commit 24d3ba0a7b44c1617c27f5045eecc4f34752ab03 upstream.
The 32-bit ARM kernel stops working if the kernel grows to the point
where veneers for __get_user_* are created.
AAPCS32 [1] states, "Register r12 (IP) may be used by a linker as a
scratch register between a routine and any subroutine it calls. It
can also be used within a routine to hold intermediate values between
subroutine calls."
However, bl instructions buried within the inline asm are unpredictable
for compilers; hence, "ip" must be added to the clobber list.
This becomes critical when veneers for __get_user_* are created because
veneers use the ip register since commit 02e541db0540 ("ARM: 8323/1:
force linker to use PIC veneers").
[1]: https://github.com/ARM-software/abi-aa/blob/2023Q1/aapcs32/aapcs32.rst
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Cc: John Stultz <jstultz@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit b0150014878c32197cfa66e3e2f79e57f66babc0 ]
Place IRQ handlers such as gic_handle_irq() in the irqentry section even
if FUNCTION_GRAPH_TRACER is not enabled. Without this, the stack
depot's filter_irq_stacks() does not correctly filter out IRQ stacks in
those configurations, which hampers deduplication and eventually leads
to "Stack depot reached limit capacity" splats with KASAN.
A similar fix was done for arm64 in commit f6794950f0e5ba37e3bbed
("arm64: set __exception_irq_entry with __irq_entry as a default").
Link: https://lore.kernel.org/r/20230803-arm-irqentry-v1-1-8aad8e260b1c@axis.com
Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
