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arm64: fix el2_setup check of CurrentEL 

The CurrentEL system register reports the Current Exception Level
of the CPU. It doesn't say anything about the stack handling, and
yet we compare it to PSR_MODE_EL2t and PSR_MODE_EL2h.

It works by chance because PSR_MODE_EL2t happens to match the right
bits, but that's otherwise a very bad idea. Just check for the EL
value instead.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
[catalin.marinas@arm.com: fixed arch/arm64/kernel/efi-entry.S]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
wifi-calibration
Marc Zyngier 2014-06-06 14:16:21 +01:00 committed by Catalin Marinas
parent 923b8f5044
commit 974c8e450b
3 changed files with 6 additions and 4 deletions
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4
arch/arm64/include/asm/ptrace.h
View File

@ -21,6 +21,10 @@
#include <uapi/asm/ptrace.h>
/* Current Exception Level values, as contained in CurrentEL */
#define CurrentEL_EL1 (1 << 2)
#define CurrentEL_EL2 (2 << 2)
/* AArch32-specific ptrace requests */
#define COMPAT_PTRACE_GETREGS 12
#define COMPAT_PTRACE_SETREGS 13

3
arch/arm64/kernel/efi-entry.S
View File

@ -78,8 +78,7 @@ ENTRY(efi_stub_entry)
/* Turn off Dcache and MMU */
mrs x0, CurrentEL
cmp x0, #PSR_MODE_EL2t
ccmp x0, #PSR_MODE_EL2h, #0x4, ne
cmp x0, #CurrentEL_EL2
b.ne 1f
mrs x0, sctlr_el2
bic x0, x0, #1 << 0 // clear SCTLR.M

3
arch/arm64/kernel/head.S
View File

@ -270,8 +270,7 @@ ENDPROC(stext)
*/
ENTRY(el2_setup)
mrs x0, CurrentEL
cmp x0, #PSR_MODE_EL2t
ccmp x0, #PSR_MODE_EL2h, #0x4, ne
cmp x0, #CurrentEL_EL2
b.ne 1f
mrs x0, sctlr_el2
CPU_BE( orr x0, x0, #(1 << 25) ) // Set the EE bit for EL2