[patch 0/7] Add extended crashkernel command line syntax

[patch 0/7] Add extended crashkernel command line syntax

[Bernhard Walle]

This patch adds a extended crashkernel syntax that makes the value of reserved
system RAM dependent on the system RAM itself:

    crashkernel=<range1>:<size1>[,<range2>:<size2>,...][@offset]
    range=start-[end]

For example:

    crashkernel=512M-2G:64M,2G-:128M

The motivation comes from distributors that configure their crashkernel command
line automatically with some configuration tool (YaST, you know ;)). Of course
that tool knows the value of System RAM, but if the user removes RAM, then
the system becomes unbootable or at least unusable and error handling
is very difficult.

This series implements this change for i386, x86_64, ia64, ppc64 and sh. That
should be all platforms that support kdump in current mainline. I tested all
platforms except sh due to the lack of a sh processor.

The patch series is against 2.6.23-rc4-mm1.



Signed-off-by: Bernhard Walle <bwalle@suse.de>

-- 

[patch 1/7] Extended crashkernel command line

[Bernhard Walle]

[-- Attachment #1: crashkernel-generic --]
[-- Type: text/plain, Size: 4687 bytes --]

This is the generic part of the patch. It adds a parse_crashkernel() function
in kernel/kexec.c that is called by the architecture specific code that
actually reserves the memory. That function takes the whole command line and
looks itself for "crashkernel=" in it.

If there are multiple occurrences, then the last one is taken.  The advantage
is that if you have a bootloader like lilo or elilo which allows you to append
a command line parameter but not to remove one (like in GRUB), then you can add
another crashkernel value for testing at the boot command line and this one
overwrites the command line in the configuration then.


Signed-off-by: Bernhard Walle <bwalle@suse.de>

---
 include/linux/kexec.h |    2 
 kernel/kexec.c        |  139 ++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 141 insertions(+)

--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -179,6 +179,8 @@ extern note_buf_t *crash_notes;
 extern u32 vmcoreinfo_note[VMCOREINFO_NOTE_SIZE/4];
 extern unsigned int vmcoreinfo_size;
 extern unsigned int vmcoreinfo_max_size;
+int parse_crashkernel(char *cmdline, unsigned long long system_ram,
+		unsigned long long *crash_size, unsigned long long *crash_base);
 
 
 #else /* !CONFIG_KEXEC */
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -1146,6 +1146,145 @@ static int __init crash_notes_memory_ini
 }
 module_init(crash_notes_memory_init)
 
+
+/*
+ * parsing the "crashkernel" commandline
+ *
+ * this code is intended to be called from architecture specific code
+ */
+
+
+/*
+ * This function parses command lines in the format
+ *
+ *   crashkernel=<ramsize-range>:<size>[,...][@<base>]
+ *
+ * The function returns 0 on success and -EINVAL on failure.
+ */
+static int parse_crashkernel_mem(char 			*cmdline,
+				 unsigned long long 	*crash_size,
+				 unsigned long long 	*crash_base,
+				 unsigned long 		system_ram)
+{
+	char *cur = cmdline;
+
+	*crash_size = 0;
+	*crash_base = 0;
+
+	/* for each entry of the comma-separated list */
+	do {
+		unsigned long long start = 0, end = ULLONG_MAX;
+		unsigned long long size = -1;
+
+		/* get the start of the range */
+		start = memparse(cur, &cur);
+		if (*cur != '-') {
+			printk(KERN_WARNING "crashkernel: '-' expected\n");
+			return -EINVAL;
+		}
+		cur++;
+
+		/* if no ':' is here, than we read the end */
+		if (*cur != ':') {
+			end = memparse(cur, &cur);
+			if (end <= start) {
+				printk(KERN_WARNING "crashkernel: end <= start\n");
+				return -EINVAL;
+			}
+		}
+
+		if (*cur != ':') {
+			printk(KERN_WARNING "crashkernel: ':' expected\n");
+			return -EINVAL;
+		}
+		cur++;
+
+		size = memparse(cur, &cur);
+		if (size < 0) {
+			printk(KERN_WARNING "crashkernel: invalid size\n");
+			return -EINVAL;
+		}
+
+		/* match ? */
+		if (system_ram >= start  && system_ram <= end) {
+			*crash_size = size;
+			break;
+		}
+	} while (*cur++ == ',');
+
+	if (*crash_size > 0) {
+		while (*cur != ' ' && *cur != '@')
+			cur++;
+		if (*cur == '@')
+			*crash_base = memparse(cur+1, &cur);
+	}
+
+	return 0;
+}
+
+/*
+ * That function parses "simple" (old) crashkernel command lines like
+ *
+ * 	crashkernel=size[@base]
+ *
+ * It returns 0 on success and -EINVAL on failure.
+ */
+static int parse_crashkernel_simple(char 		*cmdline,
+			     	    unsigned long long 	*crash_size,
+			     	    unsigned long long 	*crash_base)
+{
+	char *cur = cmdline;
+
+	*crash_size = memparse(cmdline, &cur);
+	if (cmdline == cur)
+		return -EINVAL;
+
+	if (*cur == '@')
+		*crash_base = memparse(cur+1, &cur);
+
+	return 0;
+}
+
+/*
+ * That function is the entry point for command line parsing and should be
+ * called from the arch-specific code.
+ */
+int parse_crashkernel(char 		 *cmdline,
+		      unsigned long long system_ram,
+		      unsigned long long *crash_size,
+		      unsigned long long *crash_base)
+{
+	char 	*p = cmdline, *ck_cmdline = NULL;
+	char	*first_colon, *first_space;
+
+	/* find crashkernel and use the last one if there are more */
+	p = strstr(p, "crashkernel=");
+	while (p) {
+		ck_cmdline = p;
+		p = strstr(p+1, "crashkernel=");
+	}
+
+	if (!ck_cmdline)
+		return -EINVAL;
+
+	ck_cmdline += 12; /* strlen("crashkernel=") */
+
+	/*
+	 * if the commandline contains a ':', then that's the extended
+	 * syntax -- if not, it must be the classic syntax
+	 */
+	first_colon = strchr(ck_cmdline, ':');
+	first_space = strchr(ck_cmdline, ' ');
+	if (first_colon && (!first_space || first_colon < first_space))
+		return parse_crashkernel_mem(ck_cmdline, crash_size,
+				crash_base, system_ram);
+	else
+		return parse_crashkernel_simple(ck_cmdline,
+				crash_size, crash_base);
+}
+
+
+
 void crash_save_vmcoreinfo(void)
 {
 	u32 *buf;

-- 

Re: [patch 1/7] Extended crashkernel command line

[Andrew Morton]

On Thu, 13 Sep 2007 18:14:29 +0200
Bernhard Walle <bwalle@suse.de> wrote:

> This is the generic part of the patch. It adds a parse_crashkernel() function
> in kernel/kexec.c that is called by the architecture specific code that
> actually reserves the memory. That function takes the whole command line and
> looks itself for "crashkernel=" in it.
> 
> If there are multiple occurrences, then the last one is taken.  The advantage
> is that if you have a bootloader like lilo or elilo which allows you to append
> a command line parameter but not to remove one (like in GRUB), then you can add
> another crashkernel value for testing at the boot command line and this one
> overwrites the command line in the configuration then.
> 
> 
> Signed-off-by: Bernhard Walle <bwalle@suse.de>
> 
> ---
>  include/linux/kexec.h |    2 
>  kernel/kexec.c        |  139 ++++++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 141 insertions(+)
> 
> --- a/include/linux/kexec.h
> +++ b/include/linux/kexec.h
> @@ -179,6 +179,8 @@ extern note_buf_t *crash_notes;
>  extern u32 vmcoreinfo_note[VMCOREINFO_NOTE_SIZE/4];
>  extern unsigned int vmcoreinfo_size;
>  extern unsigned int vmcoreinfo_max_size;
> +int parse_crashkernel(char *cmdline, unsigned long long system_ram,
> +		unsigned long long *crash_size, unsigned long long *crash_base);
>  
>  
>  #else /* !CONFIG_KEXEC */
> --- a/kernel/kexec.c
> +++ b/kernel/kexec.c
> @@ -1146,6 +1146,145 @@ static int __init crash_notes_memory_ini
>  }
>  module_init(crash_notes_memory_init)
>  
> +
> +/*
> + * parsing the "crashkernel" commandline
> + *
> + * this code is intended to be called from architecture specific code
> + */
> +
> +
> +/*
> + * This function parses command lines in the format
> + *
> + *   crashkernel=<ramsize-range>:<size>[,...][@<base>]
> + *
> + * The function returns 0 on success and -EINVAL on failure.
> + */
> +static int parse_crashkernel_mem(char 			*cmdline,
> +				 unsigned long long 	*crash_size,
> +				 unsigned long long 	*crash_base,
> +				 unsigned long 		system_ram)
> +{

The patchset seems to be putting a large amount of stuff into .text
which could have gone into .text.init?

[patch 2/7] Use extended crashkernel command line on i386

[Bernhard Walle]

[-- Attachment #1: crashkernel-i386 --]
[-- Type: text/plain, Size: 3191 bytes --]

This patch removes the crashkernel parsing from
arch/i386/kernel/machine_kexec.c and calls the generic function, introduced in
the last patch, in setup_bootmem_allocator().

This is necessary because the amount of System RAM must be known in this
function now because of the new syntax.


