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| author | Nicholas Piggin <npiggin@gmail.com> | 2021-03-16 13:42:05 +0300 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2021-04-14 16:04:44 +0300 |
| commit | 8f6cc75a97d162011fad3c470e5a14e298383a07 (patch) | |
| tree | 51d7b0474ce57c89ed8dabcb89ccb2201717a99a | |
| parent | 8dc7f0229b7892ccb23e19c9f30511c68cc0fdcc (diff) | |
| download | linux-8f6cc75a97d162011fad3c470e5a14e298383a07.tar.xz | |
powerpc: move norestart trap flag to bit 0
Compact the trap flags down to use the low 4 bits of regs.trap.
A few 64e interrupt trap numbers set bit 4. Although they tended to be
trivial so it wasn't a real problem[1], it is not the right thing to do,
and confusing.
[*] E.g., 0x310 hypercall goes to unknown_exception, which prints
regs->trap directly so 0x310 will appear fine, and only the syscall
interrupt will test norestart, so it won't be confused by 0x310.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210316104206.407354-12-npiggin@gmail.com
| -rw-r--r-- | arch/powerpc/include/asm/ptrace.h | 17 |
1 files changed, 11 insertions, 6 deletions
diff --git a/arch/powerpc/include/asm/ptrace.h b/arch/powerpc/include/asm/ptrace.h index 7793d6bd2d7d..9c9ab2746168 100644 --- a/arch/powerpc/include/asm/ptrace.h +++ b/arch/powerpc/include/asm/ptrace.h @@ -185,20 +185,25 @@ static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc) #define current_pt_regs() \ ((struct pt_regs *)((unsigned long)task_stack_page(current) + THREAD_SIZE) - 1) +/* + * The 4 low bits (0xf) are available as flags to overload the trap word, + * because interrupt vectors have minimum alignment of 0x10. TRAP_FLAGS_MASK + * must cover the bits used as flags, including bit 0 which is used as the + * "norestart" bit. + */ #ifdef __powerpc64__ -#define TRAP_FLAGS_MASK 0x10 -#define TRAP(regs) ((regs)->trap & ~TRAP_FLAGS_MASK) +#define TRAP_FLAGS_MASK 0x1 #else /* * On 4xx we use bit 1 in the trap word to indicate whether the exception * is a critical exception (1 means it is). */ -#define TRAP_FLAGS_MASK 0x1E -#define TRAP(regs) ((regs)->trap & ~TRAP_FLAGS_MASK) +#define TRAP_FLAGS_MASK 0xf #define IS_CRITICAL_EXC(regs) (((regs)->trap & 2) != 0) #define IS_MCHECK_EXC(regs) (((regs)->trap & 4) != 0) #define IS_DEBUG_EXC(regs) (((regs)->trap & 8) != 0) #endif /* __powerpc64__ */ +#define TRAP(regs) ((regs)->trap & ~TRAP_FLAGS_MASK) static __always_inline void set_trap(struct pt_regs *regs, unsigned long val) { @@ -222,12 +227,12 @@ static inline bool trap_is_syscall(struct pt_regs *regs) static inline bool trap_norestart(struct pt_regs *regs) { - return regs->trap & 0x10; + return regs->trap & 0x1; } static __always_inline void set_trap_norestart(struct pt_regs *regs) { - regs->trap |= 0x10; + regs->trap |= 0x1; } #define arch_has_single_step() (1) |