From: Will Deacon <will.deacon@arm.com>
To: linux-arm-kernel@lists.infradead.org
Cc: Dave.Martin@arm.com, pihsun@chromium.org,
Will Deacon <will.deacon@arm.com>, <stable@vger.kernel.org>
Subject: [PATCH 2/3] arm64: compat: Don't pull syscall number from regs in arm_compat_syscall
Date: Thu, 3 Jan 2019 18:13:59 +0000 [thread overview]
Message-ID: <1546539240-20647-3-git-send-email-will.deacon@arm.com> (raw)
In-Reply-To: <1546539240-20647-1-git-send-email-will.deacon@arm.com>
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: Dave Martin <Dave.Martin@arm.com>
Cc: Pi-Hsun Shih <pihsun@chromium.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
---
arch/arm64/kernel/sys_compat.c | 9 ++++-----
arch/arm64/kernel/syscall.c | 9 ++++-----
2 files changed, 8 insertions(+), 10 deletions(-)
diff --git a/arch/arm64/kernel/sys_compat.c b/arch/arm64/kernel/sys_compat.c
index 5972b7533fa0..54c29cd38ff9 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_syscall_end)
+ if (scno < __ARM_NR_compat_syscall_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;
--
2.1.4
next prev parent reply other threads:[~2019-01-03 18:14 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1546539240-20647-1-git-send-email-will.deacon@arm.com>
2019-01-03 18:13 ` [PATCH 1/3] arm64: compat: Avoid sending SIGILL for unallocated syscall numbers Will Deacon
2019-01-04 12:54 ` Dave Martin
2019-01-04 13:47 ` Will Deacon
2019-01-04 14:15 ` Dave Martin
2019-01-03 18:13 ` Will Deacon [this message]
2019-01-04 12:37 ` [PATCH 2/3] arm64: compat: Don't pull syscall number from regs in arm_compat_syscall Dave Martin
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