Signed-off-by: Bernhard Walle <bwalle@suse.de>


---
 arch/i386/kernel/e820.c          |    3 ++-
 arch/i386/kernel/machine_kexec.c |   22 ----------------------
 arch/i386/kernel/setup.c         |   33 ++++++++++++++++++++++++++++-----
 3 files changed, 30 insertions(+), 28 deletions(-)

--- a/arch/i386/kernel/e820.c
+++ b/arch/i386/kernel/e820.c
@@ -288,7 +288,8 @@ legacy_init_iomem_resources(struct resou
 			request_resource(res, code_resource);
 			request_resource(res, data_resource);
 #ifdef CONFIG_KEXEC
-			request_resource(res, &crashk_res);
+			if (crashk_res.start != crashk_res.end)
+				request_resource(res, &crashk_res);
 #endif
 		}
 	}
--- a/arch/i386/kernel/machine_kexec.c
+++ b/arch/i386/kernel/machine_kexec.c
@@ -149,28 +149,6 @@ NORET_TYPE void machine_kexec(struct kim
 			image->start, cpu_has_pae);
 }
 
-/* crashkernel=size@addr specifies the location to reserve for
- * a crash kernel.  By reserving this memory we guarantee
- * that linux never sets it up as a DMA target.
- * Useful for holding code to do something appropriate
- * after a kernel panic.
- */
-static int __init parse_crashkernel(char *arg)
-{
-	unsigned long size, base;
-	size = memparse(arg, &arg);
-	if (*arg == '@') {
-		base = memparse(arg+1, &arg);
-		/* FIXME: Do I want a sanity check
-		 * to validate the memory range?
-		 */
-		crashk_res.start = base;
-		crashk_res.end   = base + size - 1;
-	}
-	return 0;
-}
-early_param("crashkernel", parse_crashkernel);
-
 void arch_crash_save_vmcoreinfo(void)
 {
 #ifdef CONFIG_ARCH_DISCONTIGMEM_ENABLE
--- a/arch/i386/kernel/setup.c
+++ b/arch/i386/kernel/setup.c
@@ -381,6 +381,33 @@ extern unsigned long __init setup_memory
 extern void zone_sizes_init(void);
 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
 
+#ifdef CONFIG_KEXEC
+static void reserve_crashkernel(void)
+{
+	unsigned long long 	free_mem;
+	unsigned long long 	crash_size, crash_base;
+	int			ret;
+
+	free_mem = (max_low_pfn + highend_pfn - highstart_pfn) << PAGE_SHIFT;
+
+	ret = parse_crashkernel(boot_command_line, free_mem,
+			&crash_size, &crash_base);
+	if (ret == 0 && crash_size > 0 && crash_base > 0) {
+		printk(KERN_INFO "Reserving %ldMB of memory at %ldMB "
+				"for crashkernel (System RAM: %ldMB)\n",
+				(unsigned long)(crash_size >> 20),
+				(unsigned long)(crash_base >> 20),
+				(unsigned long)(free_mem >> 20));
+		crashk_res.start = crash_base;
+		crashk_res.end   = crash_base + crash_size - 1;
+		reserve_bootmem(crash_base, crash_size);
+	}
+}
+#else
+static inline void reserve_crashkernel(void)
+{}
+#endif
+
 void __init setup_bootmem_allocator(void)
 {
 	unsigned long bootmap_size;
@@ -456,11 +483,7 @@ void __init setup_bootmem_allocator(void
 		}
 	}
 #endif
-#ifdef CONFIG_KEXEC
-	if (crashk_res.start != crashk_res.end)
-		reserve_bootmem(crashk_res.start,
-			crashk_res.end - crashk_res.start + 1);
-#endif
+	reserve_crashkernel();
 }
 
 /*

-- 

Re: [patch 2/7] Use extended crashkernel command line on i386

[Vivek Goyal]

On Thu, Sep 13, 2007 at 06:14:30PM +0200, Bernhard Walle wrote:
> -
>  void arch_crash_save_vmcoreinfo(void)
>  {
>  #ifdef CONFIG_ARCH_DISCONTIGMEM_ENABLE
> --- a/arch/i386/kernel/setup.c
> +++ b/arch/i386/kernel/setup.c
> @@ -381,6 +381,33 @@ extern unsigned long __init setup_memory
>  extern void zone_sizes_init(void);
>  #endif /* !CONFIG_NEED_MULTIPLE_NODES */
> 
> +#ifdef CONFIG_KEXEC
> +static void reserve_crashkernel(void)
> +{
> +	unsigned long long 	free_mem;
> +	unsigned long long 	crash_size, crash_base;
> +	int			ret;
> +
> +	free_mem = (max_low_pfn + highend_pfn - highstart_pfn) << PAGE_SHIFT;
> +
> +	ret = parse_crashkernel(boot_command_line, free_mem,
> +			&crash_size, &crash_base);
> +	if (ret == 0 && crash_size > 0 && crash_base > 0) {
> +		printk(KERN_INFO "Reserving %ldMB of memory at %ldMB "
> +				"for crashkernel (System RAM: %ldMB)\n",
> +				(unsigned long)(crash_size >> 20),
> +				(unsigned long)(crash_base >> 20),
> +				(unsigned long)(free_mem >> 20));
> +		crashk_res.start = crash_base;
> +		crashk_res.end   = crash_base + crash_size - 1;
> +		reserve_bootmem(crash_base, crash_size);

Hi Bernhard,

I think we might need to do more here. Because [offset] is optional, one
would assume that things will work even if offset is not specified. But
in this patchset, that's not the case for i386 and x86_64. It will silently
fail if a user does not specify the offset. No memory will be reserved for
capture kernel.

I think we either need to make offset mandatory or put in additional
intelligence here to choose the offset automatically based on the memory
available.

Thanks
Vivek

[patch 3/7] Use extended crashkernel command line on x86_64

[Bernhard Walle]

[-- Attachment #1: crashkernel-x86_64 --]
[-- Type: text/plain, Size: 3261 bytes --]

This patch removes the crashkernel parsing from
arch/x86_64/kernel/machine_kexec.c and calls the generic function, introduced in
the last patch, in setup_bootmem_allocator().

This is necessary because the amount of System RAM must be known in this
function now because of the new syntax.


Signed-off-by: Bernhard Walle <bwalle@suse.de>


---
 arch/x86_64/kernel/e820.c          |    3 ++-
 arch/x86_64/kernel/machine_kexec.c |   27 ---------------------------
 arch/x86_64/kernel/setup.c         |   35 ++++++++++++++++++++++++++++-------
 3 files changed, 30 insertions(+), 35 deletions(-)

--- a/arch/x86_64/kernel/e820.c
+++ b/arch/x86_64/kernel/e820.c
@@ -226,7 +226,8 @@ void __init e820_reserve_resources(void)
 			request_resource(res, &code_resource);
 			request_resource(res, &data_resource);
 #ifdef CONFIG_KEXEC
-			request_resource(res, &crashk_res);
+			if (crashk_res.start != crashk_res.end)
+				request_resource(res, &crashk_res);
 #endif
 		}
 	}
--- a/arch/x86_64/kernel/machine_kexec.c
+++ b/arch/x86_64/kernel/machine_kexec.c
@@ -231,33 +231,6 @@ NORET_TYPE void machine_kexec(struct kim
 			image->start);
 }
 
-/* crashkernel=size@addr specifies the location to reserve for
- * a crash kernel.  By reserving this memory we guarantee
- * that linux never set's it up as a DMA target.
- * Useful for holding code to do something appropriate
- * after a kernel panic.
- */
-static int __init setup_crashkernel(char *arg)
-{
-	unsigned long size, base;
-	char *p;
-	if (!arg)
-		return -EINVAL;
-	size = memparse(arg, &p);
-	if (arg == p)
-		return -EINVAL;
-	if (*p == '@') {
-		base = memparse(p+1, &p);
-		/* FIXME: Do I want a sanity check to validate the
-		 * memory range?  Yes you do, but it's too early for
-		 * e820 -AK */
-		crashk_res.start = base;
-		crashk_res.end   = base + size - 1;
-	}
-	return 0;
-}
-early_param("crashkernel", setup_crashkernel);
-
 void arch_crash_save_vmcoreinfo(void)
 {
 #ifdef CONFIG_ARCH_DISCONTIGMEM_ENABLE
--- a/arch/x86_64/kernel/setup.c
+++ b/arch/x86_64/kernel/setup.c
@@ -196,6 +196,33 @@ static inline void copy_edd(void)
 }
 #endif
 
+#ifdef CONFIG_KEXEC
+static inline void reserve_crashkernel(void)
+{
+	unsigned long long 	free_mem;
+	unsigned long long 	crash_size, crash_base;
+	int			ret;
+
+	free_mem = max_low_pfn << PAGE_SHIFT;
+
+	ret = parse_crashkernel(boot_command_line, free_mem,
+			&crash_size, &crash_base);
+	if (ret == 0 && crash_size > 0 && crash_base > 0) {
+		printk(KERN_INFO "Reserving %ldMB of memory at %ldMB "
+				"for crashkernel (System RAM: %ldMB)\n",
+				(unsigned long)(crash_size >> 20),
+				(unsigned long)(crash_base >> 20),
+				(unsigned long)(free_mem >> 20));
+		crashk_res.start = crash_base;
+		crashk_res.end   = crash_base + crash_size - 1;
+		reserve_bootmem(crash_base, crash_size);
+	}
+}
+#else
+static inline void reserve_crashkernel(void)
+{}
+#endif
+
 #define EBDA_ADDR_POINTER 0x40E
 
 unsigned __initdata ebda_addr;
@@ -388,13 +415,7 @@ void __init setup_arch(char **cmdline_p)
 		}
 	}
 #endif
-#ifdef CONFIG_KEXEC
-	if (crashk_res.start != crashk_res.end) {
-		reserve_bootmem_generic(crashk_res.start,
-			crashk_res.end - crashk_res.start + 1);
-	}
-#endif
-
+	reserve_crashkernel();
 	paging_init();
 
 #ifdef CONFIG_PCI

-- 

Re: [patch 3/7] Use extended crashkernel command line on x86_64

[Andrew Morton]

On Thu, 13 Sep 2007 18:14:31 +0200
Bernhard Walle <bwalle@suse.de> wrote:

> +#ifdef CONFIG_KEXEC
> +static inline void reserve_crashkernel(void)
> +{

The x86_64 function was made inline, so it will actually end up in
.text.init.  But the i386 equivalent function was not inlined so I'm not
sure whether it will end up in .text or in .text.init.

