Re: [PATCH 4/5] RISC-V: Add native linux support.

[Andrew Burgess <andrew.burgess@embecosm.com>]

* Andreas Schwab <schwab@suse.de> [2018-10-25 12:49:09 +0200]:

> On Aug 08 2018, Jim Wilson <jimw@sifive.com> wrote:
> 
> > +  if ((regnum == RISCV_CSR_MISA_REGNUM)
> > +      || (regnum == -1))
> > +    {
> > +      /* TODO: Need to add a ptrace call for this.  */
> > +      regcache->raw_supply_zeroed (regnum);
> 
> ../../gdb/gdb/regcache.c:337: internal-error: void reg_buffer::assert_regnum(int) const: Assertion `regnum >= 0' failed.

Thanks for the report.

I pushed the patch below to fix this issue.

Thanks,
Andrew

---

[PATCH] gdb/riscv: Use correct regnum in riscv_linux_nat_target::fetch_registers

In riscv_linux_nat_target::fetch_registers, if we are asked to supply
all registers (regnum parameter is -1), then we currently end up
calling regcache::raw_supply_zeroed with the regnum -1, which is
invalid.  Instead we should be passing the regnum of the specific
register we wish to supply zeroed, in this case RISCV_CSR_MISA_REGNUM.

I removed the extra { ... } block in line with the coding standard
while editing this area.

gdb/ChangeLog:

	* riscv-linux-nat.c (riscv_linux_nat_target::fetch_registers):
	Pass correct regnum to raw_supply_zeroed.
---
 gdb/ChangeLog         | 5 +++++
 gdb/riscv-linux-nat.c | 6 ++----
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/gdb/riscv-linux-nat.c b/gdb/riscv-linux-nat.c
index 7dbfe651f2c..c09121d052b 100644
--- a/gdb/riscv-linux-nat.c
+++ b/gdb/riscv-linux-nat.c
@@ -201,10 +201,8 @@ riscv_linux_nat_target::fetch_registers (struct regcache *regcache, int regnum)
 
   if ((regnum == RISCV_CSR_MISA_REGNUM)
       || (regnum == -1))
-    {
-      /* TODO: Need to add a ptrace call for this.  */
-      regcache->raw_supply_zeroed (regnum);
-    }
+    /* TODO: Need to add a ptrace call for this.  */
+    regcache->raw_supply_zeroed (RISCV_CSR_MISA_REGNUM);
 
   /* Access to other CSRs has potential security issues, don't support them for
      now.  */
-- 
2.14.5