From: Zack Weinberg <zackw@panix.com>
To: libc-alpha@sourceware.org
Cc: adhemerval.zanella@linaro.org
Subject: Re: [PATCH v2 06/21] nptl: i386: Fix Race conditions in pthread cancellation (BZ#12683)
Date: Sun, 6 May 2018 22:49:09 -0400 [thread overview]
Message-ID: <20180507024909.5598-5-zackw@panix.com> (raw)
In-Reply-To: <20180507024909.5598-1-zackw@panix.com>
In-Reply-To: <1519679016-12241-7-git-send-email-adhemerval.zanella@linaro.org>
On 26 Feb 2018, Adhemerval Zanella wrote:
> This patch adds the i386 modifications required for the BZ#12683.
> It basically provides the required ucontext_get_pc symbol, add the
> cancelable syscall wrapper and fix a thread atomic update macro.
This also seems fine.
> On i386 an arch-specific cancellation implementation is required
> because depending of the glibc configuration and underlying kernel
> the syscall may be done using a vDSO symbol (__kernel_vsyscall).
...
> Also, since glibc supports i486, the old 'int 0x80' should be used
> in the syscall wrapper. One option could make minimum default chip
> to pentium II (which implements sysenter) or add a runtime check
> on syscall_cancel.S to use 'int 0x80' or sysenter.
If I remember correctly, there can be only one 'sysenter' instruction
in the entire user address space, due to awkward limitations of the
interface it presents to the kernel. That was why __kernel_vsyscall
was added in the first place.
We can probably live with using int 0x80 for these syscalls that may
well be blocking anyway.
> Similar to x86_64, it also remove bogus arch-specific
> THREAD_ATOMIC_BIT_SET where it always reference to current thread
> instead of the one referenced by input 'descr' argument.
Same comment as for x86_64 -- shouldn't we get rid of or repair _all_ of
the THREAD_ATOMIC_ macros that don't honor their arguments?
zw
next prev parent reply other threads:[~2018-05-07 2:49 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-26 21:03 [PATCH v2 00/21] nptl: Fix Race conditions in pthread cancellation (BZ#12683) Adhemerval Zanella
2018-02-26 21:03 ` [PATCH v2 01/21] powerpc: Create stackframe information on syscall Adhemerval Zanella
2018-02-26 21:41 ` Andreas Schwab
2018-02-27 12:05 ` Adhemerval Zanella
2018-05-07 2:49 ` Zack Weinberg
2018-05-07 13:57 ` Adhemerval Zanella
2018-02-26 21:03 ` [PATCH v2 02/21] nptl: Fix testcases for new pthread cancellation mechanism Adhemerval Zanella
2018-02-26 21:43 ` Andreas Schwab
2018-02-27 12:05 ` Adhemerval Zanella
2018-05-07 2:49 ` Zack Weinberg
2018-05-07 17:13 ` Adhemerval Zanella
2018-05-08 13:35 ` Zack Weinberg
2018-05-08 17:26 ` Adhemerval Zanella
2018-02-26 21:03 ` [PATCH v2 03/21] nptl: Fix Race conditions in pthread cancellation (BZ#12683) Adhemerval Zanella
2018-04-27 12:20 ` Zack Weinberg
2018-04-27 12:25 ` Adhemerval Zanella
2018-05-07 2:48 ` Zack Weinberg
2018-05-07 2:49 ` Zack Weinberg
2018-05-08 17:11 ` Adhemerval Zanella
2018-02-26 21:03 ` [PATCH v2 04/21] nptl: x86_64: " Adhemerval Zanella
2018-05-07 2:49 ` Zack Weinberg
2018-05-08 17:55 ` Adhemerval Zanella
2018-02-26 21:03 ` [PATCH v2 05/21] nptl: x32: " Adhemerval Zanella
2018-02-26 21:03 ` [PATCH v2 06/21] nptl: i386: " Adhemerval Zanella
2018-05-07 2:49 ` Zack Weinberg [this message]
2018-05-08 17:56 ` Adhemerval Zanella
2018-02-26 21:03 ` [PATCH v2 07/21] nptl: powerpc: " Adhemerval Zanella
2018-05-07 19:25 ` Tulio Magno Quites Machado Filho
2018-05-08 18:07 ` Adhemerval Zanella
2018-02-26 21:03 ` [PATCH v2 08/21] nptl: aarch64: " Adhemerval Zanella
2018-02-26 21:03 ` [PATCH v2 09/21] nptl: arm: " Adhemerval Zanella
2018-02-26 21:03 ` [PATCH v2 10/21] nptl: s390: " Adhemerval Zanella
2018-02-26 21:03 ` [PATCH v2 11/21] nptl: ia64: " Adhemerval Zanella
2018-02-26 21:03 ` [PATCH v2 12/21] nptl: alpha: " Adhemerval Zanella
2018-02-26 21:03 ` [PATCH v2 13/21] nptl: m68k: " Adhemerval Zanella
2018-02-26 21:03 ` [PATCH v2 14/21] nptl: microblaze: " Adhemerval Zanella
2018-02-26 21:03 ` [PATCH v2 15/21] nptl: tile: " Adhemerval Zanella
2018-02-26 21:03 ` [PATCH v2 16/21] nptl: sparc: " Adhemerval Zanella
2018-02-26 21:03 ` [PATCH v2 17/21] nptl: nios2: " Adhemerval Zanella
2018-02-26 21:03 ` [PATCH v2 18/21] nptl: sh: " Adhemerval Zanella
2018-02-26 21:03 ` [PATCH v2 19/21] nptl: mips: " Adhemerval Zanella
2018-02-26 21:03 ` [PATCH v2 20/21] nptl: hppa: " Adhemerval Zanella
2018-02-26 21:03 ` [PATCH v2 21/21] nptl: riscv: " Adhemerval Zanella
2018-02-27 1:16 ` DJ Delorie
2018-02-27 13:03 ` Adhemerval Zanella
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