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

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

[Kamil Rytarowski]

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

This file is still shared with other targets that use different 4th argument
type, that is always unused.
---
 gdb/sparc-nat.c | 22 +++++++++++++++-------
 1 file changed, 15 insertions(+), 7 deletions(-)

diff --git a/gdb/sparc-nat.c b/gdb/sparc-nat.c
index dff0f521565..9743bc3f3a0 100644
--- a/gdb/sparc-nat.c
+++ b/gdb/sparc-nat.c
@@ -78,6 +78,14 @@ typedef struct fp_status fpregset_t;
 #define PTRACE_SETFPREGS PT_SETFPREGS
 #endif

+/* Support for NetBSD threads.  */
+#ifdef __NetBSD__
+# define gdb_ptrace(request, pid, addr) \
+  ptrace (request, pid, addr, regcache->ptid ().lwp ())
+#else
+# define gdb_ptrace(request, pid, addr) ptrace (request, pid, addr, 0)
+#endif
+
 /* Register set description.  */
 const struct sparc_gregmap *sparc_gregmap;
 const struct sparc_fpregmap *sparc_fpregmap;
@@ -166,7 +174,7 @@ 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, pid, (PTRACE_TYPE_ARG3) &regs) == -1)
 	perror_with_name (_("Couldn't get registers"));

       sparc_supply_gregset (sparc_gregmap, regcache, -1, &regs);
@@ -178,7 +186,7 @@ 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, pid, (PTRACE_TYPE_ARG3) &fpregs) == -1)
 	perror_with_name (_("Couldn't get floating point status"));

       sparc_supply_fpregset (sparc_fpregmap, regcache, -1, &fpregs);
@@ -199,12 +207,12 @@ sparc_store_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, pid, (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, pid, (PTRACE_TYPE_ARG3) &regs) == -1)
 	perror_with_name (_("Couldn't write registers"));

       /* Deal with the stack regs.  */
@@ -225,7 +233,7 @@ 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, pid, (PTRACE_TYPE_ARG3) &fpregs) == -1)
 	perror_with_name (_("Couldn't get floating-point registers"));

       memcpy (&saved_fpregs, &fpregs, sizeof (fpregs));
@@ -237,8 +245,8 @@ 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, pid,
+		      (PTRACE_TYPE_ARG3) &fpregs) == -1)
 	    perror_with_name (_("Couldn't write floating-point registers"));
 	}

--
2.25.0

[PATCH v3] Add support for NetBSD threads in sparc-nat.c

[Kamil Rytarowski]

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

This file is still shared with other targets that use different 4th argument
type, that is always unused.
---
 gdb/sparc-nat.c | 30 +++++++++++++++++++++++-------
 1 file changed, 23 insertions(+), 7 deletions(-)

diff --git a/gdb/sparc-nat.c b/gdb/sparc-nat.c
index dff0f521565..be99ebb6789 100644
--- a/gdb/sparc-nat.c
+++ b/gdb/sparc-nat.c
@@ -78,6 +78,17 @@ typedef struct fp_status fpregset_t;
 #define PTRACE_SETFPREGS PT_SETFPREGS
 #endif

+static inline int
+gdb_ptrace(int request, pid_t pid, void *addr, struct regcache *regcache)
+{
+#ifdef __NetBSD__
+  /* Support for NetBSD threads.  */
+  return ptrace (request, pid, addr, regcache->ptid ().lwp ());
+#else
+  return ptrace (request, pid, addr, 0);
+#endif
+}
+
 /* Register set description.  */
 const struct sparc_gregmap *sparc_gregmap;
 const struct sparc_fpregmap *sparc_fpregmap;
@@ -166,7 +177,8 @@ 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, pid,
+		      (PTRACE_TYPE_ARG3) &regs, regcache) == -1)
 	perror_with_name (_("Couldn't get registers"));

       sparc_supply_gregset (sparc_gregmap, regcache, -1, &regs);
@@ -178,7 +190,8 @@ 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, pid,
+		      (PTRACE_TYPE_ARG3) &fpregs, regcache) == -1)
 	perror_with_name (_("Couldn't get floating point status"));

       sparc_supply_fpregset (sparc_fpregmap, regcache, -1, &fpregs);
@@ -199,12 +212,14 @@ sparc_store_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, pid,
+		      (PTRACE_TYPE_ARG3) &regs, regcache) == -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, pid,
+		      (PTRACE_TYPE_ARG3) &regs, regcache) == -1)
 	perror_with_name (_("Couldn't write registers"));