Could you fix all that up please?

Re: [patch 3/7] Use extended crashkernel command line on x86_64

[Bernhard Walle]

* Andrew Morton <akpm@linux-foundation.org> [2007-09-20 00:33]:
> 
> Could you fix all that up please?

Thanks for the comments -- should be fixed now, see the new patch
series.


Thanks,
   Bernhard

[patch 4/7] Use extended crashkernel command line on ia64

[Bernhard Walle]

[-- Attachment #1: crashkernel-ia64 --]
[-- Type: text/plain, Size: 4974 bytes --]

This patch adapts IA64 to use the generic parse_crashkernel() function
instead of its own parsing for the crashkernel command line.

Because the total amount of System RAM must be known when calling this
function, efi_memmap_init() is modified to return its accumulated total_memory
variable.

Also, the crashkernel handling is moved in an own function in
arch/ia64/kernel/setup.c to make the code more readable.


Signed-off-by: Bernhard Walle <bwalle@suse.de>

---
 arch/ia64/kernel/efi.c     |    4 +-
 arch/ia64/kernel/setup.c   |   88 +++++++++++++++++++++++----------------------
 include/asm-ia64/meminit.h |    2 -
 3 files changed, 50 insertions(+), 44 deletions(-)

--- a/arch/ia64/kernel/efi.c
+++ b/arch/ia64/kernel/efi.c
@@ -967,7 +967,7 @@ find_memmap_space (void)
  * to use.  We can allocate partial granules only if the unavailable
  * parts exist, and are WB.
  */
-void
+unsigned long
 efi_memmap_init(unsigned long *s, unsigned long *e)
 {
 	struct kern_memdesc *k, *prev = NULL;
@@ -1084,6 +1084,8 @@ efi_memmap_init(unsigned long *s, unsign
 	/* reserve the memory we are using for kern_memmap */
 	*s = (u64)kern_memmap;
 	*e = (u64)++k;
+
+	return total_memory;
 }
 
 void
--- a/arch/ia64/kernel/setup.c
+++ b/arch/ia64/kernel/setup.c
@@ -208,6 +208,48 @@ static int __init register_memory(void)
 
 __initcall(register_memory);
 
+
+#ifdef CONFIG_KEXEC
+static void setup_crashkernel(unsigned long total, int *n)
+{
+	unsigned long long base = 0, size = 0;
+	int ret;
+
+	ret = parse_crashkernel(boot_command_line, total,
+			&size, &base);
+	if (ret == 0 && size > 0) {
+		if (!base) {
+			sort_regions(rsvd_region, *n);
+			base = kdump_find_rsvd_region(size,
+					rsvd_region, *n);
+		}
+		if (base != ~0UL) {
+			printk(KERN_INFO "Reserving %ldMB of memory at %ldMB "
+					"for crashkernel (System RAM: %ldMB)\n",
+					(unsigned long)(size >> 20),
+					(unsigned long)(base >> 20),
+					(unsigned long)(total >> 20));
+			rsvd_region[*n].start =
+				(unsigned long)__va(base);
+			rsvd_region[*n].end =
+				(unsigned long)__va(base + size);
+			(*n)++;
+			crashk_res.start = base;
+			crashk_res.end = base + size - 1;
+		}
+	}
+	efi_memmap_res.start = ia64_boot_param->efi_memmap;
+	efi_memmap_res.end = efi_memmap_res.start +
+		ia64_boot_param->efi_memmap_size;
+	boot_param_res.start = __pa(ia64_boot_param);
+	boot_param_res.end = boot_param_res.start +
+		sizeof(*ia64_boot_param);
+}
+#else
+static inline void setup_crashkernel(unsigned long total, int *n)
+{}
+#endif
+
 /**
  * reserve_memory - setup reserved memory areas
  *
@@ -219,6 +261,7 @@ void __init
 reserve_memory (void)
 {
 	int n = 0;
+	unsigned long total_memory = 0;
 
 	/*
 	 * none of the entries in this table overlap
@@ -254,50 +297,11 @@ reserve_memory (void)
 		n++;
 #endif
 
-	efi_memmap_init(&rsvd_region[n].start, &rsvd_region[n].end);
+	total_memory = efi_memmap_init(&rsvd_region[n].start, &rsvd_region[n].end);
 	n++;
 
-#ifdef CONFIG_KEXEC
-	/* crashkernel=size@offset specifies the size to reserve for a crash
-	 * kernel. If offset is 0, then it is determined automatically.
-	 * By reserving this memory we guarantee that linux never set's it
-	 * up as a DMA target.Useful for holding code to do something
-	 * appropriate after a kernel panic.
-	 */
-	{
-		char *from = strstr(boot_command_line, "crashkernel=");
-		unsigned long base, size;
-		if (from) {
-			size = memparse(from + 12, &from);
-			if (*from == '@')
-				base = memparse(from+1, &from);
-			else
-				base = 0;
-			if (size) {
-				if (!base) {
-					sort_regions(rsvd_region, n);
-					base = kdump_find_rsvd_region(size,
-							      	rsvd_region, n);
-					}
-				if (base != ~0UL) {
-					rsvd_region[n].start =
-						(unsigned long)__va(base);
-					rsvd_region[n].end =
-						(unsigned long)__va(base + size);
-					n++;
-					crashk_res.start = base;
-					crashk_res.end = base + size - 1;
-				}
-			}
-		}
-		efi_memmap_res.start = ia64_boot_param->efi_memmap;
-                efi_memmap_res.end = efi_memmap_res.start +
-                        ia64_boot_param->efi_memmap_size;
-                boot_param_res.start = __pa(ia64_boot_param);
-                boot_param_res.end = boot_param_res.start +
-                        sizeof(*ia64_boot_param);
-	}
-#endif
+	setup_crashkernel(total_memory, &n);
+
 	/* end of memory marker */
 	rsvd_region[n].start = ~0UL;
 	rsvd_region[n].end   = ~0UL;
--- a/include/asm-ia64/meminit.h
+++ b/include/asm-ia64/meminit.h
@@ -35,7 +35,7 @@ extern void find_memory (void);
 extern void reserve_memory (void);
 extern void find_initrd (void);
 extern int filter_rsvd_memory (unsigned long start, unsigned long end, void *arg);
-extern void efi_memmap_init(unsigned long *, unsigned long *);
+extern unsigned long efi_memmap_init(unsigned long *s, unsigned long *e);
 extern int find_max_min_low_pfn (unsigned long , unsigned long, void *);
 
 extern unsigned long vmcore_find_descriptor_size(unsigned long address);

-- 

[patch 5/7] Use extended crashkernel command line on ppc64

[Bernhard Walle]

[-- Attachment #1: crashkernel-ppc64 --]
[-- Type: text/plain, Size: 2564 bytes --]

This patch adapts the ppc64 code to use the generic parse_crashkernel()
function introduced in the generic patch of that series.


Signed-off-by: Bernhard Walle <bwalle@suse.de>

---
 arch/powerpc/kernel/machine_kexec.c |   52 ++++++++++++++++++------------------
 1 file changed, 26 insertions(+), 26 deletions(-)

--- a/arch/powerpc/kernel/machine_kexec.c
+++ b/arch/powerpc/kernel/machine_kexec.c
@@ -61,45 +61,39 @@ NORET_TYPE void machine_kexec(struct kim
 	for(;;);
 }
 
-static int __init early_parse_crashk(char *p)
+void __init reserve_crashkernel(void)
 {
-	unsigned long size;
-
-	if (!p)
-		return 1;
-
-	size = memparse(p, &p);
+	unsigned long long crash_size = 0, crash_base;
+	int ret;
 
-	if (*p == '@')
-		crashk_res.start = memparse(p + 1, &p);
-	else
-		crashk_res.start = KDUMP_KERNELBASE;
-
-	crashk_res.end = crashk_res.start + size - 1;
-
-	return 0;
-}
-early_param("crashkernel", early_parse_crashk);
+	/* this is necessary because of lmb_phys_mem_size() */
+	lmb_analyze();
 
-void __init reserve_crashkernel(void)
-{
-	unsigned long size;
+	/* use common parsing */
+	ret = parse_crashkernel(boot_command_line, lmb_phys_mem_size(),
+			&crash_size, &crash_base);
+	if (ret == 0 && crash_size > 0) {
+		if (crash_base == 0)
+			crash_base = KDUMP_KERNELBASE;
+		crashk_res.start = crash_base;
+	} else {
+		/* handle the device tree */
+		crash_size = crashk_res.end - crashk_res.start + 1;
+	}
 
-	if (crashk_res.start == 0)
+	if (crash_size == 0)
 		return;
 
 	/* We might have got these values via the command line or the
 	 * device tree, either way sanitise them now. */
 
