diff options
| author | Jordan Niethe <jniethe5@gmail.com> | 2020-05-06 05:40:38 +0200 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2020-05-18 16:10:38 +0200 |
| commit | 6c7a4f0a9f66fc7fdc6e208559e5d562f53e0991 (patch) | |
| tree | 29e5517780650246640780ca4c15ab6d2f035bfa /arch | |
| parent | powerpc: Introduce a function for reporting instruction length (diff) | |
| download | linux-6c7a4f0a9f66fc7fdc6e208559e5d562f53e0991.tar.xz linux-6c7a4f0a9f66fc7fdc6e208559e5d562f53e0991.zip | |
powerpc/xmon: Use a function for reading instructions
Currently in xmon, mread() is used for reading instructions. In
preparation for prefixed instructions, create and use a new function,
mread_instr(), especially for reading instructions.
Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Alistair Popple <alistair@popple.id.au>
Link: https://lore.kernel.org/r/20200506034050.24806-19-jniethe5@gmail.com
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/powerpc/xmon/xmon.c | 28 |
1 files changed, 24 insertions, 4 deletions
diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c index a4f8f570dbbe..d8b29f6925be 100644 --- a/arch/powerpc/xmon/xmon.c +++ b/arch/powerpc/xmon/xmon.c @@ -122,6 +122,7 @@ static unsigned bpinstr = 0x7fe00008; /* trap */ static int cmds(struct pt_regs *); static int mread(unsigned long, void *, int); static int mwrite(unsigned long, void *, int); +static int mread_instr(unsigned long, struct ppc_inst *); static int handle_fault(struct pt_regs *); static void byterev(unsigned char *, int); static void memex(void); @@ -896,7 +897,7 @@ static void insert_bpts(void) for (i = 0; i < NBPTS; ++i, ++bp) { if ((bp->enabled & (BP_TRAP|BP_CIABR)) == 0) continue; - if (mread(bp->address, &instr, 4) != 4) { + if (!mread_instr(bp->address, &instr)) { printf("Couldn't read instruction at %lx, " "disabling breakpoint there\n", bp->address); bp->enabled = 0; @@ -946,7 +947,7 @@ static void remove_bpts(void) for (i = 0; i < NBPTS; ++i, ++bp) { if ((bp->enabled & (BP_TRAP|BP_CIABR)) != BP_TRAP) continue; - if (mread(bp->address, &instr, 4) == 4 + if (mread_instr(bp->address, &instr) && ppc_inst_equal(instr, ppc_inst(bpinstr)) && patch_instruction( (struct ppc_inst *)bp->address, ppc_inst_read(bp->instr)) != 0) @@ -1162,7 +1163,7 @@ static int do_step(struct pt_regs *regs) force_enable_xmon(); /* check we are in 64-bit kernel mode, translation enabled */ if ((regs->msr & (MSR_64BIT|MSR_PR|MSR_IR)) == (MSR_64BIT|MSR_IR)) { - if (mread(regs->nip, &instr, 4) == 4) { + if (mread_instr(regs->nip, &instr)) { stepped = emulate_step(regs, instr); if (stepped < 0) { printf("Couldn't single-step %s instruction\n", @@ -1329,7 +1330,7 @@ static long check_bp_loc(unsigned long addr) printf("Breakpoints may only be placed at kernel addresses\n"); return 0; } - if (!mread(addr, &instr, sizeof(instr))) { + if (!mread_instr(addr, &instr)) { printf("Can't read instruction at address %lx\n", addr); return 0; } @@ -2122,6 +2123,25 @@ mwrite(unsigned long adrs, void *buf, int size) return n; } +static int +mread_instr(unsigned long adrs, struct ppc_inst *instr) +{ + volatile int n; + + n = 0; + if (setjmp(bus_error_jmp) == 0) { + catch_memory_errors = 1; + sync(); + *instr = ppc_inst_read((struct ppc_inst *)adrs); + sync(); + /* wait a little while to see if we get a machine check */ + __delay(200); + n = ppc_inst_len(*instr); + } + catch_memory_errors = 0; + return n; +} + static int fault_type; static int fault_except; static char *fault_chars[] = { "--", "**", "##" }; |