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authorWill Deacon <will.deacon@arm.com>2019-01-03 18:00:39 +0000
committerWill Deacon <will.deacon@arm.com>2019-01-04 14:18:01 +0000
commit53290432145a8eb143fe29e06e9c1465d43dc723 (patch)
tree1312ac6856bc9d350194a75b1e6a4f219f8c98b0 /arch
parent169113ece0f29ebe884a6cfcf57c1ace04d8a36a (diff)
downloadlinux-53290432145a8eb143fe29e06e9c1465d43dc723.tar.gz
arm64: compat: Don't pull syscall number from regs in arm_compat_syscall
The syscall number may have been changed by a tracer, so we should pass the actual number in from the caller instead of pulling it from the saved r7 value directly. Cc: <stable@vger.kernel.org> Cc: Pi-Hsun Shih <pihsun@chromium.org> Reviewed-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm64/kernel/sys_compat.c9
-rw-r--r--arch/arm64/kernel/syscall.c9
2 files changed, 8 insertions, 10 deletions
diff --git a/arch/arm64/kernel/sys_compat.c b/arch/arm64/kernel/sys_compat.c
index a79db4e485a6..bc348ab3dd6b 100644
--- a/arch/arm64/kernel/sys_compat.c
+++ b/arch/arm64/kernel/sys_compat.c
@@ -66,12 +66,11 @@ do_compat_cache_op(unsigned long start, unsigned long end, int flags)
/*
* Handle all unrecognised system calls.
*/
-long compat_arm_syscall(struct pt_regs *regs)
+long compat_arm_syscall(struct pt_regs *regs, int scno)
{
- unsigned int no = regs->regs[7];
void __user *addr;
- switch (no) {
+ switch (scno) {
/*
* Flush a region from virtual address 'r0' to virtual address 'r1'
* _exclusive_. There is no alignment requirement on either address;
@@ -107,7 +106,7 @@ long compat_arm_syscall(struct pt_regs *regs)
* way the calling program can gracefully determine whether
* a feature is supported.
*/
- if (no < __ARM_NR_COMPAT_END)
+ if (scno < __ARM_NR_COMPAT_END)
return -ENOSYS;
break;
}
@@ -116,6 +115,6 @@ long compat_arm_syscall(struct pt_regs *regs)
(compat_thumb_mode(regs) ? 2 : 4);
arm64_notify_die("Oops - bad compat syscall(2)", regs,
- SIGILL, ILL_ILLTRP, addr, no);
+ SIGILL, ILL_ILLTRP, addr, scno);
return 0;
}
diff --git a/arch/arm64/kernel/syscall.c b/arch/arm64/kernel/syscall.c
index 032d22312881..5610ac01c1ec 100644
--- a/arch/arm64/kernel/syscall.c
+++ b/arch/arm64/kernel/syscall.c
@@ -13,16 +13,15 @@
#include <asm/thread_info.h>
#include <asm/unistd.h>
-long compat_arm_syscall(struct pt_regs *regs);
-
+long compat_arm_syscall(struct pt_regs *regs, int scno);
long sys_ni_syscall(void);
-asmlinkage long do_ni_syscall(struct pt_regs *regs)
+static long do_ni_syscall(struct pt_regs *regs, int scno)
{
#ifdef CONFIG_COMPAT
long ret;
if (is_compat_task()) {
- ret = compat_arm_syscall(regs);
+ ret = compat_arm_syscall(regs, scno);
if (ret != -ENOSYS)
return ret;
}
@@ -47,7 +46,7 @@ static void invoke_syscall(struct pt_regs *regs, unsigned int scno,
syscall_fn = syscall_table[array_index_nospec(scno, sc_nr)];
ret = __invoke_syscall(regs, syscall_fn);
} else {
- ret = do_ni_syscall(regs);
+ ret = do_ni_syscall(regs, scno);
}
regs->regs[0] = ret;