From: Yury Norov <ynorov@caviumnetworks.com>
To: "Zhangjian (Bamvor)" <bamvor.zhangjian@huawei.com>
Cc: <arnd@arndb.de>, <catalin.marinas@arm.com>,
<linux-arm-kernel@lists.infradead.org>,
<linux-kernel@vger.kernel.org>, <linux-doc@vger.kernel.org>,
<linux-arch@vger.kernel.org>, <linux-s390@vger.kernel.org>,
<libc-alpha@sourceware.org>, <schwidefsky@de.ibm.com>,
<heiko.carstens@de.ibm.com>, <pinskia@gmail.com>,
<broonie@kernel.org>, <joseph@codesourcery.com>,
<christoph.muellner@theobroma-systems.com>,
<szabolcs.nagy@arm.com>, <klimov.linux@gmail.com>,
<Nathan_Lynch@mentor.com>, <agraf@suse.de>,
<Prasun.Kapoor@caviumnetworks.com>, <kilobyte@angband.pl>,
<geert@linux-m68k.org>, <philipp.tomsich@theobroma-systems.com>,
Andrew Pinski <apinski@cavium.com>,
Andrew Pinski <Andrew.Pinski@caviumnetworks.com>,
Hanjun Guo <guohanjun@huawei.com>
Subject: Re: [PATCH 21/23] arm64: ilp32: introduce ilp32-specific handlers for sigframe and ucontext
Date: Sun, 12 Jun 2016 20:44:30 +0300 [thread overview]
Message-ID: <20160612174430.GA12067@yury-N73SV> (raw)
In-Reply-To: <5752BCC8.7080205@huawei.com>
Hi Bamvor,
Sorry, I missed this patch.
On Sat, Jun 04, 2016 at 07:34:32PM +0800, Zhangjian (Bamvor) wrote:
> Hi,
>
> I found an issue of unwind with the following code. The correct backtrace
> should be:
> (gdb) where
> #0 0x004004d0 in my_sig (sig=11) at test_force3.c:16
> #1 <signal handler called>
> #2 func2 (num=0) at test_force3.c:22
> #3 0x00400540 in func1 (num=1) at test_force3.c:28
> #4 0x00400574 in main (argc=1, argv=0xffd7bc04) at test_force3.c:33
>
> Without my patch, the backtrace is:
> (gdb) where
> #0 0x00400490 in my_sig (sig=11) at test_force3.c:16
> #1 <signal handler called>
> #2 0x004004e4 in main (argc=1, argv=0xffe6f8f4) at test_force3.c:33
>
> With my patch which fix the wrong frame pointer(setup_return calculate the offset
> of fp through ilp32_sigframe instead of sigfreame), the backtrace is:
> (gdb) where
> #0 0x00400490 in my_sig (sig=11) at test_force3.c:16
> #1 <signal handler called>
> #2 func1 () at test_force3.c:28
> #3 0x004004e4 in main (argc=1, argv=0xffe6f8f4) at test_force3.c:33
>
> I am not sure there is still some issue in kernel. But it seem that the gdb of ilp32
> does not work correctly when unwind without framepointer.
>
> The test code is:
>
> From 7e364a765097f57aed2d73f94c1688c2e7343e79 Mon Sep 17 00:00:00 2001
> From: Bamvor Jian Zhang <bamvor.zhangjian@huawei.com>
> Date: Sat, 4 Jun 2016 14:30:05 +0800
> Subject: [PATCH] arm64: ilp32: fix for wrong fp offset when calculate the
> new fp
>
> ILP32 define its own sigframe(ilp32_sigframe) because of the
> difference uc_context. setup_return do not use ilp32 specific
> sigframe to calculate the new offset of fp which lead to wrong
> fp in signal handler. At this circumstance, gdb backtrace will miss
> one item:
> (gdb) where
>
> It should be:
> (gdb) where
>
> The test code is as follows:
>
> void my_sig(int sig)
> {
> printf("sig=%d\n", sig);
> *(int *)0 = 0x0;
> }
>
> void func2(int num)
> {
> printf("%s: %d\n", __FUNCTION__, num);
> *(int *)0 = 0x0;
> func2(num-1);
> }
>
> void func1(int num)
> {
> printf("%s\n", __FUNCTION__);
> func2(num - 1);
> }
>
> int main(int argc, char **argv)
> {
> signal(11, my_sig);
> func1(argc);
> return 0;
> }
>
> This patch fix this by passing the correct offset of fp to
> setup_return.
