| Message ID | 20150528142125.GE30984@atomide.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, May 28, 2015 at 07:21:25AM -0700, Tony Lindgren wrote: > * Grazvydas Ignotas <notasas@gmail.com> [150528 04:45]: > > On Thu, May 28, 2015 at 1:55 AM, Tony Lindgren <tony@atomide.com> wrote: > > > 8 <---------------------- > > > From: Tony Lindgren <tony@atomide.com> > > > Date: Wed, 27 May 2015 15:33:57 -0700 > > > Subject: [PATCH] ARM: OMAP3: Fix booting with thumb2 kernel > > > > > > We get a NULL pointer dereference on omap3 for thumb2 compiled kernels: > > > > > > Internal error: Oops: 80000005 [#1] SMP THUMB2 > > > ... > > > [<c046497b>] (_raw_spin_unlock_irqrestore) from [<c0024375>] > > > (omap3_enter_idle_bm+0xc5/0x178) > > > [<c0024375>] (omap3_enter_idle_bm) from [<c0374e63>] > > > (cpuidle_enter_state+0x77/0x27c) > > > [<c0374e63>] (cpuidle_enter_state) from [<c00627f1>] > > > (cpu_startup_entry+0x155/0x23c) > > > [<c00627f1>] (cpu_startup_entry) from [<c06b9a47>] > > > (start_kernel+0x32f/0x338) > > > [<c06b9a47>] (start_kernel) from [<8000807f>] (0x8000807f) > > > > > > The power management related assembly on moaps needs to interact with > > > > moaps -> omaps > > Thanks, fixed now. I also added a link for why ENDPROC is needed to the > description. I'll apply the patch below into fixes today. > > Regards, > > Tony > > 8< ---------------------- > From: Tony Lindgren <tony@atomide.com> > Date: Wed, 27 May 2015 15:33:57 -0700 > Subject: [PATCH] ARM: OMAP3: Fix booting with thumb2 kernel > > We get a NULL pointer dereference on omap3 for thumb2 compiled kernels: > > Internal error: Oops: 80000005 [#1] SMP THUMB2 > ... > [<c046497b>] (_raw_spin_unlock_irqrestore) from [<c0024375>] > (omap3_enter_idle_bm+0xc5/0x178) > [<c0024375>] (omap3_enter_idle_bm) from [<c0374e63>] > (cpuidle_enter_state+0x77/0x27c) > [<c0374e63>] (cpuidle_enter_state) from [<c00627f1>] > (cpu_startup_entry+0x155/0x23c) > [<c00627f1>] (cpu_startup_entry) from [<c06b9a47>] > (start_kernel+0x32f/0x338) > [<c06b9a47>] (start_kernel) from [<8000807f>] (0x8000807f) > > The power management related assembly on omaps needs to interact with > ARM mode bootrom code, so we need to keep most of the related assembly > in ARM mode. > > Turns out this error is because of missing ENDPROC for assembly code > as suggested by Stephen Boyd <sboyd@codeaurora.org>. Let's add the > missing ENDPROC in two places to sleep34xx.S, and also remove the > earlier mystery code that was probably also caused by missing ENDPROC > for earlier kernels. > > The reason why ENDPROC makes a difference is it sets .type and then > the compiler knows what to do with the thumb bit as explained at: > > https://wiki.ubuntu.com/ARM/Thumb2PortingHowto > > Reported-by: Kevin Hilman <khilman@kernel.org> > Tested-by: Kevin Hilman <khilman@linaro.org> > Signed-off-by: Tony Lindgren <tony@atomide.com> > > --- a/arch/arm/mach-omap2/sleep34xx.S > +++ b/arch/arm/mach-omap2/sleep34xx.S > @@ -203,23 +203,8 @@ save_context_wfi: > */ > ldr r1, kernel_flush > blx r1 > - /* > - * The kernel doesn't interwork: v7_flush_dcache_all in particluar will > - * always return in Thumb state when CONFIG_THUMB2_KERNEL is enabled. > - * This sequence switches back to ARM. Note that .align may insert a > - * nop: bx pc needs to be word-aligned in order to work. > - */ > - THUMB( .thumb ) > - THUMB( .align ) > - THUMB( bx pc ) > - THUMB( nop ) > - .arm > - ^ This looks unrelated to the issue? This code is simply unnecessary after Russell introduced the "ret" macro in commit 6ebbf2ce43. That made v7_flush_dcache_all do a proper interworking return. It should probably be in a separate commit, or at least mentioned explicitly in the commit log. > b omap3_do_wfi > - > -/* > - * Local variables > - */ ^ Likewise this is just tidyup, not bug fixing. > +ENDPROC(omap34xx_cpu_suspend) > omap3_do_wfi_sram_addr: > .word omap3_do_wfi_sram > kernel_flush: > @@ -364,10 +349,7 @@ exit_nonoff_modes: > * =================================== > */ > ldmfd sp!, {r4 - r11, pc} @ restore regs and return > - > -/* > - * Local variables > - */ > +ENDPROC(omap3_do_wfi) The ENDPROC()s look appropriate here. [...] Cheers ---Dave -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
--- a/arch/arm/mach-omap2/sleep34xx.S +++ b/arch/arm/mach-omap2/sleep34xx.S @@ -203,23 +203,8 @@ save_context_wfi: */ ldr r1, kernel_flush blx r1 - /* - * The kernel doesn't interwork: v7_flush_dcache_all in particluar will - * always return in Thumb state when CONFIG_THUMB2_KERNEL is enabled. - * This sequence switches back to ARM. Note that .align may insert a - * nop: bx pc needs to be word-aligned in order to work. - */ - THUMB( .thumb ) - THUMB( .align ) - THUMB( bx pc ) - THUMB( nop ) - .arm - b omap3_do_wfi - -/* - * Local variables - */ +ENDPROC(omap34xx_cpu_suspend) omap3_do_wfi_sram_addr: .word omap3_do_wfi_sram kernel_flush: @@ -364,10 +349,7 @@ exit_nonoff_modes: * =================================== */ ldmfd sp!, {r4 - r11, pc} @ restore regs and return - -/* - * Local variables - */ +ENDPROC(omap3_do_wfi) sdrc_power: .word SDRC_POWER_V cm_idlest1_core: