module: Use RCU in find_symbol().

module_assert_mutex_or_preempt() is not needed in find_symbol(). The
function checks for RCU-sched or the module_mutex to be acquired. The
list_for_each_entry_rcu()

module: Use RCU in find_symbol().

module_assert_mutex_or_preempt() is not needed in find_symbol(). The
function checks for RCU-sched or the module_mutex to be acquired. The
list_for_each_entry_rcu() below does the same check.

Remove module_assert_mutex_or_preempt() from try_add_tainted_module().
Use RCU protection to invoke find_symbol() and update callers.

Signed-off-by: Sebastian Andrzej Siewior <[email protected]>
Acked-by: Peter Zijlstra (Intel) <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Petr Pavlu <[email protected]>

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modules: Support extended MODVERSIONS info

Adds a new format for MODVERSIONS which stores each field in a separate
ELF section. This initially adds support for variable length names, but
could later

modules: Support extended MODVERSIONS info

Adds a new format for MODVERSIONS which stores each field in a separate
ELF section. This initially adds support for variable length names, but
could later be used to add additional fields to MODVERSIONS in a
backwards compatible way if needed. Any new fields will be ignored by
old user tooling, unlike the current format where user tooling cannot
tolerate adjustments to the format (for example making the name field
longer).

Since PPC munges its version records to strip leading dots, we reproduce
the munging for the new format. Other architectures do not appear to
have architecture-specific usage of this information.

Reviewed-by: Sami Tolvanen <[email protected]>
Signed-off-by: Matthew Maurer <[email protected]>
Signed-off-by: Masahiro Yamada <[email protected]>

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module: get symbol CRC back to unsigned

Commit 71810db27c1c ("modversions: treat symbol CRCs as 32 bit
quantities") changed the CRC fields to s32 because the __kcrctab and
__kcrctab_gpl sections con

module: get symbol CRC back to unsigned

Commit 71810db27c1c ("modversions: treat symbol CRCs as 32 bit
quantities") changed the CRC fields to s32 because the __kcrctab and
__kcrctab_gpl sections contained relative references to the actual
CRC values stored in the .rodata section when CONFIG_MODULE_REL_CRCS=y.

Commit 7b4537199a4a ("kbuild: link symbol CRCs at final link, removing
CONFIG_MODULE_REL_CRCS") removed this complexity. Now, the __kcrctab
and __kcrctab_gpl sections directly contain the CRC values in all cases.

The genksyms tool outputs unsigned 32-bit CRC values, so u32 is preferred
over s32.

No functional changes are intended.

Regardless of this change, the CRC value is assigned to the u32 variable
'crcval' before the comparison, as seen in kernel/module/version.c:

crcval = *crc;

It was previously mandatory (but now optional) in order to avoid sign
extension because the following line previously compared 'unsigned long'
and 's32':

if (versions[i].crc == crcval)
return 1;

versions[i].crc is still 'unsigned long' for backward compatibility.

Signed-off-by: Masahiro Yamada <[email protected]>
Reviewed-by: Petr Pavlu <[email protected]>

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module: Move version support into a separate file

No functional change.

This patch migrates module version support out of core code into
kernel/module/version.c. In addition simple code refactoring

module: Move version support into a separate file

No functional change.

This patch migrates module version support out of core code into
kernel/module/version.c. In addition simple code refactoring to
make this possible.

Reviewed-by: Christophe Leroy <[email protected]>
Signed-off-by: Aaron Tomlin <[email protected]>
Signed-off-by: Luis Chamberlain <[email protected]>

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