> Test pass on both ILP32 and LP64 in aarch64 EE.
>
> Signed-off-by: Bamvor Jian Zhang <bamvor.zhangjian@huawei.com>
> ---
> arch/arm64/include/asm/signal_common.h | 3 ++-
> arch/arm64/kernel/signal.c | 9 +++++----
> arch/arm64/kernel/signal_ilp32.c | 4 ++--
> 3 files changed, 9 insertions(+), 7 deletions(-)
>
> diff --git a/arch/arm64/include/asm/signal_common.h b/arch/arm64/include/asm/signal_common.h
> index de93c71..a5d7b63 100644
> --- a/arch/arm64/include/asm/signal_common.h
> +++ b/arch/arm64/include/asm/signal_common.h
> @@ -29,6 +29,7 @@ int setup_sigcontex(struct sigcontext __user *uc_mcontext,
> struct pt_regs *regs);
> int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sf);
> void setup_return(struct pt_regs *regs, struct k_sigaction *ka,
> - void __user *frame, off_t sigframe_off, int usig);
> + void __user *frame, off_t sigframe_off, off_t fp_off,
> + int usig);
>
> #endif /* __ASM_SIGNAL_COMMON_H */
> diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c
> index 038bebe..e66a6e9 100644
> --- a/arch/arm64/kernel/signal.c
> +++ b/arch/arm64/kernel/signal.c
> @@ -256,14 +256,14 @@ static struct rt_sigframe __user *get_sigframe(struct ksignal *ksig,
> }
>
> void setup_return(struct pt_regs *regs, struct k_sigaction *ka,
> - void __user *frame, off_t sigframe_off, int usig)
> + void __user *frame, off_t sigframe_off, off_t fp_off,
> + int usig)
> {
> __sigrestore_t sigtramp;
>
> regs->regs[0] = usig;
> regs->sp = (unsigned long)frame;
> - regs->regs[29] = regs->sp + sigframe_off +
> - offsetof(struct sigframe, fp);
> + regs->regs[29] = regs->sp + sigframe_off + fp_off;
I think you are right here. The only nitpick is what for we send 2
offsets just to add one to another inside setup_return()?
We can do like this:
void setup_return(struct pt_regs *regs, struct k_sigaction *ka,
void __user *frame, off_t fp_off, int usig)
{
__sigrestore_t sigtramp;
regs->regs[0] = usig;
regs->sp = (unsigned long)frame;
regs->regs[29] = regs->sp + fp_off;
[...]
}
Where fp_off calculation is done by caller.
setup_return(regs, &ksig->ka, frame,
offsetof(struct rt_sigframe, sig) + offsetof(struct sigframe, fp),
usig);
For me it's more clear to understand what happens with this approach.
I don't think struct rt_sigframe will grow, but we can even introduce
some helper for it:
#define RT_SIGFRAME_FP_POS (offsetof(struct rt_sigframe, sig) + offsetof(struct sigframe, fp))
If no objections, I'll apply your patch with my fix in next series.
> regs->pc = (unsigned long)ka->sa.sa_handler;
>
> if (ka->sa.sa_flags & SA_RESTORER)
> @@ -294,7 +294,8 @@ static int setup_rt_frame(int usig, struct ksignal *ksig, sigset_t *set,
> err |= setup_sigframe(&frame->sig, regs, set);
> if (err == 0) {
> setup_return(regs, &ksig->ka, frame,
> - offsetof(struct rt_sigframe, sig), usig);
> + offsetof(struct rt_sigframe, sig),
> + offsetof(struct sigframe, fp), usig);
> if (ksig->ka.sa.sa_flags & SA_SIGINFO) {
> err |= copy_siginfo_to_user(&frame->info, &ksig->info);
> regs->regs[1] = (unsigned long)&frame->info;
> diff --git a/arch/arm64/kernel/signal_ilp32.c b/arch/arm64/kernel/signal_ilp32.c
> index a8ea73e..9030f14 100644
> --- a/arch/arm64/kernel/signal_ilp32.c
> +++ b/arch/arm64/kernel/signal_ilp32.c
> @@ -147,7 +147,6 @@ static struct ilp32_rt_sigframe __user *ilp32_get_sigframe(struct ksignal *ksig,
> struct ilp32_rt_sigframe __user *frame;
>
> sp = sp_top = sigsp(regs->sp, ksig);
> -
> sp = (sp - sizeof(struct ilp32_rt_sigframe)) & ~15;
> frame = (struct ilp32_rt_sigframe __user *)sp;
>
> @@ -183,7 +182,8 @@ int ilp32_setup_rt_frame(int usig, struct ksignal *ksig,
> err |= setup_ilp32_sigframe(&frame->sig, regs, set);
> if (err == 0) {
> setup_return(regs, &ksig->ka, frame,
> - offsetof(struct ilp32_rt_sigframe, sig), usig);
> + offsetof(struct ilp32_rt_sigframe, sig),
> + offsetof(struct ilp32_sigframe, fp), usig);
> regs->regs[1] = (unsigned long)&frame->info;
> regs->regs[2] = (unsigned long)&frame->sig.uc;
> }
> --
> 1.8.4.5
>
> Regards
>
> Bamvor
>
>
next prev parent reply other threads:[~2016-06-12 17:44 UTC|newest]
Thread overview: 73+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-24 0:04 [PATCH v6 00/21] ILP32 for ARM64 Yury Norov
2016-05-24 0:04 ` [PATCH 01/23] all: syscall wrappers: add documentation Yury Norov
2016-05-25 19:30 ` David Miller
2016-05-25 20:03 ` Yury Norov
2016-05-25 20:21 ` David Miller
2016-05-25 20:47 ` Arnd Bergmann
2016-05-25 20:50 ` David Miller
2016-05-25 21:01 ` Arnd Bergmann
2016-05-25 21:28 ` David Miller
2016-05-26 14:20 ` Catalin Marinas
2016-05-26 14:50 ` Szabolcs Nagy
2016-05-26 15:19 ` Catalin Marinas
2016-05-26 19:43 ` David Miller
2016-05-27 10:10 ` Catalin Marinas
2016-05-26 20:48 ` Yury Norov
2016-05-26 22:29 ` Catalin Marinas
2016-05-27 0:37 ` Yury Norov
2016-05-27 6:03 ` Heiko Carstens
2016-05-27 8:42 ` Arnd Bergmann
2016-05-27 9:30 ` Catalin Marinas
2016-05-27 10:49 ` Arnd Bergmann
2016-05-27 13:04 ` Catalin Marinas
2016-05-27 16:58 ` Yury Norov
2016-05-27 17:36 ` Catalin Marinas
2016-05-27 9:01 ` Catalin Marinas
2016-06-14 23:08 ` Yury Norov
2016-05-27 5:52 ` Heiko Carstens
2016-05-24 0:04 ` [PATCH 02/23] all: introduce COMPAT_WRAPPER option and enable it for s390 Yury Norov
2016-05-24 0:04 ` [PATCH 03/23] all: s390: move wrapper infrastructure to generic headers Yury Norov