-	size = crashk_res.end - crashk_res.start + 1;
-
 	if (crashk_res.start != KDUMP_KERNELBASE)
 		printk("Crash kernel location must be 0x%x\n",
 				KDUMP_KERNELBASE);
 
 	crashk_res.start = KDUMP_KERNELBASE;
-	size = PAGE_ALIGN(size);
-	crashk_res.end = crashk_res.start + size - 1;
+	crash_size = PAGE_ALIGN(crash_size);
+	crashk_res.end = crashk_res.start + crash_size - 1;
 
 	/* Crash kernel trumps memory limit */
 	if (memory_limit && memory_limit <= crashk_res.end) {
@@ -108,7 +102,13 @@ void __init reserve_crashkernel(void)
 				memory_limit);
 	}
 
-	lmb_reserve(crashk_res.start, size);
+	printk(KERN_INFO "Reserving %ldMB of memory at %ldMB "
+			"for crashkernel (System RAM: %ldMB)\n",
+			(unsigned long)(crash_size >> 20),
+			(unsigned long)(crashk_res.start >> 20),
+			(unsigned long)(lmb_phys_mem_size() >> 20));
+
+	lmb_reserve(crashk_res.start, crash_size);
 }
 
 int overlaps_crashkernel(unsigned long start, unsigned long size)

-- 

[patch 6/7] Use extended crashkernel command line on sh

[Bernhard Walle]

[-- Attachment #1: crashkernel-sh --]
[-- Type: text/plain, Size: 3031 bytes --]

This patch removes the crashkernel parsing from arch/sh/kernel/machine_kexec.c
and calls the generic function, introduced in the generic patch, in
setup_bootmem_allocator().

This is necessary because the amount of System RAM must be known in this
function now because of the new syntax.

NOTE: Due to the lack of a SH processor, this patch is untested (and
uncompiled). Because the code in that area is quite similar as i386/x86_64
(contrary to PPC and IA64), it should compile and work. However, if someone of
the SH people could test for me and provide feedback, that would be very nice.


Signed-off-by: Bernhard Walle <bwalle@suse.de>

---
 arch/sh/kernel/machine_kexec.c |   21 ---------------------
 arch/sh/kernel/setup.c         |   34 +++++++++++++++++++++++++++++-----
 2 files changed, 29 insertions(+), 26 deletions(-)

--- a/arch/sh/kernel/machine_kexec.c
+++ b/arch/sh/kernel/machine_kexec.c
@@ -104,24 +104,3 @@ NORET_TYPE void machine_kexec(struct kim
 	(*rnk)(page_list, reboot_code_buffer, image->start, vbr_reg);
 }
 
-/* crashkernel=size@addr specifies the location to reserve for
- * a crash kernel.  By reserving this memory we guarantee
- * that linux never sets it up as a DMA target.
- * Useful for holding code to do something appropriate
- * after a kernel panic.
- */
-static int __init parse_crashkernel(char *arg)
-{
-	unsigned long size, base;
-	size = memparse(arg, &arg);
-	if (*arg == '@') {
-		base = memparse(arg+1, &arg);
-		/* FIXME: Do I want a sanity check
-		 * to validate the memory range?
-		 */
-		crashk_res.start = base;
-		crashk_res.end   = base + size - 1;
-	}
-	return 0;
-}
-early_param("crashkernel", parse_crashkernel);
--- a/arch/sh/kernel/setup.c
+++ b/arch/sh/kernel/setup.c
@@ -121,6 +121,33 @@ static void __init register_bootmem_low_
 	free_bootmem(PFN_PHYS(curr_pfn), PFN_PHYS(pages));
 }
 
+#ifdef CONFIG_KEXEC
+static void reserve_crashkernel(void)
+{
+	unsigned long long 	free_mem;
+	unsigned long long 	crash_size, crash_base;
+	int			ret;
+
+	free_mem = (max_low_pfn - min_low_pfn) << PAGE_SHIFT;
+
+	ret = parse_crashkernel(boot_command_line, free_mem,
+			&crash_size, &crash_base);
+	if (ret == 0 && crash_size > 0 && crash_base > 0) {
+		printk(KERN_INFO "Reserving %ldMB of memory at %ldMB "
+				"for crashkernel (System RAM: %ldMB)\n",
+				(unsigned long)(crash_size >> 20),
+				(unsigned long)(crash_base >> 20),
+				(unsigned long)(free_mem >> 20));
+		crashk_res.start = crash_base;
+		crashk_res.end   = crash_base + crash_size - 1;
+		reserve_bootmem(crash_base, crash_size);
+	}
+}
+#else
+static inline void reserve_crashkernel(void)
+{}
+#endif
+
 void __init setup_bootmem_allocator(unsigned long free_pfn)
 {
 	unsigned long bootmap_size;
@@ -182,11 +209,8 @@ void __init setup_bootmem_allocator(unsi
 		}
 	}
 #endif
-#ifdef CONFIG_KEXEC
-	if (crashk_res.start != crashk_res.end)
-		reserve_bootmem(crashk_res.start,
-			crashk_res.end - crashk_res.start + 1);
-#endif
+
+	reserve_crashkernel();
 }
 
 #ifndef CONFIG_NEED_MULTIPLE_NODES

-- 

Re: [patch 6/7] Use extended crashkernel command line on sh

[Paul Mundt]

On Thu, Sep 13, 2007 at 06:14:34PM +0200, Bernhard Walle wrote:
> This patch removes the crashkernel parsing from arch/sh/kernel/machine_kexec.c
> and calls the generic function, introduced in the generic patch, in
> setup_bootmem_allocator().
> 
> This is necessary because the amount of System RAM must be known in this
> function now because of the new syntax.
> 
> NOTE: Due to the lack of a SH processor, this patch is untested (and
> uncompiled). Because the code in that area is quite similar as i386/x86_64
> (contrary to PPC and IA64), it should compile and work. However, if someone of
> the SH people could test for me and provide feedback, that would be very nice.
> 
> Signed-off-by: Bernhard Walle <bwalle@suse.de>
> 
Works fine on SH.

Acked-by: Paul Mundt <lethal@linux-sh.org>

[patch 7/7] Add documentation for extended crashkernel syntax

[Bernhard Walle]

[-- Attachment #1: crashkernel-documentation --]
[-- Type: text/plain, Size: 1315 bytes --]

This adds the documentation for the extended crashkernel syntax into
Documentation/kdump/kdump.txt.

Signed-off-by: Bernhard Walle <bwalle@suse.de>

---
 Documentation/kdump/kdump.txt |   26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

--- a/Documentation/kdump/kdump.txt
+++ b/Documentation/kdump/kdump.txt
@@ -231,6 +231,32 @@ Dump-capture kernel config options (Arch
   any space below the alignment point will be wasted.
 
 
+Extended crashkernel syntax
+===========================
+
+While the "crashkernel=size[@offset]" syntax is sufficient for most
+configurations, sometimes it's handy to have the reserved memory dependent
+on the value of System RAM -- that's mostly for distributors that pre-setup
+the kernel command line to avoid a unbootable system after some memory has
+been removed from the machine.
+
+The syntax is:
+
+    crashkernel=<range1>:<size1>[,<range2>:<size2>,...][@offset]
+    range=start-[end]
+
+For example:
+
+    crashkernel=512M-2G:64M,2G-:128M
+
+This would mean:
+
+    1) if the RAM is smaller than 512M, then don't reserve anything
+       (this is the "rescue" case)
+    2) if the RAM size is between 512M and 2G, then reserve 64M
+    3) if the RAM size is larger than 2G, then reserve 128M
+
+
 Boot into System Kernel
 =======================
 

-- 

Re: [patch 7/7] Add documentation for extended crashkernel syntax

[Pavel Machek]

Hi!

> This adds the documentation for the extended crashkernel syntax into
> Documentation/kdump/kdump.txt.

Should you also update kernel-parameters.txt?

> +For example:
> +
> +    crashkernel=512M-2G:64M,2G-:128M
> +
> +This would mean:
> +
> +    1) if the RAM is smaller than 512M, then don't reserve anything
> +       (this is the "rescue" case)
> +    2) if the RAM size is between 512M and 2G, then reserve 64M
> +    3) if the RAM size is larger than 2G, then reserve 128M

Why is this useful? I mean... if 64M is enough to save a dump, why use
128M? ...or does the required size somehow scale with memory in
machine? (pagetables?)
						Pavel

-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

Re: [patch 7/7] Add documentation for extended crashkernel syntax

[Bernhard Walle]

* Pavel Machek <pavel@ucw.cz> [2007-09-18 19:21]:
> > This adds the documentation for the extended crashkernel syntax into
> > Documentation/kdump/kdump.txt.
> 
> Should you also update kernel-parameters.txt?

Ok, I'll do.

> > +For example:
> > +
> > +    crashkernel=512M-2G:64M,2G-:128M
> > +
> > +This would mean:
> > +
> > +    1) if the RAM is smaller than 512M, then don't reserve anything
> > +       (this is the "rescue" case)
> > +    2) if the RAM size is between 512M and 2G, then reserve 64M
> > +    3) if the RAM size is larger than 2G, then reserve 128M
> 
> Why is this useful? I mean... if 64M is enough to save a dump, why use
> 128M? ...or does the required size somehow scale with memory in
> machine? (pagetables?)

A bit, yes (ELF core headers, DISCONT memory, per-CPU data), but
consider also that saving may be faster if you have more RAM (e.g.
saving over SSH, encryption, ...).


