Messages in this thread Patch in this message | | | Date | Thu, 5 Jun 2008 11:04:21 -0400 | From | "Thomas Tuttle" <> | Subject | [PATCH 1/5] pagemap: Modify add_to_pagemap to use copy_to_user instead of put_user. |
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While fiddling with pagemap, I discovered a bug in add_to_pagemap. When it is copying an entry that is not at the end of the buffer, it uses put_user to copy a u64 into a char* buffer. The problem is that put_user determines how much to copy based on the size of the *destination*, not the source, so it only copied one byte. To fix this, I replaced the call to put_user with a call to copy_to_user, as is used when copying the last (possibly partial) PFN into the buffer. From 3240be0d489e914bbb5a559c21413e39889934ef Mon Sep 17 00:00:00 2001 From: Thomas Tuttle <ttuttle@google.com> Date: Thu, 5 Jun 2008 09:37:24 -0400 Subject: [PATCH] Modified add_to_pagemap to use copy_to_user instead of put_user. Using put_user only copies the low byte of the pagecount, because the destination buffer is a char*.
Signed-off-by: Thomas Tuttle <ttuttle@google.com> --- fs/proc/task_mmu.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 88717c0..9915202 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -531,7 +531,7 @@ static int add_to_pagemap(unsigned long addr, u64 pfn, return PM_END_OF_BUFFER; } - if (put_user(pfn, pm->out)) + if (copy_to_user(pm->out, &pfn, PM_ENTRY_BYTES)) return -EFAULT; pm->out += PM_ENTRY_BYTES; return 0; -- 1.5.3.6
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