* [PATCH] ARM: Fix data abort accessing proc_info from __lookup_processor_type (Re: [PATCH 03/10] ARM: hotplug cpu: Keep processor information, startup code & __lookup_processor_type) [not found] <E1P2oXV-00020M-QV@rmk-PC.arm.linux.org.uk> @ 2010-10-22 18:51 ` Tony Lindgren 2010-10-22 20:14 ` Anand Gadiyar 2010-10-23 8:30 ` Russell King - ARM Linux 0 siblings, 2 replies; 4+ messages in thread From: Tony Lindgren @ 2010-10-22 18:51 UTC (permalink / raw) To: Russell King - ARM Linux; +Cc: linux-arm-kernel, linux-omap, Gadiyar, Anand * Russell King - ARM Linux <linux@arm.linux.org.uk> [101004 10:18]: > When hotplug CPU is enabled, we need to keep the list of supported CPUs, > their setup functions, and __lookup_processor_type in place so that we > can find and initialize secondary CPUs. Move these into the __CPUINIT > section. > + __CPUINIT > +__lookup_processor_type: > + adr r3, __lookup_processor_type_data > + ldmia r3, {r4 - r6} > + sub r3, r3, r4 @ get offset between virt&phys > + add r5, r5, r3 @ convert virt addresses to > + add r6, r6, r3 @ physical address space > +1: ldmia r5, {r3, r4} @ value, mask > + and r4, r4, r9 @ mask wanted bits > + teq r3, r4 > + beq 2f > + add r5, r5, #PROC_INFO_SZ @ sizeof(proc_info_list) > + cmp r5, r6 > + blo 1b > + mov r5, #0 @ unknown processor > +2: mov pc, lr > +ENDPROC(__lookup_processor_type) The ldmia r5 above can cause a data abort depending on the compiler pixies. This can happen if r5 address is unaligned. Here's a fix for that. Regards, Tony From: Tony Lindgren <tony@atomide.com> Date: Thu, 21 Oct 2010 19:00:41 -0700 Subject: [PATCH] ARM: Fix data abort accessing proc_info from __lookup_processor_type Commit 5085f3ff458521045f7e43da62b8c30ea7df2e82 added better support for CONFIG_HOTPLUG_CPU by keeping proc_info around. However, depending on the Kconfig options selected, this can make the booting fail mysteriously early on. Turns out a data abort can happen in __lookup_processor in ldmia r5 {r3, r4}. When it happens the address loaded to r5 is not aligned. Fix the problem by aligning proc_info. Reported-by: Anand Gadiyar <gadiyar@ti.com> Signed-off-by: Tony Lindgren <tony@atomide.com> diff --git a/arch/arm/kernel/vmlinux.lds.S b/arch/arm/kernel/vmlinux.lds.S index 1953e3d..a58b91d 100644 --- a/arch/arm/kernel/vmlinux.lds.S +++ b/arch/arm/kernel/vmlinux.lds.S @@ -114,6 +114,7 @@ SECTIONS *(.glue_7) *(.glue_7t) *(.got) /* Global offset table */ + . = ALIGN(4); ARM_CPU_KEEP(PROC_INFO) } ^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] ARM: Fix data abort accessing proc_info from __lookup_processor_type (Re: [PATCH 03/10] ARM: hotplug cpu: Keep processor information, startup code & __lookup_processor_type) 2010-10-22 18:51 ` [PATCH] ARM: Fix data abort accessing proc_info from __lookup_processor_type (Re: [PATCH 03/10] ARM: hotplug cpu: Keep processor information, startup code & __lookup_processor_type) Tony Lindgren @ 2010-10-22 20:14 ` Anand Gadiyar 2010-10-23 8:30 ` Russell King - ARM Linux 1 sibling, 0 replies; 4+ messages in thread From: Anand Gadiyar @ 2010-10-22 20:14 UTC (permalink / raw) To: Tony Lindgren; +Cc: Russell King - ARM Linux, linux-arm-kernel, linux-omap On 