diff options
| author | Larry Bassel <larry.bassel@linaro.org> | 2014-10-15 15:15:56 -0700 |
|---|---|---|
| committer | Larry Bassel <larry.bassel@linaro.org> | 2014-10-15 15:17:01 -0700 |
| commit | 333625b7586d2753a77f32e1f898ab7cc6cf7655 (patch) | |
| tree | 502cfdee75acaf23313b0dfed9539868e043ba3d | |
| parent | 16f8c2dfc148f67f92bcac35c2fb57f05444ee65 (diff) | |
arm64: adjust el0_sync so that a function can be called
Backport of the following patch to 3.14 LSK:
commit 6ab6463aeb5fbc75fa3227befb508fc33b34dbf1
Author: Larry Bassel <larry.bassel@linaro.org>
Date: Fri May 30 20:34:14 2014 +0100
arm64: adjust el0_sync so that a function can be called
To implement the context tracker properly on arm64,
a function call needs to be made after debugging and
interrupts are turned on, but before the lr is changed
to point to ret_to_user(). If the function call
is made after the lr is changed the function will not
return to the correct place.
For similar reasons, defer the setting of x0 so that
it doesn't need to be saved around the function call
(save far_el1 in x26 temporarily instead).
Acked-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Kevin Hilman <khilman@linaro.org>
Tested-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Larry Bassel <larry.bassel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Larry Bassel <larry.bassel@linaro.org>
| -rw-r--r-- | arch/arm64/kernel/entry.S | 19 |
1 files changed, 13 insertions, 6 deletions
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index 6d26ebc260ad..c779ef357e43 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -348,7 +348,6 @@ el0_sync: lsr x24, x25, #ESR_EL1_EC_SHIFT // exception class cmp x24, #ESR_EL1_EC_SVC64 // SVC in 64-bit state b.eq el0_svc - adr lr, ret_from_exception cmp x24, #ESR_EL1_EC_DABT_EL0 // data abort in EL0 b.eq el0_da cmp x24, #ESR_EL1_EC_IABT_EL0 // instruction abort in EL0 @@ -377,7 +376,6 @@ el0_sync_compat: lsr x24, x25, #ESR_EL1_EC_SHIFT // exception class cmp x24, #ESR_EL1_EC_SVC32 // SVC in 32-bit state b.eq el0_svc_compat - adr lr, ret_from_exception cmp x24, #ESR_EL1_EC_DABT_EL0 // data abort in EL0 b.eq el0_da cmp x24, #ESR_EL1_EC_IABT_EL0 // instruction abort in EL0 @@ -420,28 +418,31 @@ el0_da: /* * Data abort handling */ - mrs x0, far_el1 - bic x0, x0, #(0xff << 56) + mrs x26, far_el1 disable_step x1 isb enable_dbg // enable interrupts before calling the main handler enable_irq + bic x0, x26, #(0xff << 56) mov x1, x25 mov x2, sp + adr lr, ret_from_exception b do_mem_abort el0_ia: /* * Instruction abort handling */ - mrs x0, far_el1 + mrs x26, far_el1 disable_step x1 isb enable_dbg // enable interrupts before calling the main handler enable_irq + mov x0, x26 orr x1, x25, #1 << 24 // use reserved ISS bit for instruction aborts mov x2, sp + adr lr, ret_from_exception b do_mem_abort el0_fpsimd_acc: /* @@ -449,6 +450,7 @@ el0_fpsimd_acc: */ mov x0, x25 mov x1, sp + adr lr, ret_from_exception b do_fpsimd_acc el0_fpsimd_exc: /* @@ -456,19 +458,22 @@ el0_fpsimd_exc: */ mov x0, x25 mov x1, sp + adr lr, ret_from_exception b do_fpsimd_exc el0_sp_pc: /* * Stack or PC alignment exception handling */ - mrs x0, far_el1 + mrs x26, far_el1 disable_step x1 isb enable_dbg // enable interrupts before calling the main handler enable_irq + mov x0, x26 mov x1, x25 mov x2, sp + adr lr, ret_from_exception b do_sp_pc_abort el0_undef: /* @@ -477,6 +482,7 @@ el0_undef: mov x0, sp // enable interrupts before calling the main handler enable_irq + adr lr, ret_from_exception b do_undefinstr el0_dbg: /* @@ -492,6 +498,7 @@ el0_inv: mov x0, sp mov x1, #BAD_SYNC mrs x2, esr_el1 + adr lr, ret_from_exception b bad_mode ENDPROC(el0_sync) |