diff mbox series

[2/3] arm64: compat: Don't pull syscall number from regs in arm_compat_syscall

Message ID 1546539240-20647-3-git-send-email-will.deacon@arm.com (mailing list archive)
State New, archived
Headers show
Series Fix private compat syscall emulation | expand

Commit Message

Will Deacon Jan. 3, 2019, 6:13 p.m. UTC 
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(-)

Comments

Sasha Levin Jan. 4, 2019, 4:50 a.m. UTC | #1 
Hi,

[This is an automated email]

This commit has been processed because it contains a -stable tag.
The stable tag indicates that it's relevant for the following trees: all

The bot has tested the following trees: v4.20.0, v4.19.13, v4.14.91, v4.9.148, v4.4.169, v3.18.131, 

v4.20.0: Failed to apply! Possible dependencies:
    caf41328c3a5 ("arm64: compat: Avoid sending SIGILL for unallocated syscall numbers")

v4.19.13: Failed to apply! Possible dependencies:
    6fa998e83ef9 ("signal/arm64: Push siginfo generation into arm64_notify_die")
    caf41328c3a5 ("arm64: compat: Avoid sending SIGILL for unallocated syscall numbers")

v4.14.91: Failed to apply! Possible dependencies:
    1fc5dce78ad1 ("arm64/sve: Low-level SVE architectural state manipulation functions")
    2923f5ea7738 ("nds32: Exception handling")
    2c9120f3a86a ("arm64: signal: Make force_signal_inject more robust")
    3eb0f5193b49 ("signal: Ensure every siginfo we send has all bits initialized")
    3f7c86b2382e ("arm64: Update fault_info table with new exception types")
    42dbf54e8890 ("arm64: consistently log ESR and page table")
    4fb158f65ac5 ("powerpc: track allocation status of all pkeys")
    526c3ddb6aa2 ("signal/arm64: Document conflicts with SI_USER and SIGFPE,SIGTRAP,SIGBUS")
    532826f3712b ("arm64: Mirror arm for unimplemented compat syscalls")
    664eec400bf8 ("nds32: MMU fault handling and page table management")
    6fa998e83ef9 ("signal/arm64: Push siginfo generation into arm64_notify_die")
    76d2a0493a17 ("RISC-V: Init and Halt Code")
    92e3da3cf193 ("powerpc: initial pkey plumbing")
    92ff0674f5d8 ("arm64: mm: Rework unhandled user pagefaults to call arm64_force_sig_info")
    94ef7ecbdf6f ("arm64: fpsimd: Correctly annotate exception helpers called from asm")
    af40ff687bc9 ("arm64: signal: Ensure si_code is valid for all fault signals")
    bc0ee4760364 ("arm64/sve: Core task context handling")
    c5cc1f4df6b1 ("powerpc/ptrace: Add memory protection key regset")

v4.9.148: Failed to apply! Possible dependencies:
    0e3a9026396c ("arm64: mm: Update perf accounting to handle poison faults")
    32015c235603 ("arm64: exception: handle Synchronous External Abort")
    3eb0f5193b49 ("signal: Ensure every siginfo we send has all bits initialized")
    3f7c86b2382e ("arm64: Update fault_info table with new exception types")
    4e2648db9c5f ("ARM: remove indirection of asm/mach-types.h")
    526c3ddb6aa2 ("signal/arm64: Document conflicts with SI_USER and SIGFPE,SIGTRAP,SIGBUS")
    532826f3712b ("arm64: Mirror arm for unimplemented compat syscalls")
    5b53696a30d5 ("ACPI / APEI: Switch to use new generic UUID API")
    67ce16ec15ce ("arm64: mm: print out correct page table entries")
    6bc51cbaa9d7 ("signal: Remove non-uapi <asm/siginfo.h>")
    6fa998e83ef9 ("signal/arm64: Push siginfo generation into arm64_notify_die")
    7edda0886bc3 ("acpi: apei: handle SEA notification type for ARMv8")
    80dce5e37493 ("signal/ia64: Document a conflict with SI_USER with SIGFPE")
    83016b204225 ("arm64: mm: print file name of faulting vma")
    92ff0674f5d8 ("arm64: mm: Rework unhandled user pagefaults to call arm64_force_sig_info")
    96a8fae0fe09 ("ARM: convert to generated system call tables")
    a8ada146f517 ("arm64: Update the synchronous external abort fault description")
    af40ff687bc9 ("arm64: signal: Ensure si_code is valid for all fault signals")
    b9253a43370e ("signal: Move copy_siginfo_to_user to <linux/signal.h>")
    bbcc2e7b642e ("ras: acpi/apei: cper: add support for generic data v3 structure")
    c07ab957d9af ("arm64: Call __show_regs directly")
    cc731525f26a ("signal: Remove kernel interal si_code magic")
    cc9f72e474a4 ("signal/sparc: Document a conflict with SI_USER with SIGFPE")
    e2bd64d92a10 ("signal/alpha: Document a conflict with SI_USER for SIGTRAP")
    e7c600f149b8 ("arm64: hwpoison: add VM_FAULT_HWPOISON[_LARGE] handling")
    ea1b75cf9138 ("signal/mips: Document a conflict with SI_USER with SIGFPE")

