| Message ID | 1414818776-4074-2-git-send-email-Peng.Fan@freescale.com |
|---|---|
| State | RFC |
| Delegated to: | Albert ARIBAUD |
| Headers | show |
Hi Peng, On 31 October 2014 23:12, Peng Fan <Peng.Fan@freescale.com> wrote: > Add Z/z protocal support for breakpoint set/remove. > > Signed-off-by: Peng Fan <Peng.Fan@freescale.com> This looks good to me - I just have a few bits below. > --- > common/kgdb.c | 273 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > include/kgdb.h | 35 ++++++++ > 2 files changed, 308 insertions(+) > > diff --git a/common/kgdb.c b/common/kgdb.c > index d357463..fd83ccd 100644 > --- a/common/kgdb.c > +++ b/common/kgdb.c > @@ -92,6 +92,8 @@ > #include <kgdb.h> > #include <command.h> > > +#include <asm-generic/errno.h> #include <errno.h> would do > + > #undef KGDB_DEBUG Where is this used? > > /* > @@ -111,6 +113,17 @@ static int longjmp_on_fault = 0; > static int kdebug = 1; > #endif > > +struct kgdb_bkpt kgdb_break[KGDB_MAX_BREAKPOINTS] = { > + [0 ... KGDB_MAX_BREAKPOINTS-1] = { .state = BP_UNDEFINED } > +}; > + > +#ifdef CONFIG_ARM > +unsigned char gdb_bpt_instr[4] = {0xfe, 0xde, 0xff, 0xe7}; > +#else > +#error "Please implement gdb_bpt_instr!" > +#endif > + > + > static const char hexchars[]="0123456789abcdef"; > > /* Convert ch from a hex digit to an int */ > @@ -309,6 +322,200 @@ putpacket(unsigned char *buffer) > } while ((recv & 0x7f) != '+'); > } > > +int kgdb_validate_break_address(unsigned addr) > +{ > + /* Need More */ ? > + return 0; > +} > + > +static int probe_kernel_read(unsigned char *dst, void *src, size_t size) > +{ > + int i; > + unsigned char *dst_ptr = dst; > + unsigned char *src_ptr = src; > + > + for (i = 0; i < size; i++) > + *dst_ptr++ = *src_ptr++; > + > + return 0; > +} > + > +static int probe_kernel_write(char *dst, void *src, size_t size) These two above are strange function names - why 'kernel' - what does it mean in this context? Also could you must use memcpy(), either in the functions or instead of them? > +{ > + int i; > + char *dst_ptr = dst; > + char *src_ptr = src; > + > + for (i = 0; i < size; i++) > + *dst_ptr++ = *src_ptr++; > + > + return 0; > +} > + > +__weak int kgdb_arch_set_breakpoint(struct kgdb_bkpt *bpt) > +{ > + int err; > + > + err = probe_kernel_read(bpt->saved_instr, (char *)bpt->bpt_addr, > + BREAK_INSTR_SIZE); > + if (err) > + return err; > + > + err = probe_kernel_write((char *)bpt->bpt_addr, gdb_bpt_instr, > + BREAK_INSTR_SIZE); > + > + return err; > +} > + > +/* > + * Set the breakpoints whose state is BP_SET to BP_ACTIVE > + */ > +int kgdb_active_sw_breakpoints(void) > +{ > + int err; > + int ret = 0; > + int i; > + > + for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { > + if (kgdb_break[i].state != BP_SET) > + continue; > + > + err = kgdb_arch_set_breakpoint(&kgdb_break[i]); > + if (err) { > + ret = err; > + printf("KGDB: BP install failed: %lx\n", > + kgdb_break[i].bpt_addr); > + continue; > + } > + > + kgdb_break[i].state = BP_ACTIVE; > + > + /* > + * kgdb_arch_set_breakpoint touched dcache and memory. > + * cache should be flushed to let icache can see the updated > + * inst. instruction > + */ > + /* flush work is done in do_exit */ > + kgdb_flush_cache_all(); > + } > + > + return ret; > +} > + > +/* > + * Set state from BP_SET to BP_REMOVED > + */ > +int kgdb_remove_sw_breakpoint(unsigned int addr) > +{ > + int i; > + > + for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { > + if ((kgdb_break[i].state == BP_SET) && > + (kgdb_break[i].bpt_addr == addr)) { > + kgdb_break[i].state = BP_REMOVED; > + return 0; > + } > + } > + > + return -ENOENT; > +} > + > +int kgdb_set_sw_breakpoint(unsigned int addr) > +{ > + int err = kgdb_validate_break_address(addr); > + int