Re: [PATCH] linux-user: Fix mips fp64 executables loading

[Daniil Kovalev]

Hello,

On Tue, 2 May 2023 14:41:31 +0300
Michael Tokarev  wrote:

> Is it a -stable material?

Yes, this `else if` branch is present in the latest linux-stable. It was
actually introduced in 46490b572544fa908be051f7872beb2941e55ede in 2015 and
never changed since then. I suppose that just a dummy typo error occurred when
copying that to qemu-user loader: this piece of code never changed in the linux
kernel since initially committed, so this particular `else if` branch just
seems to be forgotten when copying.

Best regards, Daniil Kovalev

Re: [PATCH] linux-user: Fix mips fp64 executables loading

[Michael Tokarev]

04.04.2023 08:21, Daniil Kovalev Wrote:

If a program requires fr1, we should set the FR bit of CP0 control status
register and add F64 hardware flag. The corresponding `else if` branch
statement is copied from the linux kernel sources (see `arch_check_elf` function
in linux/arch/mips/kernel/elf.c).


Is it a -stable material?

Thanks,

/mjt

Re: [PATCH] linux-user: Fix mips fp64 executables loading

[Laurent Vivier]

Le 04/04/2023 à 07:21, Daniil Kovalev a écrit :

If a program requires fr1, we should set the FR bit of CP0 control status
register and add F64 hardware flag. The corresponding `else if` branch
statement is copied from the linux kernel sources (see `arch_check_elf` function
in linux/arch/mips/kernel/elf.c).

Signed-off-by: Daniil Kovalev 
---
  linux-user/mips/cpu_loop.c | 5 -
  1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/linux-user/mips/cpu_loop.c b/linux-user/mips/cpu_loop.c
index d5c1c7941d..8735e58bad 100644
--- a/linux-user/mips/cpu_loop.c
+++ b/linux-user/mips/cpu_loop.c
@@ -290,7 +290,10 @@ void target_cpu_copy_regs(CPUArchState *env, struct 
target_pt_regs *regs)
  env->CP0_Status |= (1 << CP0St_FR);
  env->hflags |= MIPS_HFLAG_F64;
  }
-} else  if (!prog_req.fre && !prog_req.frdefault &&
+} else if (prog_req.fr1) {
+env->CP0_Status |= (1 << CP0St_FR);
+env->hflags |= MIPS_HFLAG_F64;
+} else if (!prog_req.fre && !prog_req.frdefault &&
!prog_req.fr1 && !prog_req.single && !prog_req.soft) {
  fprintf(stderr, "qemu: Can't find a matching FPU mode\n");
  exit(1);


Applied to my linux-user-for-8.1 branch.

Thanks,
Laurent

Re: [PATCH] linux-user: Fix mips fp64 executables loading

[Jiaxun Yang]

> 2023年4月4日 06:21，Daniil Kovalev  写道：
> 
> If a program requires fr1, we should set the FR bit of CP0 control status
> register and add F64 hardware flag. The corresponding `else if` branch
> statement is copied from the linux kernel sources (see `arch_check_elf` 
> function
> in linux/arch/mips/kernel/elf.c).
> 
> Signed-off-by: Daniil Kovalev 

Reviewed-by: Jiaxun Yang 

Thanks!

> ---
> linux-user/mips/cpu_loop.c | 5 -
> 1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/linux-user/mips/cpu_loop.c b/linux-user/mips/cpu_loop.c
> index d5c1c7941d..8735e58bad 100644
> --- a/linux-user/mips/cpu_loop.c
> +++ b/linux-user/mips/cpu_loop.c
> @@ -290,7 +290,10 @@ void target_cpu_copy_regs(CPUArchState *env, struct 
> target_pt_regs *regs)
> env->CP0_Status |= (1 << CP0St_FR);
> env->hflags |= MIPS_HFLAG_F64;
> }
> -} else  if (!prog_req.fre && !prog_req.frdefault &&
> +} else if (prog_req.fr1) {
> +env->CP0_Status |= (1 << CP0St_FR);
> +env->hflags |= MIPS_HFLAG_F64;
> +} else if (!prog_req.fre && !prog_req.frdefault &&
>   !prog_req.fr1 && !prog_req.single && !prog_req.soft) {
> fprintf(stderr, "qemu: Can't find a matching FPU mode\n");
> exit(1);
> -- 
> 2.40.0
> 

[PATCH] linux-user: Fix mips fp64 executables loading

[Daniil Kovalev]

If a program requires fr1, we should set the FR bit of CP0 control status
register and add F64 hardware flag. The corresponding `else if` branch
statement is copied from the linux kernel sources (see `arch_check_elf` function
in linux/arch/mips/kernel/elf.c).

Signed-off-by: Daniil Kovalev 
---
 linux-user/mips/cpu_loop.c | 5 -
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/linux-user/mips/cpu_loop.c b/linux-user/mips/cpu_loop.c
index d5c1c7941d..8735e58bad 100644
--- a/linux-user/mips/cpu_loop.c
+++ b/linux-user/mips/cpu_loop.c
@@ -290,7 +290,10 @@ void target_cpu_copy_regs(CPUArchState *env, struct 
target_pt_regs *regs)
 env->CP0_Status |= (1 << CP0St_FR);
 env->hflags |= MIPS_HFLAG_F64;
 }
-} else  if (!prog_req.fre && !prog_req.frdefault &&
+} else if (prog_req.fr1) {
+env->CP0_Status |= (1 << CP0St_FR);
+env->hflags |= MIPS_HFLAG_F64;
+} else if (!prog_req.fre && !prog_req.frdefault &&
   !prog_req.fr1 && !prog_req.single && !prog_req.soft) {
 fprintf(stderr, "qemu: Can't find a matching FPU mode\n");
 exit(1);
-- 
2.40.0