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authorMaxime Bizon <mbizon@freebox.fr>2012-10-22 11:19:28 +0200
committerAnton Vorontsov <anton.vorontsov@linaro.org>2012-11-17 17:40:57 -0800
commitb042e47491ba5f487601b5141a3f1d8582304170 (patch)
tree3dd470e6eef9dc87c478a047850b3da718794ab2
parent53f21a8ea1d76a002103ce20abd168fe83b20ee7 (diff)
downloadlinux-b042e47491ba5f487601b5141a3f1d8582304170.tar.bz2
pstore/ram: Fix undefined usage of rounddown_pow_of_two(0)
record_size / console_size / ftrace_size can be 0 (this is how you disable the feature), but rounddown_pow_of_two(0) is undefined. As suggested by Kees Cook, use !is_power_of_2() as a condition to call rounddown_pow_of_two and avoid its undefined behavior on the value 0. This issue has been present since commit 1894a253 (ramoops: Move to fs/pstore/ram.c). Cc: stable@vger.kernel.org Signed-off-by: Maxime Bizon <mbizon@freebox.fr> Signed-off-by: Florian Fainelli <ffainelli@freebox.fr> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
-rw-r--r--fs/pstore/ram.c12
1 files changed, 8 insertions, 4 deletions
diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c
index 2b6ebbca3521..8741cea6253c 100644
--- a/fs/pstore/ram.c
+++ b/fs/pstore/ram.c
@@ -376,10 +376,14 @@ static int __devinit ramoops_probe(struct platform_device *pdev)
goto fail_out;
}
- pdata->mem_size = rounddown_pow_of_two(pdata->mem_size);
- pdata->record_size = rounddown_pow_of_two(pdata->record_size);
- pdata->console_size = rounddown_pow_of_two(pdata->console_size);
- pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size);
+ if (!is_power_of_2(pdata->mem_size))
+ pdata->mem_size = rounddown_pow_of_two(pdata->mem_size);
+ if (!is_power_of_2(pdata->record_size))
+ pdata->record_size = rounddown_pow_of_two(pdata->record_size);
+ if (!is_power_of_2(pdata->console_size))
+ pdata->console_size = rounddown_pow_of_two(pdata->console_size);
+ if (!is_power_of_2(pdata->ftrace_size))
+ pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size);
cxt->dump_read_cnt = 0;
cxt->size = pdata->mem_size;