10/22/2010 2:51 PM, Tony Lindgren wrote: > * Russell King - ARM Linux<linux@arm.linux.org.uk> [101004 10:18]: >> When hotplug CPU is enabled, we need to keep the list of supported CPUs, >> their setup functions, and __lookup_processor_type in place so that we >> can find and initialize secondary CPUs. Move these into the __CPUINIT >> section. > >> + __CPUINIT >> +__lookup_processor_type: >> + adr r3, __lookup_processor_type_data >> + ldmia r3, {r4 - r6} >> + sub r3, r3, r4 @ get offset between virt&phys >> + add r5, r5, r3 @ convert virt addresses to >> + add r6, r6, r3 @ physical address space >> +1: ldmia r5, {r3, r4} @ value, mask >> + and r4, r4, r9 @ mask wanted bits >> + teq r3, r4 >> + beq 2f >> + add r5, r5, #PROC_INFO_SZ @ sizeof(proc_info_list) >> + cmp r5, r6 >> + blo 1b >> + mov r5, #0 @ unknown processor >> +2: mov pc, lr >> +ENDPROC(__lookup_processor_type) > > The ldmia r5 above can cause a data abort depending on the compiler > pixies. This can happen if r5 address is unaligned. Here's a fix > for that. > > Regards, > > Tony > > > From: Tony Lindgren<tony@atomide.com> > Date: Thu, 21 Oct 2010 19:00:41 -0700 > Subject: [PATCH] ARM: Fix data abort accessing proc_info from __lookup_processor_type > > Commit 5085f3ff458521045f7e43da62b8c30ea7df2e82 added better support for > CONFIG_HOTPLUG_CPU by keeping proc_info around. However, depending on > the Kconfig options selected, this can make the booting fail mysteriously > early on. > > Turns out a data abort can happen in __lookup_processor in ldmia r5 {r3, r4}. > When it happens the address loaded to r5 is not aligned. Fix the problem by > aligning proc_info. > > Reported-by: Anand Gadiyar<gadiyar@ti.com> > Signed-off-by: Tony Lindgren<tony@atomide.com> Tested-by: Anand Gadiyar <gadiyar@ti.com> This patch lets linux-next as of 20101021 boot up on my OMAP4 boards. > > diff --git a/arch/arm/kernel/vmlinux.lds.S b/arch/arm/kernel/vmlinux.lds.S > index 1953e3d..a58b91d 100644 > --- a/arch/arm/kernel/vmlinux.lds.S > +++ b/arch/arm/kernel/vmlinux.lds.S > @@ -114,6 +114,7 @@ SECTIONS > *(.glue_7) > *(.glue_7t) > *(.got) /* Global offset table */ > + . = ALIGN(4); > ARM_CPU_KEEP(PROC_INFO) > } > ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] ARM: Fix data abort accessing proc_info from __lookup_processor_type (Re: [PATCH 03/10] ARM: hotplug cpu: Keep processor information, startup code & __lookup_processor_type) 2010-10-22 18:51 ` [PATCH] ARM: Fix data abort accessing proc_info from __lookup_processor_type (Re: [PATCH 03/10] ARM: hotplug cpu: Keep processor information, startup code & __lookup_processor_type) Tony Lindgren 2010-10-22 20:14 ` Anand Gadiyar @ 2010-10-23 8:30 ` Russell King - ARM Linux 2010-10-23 18:18 ` Tony Lindgren 1 sibling, 1 reply; 4+ messages in thread From: Russell King - ARM Linux @ 2010-10-23 8:30 UTC (permalink / raw) To: Tony Lindgren; +Cc: linux-arm-kernel, linux-omap, Gadiyar, Anand On Fri, Oct 22, 2010 at 11:51:08AM -0700, Tony Lindgren wrote: > diff --git a/arch/arm/kernel/vmlinux.lds.S b/arch/arm/kernel/vmlinux.lds.S > index 1953e3d..a58b91d 100644 > --- a/arch/arm/kernel/vmlinux.lds.S > +++ b/arch/arm/kernel/vmlinux.lds.S > @@ -114,6 +114,7 @@ SECTIONS > *(.glue_7) > *(.glue_7t) > *(.got) /* Global offset table */ > + . = ALIGN(4); > ARM_CPU_KEEP(PROC_INFO) The got table should also be word aligned - but the kernel doesn't use one. In any case, it would be a good idea to place it before the .got. ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] ARM: Fix data abort accessing proc_info from __lookup_processor_type (Re: [PATCH 03/10] ARM: hotplug cpu: Keep processor information, startup code & __lookup_processor_type) 2010-10-23 8:30 ` Russell King - ARM Linux @ 2010-10-23 18:18 ` Tony Lindgren 0 siblings, 0 replies; 4+ messages in thread From: Tony Lindgren @ 2010-10-23 18:18 UTC (permalink / raw) To: Russell King - ARM Linux; +Cc: linux-arm-kernel, linux-omap, Gadiyar, Anand * Russell King - ARM Linux <linux@arm.linux.org.uk> [101023 01:21]: > On Fri, Oct 22, 2010 at 11:51:08AM -0700, Tony Lindgren wrote: > > diff --git a/arch/arm/kernel/vmlinux.lds.S b/arch/arm/kernel/vmlinux.lds.S > > index 1953e3d..a58b91d 100644 > > --- a/arch/arm/kernel/vmlinux.lds.S > > +++ b/arch/arm/kernel/vmlinux.lds.S > > @@ -114,6 +114,7 @@ SECTIONS > > *(.glue_7) > > *(.glue_7t) > > *(.got) /* Global offset table */ > > + . = ALIGN(4); > > ARM_CPU_KEEP(PROC_INFO) > > The got table should also be word aligned - but the kernel doesn't use > one. In any case, it would be a good idea to place it before the .got. OK, updated patch below. By moving ARM_CPU_KEEP(PROC_INFO) around I've confirmed that it's happening at rodata.*. Do you want also another align before .glue_7 as well? Regards, Tony From: Tony Lindgren <tony@atomide.com> Date: Fri, 22 Oct 2010 12:41:55 -0700 Subject: [PATCH] ARM: Fix data abort accessing proc_info from __lookup_processor_type Commit 5085f3ff458521045f7e43da62b8c30ea7df2e82 added better support for CONFIG_HOTPLUG_CPU by keeping proc_info around. However, depending on the Kconfig options selected, this can make the booting fail mysteriously early on. Turns out a data abort can happen in __lookup_processor in ldmia r5 {r3, r4}. When it happens the address loaded to r5 is not aligned. Fix the problem by aligning proc_info. Reported-by: Anand Gadiyar <gadiyar@ti.com> Signed-off-by: Tony Lindgren <tony@atomide.com> Tested-by: Anand Gadiyar <gadiyar@ti.com> diff --git a/arch/arm/kernel/vmlinux.lds.S b/arch/arm/kernel/vmlinux.lds.S index 1953e3d..cead889 100644 --- a/arch/arm/kernel/vmlinux.lds.S +++ b/arch/arm/kernel/vmlinux.lds.S @@ -113,6 +113,7 @@ SECTIONS *(.rodata.*) *(.glue_7) *(.glue_7t) + . = ALIGN(4); *(.got) /* Global offset table */ ARM_CPU_KEEP(PROC_INFO) } ^ permalink raw reply related [flat|nested] 4+ messages in thread
end of thread, other threads:[~2010-10-23 18:18 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
[not found] <E1P2oXV-00020M-QV@rmk-PC.arm.linux.org.uk>
2010-10-22 18:51 ` [PATCH] ARM: Fix data abort accessing proc_info from __lookup_processor_type (Re: [PATCH 03/10] ARM: hotplug cpu: Keep processor information, startup code & __lookup_processor_type) Tony Lindgren
2010-10-22 20:14 ` Anand Gadiyar
2010-10-23 8:30 ` Russell King - ARM Linux
2010-10-23 18:18 ` Tony Lindgren
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox