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authorNicholas Piggin <npiggin@gmail.com>2021-03-16 20:42:05 +1000
committerMichael Ellerman <mpe@ellerman.id.au>2021-04-14 23:04:44 +1000
commit8f6cc75a97d162011fad3c470e5a14e298383a07 (patch)
tree51d7b0474ce57c89ed8dabcb89ccb2201717a99a /arch/powerpc/include/asm
parent8dc7f0229b7892ccb23e19c9f30511c68cc0fdcc (diff)
downloadlinux-8f6cc75a97d162011fad3c470e5a14e298383a07.tar.bz2
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
Diffstat (limited to 'arch/powerpc/include/asm')
-rw-r--r--arch/powerpc/include/asm/ptrace.h17
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)