arm64: fix el2_setup check of CurrentEL
authorMarc Zyngier <marc.zyngier@arm.com>
Fri, 6 Jun 2014 13:16:21 +0000 (14:16 +0100)
committerCatalin Marinas <catalin.marinas@arm.com>
Fri, 4 Jul 2014 15:16:52 +0000 (16:16 +0100)
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>
arch/arm64/include/asm/ptrace.h
arch/arm64/kernel/efi-entry.S
arch/arm64/kernel/head.S

index a429b5940be2e614a8149fcc7c7acac9d2b4fad0..501000fadb6fde2249096d3dc6ee027cba427e14 100644 (file)
 
 #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
index 66716c9b9e5fe893dd4d8218291f71f8fe8a24a6..619b1dd7bcdea70e184daacbfb5dd7797c8460c0 100644 (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
index a96d3a6a63f6a526029d0b825de18f1ffc72f9cb..a2c1195abb7f70b6633148568ca0ae830c0415db 100644 (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