diff mbox series

[v3,10/21] linux-user: Fix guest_addr_valid vs reserved_va

Message ID 20210115224645.1196742-11-richard.henderson@linaro.org
State Superseded
Headers show
Series target-arm: Implement ARMv8.5-MemTag, user mode | expand

Commit Message

Richard Henderson Jan. 15, 2021, 10:46 p.m. UTC
We must always use GUEST_ADDR_MAX, because even 32-bit hosts can
use -R <reserved_va> to restrict the memory address of the guest.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

---
 include/exec/cpu_ldst.h | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

-- 
2.25.1

Comments

Peter Maydell Jan. 19, 2021, 5:03 p.m. UTC | #1
On Fri, 15 Jan 2021 at 22:47, Richard Henderson
<richard.henderson@linaro.org> wrote:
>

> We must always use GUEST_ADDR_MAX, because even 32-bit hosts can

> use -R <reserved_va> to restrict the memory address of the guest.

>

> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

> ---

>  include/exec/cpu_ldst.h | 9 ++++-----

>  1 file changed, 4 insertions(+), 5 deletions(-)

>

> diff --git a/include/exec/cpu_ldst.h b/include/exec/cpu_ldst.h

> index 4e6ef3d542..e62f4fba00 100644

> --- a/include/exec/cpu_ldst.h

> +++ b/include/exec/cpu_ldst.h

> @@ -72,11 +72,10 @@ typedef uint64_t abi_ptr;

>  /* All direct uses of g2h and h2g need to go away for usermode softmmu.  */

>  #define g2h(x) ((void *)((uintptr_t)(abi_ptr)(x) + guest_base))

>

> -#if HOST_LONG_BITS <= TARGET_VIRT_ADDR_SPACE_BITS

> -#define guest_addr_valid(x) (1)

> -#else

> -#define guest_addr_valid(x) ((x) <= GUEST_ADDR_MAX)

> -#endif

> +static inline bool guest_addr_valid(abi_ulong x)

> +{

> +    return x <= GUEST_ADDR_MAX;

> +}


Reviewed-by: Peter Maydell <peter.maydell@linaro.org>


Looking back at patch 9 -- if we always check against
GUEST_ADDR_MAX here, should we also do that for h2g_valid(),
or are the two uses different ?
(The v2->v3 changes list for patch 9 suggests we may have
had this discussion previously, but I forget the details...)

thanks
-- PMM
Richard Henderson Jan. 19, 2021, 5:41 p.m. UTC | #2
On 1/19/21 7:03 AM, Peter Maydell wrote:
> On Fri, 15 Jan 2021 at 22:47, Richard Henderson

> <richard.henderson@linaro.org> wrote:

>>

>> We must always use GUEST_ADDR_MAX, because even 32-bit hosts can

>> use -R <reserved_va> to restrict the memory address of the guest.

>>

>> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

>> ---

>>  include/exec/cpu_ldst.h | 9 ++++-----

>>  1 file changed, 4 insertions(+), 5 deletions(-)

>>

>> diff --git a/include/exec/cpu_ldst.h b/include/exec/cpu_ldst.h

>> index 4e6ef3d542..e62f4fba00 100644

>> --- a/include/exec/cpu_ldst.h

>> +++ b/include/exec/cpu_ldst.h

>> @@ -72,11 +72,10 @@ typedef uint64_t abi_ptr;

>>  /* All direct uses of g2h and h2g need to go away for usermode softmmu.  */

>>  #define g2h(x) ((void *)((uintptr_t)(abi_ptr)(x) + guest_base))

>>

>> -#if HOST_LONG_BITS <= TARGET_VIRT_ADDR_SPACE_BITS

>> -#define guest_addr_valid(x) (1)

>> -#else

>> -#define guest_addr_valid(x) ((x) <= GUEST_ADDR_MAX)

>> -#endif

>> +static inline bool guest_addr_valid(abi_ulong x)

>> +{

>> +    return x <= GUEST_ADDR_MAX;

>> +}

> 

> Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

> 

> Looking back at patch 9 -- if we always check against

> GUEST_ADDR_MAX here, should we also do that for h2g_valid(),

> or are the two uses different ?

> (The v2->v3 changes list for patch 9 suggests we may have

> had this discussion previously, but I forget the details...)


I had thought we should always check GUEST_ADDR_MAX.

If something is outside G_A_M, then it doesn't fit
into the reserved_va that either (1) the user requested
via the command-line or (2) for which the guest has
constraints (e.g. TARGET_VIRT_ADDR_SPACE_BITS for sh4
or mips, requiring 31-bit addresses).


r~
diff mbox series

Patch

diff --git a/include/exec/cpu_ldst.h b/include/exec/cpu_ldst.h
index 4e6ef3d542..e62f4fba00 100644
--- a/include/exec/cpu_ldst.h
+++ b/include/exec/cpu_ldst.h
@@ -72,11 +72,10 @@  typedef uint64_t abi_ptr;
 /* All direct uses of g2h and h2g need to go away for usermode softmmu.  */
 #define g2h(x) ((void *)((uintptr_t)(abi_ptr)(x) + guest_base))
 
-#if HOST_LONG_BITS <= TARGET_VIRT_ADDR_SPACE_BITS
-#define guest_addr_valid(x) (1)
-#else
-#define guest_addr_valid(x) ((x) <= GUEST_ADDR_MAX)
-#endif
+static inline bool guest_addr_valid(abi_ulong x)
+{
+    return x <= GUEST_ADDR_MAX;
+}
 
 static inline bool guest_range_valid(abi_ulong start, abi_ulong len)
 {