Thanks,
   Bernhard

[patch 0/7] Add extended crashkernel command line syntax

[Bernhard Walle]

This patch adds a extended crashkernel syntax that makes the value of reserved
system RAM dependent on the system RAM itself:

    crashkernel=<range1>:<size1>[,<range2>:<size2>,...][@offset]
    range=start-[end]

For example:

    crashkernel=512M-2G:64M,2G-:128M

The motivation comes from distributors that configure their crashkernel command
line automatically with some configuration tool (YaST, you know ;)). Of course
that tool knows the value of System RAM, but if the user removes RAM, then
the system becomes unbootable or at least unusable and error handling
is very difficult.

This series implements this change for i386, x86_64, ia64, ppc64 and sh. That
should be all platforms that support kdump in current mainline. I tested all
platforms except sh due to the lack of a sh processor.

The patch series is against 2.6.23-rc4-mm1.


Modifications compared to last submit:

  - put functions in __init
  - print message when no base address is specified on i386/x86_64/sh


Signed-off-by: Bernhard Walle <bwalle@suse.de>

-- 

[patch 1/7] Extended crashkernel command line

[Bernhard Walle]

[-- Attachment #1: crashkernel-generic --]
[-- Type: text/plain, Size: 4719 bytes --]

This is the generic part of the patch. It adds a parse_crashkernel() function
in kernel/kexec.c that is called by the architecture specific code that
actually reserves the memory. That function takes the whole command line and
looks itself for "crashkernel=" in it.

If there are multiple occurrences, then the last one is taken.  The advantage
is that if you have a bootloader like lilo or elilo which allows you to append
a command line parameter but not to remove one (like in GRUB), then you can add
another crashkernel value for testing at the boot command line and this one
overwrites the command line in the configuration then.


Signed-off-by: Bernhard Walle <bwalle@suse.de>

---
 include/linux/kexec.h |    2 
 kernel/kexec.c        |  141 ++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 143 insertions(+)

--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -179,6 +179,8 @@ extern note_buf_t *crash_notes;
 extern u32 vmcoreinfo_note[VMCOREINFO_NOTE_SIZE/4];
 extern unsigned int vmcoreinfo_size;
 extern unsigned int vmcoreinfo_max_size;
+int __init parse_crashkernel(char *cmdline, unsigned long long system_ram,
+		unsigned long long *crash_size, unsigned long long *crash_base);
 
 
 #else /* !CONFIG_KEXEC */
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -1146,6 +1146,147 @@ static int __init crash_notes_memory_ini
 }
 module_init(crash_notes_memory_init)
 
+
+/*
+ * parsing the "crashkernel" commandline
+ *
+ * this code is intended to be called from architecture specific code
+ */
+
+
+/*
+ * This function parses command lines in the format
+ *
+ *   crashkernel=<ramsize-range>:<size>[,...][@<base>]
+ *
+ * The function returns 0 on success and -EINVAL on failure.
+ */
+static int __init parse_crashkernel_mem(char 			*cmdline,
+					unsigned long 		system_ram,
+					unsigned long long 	*crash_size,
+					unsigned long long 	*crash_base)
+{
+	char *cur = cmdline;
+
+	/* for each entry of the comma-separated list */
+	do {
+		unsigned long long start = 0, end = ULLONG_MAX;
+		unsigned long long size = -1;
+
+		/* get the start of the range */
+		start = memparse(cur, &cur);
+		if (*cur != '-') {
+			printk(KERN_WARNING "crashkernel: '-' expected\n");
+			return -EINVAL;
+		}
+		cur++;
+
+		/* if no ':' is here, than we read the end */
+		if (*cur != ':') {
+			end = memparse(cur, &cur);
+			if (end <= start) {
+				printk(KERN_WARNING "crashkernel: end <= start\n");
+				return -EINVAL;
+			}
+		}
+
+		if (*cur != ':') {
+			printk(KERN_WARNING "crashkernel: ':' expected\n");
+			return -EINVAL;
+		}
+		cur++;
+
+		size = memparse(cur, &cur);
+		if (size < 0) {
+			printk(KERN_WARNING "crashkernel: invalid size\n");
+			return -EINVAL;
+		}
+
+		/* match ? */
+		if (system_ram >= start  && system_ram <= end) {
+			*crash_size = size;
+			break;
+		}
+	} while (*cur++ == ',');
+
+	if (*crash_size > 0) {
+		while (*cur != ' ' && *cur != '@')
+			cur++;
+		if (*cur == '@')
+			*crash_base = memparse(cur+1, &cur);
+	}
+
+	return 0;
+}
+
+/*
+ * That function parses "simple" (old) crashkernel command lines like
+ *
+ * 	crashkernel=size[@base]
+ *
+ * It returns 0 on success and -EINVAL on failure.
+ */
+static int __init parse_crashkernel_simple(char 		*cmdline,
+					   unsigned long long 	*crash_size,
+					   unsigned long long 	*crash_base)
+{
+	char *cur = cmdline;
+
+	*crash_size = memparse(cmdline, &cur);
+	if (cmdline == cur)
+		return -EINVAL;
+
+	if (*cur == '@')
+		*crash_base = memparse(cur+1, &cur);
+
+	return 0;
+}
+
+/*
+ * That function is the entry point for command line parsing and should be
+ * called from the arch-specific code.
+ */
+int __init parse_crashkernel(char 		 *cmdline,
+			     unsigned long long system_ram,
+			     unsigned long long *crash_size,
+			     unsigned long long *crash_base)
+{
+	char 	*p = cmdline, *ck_cmdline = NULL;
+	char	*first_colon, *first_space;
+
+	*crash_size = 0;
+	*crash_base = 0;
+
+	/* find crashkernel and use the last one if there are more */
+	p = strstr(p, "crashkernel=");
+	while (p) {
+		ck_cmdline = p;
+		p = strstr(p+1, "crashkernel=");
+	}
+
+	if (!ck_cmdline)
+		return -EINVAL;
+
+	ck_cmdline += 12; /* strlen("crashkernel=") */
+
+	/*
+	 * if the commandline contains a ':', then that's the extended
+	 * syntax -- if not, it must be the classic syntax
+	 */
+	first_colon = strchr(ck_cmdline, ':');
+	first_space = strchr(ck_cmdline, ' ');
+	if (first_colon && (!first_space || first_colon < first_space))
+		return parse_crashkernel_mem(ck_cmdline, system_ram,
+				crash_size, crash_base);
+	else
+		return parse_crashkernel_simple(ck_cmdline, crash_size,
+				crash_base);
+
+	return 0;
+}
+
+
+
 void crash_save_vmcoreinfo(void)
 {
 	u32 *buf;

-- 

Re: [patch 1/7] Extended crashkernel command line

[Oleg Verych]

* Thu, 20 Sep 2007 19:18:46 +0200

[]
>  extern u32 vmcoreinfo_note[VMCOREINFO_NOTE_SIZE/4];
>  extern unsigned int vmcoreinfo_size;
>  extern unsigned int vmcoreinfo_max_size;
> +int __init parse_crashkernel(char *cmdline, unsigned long long system_ram,
> +		unsigned long long *crash_size, unsigned long long *crash_base);

(BTW, why `system_ram' is `unsigned long' in parse_crashkernel_mem() but
`unsigned long long' in parse_crashkernel()?)

> +static int __init parse_crashkernel_mem(char 			*cmdline,
> +					unsigned long 		system_ram,
> +					unsigned long long 	*crash_size,
> +					unsigned long long 	*crash_base)
> +{
> +	char *cur = cmdline;
> +
> +	/* for each entry of the comma-separated list */
> +	do {
> +		unsigned long long start = 0, end = ULLONG_MAX;
> +		unsigned long long size = -1;
[]

What is the point of not using `ulong' and `u64'?

What about another names?

 +int __init get_crashkernel_params(u64 *memsize, u64 *addrbase, char *cmdline, u64 ram);
_____

Re: [patch 1/7] Extended crashkernel command line

[Bernhard Walle]

* Oleg Verych <olecom@flower.upol.cz> [2007-09-23 01:14]:
> * Thu, 20 Sep 2007 19:18:46 +0200
> 
> []
> >  extern u32 vmcoreinfo_note[VMCOREINFO_NOTE_SIZE/4];
> >  extern unsigned int vmcoreinfo_size;
> >  extern unsigned int vmcoreinfo_max_size;
> > +int __init parse_crashkernel(char *cmdline, unsigned long long system_ram,
> > +		unsigned long long *crash_size, unsigned long long *crash_base);
> 
> (BTW, why `system_ram' is `unsigned long' in parse_crashkernel_mem() but
> `unsigned long long' in parse_crashkernel()?)

Because that's a bug, thanks for spotting that out. I will sent an
updated version of this patch until the issue below has been
clarified:

> What is the point of not using `ulong' and `u64'?
> 
> What about another names?
> 
>  +int __init get_crashkernel_params(u64 *memsize, u64 *addrbase, char *cmdline, u64 ram);

Andrew, what's your opinion on this? Whould I resend the patch with
shorter type names?


Thanks,
   Bernhard

Re: [patch 1/7] Extended crashkernel command line

[Oleg Verych]

On Sun, Sep 23, 2007 at 10:19:43PM +0200, Bernhard Walle wrote:
[]
> >  +int __init get_crashkernel_params(u64 *memsize, u64 *addrbase, char *cmdline, u64 ram);
> 
> Andrew, what's your opinion on this? Whould I resend the patch with
> shorter type names?

Also, maybe it will be better to extend linux/lib/cmdline.c->{get_range(), get_range()}
to handle that stuff? And maybe new functionality can be built up-on the current one: 

- crashkernel=512M-2G:64M,2G-:128M@offset
+ crashkernel=512M-2G,64M,2G-,128M,,offset
?

