diff options
| author | Will Deacon <will.deacon@arm.com> | 2017-11-14 14:24:29 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@google.com> | 2018-01-06 11:14:01 +0100 |
| commit | 75f5a2df1df353bb135d8935dd0bcf1f79f96b88 (patch) | |
| tree | f36d9a8dfffeb326f9af58c80b9dd0e993514cac /arch | |
| parent | 3dcb84674478b1dc2dfe292a8fe81220f4958467 (diff) | |
FROMLIST: arm64: entry: Hook up entry trampoline to exception vectors
Hook up the entry trampoline to our exception vectors so that all
exceptions from and returns to EL0 go via the trampoline, which swizzles
the vector base register accordingly. Transitioning to and from the
kernel clobbers x30, so we use tpidrro_el0 and far_el1 as scratch
registers for native tasks.
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Laura Abbott <labbott@redhat.com>
Tested-by: Shanker Donthineni <shankerd@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git
commit 4bf3286d29f3a88425d8d8cd53428cbb8f865f04)
Change-Id: Id1e175bdaa0ec2bf8e59f941502183907902a710
[ghackmann@google.com: adjust context, replacing
alternative_if_not ARM64_WORKAROUND_845719 block with upstream version]
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm64/kernel/entry.S | 49 |
1 files changed, 38 insertions, 11 deletions
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index 7d178ffb1c1b..bf52151f1e20 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -73,10 +73,26 @@ .macro kernel_ventry, el, label, regsize = 64 .align 7 +#ifdef CONFIG_UNMAP_KERNEL_AT_EL0 + .if \el == 0 + .if \regsize == 64 + mrs x30, tpidrro_el0 + msr tpidrro_el0, xzr + .else + mov x30, xzr + .endif + .endif +#endif + sub sp, sp, #S_FRAME_SIZE b el\()\el\()_\label .endm + .macro tramp_alias, dst, sym + mov_q \dst, TRAMP_VALIAS + add \dst, \dst, #(\sym - .entry.tramp.text) + .endm + .macro kernel_entry, el, regsize = 64 .if \regsize == 32 mov w0, w0 // zero upper 32 bits of x0 @@ -235,24 +251,20 @@ alternative_else_nop_endif .if \el == 0 ldr x23, [sp, #S_SP] // load return stack pointer msr sp_el0, x23 + tst x22, #PSR_MODE32_BIT // native task? + b.eq 3f + #ifdef CONFIG_ARM64_ERRATUM_845719 -alternative_if_not ARM64_WORKAROUND_845719 - nop - nop -#ifdef CONFIG_PID_IN_CONTEXTIDR - nop -#endif -alternative_else - tbz x22, #4, 1f +alternative_if ARM64_WORKAROUND_845719 #ifdef CONFIG_PID_IN_CONTEXTIDR mrs x29, contextidr_el1 msr contextidr_el1, x29 #else msr contextidr_el1, xzr #endif -1: -alternative_endif +alternative_else_nop_endif #endif +3: .endif msr elr_el1, x21 // set up the return data @@ -274,7 +286,22 @@ alternative_endif ldp x28, x29, [sp, #16 * 14] ldr lr, [sp, #S_LR] add sp, sp, #S_FRAME_SIZE // restore sp - eret // return to kernel + +#ifndef CONFIG_UNMAP_KERNEL_AT_EL0 + eret +#else + .if \el == 0 + bne 4f + msr far_el1, x30 + tramp_alias x30, tramp_exit_native + br x30 +4: + tramp_alias x30, tramp_exit_compat + br x30 + .else + eret + .endif +#endif .endm .macro irq_stack_entry |