breakno = -1; > + int i; > + > + if (err) > + return err; > + > + for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { > + if ((kgdb_break[i].state == BP_SET) && > + (kgdb_break[i].bpt_addr == addr)) > + return -EEXIST; > + } > + > + for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { > + /* removed or unused, use it */ > + if ((kgdb_break[i].state == BP_REMOVED) || > + (kgdb_break[i].state == BP_UNDEFINED)) { > + breakno = i; > + break; > + } > + } > + > + if (breakno == -1) > + return -E2BIG; > + > + kgdb_break[breakno].state = BP_SET; > + kgdb_break[breakno].type = BP_BREAKPOINT; > + kgdb_break[breakno].bpt_addr = addr; > + > + return 0; > +} > + > +__weak int kgdb_arch_remove_breakpoint(struct kgdb_bkpt *bpt) > +{ > + return probe_kernel_write((char *)bpt->bpt_addr, > + (char *)bpt->saved_instr, BREAK_INSTR_SIZE); > +} > + > +/* > + * set breakpoints whose state is BP_ACTIVE to BP_SET > + */ > +int kgdb_deactivate_sw_breakpoints(void) > +{ > + int err; > + int ret = 0; > + int i; > + > + for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { > + if (kgdb_break[i].state != BP_ACTIVE) > + continue; > + > + err = kgdb_arch_remove_breakpoint(&kgdb_break[i]); > + if (err) { > + printf("KGDB: BP remove failed: %lx\n", > + kgdb_break[i].bpt_addr); > + ret = err; > + } > + > + kgdb_break[i].state = BP_SET; > + > + /* > + * kgdb_arch_remove_breakpoint touched dcache and memory. > + * cache should be flushed to let icache can see the updated > + * inst. > + */ > + kgdb_flush_cache_all(); > + } > + > + return ret; > +} > + > +static int kgdb_remove_all_break(void) kgdb_remove_all_breakpoints() to be consistent? > +{ > + int err; > + int i; > + > + /* Clear memory breakpoints. */ > + for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { > + if (kgdb_break[i].state != BP_ACTIVE) > + goto setundefined; > + err = kgdb_arch_remove_breakpoint(&kgdb_break[i]); > + if (err) > + printf("KGDB: breakpoint remove failed: %lx\n", > + kgdb_break[i].bpt_addr); > +setundefined: > + kgdb_break[i].state = BP_UNDEFINED; > + } > + > + /* clear hardware breakpoints. */ > + /* ToDo in future. */ /* TODO: clear hardware breakpoints. */ > + > + return 0; > +} > + > /* > * This function does all command processing for interfacing to gdb. > */ > @@ -318,6 +525,7 @@ handle_exception (struct pt_regs *regs) > int addr; > int length; > char *ptr; > + char *bpt_type; > kgdb_data kd; > int i; > > @@ -376,6 +584,12 @@ handle_exception (struct pt_regs *regs) > > putpacket((unsigned char *)&remcomOutBuffer); > > + /* > + * Each time trigger a kgdb break, first deactive all active > + * breakpoints. > + */ > + kgdb_deactivate_sw_breakpoints(); > + > while (1) { > volatile int errnum; > > @@ -394,6 +608,8 @@ handle_exception (struct pt_regs *regs) > if (errnum == 0) switch (remcomInBuffer[0]) { > > case '?': /* report most recent signal */ > + kgdb_remove_all_break(); > + > remcomOutBuffer[0] = 'S'; > remcomOutBuffer[1] = hexchars[kd.sigval >> 4]; > remcomOutBuffer[2] = hexchars[kd.sigval & 0xf]; > @@ -465,6 +681,8 @@ handle_exception (struct pt_regs *regs) > kd.extype |= KGDBEXIT_WITHADDR; > } > > + kgdb_active_sw_breakpoints(); > + > goto doexit; > > case 'S': /* SSS single step with signal SS */ > @@ -479,6 +697,8 @@ handle_exception (struct pt_regs *regs) > kd.extype |= KGDBEXIT_WITHADDR; > } > > + kgdb_active_sw_breakpoints(); > + > doexit: > /* Need to flush the instruction cache here, as we may have deposited a > * breakpoint, and the icache probably has no way of knowing that a data ref to > @@ -506,6 +726,59 @@ handle_exception (struct pt_regs *regs) > kgdb_error(KGDBERR_BADPARAMS); > } > break; > + case 'z': > + /* > + * Break point remove > + * packet: zt,addr,length > + */ > + case 'Z': > + /* > + * Break point set > + * packet: Zt,addr,length > + * > + * t is type: `0' - software breakpoint, > + * `1' - hardware breakpoint, `2' - write watchpoint, > + * `3' - read watchpoint, `4' - access watchpoint; > + * addr is address; length is in bytes. For a software > + * breakpoint, length specifies the size of the > + * instruction to be patched. For hardware breakpoints > + * and watchpoints length specifies the memory region > + * to be monitored. To avoid potential problems with > + * duplicate packets, the operations should be > + * implemented in an idempotent way. > + */ > + bpt_type = &remcomInBuffer[1]; > + ptr = &remcomInBuffer[2]; > + > + if (*(ptr++) != ',') { > + errnum = -EINVAL; > + break; > + } > + > + if (!hexToInt(&ptr, &addr)) { > + errnum = -EINVAL; > + break; > + } > + > + if (*ptr++ != ',') { > + errnum = -EINVAL; > + break; > + } > + > + /* only software breakpoint is implemented */ > + if ((remcomInBuffer[0] == 'Z') && (*bpt_type == '0')) { > + errnum = kgdb_set_sw_breakpoint(addr); > + } else if ((remcomInBuffer[0] == 'z') && > + (*bpt_type == '0')) { > + errnum = kgdb_remove_sw_breakpoint(addr); > + } else { > + /* Unsupported */ > + errnum = -EINVAL; > + } > + > + if (errnum == 0) > + strcpy(remcomOutBuffer, "OK"); > + break; > } /* switch */ > > if (errnum != 0) > diff --git a/include/kgdb.h b/include/kgdb.h > index b6ba742..f9152b5 100644 > --- a/include/kgdb.h > +++ b/include/kgdb.h > @@ -20,6 +20,12 @@ > > #define KGDBEXIT_WITHADDR 0x100 > > +#if defined(CONFIG_ARM) > +#define BREAK_INSTR_SIZE 4 > +#else > +#error "BREAK_INSTR_SIZE not set" > +#endif > + > typedef > struct { > int num; > @@ -38,6 +44,29 @@ typedef > } > kgdb_data; > > +enum kgdb_bptype { > + BP_BREAKPOINT = 0, > + BP_HARDWARE_BREAKPOINT, > + BP_WRITE_WATCHPOINT, > + BP_READ_WATCHPOINT, > + BP_ACCESS_WATCHPOINT, > + BP_POKE_BREAKPOINT, > +}; > + > +enum kgdb_bpstate { > + BP_UNDEFINED = 0, > + BP_REMOVED, > + BP_SET, > + BP_ACTIVE > +}; > + > +struct kgdb_bkpt { > + unsigned long bpt_addr; > + unsigned char saved_instr[BREAK_INSTR_SIZE]; > + enum kgdb_bptype type; > + enum kgdb_bpstate state; > +}; > + > /* these functions are provided by the generic kgdb support */ > extern void kgdb_init(void); > extern void kgdb_error(int); > @@ -67,4 +96,10 @@ extern void kgdb_interruptible(int); > /* this is referenced in the trap handler for the platform */ > extern int (*debugger_exception_handler)(struct pt_regs *); > > +int kgdb_set_sw_break(unsigned int addr); > +int kgdb_remove_sw_break(unsigned int addr); > +int kgdb_validate_break_address(unsigned int addr); > + > +#define KGDB_MAX_BREAKPOINTS 32 > + > #endif /* __KGDB_H__ */ > -- > 1.8.4.5 > Regards, Simon
Hi Simon, 在 11/4/2014 2:46 PM, Simon Glass 写道: > Hi Peng, > > On 31 October 2014 23:12, Peng Fan <Peng.Fan@freescale.com> wrote: >> Add Z/z protocal support for breakpoint set/remove. >> >> Signed-off-by: Peng Fan <Peng.Fan@freescale.com> > > This looks good to me - I just have a few bits below. > >> --- >> common/kgdb.c | 273 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ >> include/kgdb.h | 35 ++++++++ >> 2 files changed, 308 insertions(+) >> >> diff --git a/common/kgdb.c b/common/kgdb.c >> index d357463..fd83ccd 100644 >> --- a/common/kgdb.c >> +++ b/common/kgdb.c >> @@ -92,6 +92,8 @@ >> #include <kgdb.h> >> #include <command.h> >> >> +#include <asm-generic/errno.h> > > #include <errno.h> would do Ok. > >> + >> #undef KGDB_DEBUG > > Where is this used? > You mean KGDB_DEBUG? >> >> /* >> @@ -111,6 +113,17 @@ static int longjmp_on_fault = 0; >> static int kdebug = 1; >> #endif >> >> +struct kgdb_bkpt kgdb_break[KGDB_MAX_BREAKPOINTS] = { >> + [0 ... KGDB_MAX_BREAKPOINTS-1] = { .state = BP_UNDEFINED } >> +}; >> + >> +#ifdef CONFIG_ARM >> +unsigned char gdb_bpt_instr[4] = {0xfe, 0xde, 0xff, 0xe7}; >> +#else >> +#error "Please implement gdb_bpt_instr!" >> +#endif >> + >> + >> static const char hexchars[]="0123456789abcdef"; >> >> /* Convert ch from a hex digit to an int */ >> @@ -309,6 +322,200 @@ putpacket(unsigned char *buffer) >> } while ((recv & 0x7f) != '+'); >> } >> >> +int kgdb_validate_break_address(unsigned addr) >> +{ >> + /* Need More */ > > ? I'll remove the comment. Actually i just want to validate whether the add parameter is fine or not using this function. > >> + return 0; >> +} >> + >> +static int probe_kernel_read(unsigned char *dst, void *src, size_t size) >> +{ >> + int i; >> + unsigned char *dst_ptr = dst; >> + unsigned char *src_ptr = src; >> + >> + for (i = 0; i < size; i++) >> + *dst_ptr++ = *src_ptr++; >> + >> + return 0; >> +} >> + >> +static int probe_kernel_write(char *dst, void *src, size_t size) > > These two above are strange function names - why 'kernel' - what does > it mean in this context? Also could you must use memcpy(), either in > the functions or instead of them? Ok. memcpy is better. I just use the function name in linux kernel, maybe misleading here. how about probe_mem_read? > >> +{ >> + int i; >> + char *dst_ptr = dst; >> + char *src_ptr = src; >> + >> + for (i = 0; i < size; i++) >> + *dst_ptr++ = *src_ptr++; >> + >> + return 0; >> +} >> + >> +__weak int kgdb_arch_set_breakpoint(struct kgdb_bkpt *bpt) >> +{ >> + int err; >> + >> + err = probe_kernel_read(bpt->saved_instr, (char *)bpt->bpt_addr, >> + BREAK_INSTR_SIZE); >> + if (err) >> + return err; >> + >> + err = probe_kernel_write((char *)bpt->bpt_addr, gdb_bpt_instr, >> + BREAK_INSTR_SIZE); >> + >> + return err; >> +} >> + >> +/* >> + * Set the breakpoints whose state is BP_SET to BP_ACTIVE >> + */ >> +int kgdb_active_sw_breakpoints(void) >> +{ >> + int err; >> + int ret = 0; >> + int i; >> + >> + for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { >> + if (kgdb_break[i].state != BP_SET) >> + continue; >> + >> + err = kgdb_arch_set_breakpoint(&kgdb_break[i]); >> + if (err) { >> + ret = err; >> + printf("KGDB: BP install failed: %lx\n", >> + kgdb_break[i].bpt_addr); >> + continue; >> + } >> + >> + kgdb_break[i].state = BP_ACTIVE; >> + >> + /* >> + * kgdb_arch_set_breakpoint touched dcache and memory. >> + * cache should be flushed to let icache can see the updated >> + * inst. > > instruction > >> + */ >> + /* flush work is done in do_exit */ >> + kgdb_flush_cache_all(); >> + } >> + >> + return ret; >> +} >> + >> +/* >> + * Set state from BP_SET to BP_REMOVED >> + */ >> +int kgdb_remove_sw_breakpoint(unsigned int addr) >> +{ >> + int i; >> + >> + for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { >> + if ((kgdb_break[i].state == BP_SET) && >> + (kgdb_break[i].bpt_addr == addr)) { >> + kgdb_break[i].state = BP_REMOVED; >> + return 0; >> + } >> + } >> + >> + return -ENOENT; >> +} >> + >> +int kgdb_set_sw_breakpoint(unsigned int addr) >> +{ >> + int err = kgdb_validate_break_address(addr); >> + int breakno = -1; >> + int i; >> + >> + if (err) >> + return err; >> + >> + for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { >> + if ((kgdb_break[i].state == BP_SET) && >> + (kgdb_break[i].bpt_addr == addr)) >> + return -EEXIST; >> + } >> + >> + for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { >> + /* removed or unused, use it */ >> + if ((kgdb_break[i].state == BP_REMOVED) || >> + (kgdb_break[i].state == BP_UNDEFINED)) { >> + breakno = i; >> + break; >> + } >> + } >> + >> + if (breakno == -1) >> + return -E2BIG; >> + >> + kgdb_break[breakno].state = BP_SET; >> + kgdb_break[breakno].type = BP_BREAKPOINT; >> + kgdb_break[breakno].bpt_addr = addr; >> + >> + return 0; >> +} >> + >> +__weak int kgdb_arch_remove_breakpoint(struct kgdb_bkpt *bpt) >> +{ >> + return probe_kernel_write((char *)bpt->bpt_addr, >> + (char *)bpt->saved_instr, BREAK_INSTR_SIZE); >> +} >> + >> +/* >> + * set breakpoints whose state is BP_ACTIVE to BP_SET >> + */ >> +int kgdb_deactivate_sw_breakpoints(void) >> +{ >> + int err; >> + int ret = 0; >> + int i; >> + >> + for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { >> + if (kgdb_break[i].state != BP_ACTIVE) >> + continue; >> + >> + err = kgdb_arch_remove_breakpoint(&kgdb_break[i]); >> + if (err) { >> + printf("KGDB: BP remove failed: %lx\n", >> + kgdb_break[i].bpt_addr); >> + ret = err; >> + } >> + >> + kgdb_break[i].state = BP_SET; >> + >> + /* >> + * kgdb_arch_remove_breakpoint touched dcache and memory. >> + * cache should be flushed to let icache can see the updated >> + * inst. >> + */ >> + kgdb_flush_cache_all(); >> + } >> + >> + return ret; >> +} >> + >> +static int kgdb_remove_all_break(void) > > kgdb_remove_all_breakpoints() to be consistent? kgdb_remove_all_breakpoints is better. > >> +{ >> + int err; >> + int i; >> + >> + /* Clear memory breakpoints. */ >> + for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { >> + if (kgdb_break[i].state != BP_ACTIVE) >> + goto setundefined; >> + err = kgdb_arch_remove_breakpoint(&kgdb_break[i]); >> + if (err) >> + printf("KGDB: breakpoint remove failed: %lx\n", >> + kgdb_break[i].bpt_addr); >> +setundefined: >> + kgdb_break[i].state = BP_UNDEFINED; >> + } >> + >> + /* clear hardware breakpoints. */ >> + /* ToDo in future. */ > > /* TODO: clear hardware breakpoints. */ Ok. > >> + >> + return 0; >> +} >> + >> /* >> * This function does all command processing for interfacing to gdb. >> */ >> @@ -318,6 +525,7 @@ handle_exception (struct pt_regs *regs) >> int addr; >> int length; >> char *ptr; >> + char *bpt_type; >> kgdb_data kd; >> int i; >> >> @@ -376,6 +584,12 @@ handle_exception (struct pt_regs *regs) >> >> putpacket((unsigned char *)&remcomOutBuffer); >> >> + /* >> + * Each time trigger a kgdb break, first deactive all active >> + * breakpoints. >> + */ >> + kgdb_deactivate_sw_breakpoints(); >> + >> while (1) { >> volatile int errnum; >> >> @@ -394,6 +608,8 @@ handle_exception (struct pt_regs *regs) >> if (errnum == 0) switch (remcomInBuffer[0]) { >> >> case '?': /* report most recent signal */ >> + kgdb_remove_all_break(); >> + >> remcomOutBuffer[0] = 'S'; >> remcomOutBuffer[1] = hexchars[kd.sigval >> 4]; >> remcomOutBuffer[2] = hexchars[kd.sigval & 0xf]; >> @@ -465,6 +681,8 @@ handle_exception (struct pt_regs *regs) >> kd.extype |= KGDBEXIT_WITHADDR; >> } >> >> + kgdb_active_sw_breakpoints(); >> + >> goto doexit; >> >> case 'S': /* SSS single step with signal SS */ >> @@ -479,6 +697,8 @@ handle_exception (struct pt_regs *regs) >> kd.extype |= KGDBEXIT_WITHADDR; >> } >> >> + kgdb_active_sw_breakpoints(); >> + >> doexit: >> /* Need to flush the instruction cache here, as we may have deposited a >> * breakpoint, and the icache probably has no way of knowing that a data ref to >> @@ -506,6 +726,59 @@ handle_exception (struct pt_regs *regs) >> kgdb_error(KGDBERR_BADPARAMS); >> } >> break; >> + case 'z': >> + /* >> + * Break point remove >> + * packet: zt,addr,length >> + */ >> + case 'Z': >> + /* >> + * Break point set >> + * packet: Zt,addr,length >> + * >> + * t is type: `0' - software breakpoint, >> + * `1' - hardware breakpoint, `2' - write watchpoint, >> + * `3' - read watchpoint, `4' - access watchpoint; >> + * addr is address; length is in bytes. For a software >> + * breakpoint, length specifies the size of the >> + * instruction to be patched. For hardware breakpoints >> + * and watchpoints