OK, OK, you are already using and maintaining new syntax, but still.
_____
(`Mail-Followup-To' ignored)

Re: [patch 1/7] Extended crashkernel command line

[Bernhard Walle]

* Oleg Verych <olecom@flower.upol.cz> [2007-09-23 23:15]:
> 
> - crashkernel=512M-2G:64M,2G-:128M@offset
> + crashkernel=512M-2G,64M,2G-,128M,,offset
> ?

I don't like this syntax.


Thanks,
   Bernhard

[patch 0/7] Add extended crashkernel command line syntax

[Bernhard Walle]

This patch adds a extended crashkernel syntax that makes the value of reserved
system RAM dependent on the system RAM itself:

    crashkernel=<range1>:<size1>[,<range2>:<size2>,...][@offset]
    range=start-[end]

For example:

    crashkernel=512M-2G:64M,2G-:128M

The motivation comes from distributors that configure their crashkernel command
line automatically with some configuration tool (YaST, you know ;)). Of course
that tool knows the value of System RAM, but if the user removes RAM, then
the system becomes unbootable or at least unusable and error handling
is very difficult.

This series implements this change for i386, x86_64, ia64, ppc64 and sh. That
should be all platforms that support kdump in current mainline. I tested all
platforms except sh due to the lack of a sh processor.

The patch series is against 2.6.23-rc8-mm1 and replaces following patches:

  - extended-crashkernel-command-line.patch
  - use-extended-crashkernel-command-line-on-i386.patch
  - use-extended-crashkernel-command-line-on-i386-fix-config_nohighmem-for-extended-crashkernel-command-line.patch
  - use-extended-crashkernel-command-line-on-i386-fix-config_nohighmem-for-extended-crashkernel-command-line-fix.patch
  - use-extended-crashkernel-command-line-on-x86_64.patch
  - use-extended-crashkernel-command-line-on-ia64.patch
  - use-extended-crashkernel-command-line-on-ia64-fix.patch
  - use-extended-crashkernel-command-line-on-ppc64.patch
  - use-extended-crashkernel-command-line-on-sh.patch
  - add-documentation-for-extended-crashkernel-syntax.patch
  - add-documentation-for-extended-crashkernel-syntax-add-extended-crashkernel-syntax-to-kernel-parameterstxt.patch


Modifications compared to last submit:

  - typecast to (unsigned long long) before shifting
  - small coding style adjustments
  - BUG_ON() in parse_crashkernel()
  - merge patch that adds documentation do Documentation/kernel-parameters.txt
    in documentation patch (this has been an extra patch previously)
  - fix build on IA64
  - fix build on i386 with CONFIG_NOHIGHMEM


Signed-off-by: Bernhard Walle <bwalle@suse.de>

-- 

[patch 1/7] Extended crashkernel command line

[Bernhard Walle]

[-- Attachment #1: crashkernel-generic --]
[-- Type: text/plain, Size: 4719 bytes --]

This is the generic part of the patch. It adds a parse_crashkernel() function
in kernel/kexec.c that is called by the architecture specific code that
actually reserves the memory. That function takes the whole command line and
looks itself for "crashkernel=" in it.

If there are multiple occurrences, then the last one is taken.  The advantage
is that if you have a bootloader like lilo or elilo which allows you to append
a command line parameter but not to remove one (like in GRUB), then you can add
another crashkernel value for testing at the boot command line and this one
overwrites the command line in the configuration then.


Signed-off-by: Bernhard Walle <bwalle@suse.de>

---
 include/linux/kexec.h |    2 
 kernel/kexec.c        |  142 ++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 144 insertions(+)

--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -187,6 +187,8 @@ extern u32 vmcoreinfo_note[VMCOREINFO_NO
 extern size_t vmcoreinfo_size;
 extern size_t vmcoreinfo_max_size;
 
+int __init parse_crashkernel(char *cmdline, unsigned long long system_ram,
+		unsigned long long *crash_size, unsigned long long *crash_base);
 
 #else /* !CONFIG_KEXEC */
 struct pt_regs;
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -1146,6 +1146,148 @@ static int __init crash_notes_memory_ini
 }
 module_init(crash_notes_memory_init)
 
+
+/*
+ * parsing the "crashkernel" commandline
+ *
+ * this code is intended to be called from architecture specific code
+ */
+
+
+/*
+ * This function parses command lines in the format
+ *
+ *   crashkernel=<ramsize-range>:<size>[,...][@<base>]
+ *
+ * The function returns 0 on success and -EINVAL on failure.
+ */
+static int __init parse_crashkernel_mem(char 			*cmdline,
+					unsigned long long	system_ram,
+					unsigned long long	*crash_size,
+					unsigned long long	*crash_base)
+{
+	char *cur = cmdline;
+
+	/* for each entry of the comma-separated list */
+	do {
+		unsigned long long start = 0, end = ULLONG_MAX;
+		unsigned long long size = -1;
+
+		/* get the start of the range */
+		start = memparse(cur, &cur);
+		if (*cur != '-') {
+			printk(KERN_WARNING "crashkernel: '-' expected\n");
+			return -EINVAL;
+		}
+		cur++;
+
+		/* if no ':' is here, than we read the end */
+		if (*cur != ':') {
+			end = memparse(cur, &cur);
+			if (end <= start) {
+				printk(KERN_WARNING "crashkernel: end <= start\n");
+				return -EINVAL;
+			}
+		}
+
+		if (*cur != ':') {
+			printk(KERN_WARNING "crashkernel: ':' expected\n");
+			return -EINVAL;
+		}
+		cur++;
+
+		size = memparse(cur, &cur);
+		if (size < 0) {
+			printk(KERN_WARNING "crashkernel: invalid size\n");
+			return -EINVAL;
+		}
+
+		/* match ? */
+		if (system_ram >= start  && system_ram <= end) {
+			*crash_size = size;
+			break;
+		}
+	} while (*cur++ == ',');
+
+	if (*crash_size > 0) {
+		while (*cur != ' ' && *cur != '@')
+			cur++;
+		if (*cur == '@')
+			*crash_base = memparse(cur+1, &cur);
+	}
+
+	return 0;
+}
+
+/*
+ * That function parses "simple" (old) crashkernel command lines like
+ *
+ * 	crashkernel=size[@base]
+ *
+ * It returns 0 on success and -EINVAL on failure.
+ */
+static int __init parse_crashkernel_simple(char 		*cmdline,
+					   unsigned long long 	*crash_size,
+					   unsigned long long 	*crash_base)
+{
+	char *cur = cmdline;
+
+	*crash_size = memparse(cmdline, &cur);
+	if (cmdline == cur)
+		return -EINVAL;
+
+	if (*cur == '@')
+		*crash_base = memparse(cur+1, &cur);
+
+	return 0;
+}
+
+/*
+ * That function is the entry point for command line parsing and should be
+ * called from the arch-specific code.
+ */
+int __init parse_crashkernel(char 		 *cmdline,
+			     unsigned long long system_ram,
+			     unsigned long long *crash_size,
+			     unsigned long long *crash_base)
+{
+	char 	*p = cmdline, *ck_cmdline = NULL;
+	char	*first_colon, *first_space;
+
+	BUG_ON(!crash_size || !crash_base);
+	*crash_size = 0;
+	*crash_base = 0;
+
+	/* find crashkernel and use the last one if there are more */
+	p = strstr(p, "crashkernel=");
+	while (p) {
+		ck_cmdline = p;
+		p = strstr(p+1, "crashkernel=");
+	}
+
+	if (!ck_cmdline)
+		return -EINVAL;
+
+	ck_cmdline += 12; /* strlen("crashkernel=") */
+
+	/*
+	 * if the commandline contains a ':', then that's the extended
+	 * syntax -- if not, it must be the classic syntax
+	 */
+	first_colon = strchr(ck_cmdline, ':');
+	first_space = strchr(ck_cmdline, ' ');
+	if (first_colon && (!first_space || first_colon < first_space))
+		return parse_crashkernel_mem(ck_cmdline, system_ram,
+				crash_size, crash_base);
+	else
+		return parse_crashkernel_simple(ck_cmdline, crash_size,
+				crash_base);
+
+	return 0;
+}
+
+
+
 void crash_save_vmcoreinfo(void)
 {
 	u32 *buf;

-- 

Re: [patch 1/7] Extended crashkernel command line

[Oleg Verych]

* Tue, 25 Sep 2007 20:22:58 +0200
>
> This is the generic part of the patch. It adds a parse_crashkernel() function
> in kernel/kexec.c that is called by the architecture specific code that
> actually reserves the memory. That function takes the whole command line and
> looks itself for "crashkernel=" in it.
[]
> +++ b/include/linux/kexec.h
> @@ -187,6 +187,8 @@ extern u32 vmcoreinfo_note[VMCOREINFO_NO
>  extern size_t vmcoreinfo_size;
>  extern size_t vmcoreinfo_max_size;
>  
> +int __init parse_crashkernel(char *cmdline, unsigned long long system_ram,
> +		unsigned long long *crash_size, unsigned long long *crash_base);

I still want to point out my consernes about `unsigned long long long'
bloat.

