| Message ID | 1470938379-1133-1-git-send-email-peter.maydell@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
It works perfectly. Thanks. Tested-by: Chanho Park <parkch98@gmail.com> On Fri, Aug 12, 2016 at 2:59 AM, Peter Maydell <peter.maydell@linaro.org> wrote: > The llseek syscall takes two 32-bit arguments, offset_high > and offset_low, which must be combined to form a single > 64-bit offset. Unfortunately we were combining them with > (uint64_t)arg2 << 32) | arg3 > and arg3 is a signed type; this meant that when promoting > arg3 to a 64-bit type it would be sign-extended. The effect > was that if the offset happened to have bit 31 set then > this bit would get sign-extended into all of bits 63..32. > Explicitly cast arg3 to abi_ulong to avoid the erroneous > sign extension. > > Reported-by: Chanho Park <parkch98@gmail.com> > Signed-off-by: Peter Maydell <peter.maydell@linaro.org> > --- > Long-standing bug and we're quite close to 2.7 but the > fix is trivial so if somebody would like to review it > I think we could put it in... > > linux-user/syscall.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/linux-user/syscall.c b/linux-user/syscall.c > index ebdb753..b4e21d3 100644 > --- a/linux-user/syscall.c > +++ b/linux-user/syscall.c > @@ -9406,7 +9406,7 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1, > { > int64_t res; > #if !defined(__NR_llseek) > - res = lseek(arg1, ((uint64_t)arg2 << 32) | arg3, arg5); > + res = lseek(arg1, ((uint64_t)arg2 << 32) | (abi_ulong)arg3, arg5); > if (res == -1) { > ret = get_errno(res); > } else { > -- > 2.7.4 >
Hi, applied to linux-user-for upstream. Riku On Mon, Aug 15, 2016 at 10:41:35PM +0900, Chanho Park wrote: > It works perfectly. > Thanks. > > Tested-by: Chanho Park <parkch98@gmail.com> > > On Fri, Aug 12, 2016 at 2:59 AM, Peter Maydell <peter.maydell@linaro.org> wrote: > > The llseek syscall takes two 32-bit arguments, offset_high > > and offset_low, which must be combined to form a single > > 64-bit offset. Unfortunately we were combining them with > > (uint64_t)arg2 << 32) | arg3 > > and arg3 is a signed type; this meant that when promoting > > arg3 to a 64-bit type it would be sign-extended. The effect > > was that if the offset happened to have bit 31 set then > > this bit would get sign-extended into all of bits 63..32. > > Explicitly cast arg3 to abi_ulong to avoid the erroneous > > sign extension. > > > > Reported-by: Chanho Park <parkch98@gmail.com> > > Signed-off-by: Peter Maydell <peter.maydell@linaro.org> > > --- > > Long-standing bug and we're quite close to 2.7 but the > > fix is trivial so if somebody would like to review it > > I think we could put it in... > > > > linux-user/syscall.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/linux-user/syscall.c b/linux-user/syscall.c > > index ebdb753..b4e21d3 100644 > > --- a/linux-user/syscall.c > > +++ b/linux-user/syscall.c > > @@ -9406,7 +9406,7 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1, > > { > > int64_t res; > > #if !defined(__NR_llseek) > > - res = lseek(arg1, ((uint64_t)arg2 << 32) | arg3, arg5); > > + res = lseek(arg1, ((uint64_t)arg2 << 32) | (abi_ulong)arg3, arg5); > > if (res == -1) { > > ret = get_errno(res); > > } else { > > -- > > 2.7.4 > > > > > > -- > Best Regards, > Chanho Park
On 16 August 2016 at 14:44, Riku Voipio <riku.voipio@iki.fi> wrote: > Hi, > > applied to linux-user-for upstream. Applied to master, thanks. -- PMM
diff --git a/linux-user/syscall.c b/linux-user/syscall.c index ebdb753..b4e21d3 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -9406,7 +9406,7 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1, { int64_t res; #if !defined(__NR_llseek) - res = lseek(arg1, ((uint64_t)arg2 << 32) | arg3, arg5); + res = lseek(arg1, ((uint64_t)arg2 << 32) | (abi_ulong)arg3, arg5); if (res == -1) { ret = get_errno(res); } else {
The llseek syscall takes two 32-bit arguments, offset_high and offset_low, which must be combined to form a single 64-bit offset. Unfortunately we were combining them with (uint64_t)arg2 << 32) | arg3 and arg3 is a signed type; this meant that when promoting arg3 to a 64-bit type it would be sign-extended. The effect was that if the offset happened to have bit 31 set then this bit would get sign-extended into all of bits 63..32. Explicitly cast arg3 to abi_ulong to avoid the erroneous sign extension. Reported-by: Chanho Park <parkch98@gmail.com> Signed-off-by: Peter Maydell <peter.maydell@linaro.org> --- Long-standing bug and we're quite close to 2.7 but the fix is trivial so if somebody would like to review it I think we could put it in... linux-user/syscall.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)