From: "Vivek Das Mohapatra" <vivek@collabora.com>
To: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Cc: libc-alpha@sourceware.org
Subject: Re: [RFC][PATCH v10 5/7] Implement dlmopen RTLD_SHARED flag (bug 22745)
Date: Wed, 2 Jun 2021 16:42:53 +0100 (BST) [thread overview]
Message-ID: <alpine.DEB.2.21.2106021638560.6900@noise.cbg.collabora.co.uk> (raw)
In-Reply-To: <982a4b32-30b0-5112-53dd-2bdc8319ee63@linaro.org>
> The 'loader' GL(dl_ns)[nsid].libc_map points to a read-only memory segment,
> I haven't debug it further.
Stared at the code for a while and did some code tweaking and figured it out:
If the library is loaded _without_ RTLD_ISOLATE then some error paths will
not result in a new namespace being initialised at all (since libc will be
shared with the main namespace), which in turn means that nsid will never be
upgraded from LM_ID_NEWLM (-1).
So in the error path you'll try a negative offset from GL(dl_ns) and Very
Bad Things will happen.
Easy enough to add a guard for. I'll address the comments so far and send a
new patch series.
next prev parent reply other threads:[~2021-06-02 15:42 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-22 15:41 [RFC][PATCH v10 0/7] Implementation of RTLD_SHARED for dlmopen Vivek Das Mohapatra
2021-03-22 15:41 ` [RFC][PATCH v10 1/7] Define a new dynamic section tag - DT_GNU_FLAGS_1 (bug 22745) Vivek Das Mohapatra
2021-05-28 14:53 ` Adhemerval Zanella
2021-03-22 15:41 ` [RFC][PATCH v10 2/7] Abstract loaded-DSO search code into a helper function Vivek Das Mohapatra
2021-05-28 14:53 ` Adhemerval Zanella
2021-03-22 15:41 ` [RFC][PATCH v10 3/7] Use the new DSO finder " Vivek Das Mohapatra
2021-05-28 14:53 ` Adhemerval Zanella
2021-03-22 15:41 ` [RFC][PATCH v10 4/7] Add DT_GNU_FLAGS_1/DF_GNU_1_UNIQUE to glibc DSOs (bug 22745) Vivek Das Mohapatra
2021-05-28 14:53 ` Adhemerval Zanella
2021-05-28 16:59 ` Adhemerval Zanella
2021-05-28 17:18 ` Andreas Schwab
2021-03-22 15:41 ` [RFC][PATCH v10 5/7] Implement dlmopen RTLD_SHARED flag " Vivek Das Mohapatra
2021-05-28 17:32 ` Adhemerval Zanella
2021-05-28 18:02 ` Adhemerval Zanella
2021-06-02 15:42 ` Vivek Das Mohapatra [this message]
2021-05-28 23:22 ` Vivek Das Mohapatra
2021-03-22 15:41 ` [RFC][PATCH v10 6/7] Add dlmopen / RTLD_SHARED tests Vivek Das Mohapatra
2021-03-22 15:41 ` [RFC][PATCH v10 7/7] Restore separate libc loading for the TLS/namespace storage test Vivek Das Mohapatra
2021-03-25 15:15 ` [RFC][PATCH v10 0/7] Implementation of RTLD_SHARED for dlmopen Vivek Das Mohapatra
2021-04-13 17:02 ` Vivek Das Mohapatra
2021-04-29 15:25 ` Vivek Das Mohapatra
2021-05-11 17:42 ` Vivek Das Mohapatra
2021-05-17 19:08 ` [PING][PATCH " Vivek Das Mohapatra
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