diff options
| author | Uwe Kleine-König <u.kleine-koenig@pengutronix.de> | 2013-12-16 10:24:46 +0100 |
|---|---|---|
| committer | Uwe Kleine-König <u.kleine-koenig@pengutronix.de> | 2014-02-03 11:46:39 +0100 |
| commit | 3f18b1bf599d3d13cd81fdf6bf869c458772adfe (patch) | |
| tree | 4129c93afad2293865a0eaff0b2b0a44c96295c0 | |
| parent | 38dbfb59d1175ef458d006556061adeaa8751b72 (diff) | |
ARM: make isa_mode macro more robust and fix for v7-M
The definition of isa_mode hardcodes the values to shift PSR_J_BIT and
PSR_T_BIT to move them to bits 1 and 0 respectively. Instead use __ffs to
calculate the shift from the #define already used for masking.
This is relevant on v7-M as there PSR_T_BIT is 0x01000000 instead of
0x00000020 for V7-[AR] and earlier. Because of that isa_mode produced
values >= 0x80000 which are unsuitable to index into isa_modes[4] there
and so made __show_regs read from undefined memory which resulted in
hangs and crashes.
Moreover isa_mode is wrong for v7-M even after this robustness fix as
there is no J-bit in the PSR register. So hardcode isa_mode to "Thumb"
for v7-M.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
| -rw-r--r-- | arch/arm/include/asm/ptrace.h | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/arch/arm/include/asm/ptrace.h b/arch/arm/include/asm/ptrace.h index 04c99f36ff7..627a03ebb98 100644 --- a/arch/arm/include/asm/ptrace.h +++ b/arch/arm/include/asm/ptrace.h @@ -27,9 +27,13 @@ struct pt_regs { #define thumb_mode(regs) (0) #endif +#ifndef CONFIG_CPU_V7M #define isa_mode(regs) \ - ((((regs)->ARM_cpsr & PSR_J_BIT) >> 23) | \ - (((regs)->ARM_cpsr & PSR_T_BIT) >> 5)) + ((((regs)->ARM_cpsr & PSR_J_BIT) >> (__ffs(PSR_J_BIT) - 1)) | \ + (((regs)->ARM_cpsr & PSR_T_BIT) >> (__ffs(PSR_T_BIT)))) +#else +#define isa_mode(regs) 1 /* Thumb */ +#endif #define processor_mode(regs) \ ((regs)->ARM_cpsr & MODE_MASK) |