[v5] Add support for NetBSD threads in sparc-nat.c

Message ID 20200317181826.6947-1-n54@gmx.com
State New
Headers show
Series
  • [v5] Add support for NetBSD threads in sparc-nat.c
Related show

Commit Message

Kamil Rytarowski March 17, 2020, 6:18 p.m.
NetBSD ptrace(2) accepts thread id (LWP) as the 4th argument for threads.

Define gdb_ptrace() a wrapper function for ptrace(2) that properly passes
the pid,lwp pair on NetBSD and the result of get_ptrace_pid() for others.
---
 gdb/sparc-nat.c | 50 ++++++++++++++++++++++---------------------------
 1 file changed, 22 insertions(+), 28 deletions(-)

--
2.25.0

Comments

Simon Marchi March 17, 2020, 7:07 p.m. | #1
On 2020-03-17 2:18 p.m., Kamil Rytarowski wrote:
> NetBSD ptrace(2) accepts thread id (LWP) as the 4th argument for threads.

> 

> Define gdb_ptrace() a wrapper function for ptrace(2) that properly passes

> the pid,lwp pair on NetBSD and the result of get_ptrace_pid() for others.

> ---

>  gdb/sparc-nat.c | 50 ++++++++++++++++++++++---------------------------

>  1 file changed, 22 insertions(+), 28 deletions(-)

> 

> diff --git a/gdb/sparc-nat.c b/gdb/sparc-nat.c

> index dff0f521565..fadcfd34474 100644

> --- a/gdb/sparc-nat.c

> +++ b/gdb/sparc-nat.c

> @@ -78,6 +78,19 @@ typedef struct fp_status fpregset_t;

>  #define PTRACE_SETFPREGS PT_SETFPREGS

>  #endif

> 

> +static int

> +gdb_ptrace (PTRACE_TYPE_ARG1 request, ptid_t ptid, PTRACE_TYPE_ARG3 addr)

> +{

> +#ifdef __NetBSD__

> +  /* Support for NetBSD threads: unlike other ptrace implementations in this

> +     file, NetBSD requires that we pass both the pid and lwp.  */

> +  return ptrace (request, ptid.pid (), addr, ptid.lwp ());

> +#else

> +  pid_t pid = get_ptrace_pid (ptid);

> +  return ptrace (request, pid, addr, 0);

> +#endif

> +}

> +

>  /* Register set description.  */

>  const struct sparc_gregmap *sparc_gregmap;

>  const struct sparc_fpregmap *sparc_fpregmap;

> @@ -137,22 +150,7 @@ void

>  sparc_fetch_inferior_registers (struct regcache *regcache, int regnum)

>  {

>    struct gdbarch *gdbarch = regcache->arch ();

> -  pid_t pid;

> -

> -  /* NOTE: cagney/2002-12-03: This code assumes that the currently

> -     selected light weight processes' registers can be written

> -     directly into the selected thread's register cache.  This works

> -     fine when given an 1:1 LWP:thread model (such as found on

> -     GNU/Linux) but will, likely, have problems when used on an N:1

> -     (userland threads) or N:M (userland multiple LWP) model.  In the

> -     case of the latter two, the LWP's registers do not necessarily

> -     belong to the selected thread (the LWP could be in the middle of

> -     executing the thread switch code).

> -

> -     These functions should instead be parameterized with an explicit

> -     object (struct regcache, struct thread_info?) into which the LWPs

> -     registers can be written.  */

> -  pid = get_ptrace_pid (regcache->ptid ());

> +  ptid_t ptid = regcache->ptid ();

> 

>    if (regnum == SPARC_G0_REGNUM)

>      {

> @@ -166,7 +164,7 @@ sparc_fetch_inferior_registers (struct regcache *regcache, int regnum)

>      {

>        gregset_t regs;

> 

> -      if (ptrace (PTRACE_GETREGS, pid, (PTRACE_TYPE_ARG3) &regs, 0) == -1)

> +      if (gdb_ptrace (PTRACE_GETREGS, ptid, (PTRACE_TYPE_ARG3) &regs) == -1)

