libgloss: Fix lseek semihosting bug on nios2 and m68k

Message ID 20200205043413.23573-1-sandra@codesourcery.com
State Accepted
Commit cd78225a50205aa07d726b7310b333e9c07471bc
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Series
  • libgloss: Fix lseek semihosting bug on nios2 and m68k
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Commit Message

Sandra Loosemore Feb. 5, 2020, 4:34 a.m.
When off_t is 32 bits, the value needs to be sign-extended to 64 bits
before shifting right to extract the high-order word.  Previously
negative offsets were incorrectly encoded.

Signed-off-by: Sandra Loosemore <sandra@codesourcery.com>

---
 libgloss/m68k/io-lseek.c  | 2 +-
 libgloss/nios2/io-lseek.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

-- 
2.8.1

Comments

Corinna Vinschen Feb. 6, 2020, 10:03 a.m. | #1
On Feb  4 21:34, Sandra Loosemore wrote:
> When off_t is 32 bits, the value needs to be sign-extended to 64 bits

> before shifting right to extract the high-order word.  Previously

> negative offsets were incorrectly encoded.

> 

> Signed-off-by: Sandra Loosemore <sandra@codesourcery.com>

> ---

>  libgloss/m68k/io-lseek.c  | 2 +-

>  libgloss/nios2/io-lseek.c | 2 +-

>  2 files changed, 2 insertions(+), 2 deletions(-)

> 

> diff --git a/libgloss/m68k/io-lseek.c b/libgloss/m68k/io-lseek.c

> index 63ec564..eaaf557 100644

> --- a/libgloss/m68k/io-lseek.c

> +++ b/libgloss/m68k/io-lseek.c

> @@ -38,7 +38,7 @@ off_t lseek (int fd, off_t offset, int whence)

>  #if HOSTED

>    gdb_parambuf_t parameters;

>    parameters[0] = (uint32_t) fd;

> -  parameters[1] = (uint32_t) ((offset >> 32) & 0xffffffff);

> +  parameters[1] = (uint32_t) ((int64_t)offset >> 32);

>    parameters[2] = (uint32_t) (offset & 0xffffffff);

>    parameters[3] = __hosted_to_gdb_lseek_flags (whence);

>    __hosted (HOSTED_LSEEK, parameters);

> diff --git a/libgloss/nios2/io-lseek.c b/libgloss/nios2/io-lseek.c

> index bfc23c1..d47fe07 100644

> --- a/libgloss/nios2/io-lseek.c

> +++ b/libgloss/nios2/io-lseek.c

> @@ -39,7 +39,7 @@ off_t lseek (int fd, off_t offset, int whence)

>  #if HOSTED

>    gdb_parambuf_t parameters;

>    parameters[0] = (uint32_t) fd;

> -  parameters[1] = (uint32_t) ((offset >> 32) & 0xffffffff);

> +  parameters[1] = (uint32_t) ((int64_t)offset >> 32);

>    parameters[2] = (uint32_t) (offset & 0xffffffff);

>    parameters[3] = __hosted_to_gdb_lseek_flags (whence);

>    __io_hosted (HOSTED_LSEEK, parameters);

> -- 

> 2.8.1


Pushed.


Thanks,
Corinna

-- 
Corinna Vinschen
Cygwin Maintainer
Red Hat

Patch

diff --git a/libgloss/m68k/io-lseek.c b/libgloss/m68k/io-lseek.c
index 63ec564..eaaf557 100644
--- a/libgloss/m68k/io-lseek.c
+++ b/libgloss/m68k/io-lseek.c
@@ -38,7 +38,7 @@  off_t lseek (int fd, off_t offset, int whence)
 #if HOSTED
   gdb_parambuf_t parameters;
   parameters[0] = (uint32_t) fd;
-  parameters[1] = (uint32_t) ((offset >> 32) & 0xffffffff);
+  parameters[1] = (uint32_t) ((int64_t)offset >> 32);
   parameters[2] = (uint32_t) (offset & 0xffffffff);
   parameters[3] = __hosted_to_gdb_lseek_flags (whence);
   __hosted (HOSTED_LSEEK, parameters);
diff --git a/libgloss/nios2/io-lseek.c b/libgloss/nios2/io-lseek.c
index bfc23c1..d47fe07 100644
--- a/libgloss/nios2/io-lseek.c
+++ b/libgloss/nios2/io-lseek.c
@@ -39,7 +39,7 @@  off_t lseek (int fd, off_t offset, int whence)
 #if HOSTED
   gdb_parambuf_t parameters;
   parameters[0] = (uint32_t) fd;
-  parameters[1] = (uint32_t) ((offset >> 32) & 0xffffffff);
+  parameters[1] = (uint32_t) ((int64_t)offset >> 32);
   parameters[2] = (uint32_t) (offset & 0xffffffff);
   parameters[3] = __hosted_to_gdb_lseek_flags (whence);
   __io_hosted (HOSTED_LSEEK, parameters);