Re: [PATCH] exec: separate MM_ANONPAGES and RLIMIT_STACK accounting

[Guenter Roeck]

Hi,

On Mon, Nov 12, 2018 at 05:09:10PM +0100, Oleg Nesterov wrote:
> get_arg_page() checks bprm->rlim_stack.rlim_cur and re-calculates the
> "extra" size for argv/envp pointers every time, this is a bit ugly and
> even not strictly correct: acct_arg_size() must not account this size.
> 
> Remove all the rlimit code in get_arg_page(). Instead, add bprm->argmin
> calculated once at the start of __do_execve_file() and change copy_strings
> to check bprm->p >= bprm->argmin.
> 
> The patch adds the new helper, prepare_arg_pages() which initializes
> bprm->argc/envc and bprm->argmin.
> 
> Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
> Acked-by: Kees Cook <keescook@xxxxxxxxxxxx>

This patch results in various qemu boot failures in -next. Bisect logs
are attached. It looks like all nommu boots are failing. I bisected an385
and m68k, but xtensa (kc705-nommu) fails with the same error.

[    5.416926] Run /sbin/init as init process
[    5.419792] Failed to execute /sbin/init (error -7)
[    5.421128] Run /sbin/init as init process
[    5.423284] Starting init: /sbin/init exists but couldn't execute it (error -7)
[    5.424747] Run /etc/init as init process
[    5.428507] Run /bin/init as init process
[    5.430478] Run /bin/sh as init process
[    5.433179] Starting init: /bin/sh exists but couldn't execute it (error -7)

Guenter

---
an385:

# bad: [8c9733fd9806c71e7f2313a280f98cb3051f93df] Add linux-next specific files for 20181123
# good: [9ff01193a20d391e8dbce4403dd5ef87c7eaaca6] Linux 4.20-rc3
git bisect start 'HEAD' 'v4.20-rc3'
# good: [34c2101b4f765edf1b91c2837da9c60fbf9f6912] Merge remote-tracking branch 'spi-nor/spi-nor/next'
git bisect good 34c2101b4f765edf1b91c2837da9c60fbf9f6912
# good: [15367a0657fc8027ff3466bf0202bde9f270259b] Merge remote-tracking branch 'kgdb/kgdb-next'
git bisect good 15367a0657fc8027ff3466bf0202bde9f270259b
# good: [d29686ab179c34c5dbaac067a9effbeeb6a8073e] Merge remote-tracking branch 'soundwire/next'
git bisect good d29686ab179c34c5dbaac067a9effbeeb6a8073e
# good: [3381311f9a261c9d2863f0d52e9499c88ccb1f44] Merge remote-tracking branch 'cgroup/for-next'
git bisect good 3381311f9a261c9d2863f0d52e9499c88ccb1f44
# good: [b5bf9c4c28a25b74475c3f3d3fe6d5d737629ab7] Merge remote-tracking branch 'pinctrl/for-next'
git bisect good b5bf9c4c28a25b74475c3f3d3fe6d5d737629ab7
# good: [a75f6952444a401f5464e977caff2a84118b66c9] fs/epoll: deal with wait_queue only once
git bisect good a75f6952444a401f5464e977caff2a84118b66c9
# good: [d83de16290eefb4372520a61744b11bddb6e8f7e] Merge remote-tracking branch 'slimbus/for-next'
git bisect good d83de16290eefb4372520a61744b11bddb6e8f7e
# good: [f2d2d58687c8300fe4ebf09d78b26cd68c825df7] Merge remote-tracking branch 'xarray/xarray'
git bisect good f2d2d58687c8300fe4ebf09d78b26cd68c825df7
# bad: [eac22eb65c3cc96d8cb2c7aac7dd816030a86955] ipc: allow boot time extension of IPCMNI from 32k to 8M
git bisect bad eac22eb65c3cc96d8cb2c7aac7dd816030a86955
# good: [fb95dde314b136e9598a56350b3de3994d272486] exec: increase BINPRM_BUF_SIZE to 256
git bisect good fb95dde314b136e9598a56350b3de3994d272486
# bad: [fb704fe633a3ca80a68282d5c3c665c4382f500b] exec-separate-mm_anonpages-and-rlimit_stack-accounting-checkpatch-fixes
git bisect bad fb704fe633a3ca80a68282d5c3c665c4382f500b
# bad: [eed684faf14610c2063c1f03e0a1f5ef56f23bb4] exec: separate MM_ANONPAGES and RLIMIT_STACK accounting
git bisect bad eed684faf14610c2063c1f03e0a1f5ef56f23bb4
# first bad commit: [eed684faf14610c2063c1f03e0a1f5ef56f23bb4] exec: separate MM_ANONPAGES and RLIMIT_STACK accounting

---
m68k:

# bad: [8c9733fd9806c71e7f2313a280f98cb3051f93df] Add linux-next specific files for 20181123
# good: [9ff01193a20d391e8dbce4403dd5ef87c7eaaca6] Linux 4.20-rc3
git bisect start 'HEAD' 'v4.20-rc3'
# good: [34c2101b4f765edf1b91c2837da9c60fbf9f6912] Merge remote-tracking branch 'spi-nor/spi-nor/next'
git bisect good 34c2101b4f765edf1b91c2837da9c60fbf9f6912
# good: [15367a0657fc8027ff3466bf0202bde9f270259b] Merge remote-tracking branch 'kgdb/kgdb-next'
git bisect good 15367a0657fc8027ff3466bf0202bde9f270259b
# good: [d29686ab179c34c5dbaac067a9effbeeb6a8073e] Merge remote-tracking branch 'soundwire/next'
git bisect good d29686ab179c34c5dbaac067a9effbeeb6a8073e
# good: [3381311f9a261c9d2863f0d52e9499c88ccb1f44] Merge remote-tracking branch 'cgroup/for-next'
git bisect good 3381311f9a261c9d2863f0d52e9499c88ccb1f44
# good: [b5bf9c4c28a25b74475c3f3d3fe6d5d737629ab7] Merge remote-tracking branch 'pinctrl/for-next'
git bisect good b5bf9c4c28a25b74475c3f3d3fe6d5d737629ab7
# good: [a75f6952444a401f5464e977caff2a84118b66c9] fs/epoll: deal with wait_queue only once
git bisect good a75f6952444a401f5464e977caff2a84118b66c9
# good: [d83de16290eefb4372520a61744b11bddb6e8f7e] Merge remote-tracking branch 'slimbus/for-next'
git bisect good d83de16290eefb4372520a61744b11bddb6e8f7e
# good: [f2d2d58687c8300fe4ebf09d78b26cd68c825df7] Merge remote-tracking branch 'xarray/xarray'
git bisect good f2d2d58687c8300fe4ebf09d78b26cd68c825df7
# bad: [eac22eb65c3cc96d8cb2c7aac7dd816030a86955] ipc: allow boot time extension of IPCMNI from 32k to 8M
git bisect bad eac22eb65c3cc96d8cb2c7aac7dd816030a86955
# good: [fb95dde314b136e9598a56350b3de3994d272486] exec: increase BINPRM_BUF_SIZE to 256
git bisect good fb95dde314b136e9598a56350b3de3994d272486
# bad: [fb704fe633a3ca80a68282d5c3c665c4382f500b] exec-separate-mm_anonpages-and-rlimit_stack-accounting-checkpatch-fixes
git bisect bad fb704fe633a3ca80a68282d5c3c665c4382f500b
# bad: [eed684faf14610c2063c1f03e0a1f5ef56f23bb4] exec: separate MM_ANONPAGES and RLIMIT_STACK accounting
git bisect bad eed684faf14610c2063c1f03e0a1f5ef56f23bb4
# first bad commit: [eed684faf14610c2063c1f03e0a1f5ef56f23bb4] exec: separate MM_ANONPAGES and RLIMIT_STACK accounting