From: Sam Ravnborg <sam@ravnborg.org>
To: Andi Kleen <andi@firstfloor.org>
Cc: linux-arch@vger.kernel.org, ebiederm@xmission.com,
paulmck@linux.vnet.ibm.com, akpm@linux-foundation.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] [2/9] Add a kernel_address() that works for data too
Date: Tue, 5 Jan 2010 09:58:53 +0100 [thread overview]
Message-ID: <20100105085853.GA28126@merkur.ravnborg.org> (raw)
In-Reply-To: <20100105021527.1AB19B17C2@basil.firstfloor.org>
On Tue, Jan 05, 2010 at 03:15:27AM +0100, Andi Kleen wrote:
>
> Add a variant of kernel_text_address() that includes kernel data.
>
> Assumes kernel is _text ... _end - init section. True everywhere?
Tim Abbott has done a great job lately to unify the various
linker scripts used by the different architectures.
Architectures are supposed to follow the skeleton outlined
in include/asm-generic/vmlinux.lds.h
But I think the skeleton needs a small update.
It describes that we mark start of .text with _stext.
But reality is that we use _text for this.
But you can trust _etext an almost all architectures.
It is a bug if it is missing.
So [_text, _etext] is the text section.
The data section may be placed before or after - it depends on the architecture.
But again - only some architectures define _sdata.
But all? define _edata.
Sam
>
> Cc: linux-arch@vger.kernel.org
> Signed-off-by: Andi Kleen <ak@linux.intel.com>
>
> ---
> include/linux/kernel.h | 1 +
> kernel/extable.c | 18 ++++++++++++++++++
> 2 files changed, 19 insertions(+)
>
> Index: linux-2.6.33-rc2-ak/include/linux/kernel.h
> ===================================================================
> --- linux-2.6.33-rc2-ak.orig/include/linux/kernel.h
> +++ linux-2.6.33-rc2-ak/include/linux/kernel.h
> @@ -205,6 +205,7 @@ extern unsigned long long memparse(const
> extern int core_kernel_text(unsigned long addr);
> extern int __kernel_text_address(unsigned long addr);
> extern int kernel_text_address(unsigned long addr);
> +extern int kernel_address(unsigned long addr);
> extern int func_ptr_is_kernel_text(void *ptr);
>
> struct pid;
> Index: linux-2.6.33-rc2-ak/kernel/extable.c
> ===================================================================
> --- linux-2.6.33-rc2-ak.orig/kernel/extable.c
> +++ linux-2.6.33-rc2-ak/kernel/extable.c
> @@ -72,6 +72,18 @@ int core_kernel_text(unsigned long addr)
> return 0;
> }
>
> +static int core_kernel_address(unsigned long addr)
> +{
> + if ((addr >= (unsigned long)_text &&
> + addr <= (unsigned long)_end)) {
> + if (addr >= (unsigned long)__init_begin &&
> + addr < (unsigned long)__init_end)
> + return system_state == SYSTEM_BOOTING;
> + return 1;
> + }
> + return 0;
> +}
> +
> int __kernel_text_address(unsigned long addr)
> {
> if (core_kernel_text(addr))
> @@ -98,6 +110,12 @@ int kernel_text_address(unsigned long ad
> return is_module_text_address(addr);
> }
>
> +/* text or data in core kernel or module */
> +int kernel_address(unsigned long addr)
> +{
> + return core_kernel_address(addr) || is_module_address(addr);
> +}
> +
> /*
> * On some architectures (PPC64, IA64) function pointers
> * are actually only tokens to some data that then holds the
> --
> To unsubscribe from this list: send the line "unsubscribe linux-arch" in
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> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
next prev parent reply other threads:[~2010-01-05 9:00 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-01-05 2:15 [PATCH] [0/9] SYSCTL: Use RCU to avoid races with string sysctls v2 Andi Kleen
2010-01-05 2:15 ` [PATCH] [1/9] Add rcustring ADT for RCU protected strings v2 Andi Kleen
2010-01-05 5:32 ` Paul E. McKenney
2010-01-05 10:47 ` Andi Kleen
2010-01-05 14:11 ` Paul E. McKenney
2010-01-05 14:19 ` Andi Kleen
2010-01-08 23:50 ` Andrew Morton
2010-01-11 12:12 ` Bert Wesarg
2010-01-11 14:26 ` Andi Kleen
2010-01-05 2:15 ` [PATCH] [2/9] Add a kernel_address() that works for data too Andi Kleen
2010-01-05 8:44 ` Russell King
2010-01-05 8:58 ` Sam Ravnborg [this message]
2010-01-05 19:04 ` Russell King
2010-01-05 19:15 ` Andi Kleen
2010-01-05 19:15 ` Andi Kleen
2010-01-08 23:51 ` Andrew Morton
2010-01-05 2:15 ` [PATCH] [3/9] SYSCTL: Add proc_rcu_string to manage sysctls using rcu strings Andi Kleen
2010-01-05 2:15 ` [PATCH] [4/9] SYSCTL: Use RCU strings for core_pattern sysctl Andi Kleen
2010-01-05 6:56 ` Eric W. Biederman
2010-01-05 11:49 ` Andi Kleen
2010-01-05 2:15 ` [PATCH] [5/9] SYSCTL: Add call_usermodehelper_cleanup() Andi Kleen
2010-01-05 2:15 ` [PATCH] [6/9] SYSCTL: Convert modprobe_path to proc_rcu_string() Andi Kleen
2010-01-05 2:15 ` [PATCH] [7/9] SYSCTL: Convert poweroff_command to proc_rcu_string Andi Kleen
2010-01-05 2:15 ` [PATCH] [8/9] SYSCTL: Convert hotplug helper string to proc_rcu_string() Andi Kleen
2010-01-05 2:15 ` [PATCH] [9/9] SYSCTL: Use RCU protected sysctl for ocfs group add helper Andi Kleen
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