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From: Matt Fleming <matt.fleming@intel.com>
To: Xishi Qiu <qiuxishi@huawei.com>
Cc: "Luck, Tony" <tony.luck@intel.com>,
	fenghua.yu@intel.com, Liujiang <jiang.liu@huawei.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-efi@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [PATCH] ia64/mm: fix a bad_page bug when crash kernel booting
Date: Mon, 04 Feb 2013 16:32:45 +0000	[thread overview]
Message-ID: <1359995565.7515.178.camel@mfleming-mobl1.ger.corp.intel.com> (raw)
In-Reply-To: <51074786.5030007@huawei.com>

On Tue, 2013-01-29 at 11:52 +0800, Xishi Qiu wrote:
> On ia64 platform, I set "crashkernel=1024M-:600M", and dmesg shows 128M-728M
> memory is reserved for crash kernel. Then "echo c > /proc/sysrq-trigger" to
> test kdump.
> 
> When crash kernel booting, efi_init() will aligns the memory address in
> IA64_GRANULE_SIZE(16M), so 720M-728M memory will be dropped, It means
> crash kernel only manage 128M-720M memory.
> 
> But initrd start and end are fixed in boot loader, it is before efi_init(),
> so initrd size maybe overflow when free_initrd_mem().

[...]

> diff --git a/arch/ia64/mm/init.c b/arch/ia64/mm/init.c
> index b755ea9..cfdb1eb 100644
> --- a/arch/ia64/mm/init.c
> +++ b/arch/ia64/mm/init.c
> @@ -207,6 +207,17 @@ free_initrd_mem (unsigned long start, unsigned long end)
>  	start = PAGE_ALIGN(start);
>  	end = end & PAGE_MASK;
> 
> +	/*
> +	 * Initrd size is fixed in boot loader, but kernel parameter max_addr
> +	 * which aligns in granules is fixed after boot loader, so initrd size
> +	 * maybe overflow.
> +	 */
> +	if (max_addr != ~0UL) {
> +		end = GRANULEROUNDDOWN(end);
> +		if (start > end)
> +			start = end;
> +	}
> +
>  	if (start < end)
>  		printk(KERN_INFO "Freeing initrd memory: %ldkB freed\n", (end - start) >> 10);

I don't think this is the correct fix.

Now, my ia64-fu is weak, but could it be that there's actually a bug in
efi_init() and that the following patch would be the best way to fix
this?

---

diff --git a/arch/ia64/kernel/efi.c b/arch/ia64/kernel/efi.c
index f034563..8d579f1 100644
--- a/arch/ia64/kernel/efi.c
+++ b/arch/ia64/kernel/efi.c
@@ -482,7 +482,7 @@ efi_init (void)
 		if (memcmp(cp, "mem=", 4) == 0) {
 			mem_limit = memparse(cp + 4, &cp);
 		} else if (memcmp(cp, "max_addr=", 9) == 0) {
-			max_addr = GRANULEROUNDDOWN(memparse(cp + 9, &cp));
+			max_addr = GRANULEROUNDUP(memparse(cp + 9, &cp));
 		} else if (memcmp(cp, "min_addr=", 9) == 0) {
 			min_addr = GRANULEROUNDDOWN(memparse(cp + 9, &cp));
 		} else {



WARNING: multiple messages have this Message-ID (diff)
From: Matt Fleming <matt.fleming@intel.com>
To: Xishi Qiu <qiuxishi@huawei.com>
Cc: "Luck, Tony" <tony.luck@intel.com>,
	fenghua.yu@intel.com, Liujiang <jiang.liu@huawei.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-efi@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [PATCH] ia64/mm: fix a bad_page bug when crash kernel booting
Date: Mon, 04 Feb 2013 16:32:45 +0000	[thread overview]
Message-ID: <1359995565.7515.178.camel@mfleming-mobl1.ger.corp.intel.com> (raw)
In-Reply-To: <51074786.5030007@huawei.com>

On Tue, 2013-01-29 at 11:52 +0800, Xishi Qiu wrote:
> On ia64 platform, I set "crashkernel=1024M-:600M", and dmesg shows 128M-728M
> memory is reserved for crash kernel. Then "echo c > /proc/sysrq-trigger" to
> test kdump.
> 
> When crash kernel booting, efi_init() will aligns the memory address in
> IA64_GRANULE_SIZE(16M), so 720M-728M memory will be dropped, It means
> crash kernel only manage 128M-720M memory.
> 
> But initrd start and end are fixed in boot loader, it is before efi_init(),
> so initrd size maybe overflow when free_initrd_mem().

[...]

> diff --git a/arch/ia64/mm/init.c b/arch/ia64/mm/init.c
> index b755ea9..cfdb1eb 100644
> --- a/arch/ia64/mm/init.c
> +++ b/arch/ia64/mm/init.c
> @@ -207,6 +207,17 @@ free_initrd_mem (unsigned long start, unsigned long end)
>  	start = PAGE_ALIGN(start);
>  	end = end & PAGE_MASK;
> 
> +	/*
> +	 * Initrd size is fixed in boot loader, but kernel parameter max_addr
> +	 * which aligns in granules is fixed after boot loader, so initrd size
> +	 * maybe overflow.
> +	 */
> +	if (max_addr != ~0UL) {
> +		end = GRANULEROUNDDOWN(end);
> +		if (start > end)
> +			start = end;
> +	}
> +
>  	if (start < end)
>  		printk(KERN_INFO "Freeing initrd memory: %ldkB freed\n", (end - start) >> 10);

I don't think this is the correct fix.

Now, my ia64-fu is weak, but could it be that there's actually a bug in
efi_init() and that the following patch would be the best way to fix
this?

---

diff --git a/arch/ia64/kernel/efi.c b/arch/ia64/kernel/efi.c
index f034563..8d579f1 100644
--- a/arch/ia64/kernel/efi.c
+++ b/arch/ia64/kernel/efi.c
@@ -482,7 +482,7 @@ efi_init (void)
 		if (memcmp(cp, "mem=", 4) == 0) {
 			mem_limit = memparse(cp + 4, &cp);
 		} else if (memcmp(cp, "max_addr=", 9) == 0) {
-			max_addr = GRANULEROUNDDOWN(memparse(cp + 9, &cp));
+			max_addr = GRANULEROUNDUP(memparse(cp + 9, &cp));
 		} else if (memcmp(cp, "min_addr=", 9) == 0) {
 			min_addr = GRANULEROUNDDOWN(memparse(cp + 9, &cp));
 		} else {


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WARNING: multiple messages have this Message-ID (diff)
From: Matt Fleming <matt.fleming@intel.com>
To: Xishi Qiu <qiuxishi@huawei.com>
Cc: "Luck, Tony" <tony.luck@intel.com>,
	fenghua.yu@intel.com, Liujiang <jiang.liu@huawei.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-efi@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [PATCH] ia64/mm: fix a bad_page bug when crash kernel booting
Date: Mon, 04 Feb 2013 16:32:45 +0000	[thread overview]
Message-ID: <1359995565.7515.178.camel@mfleming-mobl1.ger.corp.intel.com> (raw)
In-Reply-To: <51074786.5030007@huawei.com>

On Tue, 2013-01-29 at 11:52 +0800, Xishi Qiu wrote:
> On ia64 platform, I set "crashkernel\x1024M-:600M", and dmesg shows 128M-728M
> memory is reserved for crash kernel. Then "echo c > /proc/sysrq-trigger" to
> test kdump.
> 
> When crash kernel booting, efi_init() will aligns the memory address in
> IA64_GRANULE_SIZE(16M), so 720M-728M memory will be dropped, It means
> crash kernel only manage 128M-720M memory.
> 
> But initrd start and end are fixed in boot loader, it is before efi_init(),
> so initrd size maybe overflow when free_initrd_mem().

[...]

> diff --git a/arch/ia64/mm/init.c b/arch/ia64/mm/init.c
> index b755ea9..cfdb1eb 100644
> --- a/arch/ia64/mm/init.c
> +++ b/arch/ia64/mm/init.c
> @@ -207,6 +207,17 @@ free_initrd_mem (unsigned long start, unsigned long end)
>  	start = PAGE_ALIGN(start);
>  	end = end & PAGE_MASK;
> 
> +	/*
> +	 * Initrd size is fixed in boot loader, but kernel parameter max_addr
> +	 * which aligns in granules is fixed after boot loader, so initrd size
> +	 * maybe overflow.
> +	 */
> +	if (max_addr != ~0UL) {
> +		end = GRANULEROUNDDOWN(end);
> +		if (start > end)
> +			start = end;
> +	}
> +
>  	if (start < end)
>  		printk(KERN_INFO "Freeing initrd memory: %ldkB freed\n", (end - start) >> 10);

I don't think this is the correct fix.

