| Message ID | 1436542126-2634-1-git-send-email-khilman@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Greg, On Fri, Jul 10, 2015 at 10:28 AM, Kevin Hilman <khilman@kernel.org> wrote: > From: Tony Lindgren <tony@atomide.com> > > 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 fix the > problem by adding ENDPROC in two places to sleep34xx.S. > > Let's also remove the now duplicate custom code for mode switching. > This has been unnecessary since commit 6ebbf2ce437b ("ARM: convert > all "mov.* pc, reg" to "bx reg" for ARMv6+"). > > And let's also remove the comments about local variables, they are > now just confusing after the ENDPROC. > > 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> > (cherry picked from commit d8a50941c91a68da202aaa96a3dacd471ea9c693) > Cc: <stable@vger.kernel.org> # v4.0+ > Signed-off-by: Kevin Hilman <khilman@linaro.org> This one seems to be missing in v4.0.9, though it was submitted ~10 days before. I missed noticing it was not present in the stable queue because I've been on vacation. I know you mentioned you were wrapping up v4.0, but any chance of this being included? Thanks, Kevin -- 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
On Thu, Jul 30, 2015 at 03:27:54PM -0500, Kevin Hilman wrote: > Hi Greg, > > On Fri, Jul 10, 2015 at 10:28 AM, Kevin Hilman <khilman@kernel.org> wrote: > > From: Tony Lindgren <tony@atomide.com> > > > > 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 fix the > > problem by adding ENDPROC in two places to sleep34xx.S. > > > > Let's also remove the now duplicate custom code for mode switching. > > This has been unnecessary since commit 6ebbf2ce437b ("ARM: convert > > all "mov.* pc, reg" to "bx reg" for ARMv6+"). > > > > And let's also remove the comments about local variables, they are > > now just confusing after the ENDPROC. > > > > 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> > > (cherry picked from commit d8a50941c91a68da202aaa96a3dacd471ea9c693) > > Cc: <stable@vger.kernel.org> # v4.0+ > > Signed-off-by: Kevin Hilman <khilman@linaro.org> > > This one seems to be missing in v4.0.9, though it was submitted ~10 > days before. I missed noticing it was not present in the stable queue > because I've been on vacation. > > I know you mentioned you were wrapping up v4.0, but any chance of this > being included? There isn't going to be any more 4.0-stable releases, sorry, so it doesn't really matter as everyone should be on 4.1 by now :) thanks, greg k-h -- 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
diff --git a/arch/arm/mach-omap2/sleep34xx.S b/arch/arm/mach-omap2/sleep34xx.S index d1dedc8195ed..eafd120b53f1 100644 --- 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: