diff options
authorAl Viro <viro@ZenIV.linux.org.uk>2012-12-09 06:16:14 +0000
committerHelge Deller <deller@gmx.de>2013-02-20 22:51:11 +0100
commit52ab532ea76d30b7e7a7b98021e2e873e83029a5 (patch)
parent872420b3b869d47b1f1dd93418c34e306d962668 (diff)
parisc: fix ptrace breakage
1) PTRACE_SYSCALL doesn't work for 64bit process on parisc64. Compat syscall table is used instead of 64bit one. IMO we should either refuse to allow PTRACE_SYSCALL for 64bit processes or duplicate the logics choosing the right syscall table into .Ltracesys. 2) if you have let the tracee run with PTRACE_SYSCALL and it had stopped, you can use PTRACE_POKEUSR to modify syscall number (r20) and arguments 1--4 (r26--r23). Modifications will have effect. However, modifying arguments 5 and 6 (r22 and r21 resp.) works only when process (32bit one) runs on 64bit host - on 32bit one it has no effect. AFAICS, the diff below should fix that one. Signed-off-by: Al Viro <viro@ZenIV.linux.org.uk> Tested-by: John David Anglin <dave.anglin@bell.net> Signed-off-by: Helge Deller <deller@gmx.de>
1 files changed, 4 insertions, 1 deletions
diff --git a/arch/parisc/kernel/syscall.S b/arch/parisc/kernel/syscall.S
index 86742df0b19..5e055240f00 100644
--- a/arch/parisc/kernel/syscall.S
+++ b/arch/parisc/kernel/syscall.S
@@ -309,10 +309,13 @@ tracesys_next:
LDREG TASK_PT_GR25(%r1), %r25
LDREG TASK_PT_GR24(%r1), %r24
LDREG TASK_PT_GR23(%r1), %r23
-#ifdef CONFIG_64BIT
LDREG TASK_PT_GR22(%r1), %r22
LDREG TASK_PT_GR21(%r1), %r21
+#ifdef CONFIG_64BIT
ldo -16(%r30),%r29 /* Reference param save area */
+ stw %r22, -52(%r30) /* 5th argument */
+ stw %r21, -56(%r30) /* 6th argument */
comiclr,>>= __NR_Linux_syscalls, %r20, %r0