>  	perror_with_name (_("Couldn't get registers"));

> 

>        sparc_supply_gregset (sparc_gregmap, regcache, -1, &regs);

> @@ -178,7 +176,7 @@ sparc_fetch_inferior_registers (struct regcache *regcache, int regnum)

>      {

>        fpregset_t fpregs;

> 

> -      if (ptrace (PTRACE_GETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)

> +      if (gdb_ptrace (PTRACE_GETFPREGS, ptid, (PTRACE_TYPE_ARG3) &fpregs) == -1)

>  	perror_with_name (_("Couldn't get floating point status"));

> 

>        sparc_supply_fpregset (sparc_fpregmap, regcache, -1, &fpregs);

> @@ -189,22 +187,18 @@ void

>  sparc_store_inferior_registers (struct regcache *regcache, int regnum)

>  {

>    struct gdbarch *gdbarch = regcache->arch ();

> -  pid_t pid;

> -

> -  /* NOTE: cagney/2002-12-02: See comment in fetch_inferior_registers

> -     about threaded assumptions.  */

> -  pid = get_ptrace_pid (regcache->ptid ());

> +  ptid_t ptid = regcache->ptid ();

> 

>    if (regnum == -1 || sparc_gregset_supplies_p (gdbarch, regnum))

>      {

>        gregset_t regs;

> 

> -      if (ptrace (PTRACE_GETREGS, pid, (PTRACE_TYPE_ARG3) &regs, 0) == -1)

> +      if (gdb_ptrace (PTRACE_GETREGS, ptid, (PTRACE_TYPE_ARG3) &regs) == -1)

>  	perror_with_name (_("Couldn't get registers"));

> 

>        sparc_collect_gregset (sparc_gregmap, regcache, regnum, &regs);

> 

> -      if (ptrace (PTRACE_SETREGS, pid, (PTRACE_TYPE_ARG3) &regs, 0) == -1)

> +      if (gdb_ptrace (PTRACE_SETREGS, ptid, (PTRACE_TYPE_ARG3) &regs) == -1)

>  	perror_with_name (_("Couldn't write registers"));

> 

>        /* Deal with the stack regs.  */

> @@ -225,7 +219,7 @@ sparc_store_inferior_registers (struct regcache *regcache, int regnum)

>      {

>        fpregset_t fpregs, saved_fpregs;

> 

> -      if (ptrace (PTRACE_GETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)

> +      if (gdb_ptrace (PTRACE_GETFPREGS, ptid, (PTRACE_TYPE_ARG3) &fpregs) == -1)

>  	perror_with_name (_("Couldn't get floating-point registers"));

> 

>        memcpy (&saved_fpregs, &fpregs, sizeof (fpregs));

> @@ -237,8 +231,8 @@ sparc_store_inferior_registers (struct regcache *regcache, int regnum)

>  	 to write the registers if nothing changed.  */

>        if (memcmp (&saved_fpregs, &fpregs, sizeof (fpregs)) != 0)

>  	{

> -	  if (ptrace (PTRACE_SETFPREGS, pid,

> -		      (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)

> +	  if (gdb_ptrace (PTRACE_SETFPREGS, ptid,

> +			  (PTRACE_TYPE_ARG3) &fpregs) == -1)

>  	    perror_with_name (_("Couldn't write floating-point registers"));

>  	}

> 

> --

> 2.25.0

> 


Thanks, this version LGTM.

Simon
Simon Marchi March 17, 2020, 7:09 p.m. | #2
On 2020-03-17 3:07 p.m., Simon Marchi wrote:
> On 2020-03-17 2:18 p.m., Kamil Rytarowski wrote:

>> NetBSD ptrace(2) accepts thread id (LWP) as the 4th argument for threads.

>>

>> Define gdb_ptrace() a wrapper function for ptrace(2) that properly passes

>> the pid,lwp pair on NetBSD and the result of get_ptrace_pid() for others.

>> ---

>>  gdb/sparc-nat.c | 50 ++++++++++++++++++++++---------------------------

>>  1 file changed, 22 insertions(+), 28 deletions(-)

>>

>> diff --git a/gdb/sparc-nat.c b/gdb/sparc-nat.c

>> index dff0f521565..fadcfd34474 100644

>> --- a/gdb/sparc-nat.c

>> +++ b/gdb/sparc-nat.c

>> @@ -78,6 +78,19 @@ typedef struct fp_status fpregset_t;

>>  #define PTRACE_SETFPREGS PT_SETFPREGS

>>  #endif

>>

>> +static int

>> +gdb_ptrace (PTRACE_TYPE_ARG1 request, ptid_t ptid, PTRACE_TYPE_ARG3 addr)

>> +{

>> +#ifdef __NetBSD__

>> +  /* Support for NetBSD threads: unlike other ptrace implementations in this

>> +     file, NetBSD requires that we pass both the pid and lwp.  */

>> +  return ptrace (request, ptid.pid (), addr, ptid.lwp ());

>> +#else

>> +  pid_t pid = get_ptrace_pid (ptid);

>> +  return ptrace (request, pid, addr, 0);

>> +#endif

>> +}

>> +

>>  /* Register set description.  */

>>  const struct sparc_gregmap *sparc_gregmap;

>>  const struct sparc_fpregmap *sparc_fpregmap;

>> @@ -137,22 +150,7 @@ void

>>  sparc_fetch_inferior_registers (struct regcache *regcache, int regnum)

>>  {

>>    struct gdbarch *gdbarch = regcache->arch ();

>> -  pid_t pid;

>> -

>> -  /* NOTE: cagney/2002-12-03: This code assumes that the currently

>> -     selected light weight processes' registers can be written

>> -     directly into the selected thread's register cache.  This works

>> -     fine when given an 1:1 LWP:thread model (such as found on

>> -     GNU/Linux) but will, likely, have problems when used on an N:1

>> -     (userland threads) or N:M (userland multiple LWP) model.  In the

>> -     case of the latter two, the LWP's registers do not necessarily

>> -     belong to the selected thread (the LWP could be in the middle of

>> -     executing the thread switch code).

>> -

>> -     These functions should instead be parameterized with an explicit

>> -     object (struct regcache, struct thread_info?) into which the LWPs

>> -     registers can be written.  */

>> -  pid = get_ptrace_pid (regcache->ptid ());

>> +  ptid_t ptid = regcache->ptid ();

>>

>>    if (regnum == SPARC_G0_REGNUM)

>>      {

>> @@ -166,7 +164,7 @@ sparc_fetch_inferior_registers (struct regcache *regcache, int regnum)

>>      {

>>        gregset_t regs;

>>

>> -      if (ptrace (PTRACE_GETREGS, pid, (PTRACE_TYPE_ARG3) &regs, 0) == -1)

>> +      if (gdb_ptrace (PTRACE_GETREGS, ptid, (PTRACE_TYPE_ARG3) &regs) == -1)

>>  	perror_with_name (_("Couldn't get registers"));

>>

>>        sparc_supply_gregset (sparc_gregmap, regcache, -1, &regs);

>> @@ -178,7 +176,7 @@ sparc_fetch_inferior_registers (struct regcache *regcache, int regnum)

>>      {

>>        fpregset_t fpregs;

>>

>> -      if (ptrace (PTRACE_GETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)

>> +      if (gdb_ptrace (PTRACE_GETFPREGS, ptid, (PTRACE_TYPE_ARG3) &fpregs) == -1)

>>  	perror_with_name (_("Couldn't get floating point status"));

>>

>>        sparc_supply_fpregset (sparc_fpregmap, regcache, -1, &fpregs);

>> @@ -189,22 +187,18 @@ void

>>  sparc_store_inferior_registers (struct regcache *regcache, int regnum)

>>  {

>>    struct gdbarch *gdbarch = regcache->arch ();

>> -  pid_t pid;

>> -

>> -  /* NOTE: cagney/2002-12-02: See comment in fetch_inferior_registers

>> -     about threaded assumptions.  */

>> -  pid = get_ptrace_pid (regcache->ptid ());