>  #else /* !CONFIG_KEXEC */
>  struct pt_regs;
> --- a/kernel/kexec.c
> +++ b/kernel/kexec.c
[]
> +/*
> + * This function parses command lines in the format
> + *
> + *   crashkernel=<ramsize-range>:<size>[,...][@<base>]

#v+
olecom@flower:/tmp$ grep '@offset' <extended-crashkernel-cmdline.mbox
    crashkernel=<range1>:<size1>[,<range2>:<size2>,...][@offset]
-       /* crashkernel=size@offset specifies the size to reserve for a crash
+While the "crashkernel=size[@offset]" syntax is sufficient for most
+    crashkernel=<range1>:<size1>[,<range2>:<size2>,...][@offset]
+       crashkernel=range1:size1[,range2:size2,...][@offset]
olecom@flower:/tmp$ grep '@base' <extended-crashkernel-cmdline.mbox
+ *     crashkernel=size[@base]
olecom@flower:/tmp$ grep '@<base' <extended-crashkernel-cmdline.mbox
+ *   crashkernel=<ramsize-range>:<size>[,...][@<base>]
olecom@flower:/tmp$ grep '@<offset' <extended-crashkernel-cmdline.mbox
olecom@flower:/tmp$
#v-

> + *
> + * The function returns 0 on success and -EINVAL on failure.
> + */
> +static int __init parse_crashkernel_mem(char 			*cmdline,
> +					unsigned long long	system_ram,
> +					unsigned long long	*crash_size,
> +					unsigned long long	*crash_base)
> +{
> +	char *cur = cmdline;
> +
> +	/* for each entry of the comma-separated list */
> +	do {
> +		unsigned long long start = 0, end = ULLONG_MAX;
> +		unsigned long long size = -1;

memparse(), as a wrapper for somple_strtoll(), always have a return value
(zero by default).
<http://article.gmane.org/gmane.linux.kernel/583426>

Consider coded error path now, please.

And why not to make overall result reliable? This is kernel after all.

I.e. if there's valid `crashkernel=' option, but some parsing errors, why
not to apply some heuristics with warning in syslog, if user have some
conf, bootloader (random) errors, but feature still works?

> +
> +		/* get the start of the range */
> +		start = memparse(cur, &cur);
> +		if (*cur != '-') {
> +			printk(KERN_WARNING "crashkernel: '-' expected\n");
> +			return -EINVAL;
> +		}
> +		cur++;
> +
> +		/* if no ':' is here, than we read the end */
> +		if (*cur != ':') {
> +			end = memparse(cur, &cur);
> +			if (end <= start) {
> +				printk(KERN_WARNING "crashkernel: end <= start\n");
> +				return -EINVAL;
> +			}
> +		}
> +
> +		if (*cur != ':') {
> +			printk(KERN_WARNING "crashkernel: ':' expected\n");
> +			return -EINVAL;
> +		}
> +		cur++;
> +
> +		size = memparse(cur, &cur);
> +		if (size < 0) {
> +			printk(KERN_WARNING "crashkernel: invalid size\n");
> +			return -EINVAL;
> +		}
> +
> +		/* match ? */
> +		if (system_ram >= start  && system_ram <= end) {
> +			*crash_size = size;
> +			break;
> +		}
> +	} while (*cur++ == ',');
> +
> +	if (*crash_size > 0) {
> +		while (*cur != ' ' && *cur != '@')
> +			cur++;
> +		if (*cur == '@')
> +			*crash_base = memparse(cur+1, &cur);
> +	}
> +
> +	return 0;
> +}
--
-o--=O`C
 #oo'L O
<___=E M

Re: [patch 1/7] Extended crashkernel command line

[Bernhard Walle]

* Oleg Verych <olecom@flower.upol.cz> [2007-09-25 22:53]:
> * Tue, 25 Sep 2007 20:22:58 +0200
> >
> > +++ b/include/linux/kexec.h
> > @@ -187,6 +187,8 @@ extern u32 vmcoreinfo_note[VMCOREINFO_NO
> >  extern size_t vmcoreinfo_size;
> >  extern size_t vmcoreinfo_max_size;
> >  
> > +int __init parse_crashkernel(char *cmdline, unsigned long long system_ram,
> > +		unsigned long long *crash_size, unsigned long long *crash_base);
> 
> I still want to point out my consernes about `unsigned long long long'
> bloat.

What "concerns" (it's unsigned long long and not unsigned long long
long)? Is is common coding style in the Linux kernel to *not* use
unsigned long long? This type *is* used e.g. in
arch/i386/kernel/e820.c also for pysical memory values.

> #v+
> olecom@flower:/tmp$ grep '@offset' <extended-crashkernel-cmdline.mbox
>     crashkernel=<range1>:<size1>[,<range2>:<size2>,...][@offset]
> -       /* crashkernel=size@offset specifies the size to reserve for a crash
> +While the "crashkernel=size[@offset]" syntax is sufficient for most
> +    crashkernel=<range1>:<size1>[,<range2>:<size2>,...][@offset]
> +       crashkernel=range1:size1[,range2:size2,...][@offset]
> olecom@flower:/tmp$ grep '@base' <extended-crashkernel-cmdline.mbox
> + *     crashkernel=size[@base]
> olecom@flower:/tmp$ grep '@<base' <extended-crashkernel-cmdline.mbox
> + *   crashkernel=<ramsize-range>:<size>[,...][@<base>]
> olecom@flower:/tmp$ grep '@<offset' <extended-crashkernel-cmdline.mbox
> olecom@flower:/tmp$
> #v-

The patch below fixes this.

> > + *
> > + * The function returns 0 on success and -EINVAL on failure.
> > + */
> > +static int __init parse_crashkernel_mem(char 			*cmdline,
> > +					unsigned long long	system_ram,
> > +					unsigned long long	*crash_size,
> > +					unsigned long long	*crash_base)
> > +{
> > +	char *cur = cmdline;
> > +
> > +	/* for each entry of the comma-separated list */
> > +	do {
> > +		unsigned long long start = 0, end = ULLONG_MAX;
> > +		unsigned long long size = -1;
> 
> memparse(), as a wrapper for somple_strtoll(), always have a return value
> (zero by default).
> <http://article.gmane.org/gmane.linux.kernel/583426>

Next reply (because of a different patch).


---

Only use 'offset' and not 'base' for the address where the reserved area
starts.


Signed-off-by: Bernhard Walle <bwalle@suse.de>

---
 kernel/kexec.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -1157,7 +1157,7 @@ module_init(crash_notes_memory_init)
 /*
  * This function parses command lines in the format
  *
- *   crashkernel=<ramsize-range>:<size>[,...][@<base>]
+ *   crashkernel=ramsize-range:size[,...][@offset]
  *
  * The function returns 0 on success and -EINVAL on failure.
  */
@@ -1222,7 +1222,7 @@ static int __init parse_crashkernel_mem(
 /*
  * That function parses "simple" (old) crashkernel command lines like
  *
- * 	crashkernel=size[@base]
+ * 	crashkernel=size[@offset]
  *
  * It returns 0 on success and -EINVAL on failure.
  */

Re: [patch 1/7] Extended crashkernel command line

[Bernhard Walle]

* Oleg Verych <olecom@flower.upol.cz> [2007-09-25 22:53]:
> 
> > + *
> > + * The function returns 0 on success and -EINVAL on failure.
> > + */
> > +static int __init parse_crashkernel_mem(char 			*cmdline,
> > +					unsigned long long	system_ram,
> > +					unsigned long long	*crash_size,
> > +					unsigned long long	*crash_base)
> > +{
> > +	char *cur = cmdline;
> > +
> > +	/* for each entry of the comma-separated list */
> > +	do {
> > +		unsigned long long start = 0, end = ULLONG_MAX;
> > +		unsigned long long size = -1;
> 
> memparse(), as a wrapper for somple_strtoll(), always have a return value
> (zero by default).
> <http://article.gmane.org/gmane.linux.kernel/583426>

Ok, that's fixed now, see patch below.

> And why not to make overall result reliable? This is kernel after all.
> 
> I.e. if there's valid `crashkernel=' option, but some parsing errors, why
> not to apply some heuristics with warning in syslog, if user have some
> conf, bootloader (random) errors, but feature still works?

I'm against guessing. The user has to specify a parameter which is
right according to syntax.

However, I plan to make a patch that the kernel can detect a sensible
offset automatically for i386 and x86_64 as it's done in ia64. Since
both architectures have a relocatable kernel now, that makes perfectly
sense. But that's another patch.

---

This patches improves error handling in parse_crashkernel_mem() by comparing
the return pointer of memparse() with the input pointer and also replaces
all printk(KERN_WARNING msg) with pr_warning(msg).


Signed-off-by: Bernhard Walle <bwalle@suse.de>

---
 kernel/kexec.c |   31 ++++++++++++++++++++++++-------
 1 file changed, 24 insertions(+), 7 deletions(-)

--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -1172,33 +1172,50 @@ static int __init parse_crashkernel_mem(
 	do {
 		unsigned long long start = 0, end = ULLONG_MAX;
 		unsigned long long size = -1;
+		char *tmp;
 
 		/* get the start of the range */
-		start = memparse(cur, &cur);
+		start = memparse(cur, &tmp);
+		if (cur == tmp) {
+			pr_warning("crashkernel: Memory value expected\n");
+			return -EINVAL;
+		}
+		cur = tmp;
 		if (*cur != '-') {
-			printk(KERN_WARNING "crashkernel: '-' expected\n");
+			pr_warning("crashkernel: '-' expected\n");
 			return -EINVAL;
 		}
 		cur++;
 
 		/* if no ':' is here, than we read the end */
 		if (*cur != ':') {
-			end = memparse(cur, &cur);
+			end = memparse(cur, &tmp);
+			if (cur == tmp) {
+				pr_warning("crashkernel: Memory "
+						"value expected\n");
+				return -EINVAL;
+			}
+			cur = tmp;
 			if (end <= start) {
-				printk(KERN_WARNING "crashkernel: end <= start\n");
+				pr_warning("crashkernel: end <= start\n");
 				return -EINVAL;
 			}
 		}
 
 		if (*cur != ':') {
-			printk(KERN_WARNING "crashkernel: ':' expected\n");
+			pr_warning("crashkernel: ':' expected\n");
 			return -EINVAL;
 		}
 		cur++;
 
-		size = memparse(cur, &cur);
+		size = memparse(cur, &tmp);
+		if (cur == tmp) {
+			pr_warning("Memory value expected\n");
+			return -EINVAL;
+		}
+		cur = tmp;
 		if (size < 0) {
-			printk(KERN_WARNING "crashkernel: invalid size\n");
+			pr_warning("crashkernel: invalid size\n");
 			return -EINVAL;
 		}
 

Re: [patch 1/7] Extended crashkernel command line

[Oleg Verych]

Wed, Sep 26, 2007 at 06:16:02PM +0200, Bernhard Walle (part two, see bottom):
> > memparse(), as a wrapper for somple_strtoll(), always have a return value
> > (zero by default).
> > <http://article.gmane.org/gmane.linux.kernel/583426>

Sorry for my typos, i should write `simple_strtoull()'. This function
(ULL from str) have always return value grater or equal to zero.

