Commit Graph

3 Commits

Author SHA1 Message Date
James Morse
bfe298745a arm64: entry-common: don't touch daif before bp-hardening
The previous patches mechanically transformed the assembly version of
entry.S to entry-common.c for synchronous exceptions.

The C version of local_daif_restore() doesn't quite do the same thing
as the assembly versions if pseudo-NMI is in use. In particular,
| local_daif_restore(DAIF_PROCCTX_NOIRQ)
will still allow pNMI to be delivered. This is not the behaviour
do_el0_ia_bp_hardening() and do_sp_pc_abort() want as it should not
be possible for the PMU handler to run as an NMI until the bp-hardening
sequence has run.

The bp-hardening calls were placed where they are because this was the
first C code to run after the relevant exceptions. As we've now moved
that point earlier, move the checks and calls earlier too.

This makes it clearer that this stuff runs before any kind of exception,
and saves modifying PSTATE twice.

Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Cc: Julien Thierry <julien.thierry.kdev@gmail.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-10-28 11:22:54 +00:00
Mark Rutland
582f95835a arm64: entry: convert el0_sync to C
This is largely a 1-1 conversion of asm to C, with a couple of caveats.

The el0_sync{_compat} switches explicitly handle all the EL0 debug
cases, so el0_dbg doesn't have to try to bail out for unexpected EL1
debug ESR values. This also means that an unexpected vector catch from
AArch32 is routed to el0_inv.

We *could* merge the native and compat switches, which would make the
diffstat negative, but I've tried to stay as close to the existing
assembly as possible for the moment.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
[split out of a bigger series, added nokprobes. removed irq trace
 calls as the C helpers do this. renamed el0_dbg's use of FAR]
Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Cc: Julien Thierry <julien.thierry.kdev@gmail.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-10-28 11:22:49 +00:00
Mark Rutland
ed3768db58 arm64: entry: convert el1_sync to C
This patch converts the EL1 sync entry assembly logic to C code.

Doing this will allow us to make changes in a slightly more
readable way. A case in point is supporting kernel-first RAS.
do_sea() should be called on the CPU that took the fault.

Largely the assembly code is converted to C in a relatively
straightforward manner.

Since all sync sites share a common asm entry point, the ASM_BUG()
instances are no longer required for effective backtraces back to
assembly, and we don't need similar BUG() entries.

The ESR_ELx.EC codes for all (supported) debug exceptions are now
checked in the el1_sync_handler's switch statement, which renders the
check in el1_dbg redundant. This both simplifies the el1_dbg handler,
and makes the EL1 exception handling more robust to
currently-unallocated ESR_ELx.EC encodings.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
[split out of a bigger series, added nokprobes, moved prototypes]
Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Cc: Julien Thierry <julien.thierry.kdev@gmail.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-10-28 11:22:47 +00:00