>> +  ptid_t ptid = regcache->ptid ();

>>

>>    if (regnum == -1 || sparc_gregset_supplies_p (gdbarch, regnum))

>>      {

>>        gregset_t regs;

>>

>> -      if (ptrace (PTRACE_GETREGS, pid, (PTRACE_TYPE_ARG3) &regs, 0) == -1)

>> +      if (gdb_ptrace (PTRACE_GETREGS, ptid, (PTRACE_TYPE_ARG3) &regs) == -1)

>>  	perror_with_name (_("Couldn't get registers"));

>>

>>        sparc_collect_gregset (sparc_gregmap, regcache, regnum, &regs);

>>

>> -      if (ptrace (PTRACE_SETREGS, pid, (PTRACE_TYPE_ARG3) &regs, 0) == -1)

>> +      if (gdb_ptrace (PTRACE_SETREGS, ptid, (PTRACE_TYPE_ARG3) &regs) == -1)

>>  	perror_with_name (_("Couldn't write registers"));

>>

>>        /* Deal with the stack regs.  */

>> @@ -225,7 +219,7 @@ sparc_store_inferior_registers (struct regcache *regcache, int regnum)

>>      {

>>        fpregset_t fpregs, saved_fpregs;

>>

>> -      if (ptrace (PTRACE_GETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)

>> +      if (gdb_ptrace (PTRACE_GETFPREGS, ptid, (PTRACE_TYPE_ARG3) &fpregs) == -1)

>>  	perror_with_name (_("Couldn't get floating-point registers"));

>>

>>        memcpy (&saved_fpregs, &fpregs, sizeof (fpregs));

>> @@ -237,8 +231,8 @@ sparc_store_inferior_registers (struct regcache *regcache, int regnum)

>>  	 to write the registers if nothing changed.  */

>>        if (memcmp (&saved_fpregs, &fpregs, sizeof (fpregs)) != 0)

>>  	{

>> -	  if (ptrace (PTRACE_SETFPREGS, pid,

>> -		      (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)

>> +	  if (gdb_ptrace (PTRACE_SETFPREGS, ptid,

>> +			  (PTRACE_TYPE_ARG3) &fpregs) == -1)

>>  	    perror_with_name (_("Couldn't write floating-point registers"));

>>  	}

>>

>> --

>> 2.25.0

>>

> 

> Thanks, this version LGTM.

> 

> Simon


Don't forget the ChangeLog entry though.

Simon

Patch

diff --git a/gdb/sparc-nat.c b/gdb/sparc-nat.c
index dff0f521565..fadcfd34474 100644
--- a/gdb/sparc-nat.c
+++ b/gdb/sparc-nat.c
@@ -78,6 +78,19 @@  typedef struct fp_status fpregset_t;
 #define PTRACE_SETFPREGS PT_SETFPREGS
 #endif

+static int
+gdb_ptrace (PTRACE_TYPE_ARG1 request, ptid_t ptid, PTRACE_TYPE_ARG3 addr)
+{
+#ifdef __NetBSD__
+  /* Support for NetBSD threads: unlike other ptrace implementations in this
+     file, NetBSD requires that we pass both the pid and lwp.  */
+  return ptrace (request, ptid.pid (), addr, ptid.lwp ());
+#else
+  pid_t pid = get_ptrace_pid (ptid);
+  return ptrace (request, pid, addr, 0);
+#endif
+}
+
 /* Register set description.  */
 const struct sparc_gregmap *sparc_gregmap;
 const struct sparc_fpregmap *sparc_fpregmap;
@@ -137,22 +150,7 @@  void
 sparc_fetch_inferior_registers (struct regcache *regcache, int regnum)
 {
   struct gdbarch *gdbarch = regcache->arch ();
-  pid_t pid;
-
-  /* NOTE: cagney/2002-12-03: This code assumes that the currently
-     selected light weight processes' registers can be written
-     directly into the selected thread's register cache.  This works
-     fine when given an 1:1 LWP:thread model (such as found on
-     GNU/Linux) but will, likely, have problems when used on an N:1
-     (userland threads) or N:M (userland multiple LWP) model.  In the
-     case of the latter two, the LWP's registers do not necessarily
-     belong to the selected thread (the LWP could be in the middle of
-     executing the thread switch code).
-
-     These functions should instead be parameterized with an explicit
-     object (struct regcache, struct thread_info?) into which the LWPs
-     registers can be written.  */
-  pid = get_ptrace_pid (regcache->ptid ());
+  ptid_t ptid = regcache->ptid ();

