powerpc: Make single-stepping emulation (mostly) usable on 32-bit

The sc instruction emulation can't be done the same way on 32-bit
as 64-bit yet, but this should work OK.

Signed-off-by: Paul Mackerras <paulus@samba.org>
This commit is contained in:
Paul Mackerras
2005-10-28 22:48:08 +10:00
parent d73e0c99f5
commit c032524f0d
3 changed files with 28 additions and 1 deletions

View File

@ -10,13 +10,18 @@
*/
#include <linux/kernel.h>
#include <linux/ptrace.h>
#include <linux/config.h>
#include <asm/sstep.h>
#include <asm/processor.h>
extern char system_call_common[];
#ifdef CONFIG_PPC64
/* Bits in SRR1 that are copied from MSR */
#define MSR_MASK 0xffffffff87c0ffff
#else
#define MSR_MASK 0x87c0ffff
#endif
/*
* Determine whether a conditional branch instruction would branch.
@ -66,6 +71,7 @@ int emulate_step(struct pt_regs *regs, unsigned int instr)
if (branch_taken(instr, regs))
regs->nip = imm;
return 1;
#ifdef CONFIG_PPC64
case 17: /* sc */
/*
* N.B. this uses knowledge about how the syscall
@ -79,6 +85,7 @@ int emulate_step(struct pt_regs *regs, unsigned int instr)
regs->nip = (unsigned long) &system_call_common;
regs->msr = MSR_KERNEL;
return 1;
#endif
case 18: /* b */
imm = instr & 0x03fffffc;
if (imm & 0x02000000)
@ -121,6 +128,15 @@ int emulate_step(struct pt_regs *regs, unsigned int instr)
if ((regs->msr & MSR_SF) == 0)
regs->nip &= 0xffffffffUL;
return 1;
case 0x124: /* mtmsr */
imm = regs->gpr[rd];
if ((imm & MSR_RI) == 0)
/* can't step mtmsr that would clear MSR_RI */
return -1;
regs->msr = imm;
regs->nip += 4;
return 1;
#ifdef CONFIG_PPC64
case 0x164: /* mtmsrd */
/* only MSR_EE and MSR_RI get changed if bit 15 set */
/* mtmsrd doesn't change MSR_HV and MSR_ME */
@ -135,6 +151,7 @@ int emulate_step(struct pt_regs *regs, unsigned int instr)
if ((imm & MSR_SF) == 0)
regs->nip &= 0xffffffffUL;
return 1;
#endif
}
}
return 0;