Patchwork monitor: Prevent sign-extension of 32-bit addresses printed by info mem

login
register
mail settings
Submitter Austin Clements
Date Aug. 15, 2011, 3:19 a.m.
Message ID <1313378361-15610-1-git-send-email-amdragon@mit.edu>
Download mbox | patch
Permalink /patch/109976/
State New
Headers show

Comments

Austin Clements - Aug. 15, 2011, 3:19 a.m.
Previously, on 32-bit i386, info mem used signed 32-bit int's to store
the page table indexes.  As a result, address calculation was done in
32 bits and then incorrectly sign-extended to 64 bits, yielding output
like

ffffffffef000000-ffffffffef031000 0000000000031000 ur-
ffffffffef7bc000-ffffffffef7bd000 0000000000001000 urw
ffffffffef7bd000-ffffffffef7be000 0000000000001000 ur-

This makes these indexes unsigned, which yields correct output

00000000ef000000-00000000ef031000 0000000000031000 ur-
00000000ef7bc000-00000000ef7bd000 0000000000001000 urw
00000000ef7bd000-00000000ef7be000 0000000000001000 ur-

Signed-off-by: Austin Clements <amdragon@mit.edu>
---
 monitor.c |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)
Blue Swirl - Aug. 21, 2011, 6:26 p.m.
On Mon, Aug 15, 2011 at 3:19 AM, Austin Clements <amdragon@mit.edu> wrote:
> Previously, on 32-bit i386, info mem used signed 32-bit int's to store
> the page table indexes.  As a result, address calculation was done in
> 32 bits and then incorrectly sign-extended to 64 bits, yielding output
> like
>
> ffffffffef000000-ffffffffef031000 0000000000031000 ur-
> ffffffffef7bc000-ffffffffef7bd000 0000000000001000 urw
> ffffffffef7bd000-ffffffffef7be000 0000000000001000 ur-
>
> This makes these indexes unsigned, which yields correct output
>
> 00000000ef000000-00000000ef031000 0000000000031000 ur-
> 00000000ef7bc000-00000000ef7bd000 0000000000001000 urw
> 00000000ef7bd000-00000000ef7be000 0000000000001000 ur-
>
> Signed-off-by: Austin Clements <amdragon@mit.edu>

Thanks, applied. I think 'info tlb' needs a similar fix.

> ---
>  monitor.c |    6 ++++--
>  1 files changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/monitor.c b/monitor.c
> index 718935b..6a4f8c2 100644
> --- a/monitor.c
> +++ b/monitor.c
> @@ -2224,7 +2224,8 @@ static void mem_print(Monitor *mon, target_phys_addr_t *pstart,
>
>  static void mem_info_32(Monitor *mon, CPUState *env)
>  {
> -    int l1, l2, prot, last_prot;
> +    unsigned int l1, l2;
> +    int prot, last_prot;
>     uint32_t pgd, pde, pte;
>     target_phys_addr_t start, end;
>
> @@ -2261,7 +2262,8 @@ static void mem_info_32(Monitor *mon, CPUState *env)
>
>  static void mem_info_pae32(Monitor *mon, CPUState *env)
>  {
> -    int l1, l2, l3, prot, last_prot;
> +    unsigned int l1, l2, l3;
> +    int prot, last_prot;
>     uint64_t pdpe, pde, pte;
>     uint64_t pdp_addr, pd_addr, pt_addr;
>     target_phys_addr_t start, end;
> --
> 1.7.5.4
>
>
>
Austin Clements - Aug. 21, 2011, 6:48 p.m.
Quoth Blue Swirl on Aug 21 at  6:26 pm:
> On Mon, Aug 15, 2011 at 3:19 AM, Austin Clements <amdragon@mit.edu> wrote:
> > Previously, on 32-bit i386, info mem used signed 32-bit int's to store
> > the page table indexes.  As a result, address calculation was done in
> > 32 bits and then incorrectly sign-extended to 64 bits, yielding output
> > like
> >
> > ffffffffef000000-ffffffffef031000 0000000000031000 ur-
> > ffffffffef7bc000-ffffffffef7bd000 0000000000001000 urw
> > ffffffffef7bd000-ffffffffef7be000 0000000000001000 ur-
> >
> > This makes these indexes unsigned, which yields correct output
> >
> > 00000000ef000000-00000000ef031000 0000000000031000 ur-
> > 00000000ef7bc000-00000000ef7bd000 0000000000001000 urw
> > 00000000ef7bd000-00000000ef7be000 0000000000001000 ur-
> >
> > Signed-off-by: Austin Clements <amdragon@mit.edu>
> 
> Thanks, applied. I think 'info tlb' needs a similar fix.

Quite right.  I'll follow up with the info tlb patch.

Patch

diff --git a/monitor.c b/monitor.c
index 718935b..6a4f8c2 100644
--- a/monitor.c
+++ b/monitor.c
@@ -2224,7 +2224,8 @@  static void mem_print(Monitor *mon, target_phys_addr_t *pstart,
 
 static void mem_info_32(Monitor *mon, CPUState *env)
 {
-    int l1, l2, prot, last_prot;
+    unsigned int l1, l2;
+    int prot, last_prot;
     uint32_t pgd, pde, pte;
     target_phys_addr_t start, end;
 
@@ -2261,7 +2262,8 @@  static void mem_info_32(Monitor *mon, CPUState *env)
 
 static void mem_info_pae32(Monitor *mon, CPUState *env)
 {
-    int l1, l2, l3, prot, last_prot;
+    unsigned int l1, l2, l3;
+    int prot, last_prot;
     uint64_t pdpe, pde, pte;
     uint64_t pdp_addr, pd_addr, pt_addr;
     target_phys_addr_t start, end;