Re: [patch 1/2] kprobes i386 quick fix mark-ro-data
> Please find the quick fix as per your suggestion below. I've already done it myself. But I ended up doing it the other way around -- making DEBUG_RODATA dependent on !KPROBES because I figured KPROBES is more important than DEBUG_RODATA and it is less confusing for the user this way. -Andi - 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/
Re: [patch 1/2] kprobes i386 quick fix mark-ro-data
On Mon, Jun 18, 2007 at 09:32:56PM +0200, Andi Kleen wrote: > On Monday 18 June 2007 20:56:32 Andrew Morton wrote: > > On Mon, 18 Jun 2007 14:44:57 -0400 > > Chuck Ebbert <[EMAIL PROTECTED]> wrote: > > > > > > I fancy it's done by the kprobe_page_fault handler, but I do not see > > > > clearly how writing the breakpoint from arch_arm_kprobe() in > > > > non-writeable memory is done. > > > > > > Looks like it's not merged yet: > > > > > > http://lkml.org/lkml/2007/6/7/2 > > > > > > This needs to go in before 2.6.22-final > > > > Andi, I'll include the below two patches in the next batch, OK? > > It won't work reliably unless some of the c_p_a() fixes get in first. > > > > > > > > > +extern int kernel_text_is_ro; > > No externs in .c files Yes. > > > I also don't like kernel_text_is_read_only() much, it would > be better to just lookup_address() it and check the write flag. Yes, I will look into this approach. > > But for 2.6.22 as a quick fix it might be better to just > make KPROBES dependent on !DEBUG_RODATA. That would be a one liner. > Please find the quick fix as per your suggestion below. Thanks Prasanna This patch is a quick fix to enable kprobes only if DEBUG_RODATA is not configured. Since DEBUG_RODATA markes the kernel text pages as read-only. Signed-off-by: Prasanna S P. <[EMAIL PROTECTED]> arch/i386/Kconfig |6 +++--- 1 files changed, 3 insertions(+), 3 deletions(-) diff -puN arch/i386/Kconfig~kprobes-quick-fix-mark-ro-data-i386 arch/i386/Kconfig --- linux-2.6.22-rc5/arch/i386/Kconfig~kprobes-quick-fix-mark-ro-data-i386 2007-06-19 14:55:31.0 +0530 +++ linux-2.6.22-rc5-prasanna/arch/i386/Kconfig 2007-06-19 14:55:31.0 +0530 @@ -1212,6 +1212,8 @@ source "drivers/Kconfig" source "fs/Kconfig" +source "arch/i386/Kconfig.debug" + menu "Instrumentation Support" depends on EXPERIMENTAL @@ -1219,7 +1221,7 @@ source "arch/i386/oprofile/Kconfig" config KPROBES bool "Kprobes (EXPERIMENTAL)" - depends on KALLSYMS && EXPERIMENTAL && MODULES + depends on KALLSYMS && EXPERIMENTAL && MODULES && !DEBUG_RODATA help Kprobes allows you to trap at almost any kernel address and execute a callback function. register_kprobe() establishes @@ -1228,8 +1230,6 @@ config KPROBES If in doubt, say "N". endmenu -source "arch/i386/Kconfig.debug" - source "security/Kconfig" source "crypto/Kconfig" _ -- Prasanna S.P. Linux Technology Center India Software Labs, IBM Bangalore Email: [EMAIL PROTECTED] Ph: 91-80-41776329 - 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/
Re: [patch 1/2] kprobes i386 quick fix mark-ro-data
On Mon, Jun 18, 2007 at 09:32:56PM +0200, Andi Kleen wrote: On Monday 18 June 2007 20:56:32 Andrew Morton wrote: On Mon, 18 Jun 2007 14:44:57 -0400 Chuck Ebbert [EMAIL PROTECTED] wrote: I fancy it's done by the kprobe_page_fault handler, but I do not see clearly how writing the breakpoint from arch_arm_kprobe() in non-writeable memory is done. Looks like it's not merged yet: http://lkml.org/lkml/2007/6/7/2 This needs to go in before 2.6.22-final Andi, I'll include the below two patches in the next batch, OK? It won't work reliably unless some of the c_p_a() fixes get in first. +extern int kernel_text_is_ro; No externs in .c files Yes. I also don't like kernel_text_is_read_only() much, it would be better to just lookup_address() it and check the write flag. Yes, I will look into this approach. But for 2.6.22 as a quick fix it might be better to just make KPROBES dependent on !DEBUG_RODATA. That would be a one liner. Please find the quick fix as per your suggestion below. Thanks Prasanna This patch is a quick fix to enable kprobes only if DEBUG_RODATA is not configured. Since DEBUG_RODATA markes the kernel text pages as read-only. Signed-off-by: Prasanna S P. [EMAIL PROTECTED] arch/i386/Kconfig |6 +++--- 1 files changed, 3 insertions(+), 3 deletions(-) diff -puN arch/i386/Kconfig~kprobes-quick-fix-mark-ro-data-i386 arch/i386/Kconfig --- linux-2.6.22-rc5/arch/i386/Kconfig~kprobes-quick-fix-mark-ro-data-i386 2007-06-19 14:55:31.0 +0530 +++ linux-2.6.22-rc5-prasanna/arch/i386/Kconfig 2007-06-19 14:55:31.0 +0530 @@ -1212,6 +1212,8 @@ source drivers/Kconfig source fs/Kconfig +source arch/i386/Kconfig.debug + menu Instrumentation Support depends on EXPERIMENTAL @@ -1219,7 +1221,7 @@ source arch/i386/oprofile/Kconfig config KPROBES bool Kprobes (EXPERIMENTAL) - depends on KALLSYMS EXPERIMENTAL MODULES + depends on KALLSYMS EXPERIMENTAL MODULES !DEBUG_RODATA help Kprobes allows you to trap at almost any kernel address and execute a callback function. register_kprobe() establishes @@ -1228,8 +1230,6 @@ config KPROBES If in doubt, say N. endmenu -source arch/i386/Kconfig.debug - source security/Kconfig source crypto/Kconfig _ -- Prasanna S.P. Linux Technology Center India Software Labs, IBM Bangalore Email: [EMAIL PROTECTED] Ph: 91-80-41776329 - 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/
Re: [patch 1/2] kprobes i386 quick fix mark-ro-data
Please find the quick fix as per your suggestion below. I've already done it myself. But I ended up doing it the other way around -- making DEBUG_RODATA dependent on !KPROBES because I figured KPROBES is more important than DEBUG_RODATA and it is less confusing for the user this way. -Andi - 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/
