linux/arch
Mark Rutland ec841aab8d arm64: entry: handle all vectors with C
We have 16 architectural exception vectors, and depending on kernel
configuration we handle 8 or 12 of these with C code, with the remaining
8 or 4 of these handled as special cases in the entry assembly.

It would be nicer if the entry assembly were uniform for all exceptions,
and we deferred any specific handling of the exceptions to C code. This
way the entry assembly can be more easily templated without ifdeffery or
special cases, and it's easier to modify the handling of these cases in
future (e.g. to dump additional registers other context).

This patch reworks the entry code so that we always have a C handler for
every architectural exception vector, with the entry assembly being
completely uniform. We now have to handle exceptions from EL1t and EL1h,
and also have to handle exceptions from AArch32 even when the kernel is
built without CONFIG_COMPAT. To make this clear and to simplify
templating, we rename the top-level exception handlers with a consistent
naming scheme:

  asm: <el+sp>_<regsize>_<type>
  c:   <el+sp>_<regsize>_<type>_handler

.. where:

  <el+sp> is `el1t`, `el1h`, or `el0t`
  <regsize> is `64` or `32`
  <type> is `sync`, `irq`, `fiq`, or `error`

... e.g.

  asm: el1h_64_sync
  c:   el1h_64_sync_handler

... with lower-level handlers simply using "el1" and "compat" as today.

For unexpected exceptions, this information is passed to
__panic_unhandled(), so it can report the specific vector an unexpected
exception was taken from, e.g.

| Unhandled 64-bit el1t sync exception

For vectors we never expect to enter legitimately, the C code is
generated using a macro to avoid code duplication. The exceptions are
handled via __panic_unhandled(), replacing bad_mode() (which is
removed).

The `kernel_ventry` and `entry_handler` assembly macros are updated to
handle the new naming scheme. In theory it should be possible to
generate the entry functions at the same time as the vectors using a
single table, but this will require reworking the linker script to split
the two into separate sections, so for now we have separate tables.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210607094624.34689-15-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2021-06-07 11:35:55 +01:00
..
alpha quota: Disable quotactl_path syscall 2021-05-17 14:39:56 +02:00
arc ARC: mm: Use max_high_pfn as a HIGHMEM zone border 2021-05-10 12:38:59 -07:00
arm A few fixes for irqchip drivers: 2021-05-23 06:28:20 -10:00
arm64 arm64: entry: handle all vectors with C 2021-06-07 11:35:55 +01:00
csky arch/csky patches for 5.13-rc1 2021-05-03 12:58:31 -07:00
h8300 arch: rearrange headers inclusion order in asm/bitops for m68k, sh and h8300 2021-05-06 19:24:11 -07:00
hexagon Merge branch 'akpm' (patches from Andrew) 2021-05-07 00:34:51 -07:00
ia64 quota: Disable quotactl_path syscall 2021-05-17 14:39:56 +02:00
m68k Merge branch 'for-v5.13-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2021-05-21 06:12:52 -10:00
microblaze quota: Disable quotactl_path syscall 2021-05-17 14:39:56 +02:00
mips quota: Disable quotactl_path syscall 2021-05-17 14:39:56 +02:00
nds32 tracing updates for 5.13 2021-05-03 11:19:54 -07:00
nios2 Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2021-05-02 09:14:01 -07:00
openrisc OpenRISC fixes for 5.13 2021-05-21 06:06:19 -10:00
parisc quota: Disable quotactl_path syscall 2021-05-17 14:39:56 +02:00
powerpc powerpc fixes for 5.13 #4 2021-05-23 06:07:33 -10:00
riscv riscv: remove unused handle_exception symbol 2021-05-06 09:40:16 -07:00
s390 quota: Disable quotactl_path syscall 2021-05-17 14:39:56 +02:00
sh \n 2021-05-20 06:20:15 -10:00
sparc quota: Disable quotactl_path syscall 2021-05-17 14:39:56 +02:00
um Merge branch 'akpm' (patches from Andrew) 2021-05-07 00:34:51 -07:00
x86 Two perf fixes: 2021-05-23 06:32:40 -10:00
xtensa quota: Disable quotactl_path syscall 2021-05-17 14:39:56 +02:00
.gitignore .gitignore: prefix local generated files with a slash 2021-05-02 00:43:35 +09:00
Kconfig Add Landlock, a new LSM from Mickaël Salaün <mic@linux.microsoft.com> 2021-05-01 18:50:44 -07:00