   if (regnum == SPARC_G0_REGNUM)
     {
@@ -166,7 +164,7 @@  sparc_fetch_inferior_registers (struct regcache *regcache, int regnum)
     {
       gregset_t regs;

-      if (ptrace (PTRACE_GETREGS, pid, (PTRACE_TYPE_ARG3) &regs, 0) == -1)
+      if (gdb_ptrace (PTRACE_GETREGS, ptid, (PTRACE_TYPE_ARG3) &regs) == -1)
 	perror_with_name (_("Couldn't get registers"));

       sparc_supply_gregset (sparc_gregmap, regcache, -1, &regs);
@@ -178,7 +176,7 @@  sparc_fetch_inferior_registers (struct regcache *regcache, int regnum)
     {
       fpregset_t fpregs;

-      if (ptrace (PTRACE_GETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
+      if (gdb_ptrace (PTRACE_GETFPREGS, ptid, (PTRACE_TYPE_ARG3) &fpregs) == -1)
 	perror_with_name (_("Couldn't get floating point status"));

       sparc_supply_fpregset (sparc_fpregmap, regcache, -1, &fpregs);
@@ -189,22 +187,18 @@  void
 sparc_store_inferior_registers (struct regcache *regcache, int regnum)
 {
   struct gdbarch *gdbarch = regcache->arch ();
-  pid_t pid;
-
-  /* NOTE: cagney/2002-12-02: See comment in fetch_inferior_registers
-     about threaded assumptions.  */
-  pid = get_ptrace_pid (regcache->ptid ());
+  ptid_t ptid = regcache->ptid ();

   if (regnum == -1 || sparc_gregset_supplies_p (gdbarch, regnum))
     {
       gregset_t regs;

-      if (ptrace (PTRACE_GETREGS, pid, (PTRACE_TYPE_ARG3) &regs, 0) == -1)
+      if (gdb_ptrace (PTRACE_GETREGS, ptid, (PTRACE_TYPE_ARG3) &regs) == -1)
 	perror_with_name (_("Couldn't get registers"));

       sparc_collect_gregset (sparc_gregmap, regcache, regnum, &regs);

-      if (ptrace (PTRACE_SETREGS, pid, (PTRACE_TYPE_ARG3) &regs, 0) == -1)
+      if (gdb_ptrace (PTRACE_SETREGS, ptid, (PTRACE_TYPE_ARG3) &regs) == -1)
 	perror_with_name (_("Couldn't write registers"));

       /* Deal with the stack regs.  */
@@ -225,7 +219,7 @@  sparc_store_inferior_registers (struct regcache *regcache, int regnum)
     {
       fpregset_t fpregs, saved_fpregs;

-      if (ptrace (PTRACE_GETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
+      if (gdb_ptrace (PTRACE_GETFPREGS, ptid, (PTRACE_TYPE_ARG3) &fpregs) == -1)
 	perror_with_name (_("Couldn't get floating-point registers"));

       memcpy (&saved_fpregs, &fpregs, sizeof (fpregs));
@@ -237,8 +231,8 @@  sparc_store_inferior_registers (struct regcache *regcache, int regnum)
 	 to write the registers if nothing changed.  */
       if (memcmp (&saved_fpregs, &fpregs, sizeof (fpregs)) != 0)
 	{
-	  if (ptrace (PTRACE_SETFPREGS, pid,
-		      (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
+	  if (gdb_ptrace (PTRACE_SETFPREGS, ptid,
+			  (PTRACE_TYPE_ARG3) &fpregs) == -1)
 	    perror_with_name (_("Couldn't write floating-point registers"));
 	}