Thus,

> 
> Signed-off-by: Bernhard Walle <bwalle@suse.de>
> 
> ---
>  kernel/kexec.c |   31 ++++++++++++++++++++++++-------
>  1 file changed, 24 insertions(+), 7 deletions(-)
> 
> --- a/kernel/kexec.c
> +++ b/kernel/kexec.c
> @@ -1172,33 +1172,50 @@ static int __init parse_crashkernel_mem(
>  	do {
>  		unsigned long long start = 0, end = ULLONG_MAX;
>  		unsigned long long size = -1;

no need in assigning values here, unless you plan to use them in case
of `return -EINVAL', but i can not see that,

> +		char *tmp;
>  
>  		/* get the start of the range */
> -		start = memparse(cur, &cur);
> +		start = memparse(cur, &tmp);
> +		if (cur == tmp) {
> +			pr_warning("crashkernel: Memory value expected\n");
> +			return -EINVAL;
> +		}
> +		cur = tmp;
>  		if (*cur != '-') {
> -			printk(KERN_WARNING "crashkernel: '-' expected\n");
> +			pr_warning("crashkernel: '-' expected\n");
>  			return -EINVAL;
>  		}
>  		cur++;
>  
>  		/* if no ':' is here, than we read the end */
>  		if (*cur != ':') {
> -			end = memparse(cur, &cur);
> +			end = memparse(cur, &tmp);
> +			if (cur == tmp) {
> +				pr_warning("crashkernel: Memory "
> +						"value expected\n");
> +				return -EINVAL;
> +			}
> +			cur = tmp;
>  			if (end <= start) {
> -				printk(KERN_WARNING "crashkernel: end <= start\n");
> +				pr_warning("crashkernel: end <= start\n");
>  				return -EINVAL;
>  			}
>  		}
>  
>  		if (*cur != ':') {
> -			printk(KERN_WARNING "crashkernel: ':' expected\n");
> +			pr_warning("crashkernel: ':' expected\n");
>  			return -EINVAL;
>  		}
>  		cur++;
>  
> -		size = memparse(cur, &cur);
> +		size = memparse(cur, &tmp);
> +		if (cur == tmp) {
> +			pr_warning("Memory value expected\n");
> +			return -EINVAL;
> +		}
> +		cur = tmp;
>  		if (size < 0) {

`size' cannot be less that zero here (wonder, if it matters to have
userspace model of this parser and actually feed it with garbage input).

> -			printk(KERN_WARNING "crashkernel: invalid size\n");
> +			pr_warning("crashkernel: invalid size\n");
>  			return -EINVAL;
>  		}
>  


Wed, Sep 26, 2007 at 06:16:02PM +0200, Bernhard Walle (part one):
> Ok, that's fixed now, see patch below.
> 
> > And why not to make overall result reliable? This is kernel after all.
> > 
> > I.e. if there's valid `crashkernel=' option, but some parsing errors, why
> > not to apply some heuristics with warning in syslog, if user have some
> > conf, bootloader (random) errors, but feature still works?
> 
> I'm against guessing. The user has to specify a parameter which is
> right according to syntax.
> 
> However, I plan to make a patch that the kernel can detect a sensible
> offset automatically for i386 and x86_64 as it's done in ia64. Since
> both architectures have a relocatable kernel now, that makes perfectly
> sense. But that's another patch.

I was thinking about errors in YaST or typos in bootloader config, that
may appear sometimes. And kernel must tolerate this kind of userspace
input to be more reliable. But you know better, i just am waving hands.
____
("Mail-Followup-To:" respected)

Re: [patch 1/7] Extended crashkernel command line

[Bernhard Walle]

* Oleg Verych <olecom@flower.upol.cz> [2007-09-26 20:18]:
> 
> I was thinking about errors in YaST or typos in bootloader config, that
> may appear sometimes. And kernel must tolerate this kind of userspace
> input to be more reliable. But you know better, i just am waving hands.

Of course the kernel must be able to handle them -- outputting an
error message that can be read by the user and not crashing. But I
don't expect that the kernel then reservate crash memory by guessing
of values.



Thanks,
   Bernhard

Re: [patch 1/7] Extended crashkernel command line

[Bernhard Walle]

* Oleg Verych <olecom@flower.upol.cz> [2007-09-26 20:18]:
> > 
> > --- a/kernel/kexec.c
> > +++ b/kernel/kexec.c
> > @@ -1172,33 +1172,50 @@ static int __init parse_crashkernel_mem(
> >  	do {
> >  		unsigned long long start = 0, end = ULLONG_MAX;
> >  		unsigned long long size = -1;
> 
> no need in assigning values here, unless you plan to use them in case
> of `return -EINVAL', but i can not see that,

What about this (and yes, I tested with some wrong strings with Qemu):

----

This patch improves error handling in parse_crashkernel_mem() by comparing
the return pointer of memparse() with the input pointer and also replaces
all printk(KERN_WARNING msg) with pr_warning(msg).


Signed-off-by: Bernhard Walle <bwalle@suse.de>

---
 kernel/kexec.c |   54 +++++++++++++++++++++++++++++++++++++++---------------
 1 file changed, 39 insertions(+), 15 deletions(-)

--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -1167,44 +1167,59 @@ static int __init parse_crashkernel_mem(
 					unsigned long long	*crash_size,
 					unsigned long long	*crash_base)
 {
-	char *cur = cmdline;
+	char *cur = cmdline, *tmp;
 
 	/* for each entry of the comma-separated list */
 	do {
-		unsigned long long start = 0, end = ULLONG_MAX;
-		unsigned long long size = -1;
+		unsigned long long start, end = ULLONG_MAX, size;
 
 		/* get the start of the range */
-		start = memparse(cur, &cur);
+		start = memparse(cur, &tmp);
+		if (cur == tmp) {
+			pr_warning("crashkernel: Memory value expected\n");
+			return -EINVAL;
+		}
+		cur = tmp;
 		if (*cur != '-') {
-			printk(KERN_WARNING "crashkernel: '-' expected\n");
+			pr_warning("crashkernel: '-' expected\n");
 			return -EINVAL;
 		}
 		cur++;
 
 		/* if no ':' is here, than we read the end */
 		if (*cur != ':') {
-			end = memparse(cur, &cur);
+			end = memparse(cur, &tmp);
+			if (cur == tmp) {
+				pr_warning("crashkernel: Memory "
+						"value expected\n");
+				return -EINVAL;
+			}
+			cur = tmp;
 			if (end <= start) {
-				printk(KERN_WARNING "crashkernel: end <= start\n");
+				pr_warning("crashkernel: end <= start\n");
 				return -EINVAL;
 			}
 		}
 
 		if (*cur != ':') {
-			printk(KERN_WARNING "crashkernel: ':' expected\n");
+			pr_warning("crashkernel: ':' expected\n");
 			return -EINVAL;
 		}
 		cur++;
 
-		size = memparse(cur, &cur);
-		if (size < 0) {
-			printk(KERN_WARNING "crashkernel: invalid size\n");
+		size = memparse(cur, &tmp);
+		if (cur == tmp) {
+			pr_warning("Memory value expected\n");
+			return -EINVAL;
+		}
+		cur = tmp;
+		if (size >= system_ram) {
+			pr_warning("crashkernel: invalid size\n");
 			return -EINVAL;
 		}
 
 		/* match ? */
-		if (system_ram >= start  && system_ram <= end) {
+		if (system_ram >= start && system_ram <= end) {
 			*crash_size = size;
 			break;
 		}
@@ -1213,8 +1228,15 @@ static int __init parse_crashkernel_mem(
 	if (*crash_size > 0) {
 		while (*cur != ' ' && *cur != '@')
 			cur++;
-		if (*cur == '@')
-			*crash_base = memparse(cur+1, &cur);
+		if (*cur == '@') {
+			cur++;
+			*crash_base = memparse(cur, &tmp);
+			if (cur == tmp) {
+				pr_warning("Memory value expected "
+						"after '@'\n");
+				return -EINVAL;
+			}
+		}
 	}
 
 	return 0;
@@ -1234,8 +1256,10 @@ static int __init parse_crashkernel_simp
 	char *cur = cmdline;
 
 	*crash_size = memparse(cmdline, &cur);
-	if (cmdline == cur)
+	if (cmdline == cur) {
+		pr_warning("crashkernel: memory value expected\n");
 		return -EINVAL;
+	}
 
 	if (*cur == '@')
 		*crash_base = memparse(cur+1, &cur);