length specifies the memory region >> + * to be monitored. To avoid potential problems with >> + * duplicate packets, the operations should be >> + * implemented in an idempotent way. >> + */ >> + bpt_type = &remcomInBuffer[1]; >> + ptr = &remcomInBuffer[2]; >> + >> + if (*(ptr++) != ',') { >> + errnum = -EINVAL; >> + break; >> + } >> + >> + if (!hexToInt(&ptr, &addr)) { >> + errnum = -EINVAL; >> + break; >> + } >> + >> + if (*ptr++ != ',') { >> + errnum = -EINVAL; >> + break; >> + } >> + >> + /* only software breakpoint is implemented */ >> + if ((remcomInBuffer[0] == 'Z') && (*bpt_type == '0')) { >> + errnum = kgdb_set_sw_breakpoint(addr); >> + } else if ((remcomInBuffer[0] == 'z') && >> + (*bpt_type == '0')) { >> + errnum = kgdb_remove_sw_breakpoint(addr); >> + } else { >> + /* Unsupported */ >> + errnum = -EINVAL; >> + } >> + >> + if (errnum == 0) >> + strcpy(remcomOutBuffer, "OK"); >> + break; >> } /* switch */ >> >> if (errnum != 0) >> diff --git a/include/kgdb.h b/include/kgdb.h >> index b6ba742..f9152b5 100644 >> --- a/include/kgdb.h >> +++ b/include/kgdb.h >> @@ -20,6 +20,12 @@ >> >> #define KGDBEXIT_WITHADDR 0x100 >> >> +#if defined(CONFIG_ARM) >> +#define BREAK_INSTR_SIZE 4 >> +#else >> +#error "BREAK_INSTR_SIZE not set" >> +#endif >> + >> typedef >> struct { >> int num; >> @@ -38,6 +44,29 @@ typedef >> } >> kgdb_data; >> >> +enum kgdb_bptype { >> + BP_BREAKPOINT = 0, >> + BP_HARDWARE_BREAKPOINT, >> + BP_WRITE_WATCHPOINT, >> + BP_READ_WATCHPOINT, >> + BP_ACCESS_WATCHPOINT, >> + BP_POKE_BREAKPOINT, >> +}; >> + >> +enum kgdb_bpstate { >> + BP_UNDEFINED = 0, >> + BP_REMOVED, >> + BP_SET, >> + BP_ACTIVE >> +}; >> + >> +struct kgdb_bkpt { >> + unsigned long bpt_addr; >> + unsigned char saved_instr[BREAK_INSTR_SIZE]; >> + enum kgdb_bptype type; >> + enum kgdb_bpstate state; >> +}; >> + >> /* these functions are provided by the generic kgdb support */ >> extern void kgdb_init(void); >> extern void kgdb_error(int); >> @@ -67,4 +96,10 @@ extern void kgdb_interruptible(int); >> /* this is referenced in the trap handler for the platform */ >> extern int (*debugger_exception_handler)(struct pt_regs *); >> >> +int kgdb_set_sw_break(unsigned int addr); >> +int kgdb_remove_sw_break(unsigned int addr); >> +int kgdb_validate_break_address(unsigned int addr); >> + >> +#define KGDB_MAX_BREAKPOINTS 32 >> + >> #endif /* __KGDB_H__ */ >> -- >> 1.8.4.5 >> > > Regards, > Simon > Thanks for reviewing. Regards, Peng.
diff --git a/common/kgdb.c b/common/kgdb.c index d357463..fd83ccd 100644 --- a/common/kgdb.c +++ b/common/kgdb.c @@ -92,6 +92,8 @@ #include <kgdb.h> #include <command.h> +#include <asm-generic/errno.h> + #undef KGDB_DEBUG /* @@ -111,6 +113,17 @@ static int longjmp_on_fault = 0; static int kdebug = 1; #endif +struct kgdb_bkpt kgdb_break[KGDB_MAX_BREAKPOINTS] = { + [0 ... KGDB_MAX_BREAKPOINTS-1] = { .state = BP_UNDEFINED } +}; + +#ifdef CONFIG_ARM +unsigned char gdb_bpt_instr[4] = {0xfe, 0xde, 0xff, 0xe7}; +#else +#error "Please implement gdb_bpt_instr!" +#endif + + static const char hexchars[]="0123456789abcdef"; /* Convert ch from a hex digit to an int */ @@ -309,6 +322,200 @@ putpacket(unsigned char *buffer) } while ((recv & 0x7f) != '+'); } +int kgdb_validate_break_address(unsigned addr) +{ + /* Need More */ + return 0; +} + +static int probe_kernel_read(unsigned char *dst, void *src, size_t size) +{ + int i; + unsigned char *dst_ptr = dst; + unsigned char *src_ptr = src; + + for (i = 0; i < size; i++) + *dst_ptr++ = *src_ptr++; + + return 0; +} + +static int probe_kernel_write(char *dst, void *src, size_t size) +{ + int i; + char *dst_ptr = dst; + char *src_ptr = src; + + for (i = 0; i < size; i++) + *dst_ptr++ = *src_ptr++; + + return 0; +} + +__weak int