       /* Deal with the stack regs.  */
@@ -225,7 +240,8 @@ 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, pid,
+		      (PTRACE_TYPE_ARG3) &fpregs, regcache) == -1)
 	perror_with_name (_("Couldn't get floating-point registers"));

       memcpy (&saved_fpregs, &fpregs, sizeof (fpregs));
@@ -237,8 +253,8 @@ 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, pid,
+		      (PTRACE_TYPE_ARG3) &fpregs, regcache) == -1)
 	    perror_with_name (_("Couldn't write floating-point registers"));
 	}

--
2.25.0

Re: [PATCH v3] Add support for NetBSD threads in sparc-nat.c

[Simon Marchi]

On 2020-03-17 11:10 a.m., Kamil Rytarowski wrote:
> NetBSD ptrace(2) accepts thread id (LWP) as the 4th argument for threads.
> 
> This file is still shared with other targets that use different 4th argument
> type, that is always unused.
> ---
>  gdb/sparc-nat.c | 30 +++++++++++++++++++++++-------
>  1 file changed, 23 insertions(+), 7 deletions(-)
> 
> diff --git a/gdb/sparc-nat.c b/gdb/sparc-nat.c
> index dff0f521565..be99ebb6789 100644
> --- a/gdb/sparc-nat.c
> +++ b/gdb/sparc-nat.c
> @@ -78,6 +78,17 @@ typedef struct fp_status fpregset_t;
>  #define PTRACE_SETFPREGS PT_SETFPREGS
>  #endif
> 
> +static inline int

Remove the `inline`.

> +gdb_ptrace(int request, pid_t pid, void *addr, struct regcache *regcache)

Space before parenthesis.

> +{
> +#ifdef __NetBSD__
> +  /* Support for NetBSD threads.  */

Could you add a bit more to this comment, for example:

  /* Support for NetBSD threads: unlike most other ptrace implementations, NetBSD
     requires that we pass both the pid and lwp.  */

> +  return ptrace (request, pid, addr, regcache->ptid ().lwp ());
> +#else
> +  return ptrace (request, pid, addr, 0);
> +#endif
> +}

I think it would make more sense to just pass the whole ptid, rather than passing the regcache:

static int
gdb_ptrace (int request, ptid_t ptid, void *addr)
{
#ifdef __NetBSD__
  /* Support for NetBSD threads: unlike most other ptrace implementations, NetBSD
     requires that we pass both the pid and lwp.  */
  return ptrace (request, ptid.pid (), addr, ptid.lwp ());
#else
  int pid = get_ptrace_pid (ptid);
  return ptrace (request, pid, addr, 0);
#endif
}

Simon

[PATCH v4] Add support for NetBSD threads in sparc-nat.c

[Kamil Rytarowski]

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

This file is still shared with other targets that use different 4th argument
type, that is always unused.
---
 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..10cc01375ed 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 (int request, ptid_t pid, void *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

Re: [PATCH v4] Add support for NetBSD threads in sparc-nat.c

[Simon Marchi]

On 2020-03-17 12:46 p.m., Kamil Rytarowski wrote:
> NetBSD ptrace(2) accepts thread id (LWP) as the 4th argument for threads.
> 
> This file is still shared with other targets that use different 4th argument
> type, that is always unused.
> ---
>  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..10cc01375ed 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 (int request, ptid_t pid, void *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 ());

Does that even build?  ptid isn't the name of a parameter, and the parenthesis after
"ptid" should not be there.  Rename the pid parameter to ptid, and replace the above
with "ptid.pid ()" and "ptid.lwp ()".

Simon

Re: [PATCH v4] Add support for NetBSD threads in sparc-nat.c

[Simon Marchi]

On 2020-03-17 12:51 p.m., Simon Marchi wrote:
> On 2020-03-17 12:46 p.m., Kamil Rytarowski wrote:
>> NetBSD ptrace(2) accepts thread id (LWP) as the 4th argument for threads.
>>
>> This file is still shared with other targets that use different 4th argument
>> type, that is always unused.
>> ---
>>  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..10cc01375ed 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 (int request, ptid_t pid, void *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 ());
> 
> Does that even build?  ptid isn't the name of a parameter, and the parenthesis after
> "ptid" should not be there.  Rename the pid parameter to ptid, and replace the above
> with "ptid.pid ()" and "ptid.lwp ()".
> 
> Simon
> 

I tried to build this using a sparc-linux cross-compiler, and I think we need
to adjust gdb_ptrace to account for the various possible arguments types.  The
following version of the function builds fine with sparc64-linux-gnu-gcc, can you
try it with NetBSD?

static PTRACE_TYPE_RET
gdb_ptrace (PTRACE_TYPE_ARG1 request, ptid_t ptid, PTRACE_TYPE_ARG4 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
}

Alternatively, we could keep address as a "void *", and cast the value inside gdb_ptrace:

  return ptrace (request, ptid.pid (), (PTRACE_TYPE_ARG4) addr, ptid.lwp ());

All the callers of gdb_ptrace wouldn't have to cast that themselves, which is perhaps
a bit nicer.

Simon

Re: [PATCH v4] Add support for NetBSD threads in sparc-nat.c

[Kamil Rytarowski]

[-- Attachment #1.1: Type: text/plain, Size: 2493 bytes --]

On 17.03.2020 17:59, Simon Marchi wrote:
> On 2020-03-17 12:51 p.m., Simon Marchi wrote:
>> On 2020-03-17 12:46 p.m., Kamil Rytarowski wrote:
>>> NetBSD ptrace(2) accepts thread id (LWP) as the 4th argument for threads.
>>>
>>> This file is still shared with other targets that use different 4th argument
>>> type, that is always unused.
>>> ---
>>>  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..10cc01375ed 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 (int request, ptid_t pid, void *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 ());
>>
>> Does that even build?  ptid isn't the name of a parameter, and the parenthesis after
>> "ptid" should not be there.  Rename the pid parameter to ptid, and replace the above
>> with "ptid.pid ()" and "ptid.lwp ()".
>>
>> Simon
>>
> 
> I tried to build this using a sparc-linux cross-compiler, and I think we need
> to adjust gdb_ptrace to account for the various possible arguments types.  The
> following version of the function builds fine with sparc64-linux-gnu-gcc, can you
> try it with NetBSD?
> 
> static PTRACE_TYPE_RET
> gdb_ptrace (PTRACE_TYPE_ARG1 request, ptid_t ptid, PTRACE_TYPE_ARG4 addr)

Does it work for you if you use PTRACE_TYPE_ARG3? addr is the 3rd argument.

PTRACE_TYPE_ARG4 is int on BSDs.

> {
> #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
> }
> 
> Alternatively, we could keep address as a "void *", and cast the value inside gdb_ptrace:
> 
>   return ptrace (request, ptid.pid (), (PTRACE_TYPE_ARG4) addr, ptid.lwp ());
> 
> All the callers of gdb_ptrace wouldn't have to cast that themselves, which is perhaps
> a bit nicer.
> 
> Simon
> 



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Re: [PATCH v4] Add support for NetBSD threads in sparc-nat.c

[Simon Marchi]

On 2020-03-17 1:07 p.m., Kamil Rytarowski wrote:
> On 17.03.2020 17:59, Simon Marchi wrote:
>> I tried to build this using a sparc-linux cross-compiler, and I think we need
>> to adjust gdb_ptrace to account for the various possible arguments types.  The
>> following version of the function builds fine with sparc64-linux-gnu-gcc, can you
>> try it with NetBSD?
>>
>> static PTRACE_TYPE_RET
>> gdb_ptrace (PTRACE_TYPE_ARG1 request, ptid_t ptid, PTRACE_TYPE_ARG4 addr)
> 
> Does it work for you if you use PTRACE_TYPE_ARG3? addr is the 3rd argument.
> 
> PTRACE_TYPE_ARG4 is int on BSDs.

Err yes sorry, it should be PTRACE_TYPE_ARG3, my bad.

Simon

Re: [PATCH v4] Add support for NetBSD threads in sparc-nat.c

[Kamil Rytarowski]

[-- Attachment #1.1: Type: text/plain, Size: 791 bytes --]

On 17.03.2020 18:10, Simon Marchi wrote:
> On 2020-03-17 1:07 p.m., Kamil Rytarowski wrote:
>> On 17.03.2020 17:59, Simon Marchi wrote:
>>> I tried to build this using a sparc-linux cross-compiler, and I think we need
>>> to adjust gdb_ptrace to account for the various possible arguments types.  The
>>> following version of the function builds fine with sparc64-linux-gnu-gcc, can you
>>> try it with NetBSD?
>>>
>>> static PTRACE_TYPE_RET
>>> gdb_ptrace (PTRACE_TYPE_ARG1 request, ptid_t ptid, PTRACE_TYPE_ARG4 addr)
>>
>> Does it work for you if you use PTRACE_TYPE_ARG3? addr is the 3rd argument.
>>
>> PTRACE_TYPE_ARG4 is int on BSDs.
> 
> Err yes sorry, it should be PTRACE_TYPE_ARG3, my bad.
> 
> Simon
> 

I've tested v5 with the NetBSD/sparc build (32-bit).


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

[Kamil Rytarowski]

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

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

[Simon Marchi]

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

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

[Simon Marchi]

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