Jeff Dike wrote:
> The libc free wrapper wasn't correctly detecting buffers obtained with
> malloc(). This is now done by seeing if the page was reserved. This is
> the case for memory which is left aside for libc and isn't given to
> the page allocator. If we free a pointer in a reserved page, it is
> given to free() rather than kfree().
I want to get rid of PG_reserved eventually. Is it possible to use PG_arch_1
for this?
>
> Signed-off-by: Jeff Dike <[EMAIL PROTECTED]>
> --
> arch/um/include/user.h | 1 +
> arch/um/kernel/um_arch.c | 7 +++++++
> arch/um/os-Linux/main.c | 6 +++++-
> 3 files changed, 13 insertions(+), 1 deletion(-)
>
> Index: linux-2.6.21-mm/arch/um/include/user.h
> ===================================================================
> --- linux-2.6.21-mm.orig/arch/um/include/user.h 2007-04-26
> 17:33:01.000000000 -0400
> +++ linux-2.6.21-mm/arch/um/include/user.h 2007-04-27 14:21:35.000000000
> -0400
> @@ -27,5 +27,6 @@ extern int in_aton(char *str);
> extern int open_gdb_chan(void);
> extern size_t strlcpy(char *, const char *, size_t);
> extern size_t strlcat(char *, const char *, size_t);
> +extern int reserved_address(void *addr);
>
> #endif
> Index: linux-2.6.21-mm/arch/um/kernel/um_arch.c
> ===================================================================
> --- linux-2.6.21-mm.orig/arch/um/kernel/um_arch.c 2007-04-26
> 17:41:21.000000000 -0400
> +++ linux-2.6.21-mm/arch/um/kernel/um_arch.c 2007-04-27 14:30:36.000000000
> -0400
> @@ -500,6 +500,13 @@ void __init check_bugs(void)
> os_check_bugs();
> }
>
> +int reserved_address(void *addr)
> +{
> + struct page *page = virt_to_page(addr);
> +
> + return(PageReserved(page));
> +}
> +
> void apply_alternatives(struct alt_instr *start, struct alt_instr *end)
> {
> }
> Index: linux-2.6.21-mm/arch/um/os-Linux/main.c
> ===================================================================
> --- linux-2.6.21-mm.orig/arch/um/os-Linux/main.c 2007-04-26
> 17:41:10.000000000 -0400
> +++ linux-2.6.21-mm/arch/um/os-Linux/main.c 2007-04-27 14:30:31.000000000
> -0400
> @@ -266,6 +266,8 @@ void __wrap_free(void *ptr)
> /* We need to know how the allocation happened, so it can be correctly
> * freed. This is done by seeing what region of memory the pointer is
> * in -
> + * in a reserved page - free, assume the pointer was
> + * acquired with malloc, since it couldn't have been kmalloced.
> * physical memory - kmalloc/kfree
> * kernel virtual memory - vmalloc/vfree
> * anywhere else - malloc/free
> @@ -281,7 +283,9 @@ void __wrap_free(void *ptr)
> * there is a possibility for memory leaks.
> */
>
> - if((addr >= uml_physmem) && (addr < high_physmem)){
> + if(kmalloc_ok && reserved_address(ptr))
> + __real_free(ptr);
> + else if((addr >= uml_physmem) && (addr < high_physmem)){
> if(CAN_KMALLOC())
> kfree(ptr);
> }
> -
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to [EMAIL PROTECTED]
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
>
--
SUSE Labs, Novell Inc.
-------------------------------------------------------------------------
This SF.net email is sponsored by DB2 Express
Download DB2 Express C - the FREE version of DB2 express and take
control of your XML. No limits. Just data. Click to get it now.
http://sourceforge.net/powerbar/db2/
_______________________________________________
User-mode-linux-devel mailing list
User-mode-linux-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel
