Unbreaks the testcase from
http://lists.nongnu.org/archive/html/qemu-arm/2018-01/msg00514.html
Signed-off-by: Guido Günther <agx@sigxcpu.org>
---
linux-user/host/aarch64/safe-syscall.inc.S | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/linux-user/host/aarch64/safe-syscall.inc.S b/linux-user/host/aarch64/safe-syscall.inc.S
index 58a2329b37..e4fbc31454 100644
--- a/linux-user/host/aarch64/safe-syscall.inc.S
+++ b/linux-user/host/aarch64/safe-syscall.inc.S
@@ -36,7 +36,7 @@ safe_syscall_base:
* and return the result in x0
* and the syscall instruction needs
* x8 == syscall number
- * x0 ... x7 == syscall arguments
+ * x0 ... x5 == syscall arguments
* and returns the result in x0
* Shuffle everything around appropriately.
*/
@@ -47,7 +47,7 @@ safe_syscall_base:
mov x2, x4
mov x3, x5
mov x4, x6
- mov x6, x7
+ mov x5, x7
ldr x7, [sp]
/* This next sequence of code works in conjunction with the
--
2.15.1
CC: Richard has he wrote this code. Thanks, Laurent Le 24/01/2018 à 10:14, Guido Günther a écrit : > Unbreaks the testcase from > > http://lists.nongnu.org/archive/html/qemu-arm/2018-01/msg00514.html > > Signed-off-by: Guido Günther <agx@sigxcpu.org> > --- > linux-user/host/aarch64/safe-syscall.inc.S | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/linux-user/host/aarch64/safe-syscall.inc.S b/linux-user/host/aarch64/safe-syscall.inc.S > index 58a2329b37..e4fbc31454 100644 > --- a/linux-user/host/aarch64/safe-syscall.inc.S > +++ b/linux-user/host/aarch64/safe-syscall.inc.S > @@ -36,7 +36,7 @@ safe_syscall_base: > * and return the result in x0 > * and the syscall instruction needs > * x8 == syscall number > - * x0 ... x7 == syscall arguments > + * x0 ... x5 == syscall arguments > * and returns the result in x0 > * Shuffle everything around appropriately. > */ > @@ -47,7 +47,7 @@ safe_syscall_base: > mov x2, x4 > mov x3, x5 > mov x4, x6 > - mov x6, x7 > + mov x5, x7 > ldr x7, [sp] > > /* This next sequence of code works in conjunction with the >
Le 24/01/2018 à 10:14, Guido Günther a écrit : > Unbreaks the testcase from > > http://lists.nongnu.org/archive/html/qemu-arm/2018-01/msg00514.html > > Signed-off-by: Guido Günther <agx@sigxcpu.org> > --- > linux-user/host/aarch64/safe-syscall.inc.S | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/linux-user/host/aarch64/safe-syscall.inc.S b/linux-user/host/aarch64/safe-syscall.inc.S > index 58a2329b37..e4fbc31454 100644 > --- a/linux-user/host/aarch64/safe-syscall.inc.S > +++ b/linux-user/host/aarch64/safe-syscall.inc.S > @@ -36,7 +36,7 @@ safe_syscall_base: > * and return the result in x0 > * and the syscall instruction needs > * x8 == syscall number > - * x0 ... x7 == syscall arguments > + * x0 ... x5 == syscall arguments > * and returns the result in x0 > * Shuffle everything around appropriately. > */ > @@ -47,7 +47,7 @@ safe_syscall_base: > mov x2, x4 > mov x3, x5 > mov x4, x6 > - mov x6, x7 > + mov x5, x7 > ldr x7, [sp] > > /* This next sequence of code works in conjunction with the > According to glibc/unix/sysv/linux/aarch64/syscall.S: AArch64 system calls take between 0 and 7 arguments. ... and any other system call arguments are in register x1..x7. And it seems for qemu last argument is on the stack. ... x2 ... x7, (stack) == syscall arguments ... Should we have something like this? @@ -47,8 +47,8 @@ safe_syscall_base: mov x2, x4 mov x3, x5 mov x4, x6 - mov x6, x7 - ldr x7, [sp] + mov x5, x7 + ldr x6, [sp] /* This next sequence of code works in conjunction with the * rewind_if_safe_syscall_function(). If a signal is taken But do we need to set x7 from the stack too? Thanks, Laurent
Hi, On Wed, Jan 24, 2018 at 10:59:05AM +0100, Laurent Vivier wrote: > Le 24/01/2018 à 10:14, Guido Günther a écrit : > > Unbreaks the testcase from > > > > http://lists.nongnu.org/archive/html/qemu-arm/2018-01/msg00514.html > > > > Signed-off-by: Guido Günther <agx@sigxcpu.org> > > --- > > linux-user/host/aarch64/safe-syscall.inc.S | 4 ++-- > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/linux-user/host/aarch64/safe-syscall.inc.S b/linux-user/host/aarch64/safe-syscall.inc.S > > index 58a2329b37..e4fbc31454 100644 > > --- a/linux-user/host/aarch64/safe-syscall.inc.S > > +++ b/linux-user/host/aarch64/safe-syscall.inc.S > > @@ -36,7 +36,7 @@ safe_syscall_base: > > * and return the result in x0 > > * and the syscall instruction needs > > * x8 == syscall number > > - * x0 ... x7 == syscall arguments > > + * x0 ... x5 == syscall arguments > > * and returns the result in x0 > > * Shuffle everything around appropriately. > > */ > > @@ -47,7 +47,7 @@ safe_syscall_base: > > mov x2, x4 > > mov x3, x5 > > mov x4, x6 > > - mov x6, x7 > > + mov x5, x7 > > ldr x7, [sp] > > > > /* This next sequence of code works in conjunction with the > > > > According to glibc/unix/sysv/linux/aarch64/syscall.S: > > AArch64 system calls take between 0 and 7 arguments. > ... and any other system call arguments are in register x1..x7. > > And it seems for qemu last argument is on the stack. > ... > x2 ... x7, (stack) == syscall arguments > ... > > Should we have something like this? > > @@ -47,8 +47,8 @@ safe_syscall_base: > mov x2, x4 > mov x3, x5 > mov x4, x6 > - mov x6, x7 > - ldr x7, [sp] > + mov x5, x7 > + ldr x6, [sp] > > /* This next sequence of code works in conjunction with the > * rewind_if_safe_syscall_function(). If a signal is taken > > But do we need to set x7 from the stack too? That makes sense. The maximum number of arguments in linux-user/syscall.c is syscall6 so we won't notice but it's better to have this correct, I'll send an updated patch. Cheers -- Guido
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