v4.4.169: Failed to apply! Possible dependencies:
    09a6adf53d42 ("arm64: mm: unaligned access by user-land should be received as SIGBUS")
    0a8ea52c3eb1 ("arm64: Add HAVE_REGS_AND_STACK_ACCESS_API feature")
    0e3a9026396c ("arm64: mm: Update perf accounting to handle poison faults")
    2dd0e8d2d2a1 ("arm64: Kprobes with single stepping support")
    3eb0f5193b49 ("signal: Ensure every siginfo we send has all bits initialized")
    3eca86e75ec7 ("arm64: Remove fixmap include fragility")
    532826f3712b ("arm64: Mirror arm for unimplemented compat syscalls")
    67ce16ec15ce ("arm64: mm: print out correct page table entries")
    6fa998e83ef9 ("signal/arm64: Push siginfo generation into arm64_notify_die")
    83016b204225 ("arm64: mm: print file name of faulting vma")
    92ff0674f5d8 ("arm64: mm: Rework unhandled user pagefaults to call arm64_force_sig_info")
    bbb1681ee365 ("arm64: mm: mark fault_info table const")
    c07ab957d9af ("arm64: Call __show_regs directly")
    cab15ce604e5 ("arm64: Introduce execute-only page access permissions")
    d59bee887231 ("arm64: Add more test functions to insn.c")
    e04a28d45ff3 ("arm64: debug: re-enable irqs before sending breakpoint SIGTRAP")
    e7c600f149b8 ("arm64: hwpoison: add VM_FAULT_HWPOISON[_LARGE] handling")

v3.18.131: Failed to apply! Possible dependencies:
    04597a65c5ef ("arm64: Track system support for mixed endian EL0")
    1b907f46db07 ("arm64: kconfig: move emulation option under kernel features")
    2d888f48e056 ("arm64: Emulate SETEND for AArch32 tasks")
    338d4f49d6f7 ("arm64: kernel: Add support for Privileged Access Never")
    359b706473b4 ("arm64: Extract feature parsing code from cpu_errata.c")
    3eb0f5193b49 ("signal: Ensure every siginfo we send has all bits initialized")
    532826f3712b ("arm64: Mirror arm for unimplemented compat syscalls")
    587064b610c7 ("arm64: Add framework for legacy instruction emulation")
    6fa998e83ef9 ("signal/arm64: Push siginfo generation into arm64_notify_die")
    7209c868600b ("arm64: mm: Set PSTATE.PAN from the cpu_enable_pan() call")
    736d474f0faf ("arm64: Consolidate hotplug notifier for instruction emulation")
    870828e57b14 ("arm64: kernel: Move config_sctlr_el1")
    92ff0674f5d8 ("arm64: mm: Rework unhandled user pagefaults to call arm64_force_sig_info")
    94a9e04aa16a ("arm64: alternative: Introduce feature for GICv3 CPU interface")
    9b79f52d1a70 ("arm64: Add support for hooks to handle undefined instructions")
    a4980448ed65 ("arm: Remove signal translation and exec_domain")
    bd35a4adc413 ("arm64: Port SWP/SWPB emulation support from arm")
    c852f3205846 ("arm64: Emulate CP15 Barrier instructions")
    c9453a3ab1a3 ("arm64: alternatives: fix pr_fmt string for consistency")
    e7c600f149b8 ("arm64: hwpoison: add VM_FAULT_HWPOISON[_LARGE] handling")


How should we proceed with this patch?

--
Thanks,
Sasha
Dave Martin Jan. 4, 2019, 12:37 p.m. UTC | #2 
On Thu, Jan 03, 2019 at 06:13:59PM +0000, Will Deacon wrote:
> 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.

Reviewed-by: Dave Martin <Dave.Martin@arm.com>

I was confused by the history here: commit 4141c857fd09 ("arm64: convert
raw syscall invocation to C") breaks syscall changing via
discarding the return from syscall_trace_enter() (which would also break
this case for compat), but the subsequent patch that migrates the
syscall code to C appears to fix it again.

> 
> 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
> 
> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
diff mbox series

Patch

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;