ACK: [SRU][G/master-next] [PATCH] UBUNTU: [Config] armhf: ARM_MODULE_PLTS=y

[Seth Forshee]

On Wed, Oct 14, 2020 at 11:20:50AM +0200, Paolo Pisati wrote:
> BugLink: https://bugs.launchpad.net/bugs/1899519
> 
> [Impact]
> 
> Groovy armhf LPAE kernel fails to load kmods (and thus fail to boot):
> 
> ...
> [ 16.753306] gpio_keys: section 4 reloc 29 sym '_raw_spin_lock_irqsave': relocation 28 out of range (0xbf00f23c -> 0xc10a90ec)
> [ 22.799409] linear: section 4 reloc 43 sym '__stack_chk_fail': relocation 28 out of range (0xbf0195e8 -> 0xc10a1dd8)
> [ 23.000670] multipath: section 4 reloc 31 sym '__stack_chk_fail': relocation 28 out of range (0xbf021268 -> 0xc10a1dd8)
> [ 23.227437] raid0: section 4 reloc 53 sym '__stack_chk_fail': relocation 28 out of range (0xbf02a548 -> 0xc10a1dd8)
> [ 23.460764] raid1: section 4 reloc 18 sym '_cond_resched': relocation 28 out of range (0xbf035390 -> 0xc10a3b4c)
> ...
> 
> [Fix]
> 
> Enable CONFIG_ARM_MODULE_PLTS for armhf
> 
> [Regression potential]
> 
> Quoting the arch/arm/Kconfig:
> 
> "
> Allocate Procedure Linkage Tables when loading modules so that jumps and calls
> whose targets are too far away for their relative offsets to be encoded in the
> instructions themselves can be bounced via veneers in the module's PLT.
> 
> This allows modules to be allocated in the generic vmalloc area after the
> dedicated module memory area has been exhausted. The modules will use slightly
> more memory, but after rounding up to page size, the actual memory footprint is
> usually the same.
> 
> Disabling this [option] is usually safe for small single-platform
> configurations.
> "
> 
> Signed-off-by: Paolo Pisati <paolo.pisati at canonical.com>

Acked-by: Seth Forshee <seth.forshee at canonical.com>