2007-09-25 06:55:38

by Bernhard Walle

Subject: [PATCH] Fix CONFIG_NOHIGHMEM for extended crashkernel command line

This patch fixes a build error with CONFIG_KEXEC=y and CONFIG_NOHIGHMEM=y.

linux-2.6-mm$ LANG=C make
CHK include/linux/version.h
CHK include/linux/utsrelease.h
CALL scripts/checksyscalls.sh
CHK include/linux/compile.h
CC arch/i386/kernel/setup.o
arch/i386/kernel/setup.c: In function 'reserve_crashkernel':
arch/i386/kernel/setup.c:391: error: 'highend_pfn' undeclared (first use in this function)
arch/i386/kernel/setup.c:391: error: (Each undeclared identifier is reported only once
arch/i386/kernel/setup.c:391: error: for each function it appears in.)
arch/i386/kernel/setup.c:391: error: 'highstart_pfn' undeclared (first use in this function)
make[1]: *** [arch/i386/kernel/setup.o] Error 1
make: *** [arch/i386/kernel] Error 2


Signed-off-by: Bernhard Walle <[email protected]>

---
arch/i386/kernel/setup.c | 16 +++++++++++++++-
1 file changed, 15 insertions(+), 1 deletion(-)

--- a/arch/i386/kernel/setup.c
+++ b/arch/i386/kernel/setup.c
@@ -381,6 +381,20 @@ extern unsigned long __init setup_memory
extern void zone_sizes_init(void);
#endif /* !CONFIG_NEED_MULTIPLE_NODES */

+
+#ifdef CONFIG_HIGHMEM
+static inline unsigned long long get_total_mem(void)
+{
+ return (max_low_pfn + highend_pfn - highstart_pfn) << PAGE_SHIFT;
+}
+#else
+static inline unsigned long long get_total_mem(void)
+{
+ return max_low_pfn << PAGE_SHIFT;
+}
+#endif
+
+
#ifdef CONFIG_KEXEC
static void __init reserve_crashkernel(void)
{
@@ -388,7 +402,7 @@ static void __init reserve_crashkernel(v
unsigned long long crash_size, crash_base;
int ret;

- free_mem = (max_low_pfn + highend_pfn - highstart_pfn) << PAGE_SHIFT;
+ free_mem = get_total_mem();

ret = parse_crashkernel(boot_command_line, free_mem,
&crash_size, &crash_base);

2007-09-25 07:06:39

by Andrew Morton

Subject: Re: [PATCH] Fix CONFIG_NOHIGHMEM for extended crashkernel command line

On Tue, 25 Sep 2007 08:55:29 +0200 Bernhard Walle <[email protected]> wrote:

> @@ -381,6 +381,20 @@ extern unsigned long __init setup_memory
> extern void zone_sizes_init(void);
> #endif /* !CONFIG_NEED_MULTIPLE_NODES */
>
> +

Only one line is needed between functions, please.

> +#ifdef CONFIG_HIGHMEM
> +static inline unsigned long long get_total_mem(void)
> +{
> + return (max_low_pfn + highend_pfn - highstart_pfn) << PAGE_SHIFT;
> +}
> +#else
> +static inline unsigned long long get_total_mem(void)
> +{
> + return max_low_pfn << PAGE_SHIFT;
> +}
> +#endif
> +
> +

Full of bugs. (unsigned long << foo) returns an unsigned long. With >4G
there will be truncation.

Please review the full patchset for other occurrences of this.