2016-05-24 0:04 ` [PATCH 04/23] all: s390: move compat_wrappers.c from arch/s390/kernel to kernel/ Yury Norov
2016-05-24 0:04 ` [PATCH 05/23] all: wrap needed syscalls in generic unistd Yury Norov
2016-05-24 0:04 ` [PATCH 06/23] compat ABI: use non-compat openat and open_by_handle_at variants Yury Norov
2016-05-24 0:04 ` [PATCH 07/23] 32-bit ABI: introduce ARCH_32BIT_OFF_T config option Yury Norov
2016-05-24 0:04 ` [PATCH 08/23] arm64: ilp32: add documentation on the ILP32 ABI for ARM64 Yury Norov
2016-05-24 0:04 ` [PATCH 09/23] arm64: ensure the kernel is compiled for LP64 Yury Norov
2016-05-24 0:04 ` [PATCH 10/23] arm64: rename COMPAT to AARCH32_EL0 in Kconfig Yury Norov
2016-05-24 0:04 ` [PATCH 11/23] arm64:uapi: set __BITS_PER_LONG correctly for ILP32 and LP64 Yury Norov
2016-05-24 0:04 ` [PATCH 12/23] thread: move thread bits accessors to separated file Yury Norov
2016-05-24 0:04 ` [PATCH 13/23] arm64: introduce is_a32_task and is_a32_thread (for AArch32 compat) Yury Norov
2016-06-12 12:21 ` Zhangjian (Bamvor)
2016-06-12 13:08 ` Zhangjian (Bamvor)
2016-06-12 17:56 ` Yury Norov
2016-05-24 0:04 ` [PATCH 14/23] arm64: ilp32: add is_ilp32_compat_{task,thread} and TIF_32BIT_AARCH64 Yury Norov
2016-05-24 0:04 ` [PATCH 15/23] arm64: introduce binfmt_elf32.c Yury Norov
2016-05-24 0:04 ` [PATCH 16/23] arm64: ilp32: introduce binfmt_ilp32.c Yury Norov
2016-05-26 13:49 ` Zhangjian (Bamvor)
2016-05-26 21:08 ` Yury Norov
2016-06-15 0:40 ` Yury Norov
2016-06-13 3:05 ` Zhangjian (Bamvor)
2016-06-13 13:22 ` Zhangjian (Bamvor)
2016-05-24 0:04 ` [PATCH 17/23] arm64: ptrace: handle ptrace_request differently for aarch32 and ilp32 Yury Norov
2016-06-08 1:34 ` zhouchengming
2016-06-08 17:00 ` Yury Norov
2016-06-25 9:36 ` zhouchengming
2016-06-25 14:15 ` Bamvor Zhang
2016-06-27 2:09 ` zhouchengming
2016-05-24 0:04 ` [PATCH 18/23] arm64: ilp32: add sys_ilp32.c and a separate table (in entry.S) to use it Yury Norov
2016-05-25 20:26 ` Arnd Bergmann
2016-05-24 0:04 ` [PATCH 19/23] arm64: signal: share lp64 signal routines to ilp32 Yury Norov
2016-05-24 0:04 ` [PATCH 20/23] arm64: signal32: move ilp32 and aarch32 common code to separated file Yury Norov
2016-05-24 0:04 ` [PATCH 21/23] arm64: ilp32: introduce ilp32-specific handlers for sigframe and ucontext Yury Norov
2016-06-04 11:34 ` Zhangjian (Bamvor)
2016-06-12 12:34 ` Zhangjian (Bamvor)
2016-06-12 13:12 ` Zhangjian (Bamvor)
2016-06-12 17:44 ` Yury Norov [this message]
2016-06-16 11:21 ` Zhangjian (Bamvor)
2016-06-12 12:39 ` Zhangjian (Bamvor)
2016-05-24 0:04 ` [PATCH 22/23] arm64:ilp32: add vdso-ilp32 and use for signal return Yury Norov
2016-05-24 0:04 ` [PATCH 23/23] arm64:ilp32: add ARM64_ILP32 to Kconfig Yury Norov
2016-05-25 10:42 ` [PATCH v6 00/21] ILP32 for ARM64 Szabolcs Nagy
2016-05-25 16:41 ` Yury Norov
2016-06-02 19:03 ` Yury Norov
2016-06-03 11:02 ` Szabolcs Nagy
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