a/kexec/kexec-xen.c
> >>+++ b/kexec/kexec-xen.c
> >>@@ -105,6 +105,27 @@ 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 = -1;
> >>+
> >>+#ifdef HAVE_KEXEC_CMD_STATUS
> >>+	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);
> >>+#endif
> >>+
> >>+	return ret;
> >>+}
> >>+
> >> void xen_kexec_exec(void)
> >> {
> >> 	xc_interface *xch;
> >>@@ -130,6 +151,11 @@ int xen_kexec_unload(uint64_t kexec_flags)
> >> 	return -1;
> >> }
> >>
> >>+int xen_kexec_status(uint64_t kexec_flags)
> >>+{
> >>+	return -1;
> >>+}
> >>+
> >> void xen_kexec_exec(void)
> >> {
> >> }
> >>diff --git a/kexec/kexec.8 b/kexec/kexec.8
> >>index 4d0c1d1..f4b39a6 100644
> >>--- a/kexec/kexec.8
> >>+++ b/kexec/kexec.8
> >>@@ -107,6 +107,12 @@ command:
> >> .B \-d\ (\-\-debug)
> >> Enable debugging messages.
> >> .TP
> >>+.B \-S\ (\-\-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 this option supersedes other options
> >>+and it will
> >>+.BR not\ load\ or\ unload\ the\ kernel.
> >
> >Same as above. I think that you have missed my earlier comments.
> >I suppose that you can join "+and it will" and "+.BR not\ load\ or\
> >unload\ the\ kernel." into one line.
>
> In that file, all dot directives start with the dot in the
> first column. I did the same for the .BR in this statement.

OK, let's leave it then.

Daniel

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Re: [PATCH v3] kexec: implemented XEN KEXEC STATUS to determine if an image is loaded

[Daniel Kiper]

On Tue, Jan 24, 2017 at 04:47:09PM -0600, Eric DeVolder wrote:
> On 01/24/2017 01:16 PM, Daniel Kiper wrote:
> >On Tue, Jan 24, 2017 at 12:55:35PM -0600, Eric DeVolder wrote:

[...]

> >>diff --git a/kexec/kexec.c b/kexec/kexec.c
> >>index 500e5a9..defbbe3 100644
> >>--- a/kexec/kexec.c
> >>+++ b/kexec/kexec.c
> >>@@ -51,6 +51,9 @@
> >> #include "kexec-lzma.h"
> >> #include <arch/options.h>
> >>
> >>+#define KEXEC_LOADED_PATH "/sys/kernel/kexec_loaded"
> >>+#define KEXEC_CRASH_LOADED_PATH "/sys/kernel/kexec_crash_loaded"
> >>+
> >> unsigned long long mem_min = 0;
> >> unsigned long long mem_max = ULONG_MAX;
> >> static unsigned long kexec_flags = 0;
> >>@@ -58,6 +61,8 @@ static unsigned long kexec_flags = 0;
> >> static unsigned long kexec_file_flags = 0;
> >> int kexec_debug = 0;
> >>
> >>+static int kexec_loaded(const char *file);
> >>+
> >
> >Why are you shuffling this...
> >
> >> void dbgprint_mem_range(const char *prefix, struct memory_range *mr, int nr_mr)
> >> {
> >> 	int i;
> >>@@ -890,8 +895,6 @@ static int my_exec(void)
> >> 	return -1;
> >> }
> >>
> >>-static int kexec_loaded(void);
> >>-
> >
> >...and this. Could not you leave this forward declaration here (of
> >course with arg change)? Or is it possible to drop it at all?
>
> It is possible to relocate kexec_loaded() so that the forward
> declaration is not needed. I will do so.

Great!

Daniel

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