kgdb_arch_set_breakpoint(struct kgdb_bkpt *bpt) +{ + int err; + + err = probe_kernel_read(bpt->saved_instr, (char *)bpt->bpt_addr, + BREAK_INSTR_SIZE); + if (err) + return err; + + err = probe_kernel_write((char *)bpt->bpt_addr, gdb_bpt_instr, + BREAK_INSTR_SIZE); + + return err; +} + +/* + * Set the breakpoints whose state is BP_SET to BP_ACTIVE + */ +int kgdb_active_sw_breakpoints(void) +{ + int err; + int ret = 0; + int i; + + for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { + if (kgdb_break[i].state != BP_SET) + continue; + + err = kgdb_arch_set_breakpoint(&kgdb_break[i]); + if (err) { + ret = err; + printf("KGDB: BP install failed: %lx\n", + kgdb_break[i].bpt_addr); + continue; + } + + kgdb_break[i].state = BP_ACTIVE; + + /* + * kgdb_arch_set_breakpoint touched dcache and memory. + * cache should be flushed to let icache can see the updated + * inst. + */ + /* flush work is done in do_exit */ + kgdb_flush_cache_all(); + } + + return ret; +} + +/* + * Set state from BP_SET to BP_REMOVED + */ +int kgdb_remove_sw_breakpoint(unsigned int addr) +{ + int i; + + for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { + if ((kgdb_break[i].state == BP_SET) && + (kgdb_break[i].bpt_addr == addr)) { + kgdb_break[i].state = BP_REMOVED; + return 0; + } + } + + return -ENOENT; +} + +int kgdb_set_sw_breakpoint(unsigned int addr) +{ + int err = kgdb_validate_break_address(addr); + int breakno = -1; + int i; + + if (err) + return err; + + for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { + if ((kgdb_break[i].state == BP_SET) && + (kgdb_break[i].bpt_addr == addr)) + return -EEXIST; + } + + for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { + /* removed or unused, use it */ + if ((kgdb_break[i].state == BP_REMOVED) || + (kgdb_break[i].state == BP_UNDEFINED)) { + breakno = i; + break; + } + } + + if (breakno == -1) + return -E2BIG; + + kgdb_break[breakno].state = BP_SET; + kgdb_break[breakno].type = BP_BREAKPOINT; + kgdb_break[breakno].bpt_addr = addr; + + return 0; +} + +__weak int kgdb_arch_remove_breakpoint(struct kgdb_bkpt *bpt) +{ + return probe_kernel_write((char *)bpt->bpt_addr, + (char *)bpt->saved_instr, BREAK_INSTR_SIZE); +} + +/* + * set breakpoints whose state is BP_ACTIVE to BP_SET + */ +int kgdb_deactivate_sw_breakpoints(void) +{ + int err; + int ret = 0; + int i; + + for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { + if (kgdb_break[i].state != BP_ACTIVE) + continue; + + err = kgdb_arch_remove_breakpoint(&kgdb_break[i]); + if (err) { + printf("KGDB: BP remove failed: %lx\n", + kgdb_break[i].bpt_addr); + ret = err; + } + + kgdb_break[i].state = BP_SET; + + /* + * kgdb_arch_remove_breakpoint touched dcache and memory. + * cache should be flushed to let icache can see the updated + * inst. + */ + kgdb_flush_cache_all(); + } + + return ret; +} + +static int kgdb_remove_all_break(void) +{ + int err; + int i; + + /* Clear memory breakpoints. */ + for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { + if (kgdb_break[i].state != BP_ACTIVE) + goto setundefined; + err = kgdb_arch_remove_breakpoint(&kgdb_break[i]); + if (err) + printf("KGDB: breakpoint remove failed: %lx\n", + kgdb_break[i].bpt_addr); +setundefined: + kgdb_break[i].state = BP_UNDEFINED; + } + + /* clear hardware breakpoints. */ + /* ToDo in future. */ + + return 0; +} + /* * This function does all command processing for interfacing to gdb. */ @@ -318,6 +525,7 @@ handle_exception (struct pt_regs *regs) int addr; int length; char *ptr; + char *bpt_type; kgdb_data kd; int i; @@ -376,6 +584,12 @@ handle_exception (struct pt_regs *regs) putpacket((unsigned char *)&remcomOutBuffer); + /* + * Each time trigger a kgdb break, first deactive all active + * breakpoints. + */ + kgdb_deactivate_sw_breakpoints(); + while (1) { volatile int errnum; @@ -394,6 +608,8 @@ handle_exception (struct pt_regs *regs) if (errnum == 0) switch (remcomInBuffer[0]) { case '?': /* report most recent signal */ + kgdb_remove_all_break(); + remcomOutBuffer[0] = 'S'; remcomOutBuffer[1] = hexchars[kd.sigval >> 4]; remcomOutBuffer[2] = hexchars[kd.sigval & 0xf]; @@ -465,6 +681,8 @@ handle_exception (struct pt_regs *regs) kd.extype |= KGDBEXIT_WITHADDR; } + kgdb_active_sw_breakpoints(); + goto doexit; case 'S': /* SSS single step with signal SS */ @@ -479,6 +697,8 @@ handle_exception (struct pt_regs *regs) kd.extype |= KGDBEXIT_WITHADDR; } + kgdb_active_sw_breakpoints(); + doexit: /* Need to flush the instruction cache here, as we may have deposited a * breakpoint, and the icache probably has no way of knowing that a data ref to @@ -506,6 +726,59 @@ handle_exception (struct pt_regs *regs) kgdb_error(KGDBERR_BADPARAMS); } break; + case 'z': + /* + * Break point remove + * packet: zt,addr,length + */ + case 'Z': + /* + * Break point set + * packet: Zt,addr,length + * + * t is type: `0' - software breakpoint, + * `1' - hardware breakpoint, `2' - write watchpoint, + * `3' - read watchpoint, `4' - access watchpoint; + * addr is address; length is in bytes. For a software + * breakpoint, length specifies the size of the + * instruction to be patched. For hardware breakpoints + * and watchpoints length specifies the memory region + * to be monitored. To avoid potential problems with + * duplicate packets, the operations should be + * implemented in an idempotent way. + */ + bpt_type = &remcomInBuffer[1]; + ptr = &remcomInBuffer[2]; + + if (*(ptr++) != ',') { + errnum = -EINVAL; + break; + } + + if (!hexToInt(&ptr, &addr)) { + errnum = -EINVAL; + break; + } + + if (*ptr++ != ',') { + errnum = -EINVAL; + break; + } + + /* only software breakpoint is implemented */ + if ((remcomInBuffer[0] == 'Z') && (*bpt_type == '0')) { + errnum = kgdb_set_sw_breakpoint(addr); + } else if ((remcomInBuffer[0] == 'z') && + (*bpt_type == '0')) { + errnum = kgdb_remove_sw_breakpoint(addr); + } else { + /* Unsupported */ + errnum = -EINVAL; + } + + if (errnum == 0) + strcpy(remcomOutBuffer, "OK"); + break; } /* switch */ if (errnum != 0) diff --git a/include/kgdb.h b/include/kgdb.h index b6ba742..f9152b5 100644 --- a/include/kgdb.h +++ b/include/kgdb.h @@ -20,6 +20,12 @@ #define KGDBEXIT_WITHADDR 0x100 +#if defined(CONFIG_ARM) +#define BREAK_INSTR_SIZE 4 +#else +#error "BREAK_INSTR_SIZE not set" +#endif + typedef struct { int num; @@ -38,6 +44,29 @@ typedef } kgdb_data; +enum kgdb_bptype { + BP_BREAKPOINT = 0, + BP_HARDWARE_BREAKPOINT, + BP_WRITE_WATCHPOINT, + BP_READ_WATCHPOINT, + BP_ACCESS_WATCHPOINT, + BP_POKE_BREAKPOINT, +}; + +enum kgdb_bpstate { + BP_UNDEFINED = 0, + BP_REMOVED, + BP_SET, + BP_ACTIVE +}; + +struct kgdb_bkpt { + unsigned long bpt_addr; + unsigned char saved_instr[BREAK_INSTR_SIZE]; + enum kgdb_bptype type; + enum kgdb_bpstate state; +}; + /* these functions are provided by the generic kgdb support */ extern void kgdb_init(void); extern void kgdb_error(int); @@ -67,4 +96,10 @@ extern void kgdb_interruptible(int); /* this is referenced in the trap handler for the platform */ extern int (*debugger_exception_handler)(struct pt_regs *); +int kgdb_set_sw_break(unsigned int addr); +int kgdb_remove_sw_break(unsigned int addr); +int kgdb_validate_break_address(unsigned int addr); + +#define KGDB_MAX_BREAKPOINTS 32 + #endif /* __KGDB_H__ */
Add Z/z protocal support for breakpoint set/remove. Signed-off-by: Peng Fan <Peng.Fan@freescale.com> --- common/kgdb.c | 273 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ include/kgdb.h | 35 ++++++++ 2 files changed, 308 insertions(+)