Now, my ia64-fu is weak, but could it be that there's actually a bug in
efi_init() and that the following patch would be the best way to fix
this?

---

diff --git a/arch/ia64/kernel/efi.c b/arch/ia64/kernel/efi.c
index f034563..8d579f1 100644
--- a/arch/ia64/kernel/efi.c
+++ b/arch/ia64/kernel/efi.c
@@ -482,7 +482,7 @@ efi_init (void)
 		if (memcmp(cp, "mem=", 4) = 0) {
 			mem_limit = memparse(cp + 4, &cp);
 		} else if (memcmp(cp, "max_addr=", 9) = 0) {
-			max_addr = GRANULEROUNDDOWN(memparse(cp + 9, &cp));
+			max_addr = GRANULEROUNDUP(memparse(cp + 9, &cp));
 		} else if (memcmp(cp, "min_addr=", 9) = 0) {
 			min_addr = GRANULEROUNDDOWN(memparse(cp + 9, &cp));
 		} else {



  reply	other threads:[~2013-02-04 16:32 UTC|newest]

Thread overview: 54+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-01-29  3:52 [PATCH] ia64/mm: fix a bad_page bug when crash kernel booting Xishi Qiu
2013-01-29  3:52 ` Xishi Qiu
2013-01-29  3:52 ` Xishi Qiu
2013-01-29  3:52 ` Xishi Qiu
2013-02-04 16:32 ` Matt Fleming [this message]
2013-02-04 16:32   ` Matt Fleming
2013-02-04 16:32   ` Matt Fleming
2013-02-05  3:48   ` Xishi Qiu
2013-02-05  3:48     ` Xishi Qiu
2013-02-05  3:48     ` Xishi Qiu
2013-02-05  3:48     ` Xishi Qiu
2013-02-07  2:32   ` [PATCH V2] " Xishi Qiu
2013-02-07  2:32     ` Xishi Qiu
2013-02-07  2:32     ` Xishi Qiu
2013-02-07  2:32     ` Xishi Qiu
2013-02-07  6:09     ` [PATCH V3] " Xishi Qiu
2013-02-07  6:09       ` Xishi Qiu
2013-02-07  6:09       ` Xishi Qiu
2013-02-07  6:09       ` Xishi Qiu
2013-02-13  0:11       ` Tony Luck
2013-02-13  0:11         ` Tony Luck
2013-02-13  0:11         ` Tony Luck
2013-02-13  0:11         ` Tony Luck
2013-02-13  0:19         ` Andrew Morton
2013-02-13  0:19           ` Andrew Morton
2013-02-13  0:19           ` Andrew Morton
2013-02-13  0:19           ` Andrew Morton
2013-02-13  0:32           ` Tony Luck
2013-02-13  0:32             ` Tony Luck
2013-02-13  0:32             ` Tony Luck
2013-02-13  0:22         ` Andrew Morton
2013-02-13  0:22           ` Andrew Morton
2013-02-13  0:22           ` Andrew Morton
2013-02-13  0:22           ` Andrew Morton
2013-02-13 10:07       ` Matt Fleming
2013-02-13 10:07         ` Matt Fleming
2013-02-13 10:07         ` Matt Fleming
2013-02-16  1:55         ` Xishi Qiu
2013-02-16  1:55           ` Xishi Qiu
2013-02-16  1:55           ` Xishi Qiu
2013-02-16  1:55           ` Xishi Qiu
2013-02-19 21:38       ` Luck, Tony
2013-02-19 21:38         ` Luck, Tony
2013-02-19 21:38         ` Luck, Tony
2013-02-19 21:56       ` Tony Luck
2013-02-19 21:56         ` Tony Luck
2013-02-19 21:56         ` Tony Luck
2013-02-19 21:56         ` Tony Luck
2013-02-20  1:38         ` Xishi Qiu
2013-02-20  1:38           ` Xishi Qiu
2013-02-20  1:38           ` Xishi Qiu
2013-02-21 18:21           ` Tony Luck
2013-02-21 18:21             ` Tony Luck
2013-02-21 18:21             ` Tony Luck

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