From: "Luis R. Rodriguez" <mcgrof@kernel.org>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: "Luis R. Rodriguez" <mcgrof@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
X86 ML <x86@kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Andy Lutomirski <luto@amacapital.net>,
Boris Ostrovsky <boris.ostrovsky@oracle.com>,
Rusty Russell <rusty@rustcorp.com.au>,
David Vrabel <david.vrabel@citrix.com>,
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
Michael Brown <mcb30@ipxe.org>, Juergen Gross <jgross@suse.com>,
Ming Lei <ming.lei@canonical.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Arnd Bergmann <arnd@arndb.de>,
linux-arch@vger.kernel.org, Russell King <linux@arm.linux.org.uk>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
jbaron@akamai.com, ananth@in.ibm.com,
anil.s.keshavamurthy@intel.com,
David Miller <davem@davemloft.net>,
Masami Hiramatsu <masami.hiram>
Subject: Re: [RFC v2 2/7] tables.h: add linker table support
Date: Wed, 24 Feb 2016 01:54:58 +0100 [thread overview]
Message-ID: <20160224005458.GK25240@wotan.suse.de> (raw)
In-Reply-To: <56CCF41F.8080507@zytor.com>
On Tue, Feb 23, 2016 at 04:06:55PM -0800, H. Peter Anvin wrote:
> On 02/23/2016 03:36 PM, Luis R. Rodriguez wrote:
> >
> >> 4. the only useful operator on a range is "is address X inside this
> >> range"; this operator is likely *not* useful for a table, since
^^^^^^^^^^^^
> >> if you have to ever invoke it you are probably doing something very
> >> wrong.
> >
> > kprobe uses it :P
> >
>
> Could you explain how?
Sorry I misread this as "unless you are a table", kprobes has two
ranges, one is a table (blacklist) and the other just a range
(for kprobes); only kprobes uses "address inside this range",
as reflected below. So I agree with you.
index d10ab6b9b5e0..d816c659f358 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -1328,8 +1328,7 @@ out:
bool __weak arch_within_kprobe_blacklist(unsigned long addr)
{
/* The __kprobes marked functions and entry code must not be probed */
- return addr >= (unsigned long)__kprobes_text_start &&
- addr < (unsigned long)__kprobes_text_end;
+ return LINKTABLE_ADDR_WITHIN(kprobes, addr);
}
bool within_kprobe_blacklist(unsigned long addr)
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index d10ab6b9b5e0..d816c659f358 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -1328,8 +1328,7 @@ out:
bool __weak arch_within_kprobe_blacklist(unsigned long addr)
{
/* The __kprobes marked functions and entry code must not be probed */
- return addr >= (unsigned long)__kprobes_text_start &&
- addr < (unsigned long)__kprobes_text_end;
+ return LINKTABLE_ADDR_WITHIN(kprobes, addr);
}
What about rebranding general section primitives under section.h
#define DECLARE_SECTION_TEXT_TYPE(type, name) \
extern const type name[], name##__end[];
#define DECLARE_SECTION_TEXT(name) \
DECLARE_SECTION_TEXT_TYPE(char, name)
Then tables.h would use the TYPE version:
#define DECLARE_LINKTABLE_TEXT(type, name) \
DECLARE_SECTION_TEXT_TYPE(type, name)
Since I've been making _TEXT the implicit type for section names(SECTION_INIT
is .init.text) the above could just be DECLARE_SECTION_TYPE() and DECLARE_SECTION()
for text if we prefer.
Luis
next prev parent reply other threads:[~2016-02-24 0:54 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-19 13:45 [RFC v2 0/7] linux: add linker tables Luis R. Rodriguez
2016-02-19 13:45 ` [RFC v2 1/7] sections.h: add sections header to collect all section info Luis R. Rodriguez
2016-02-19 16:23 ` Greg KH
2016-02-19 20:06 ` Luis R. Rodriguez
2016-02-19 21:25 ` Greg KH
2016-02-19 21:59 ` Luis R. Rodriguez
2016-02-19 13:45 ` [RFC v2 2/7] tables.h: add linker table support Luis R. Rodriguez
2016-02-19 20:25 ` H. Peter Anvin
2016-02-19 21:48 ` Luis R. Rodriguez
2016-02-23 23:08 ` Luis R. Rodriguez
2016-02-23 23:22 ` H. Peter Anvin
2016-02-23 23:36 ` Luis R. Rodriguez
2016-02-24 0:06 ` H. Peter Anvin
2016-02-24 0:54 ` Luis R. Rodriguez [this message]
2016-02-19 20:33 ` H. Peter Anvin
2016-02-19 21:12 ` Luis R. Rodriguez
2016-02-19 13:45 ` [RFC v2 3/7] firmware: port built-in section to linker table Luis R. Rodriguez
2016-02-29 10:12 ` David Woodhouse
2016-02-29 18:56 ` Luis R. Rodriguez
2016-05-02 18:34 ` Kees Cook
2016-05-02 18:41 ` Greg KH
2016-05-03 17:08 ` Luis R. Rodriguez
2016-05-03 17:07 ` Luis R. Rodriguez
2016-05-03 17:10 ` Luis R. Rodriguez
2016-05-03 17:11 ` Luis R. Rodriguez
2016-05-03 17:21 ` Kees Cook
2016-05-03 18:12 ` Greg KH
2016-03-01 16:10 ` James Bottomley
2016-03-01 17:54 ` Luis R. Rodriguez
2016-04-29 19:24 ` Luis R. Rodriguez
2016-02-19 13:45 ` [RFC v2 4/7] asm/sections: add a generic push_section_tbl() Luis R. Rodriguez
2016-02-19 20:26 ` H. Peter Anvin
2016-02-19 21:06 ` Luis R. Rodriguez
2016-02-22 2:55 ` H. Peter Anvin
2016-02-26 14:56 ` Heiko Carstens
2016-05-20 19:53 ` Luis R. Rodriguez
2016-02-19 13:45 ` [RFC v2 5/7] jump_label: port __jump_table to linker tables Luis R. Rodriguez
2016-02-19 13:45 ` [RFC v2 6/7] dynamic_debug: port to use " Luis R. Rodriguez
2016-02-19 13:45 ` [RFC v2 7/7] kprobes: port to linker table Luis R. Rodriguez
2016-02-19 14:15 ` Russell King - ARM Linux
2016-02-19 14:55 ` Luis R. Rodriguez
2016-02-22 1:34 ` 平松雅巳 / HIRAMATU,MASAMI
2016-02-23 0:52 ` [Xen-devel] " Luis R. Rodriguez
2016-07-21 23:53 ` Luis R. Rodriguez
2016-02-19 20:16 ` [RFC v2 0/7] linux: add linker tables H. Peter Anvin
2016-02-19 21:19 ` Luis R. Rodriguez
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