kernel.git/arch/parisc/kernel, branch linux-6.7.y

parisc/unaligned: Rewrite 64-bit inline assembly of emulate_ldd()

2024-04-03T13:11:12Z

[ Upstream commit e5db6a74571a8baf87a116ea39aab946283362ff ] Convert to use real temp variables instead of clobbering processor registers. This aligns the 64-bit inline assembly code with the 32-bit assembly code which was rewritten with commit 427c1073a2a1 ("parisc/unaligned: Rewrite 32-bit inline assembly of emulate_ldd()"). While at it, fix comment in 32-bit rewrite code. Temporary variables are now used for both 32-bit and 64-bit code, so move their declarations to the function header. No functional change intended. Signed-off-by: Guenter Roeck Cc: stable@vger.kernel.org # v6.0+ Signed-off-by: Helge Deller Signed-off-by: Sasha Levin

parisc/ftrace: add missing CONFIG_DYNAMIC_FTRACE check

2024-03-26T22:17:52Z

[ Upstream commit 250f5402e636a5cec9e0e95df252c3d54307210f ] Fixes a bug revealed by -Wmissing-prototypes when CONFIG_FUNCTION_GRAPH_TRACER is enabled but not CONFIG_DYNAMIC_FTRACE: arch/parisc/kernel/ftrace.c:82:5: error: no previous prototype for 'ftrace_enable_ftrace_graph_caller' [-Werror=missing-prototypes] 82 | int ftrace_enable_ftrace_graph_caller(void) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/parisc/kernel/ftrace.c:88:5: error: no previous prototype for 'ftrace_disable_ftrace_graph_caller' [-Werror=missing-prototypes] 88 | int ftrace_disable_ftrace_graph_caller(void) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Signed-off-by: Max Kellermann Signed-off-by: Helge Deller Signed-off-by: Sasha Levin

parisc: Fix stack unwinder

2024-03-01T12:41:55Z

[ Upstream commit 882a2a724ee964c1ebe7268a91d5c8c8ddc796bf ] Debugging shows a large number of unaligned access traps in the unwinder code. Code analysis reveals a number of issues with this code: - handle_interruption is passed twice through dereference_kernel_function_descriptor() - ret_from_kernel_thread, syscall_exit, intr_return, _switch_to_ret, and _call_on_stack are passed through dereference_kernel_function_descriptor() even though they are not declared as function pointers. To fix the problems, drop one of the calls to dereference_kernel_function_descriptor() for handle_interruption, and compare the other pointers directly. Fixes: 6414b30b39f9 ("parisc: unwind: Avoid missing prototype warning for handle_interruption()") Fixes: 8e0ba125c2bf ("parisc/unwind: fix unwinder when CONFIG_64BIT is enabled") Cc: Helge Deller Cc: Sven Schnelle Cc: John David Anglin Cc: Charlie Jenkins Cc: David Laight Signed-off-by: Guenter Roeck Signed-off-by: Helge Deller Signed-off-by: Sasha Levin

Revert "parisc: Only list existing CPUs in cpu_possible_mask"

2024-03-01T12:41:46Z

commit 82b143aeb169b8b55798d7d2063032e1a6ceeeb0 upstream. This reverts commit 0921244f6f4f0d05698b953fe632a99b38907226. It broke CPU hotplugging because it modifies the __cpu_possible_mask after bootup, so that it will be different than nr_cpu_ids, which then effictively breaks the workqueue setup code and triggers crashes when shutting down CPUs at runtime. Guenter was the first who noticed the wrong values in __cpu_possible_mask, since the cpumask Kunit tests were failig. Reverting this commit fixes both issues, but sadly brings back this uncritical runtime warning: register_cpu_capacity_sysctl: too early to get CPU4 device! Signed-off-by: Helge Deller Reported-by: Guenter Roeck Link: https://lkml.org/lkml/2024/2/4/146 Link: https://lore.kernel.org/lkml/Zb0mbHlIud_bqftx@slm.duckdns.org/t/ Cc: stable@vger.kernel.org # 6.0+ Signed-off-by: Greg Kroah-Hartman

parisc: BTLB: Fix crash when setting up BTLB at CPU bringup

2024-02-23T08:51:38Z

commit 913b9d443a0180cf0de3548f1ab3149378998486 upstream. When using hotplug and bringing up a 32-bit CPU, ask the firmware about the BTLB information to set up the static (block) TLB entries. For that write access to the static btlb_info struct is needed, but since it is marked __ro_after_init the kernel segfaults with missing write permissions. Fix the crash by dropping the __ro_after_init annotation. Fixes: e5ef93d02d6c ("parisc: BTLB: Initialize BTLB tables at CPU startup") Signed-off-by: Helge Deller Cc: # v6.6+ Signed-off-by: Greg Kroah-Hartman

parisc: Fix random data corruption from exception handler

2024-02-23T08:51:38Z

commit 8b1d72395635af45410b66cc4c4ab37a12c4a831 upstream. The current exception handler implementation, which assists when accessing user space memory, may exhibit random data corruption if the compiler decides to use a different register than the specified register %r29 (defined in ASM_EXCEPTIONTABLE_REG) for the error code. If the compiler choose another register, the fault handler will nevertheless store -EFAULT into %r29 and thus trash whatever this register is used for. Looking at the assembly I found that this happens sometimes in emulate_ldd(). To solve the issue, the easiest solution would be if it somehow is possible to tell the fault handler which register is used to hold the error code. Using %0 or %1 in the inline assembly is not posssible as it will show up as e.g. %r29 (with the "%r" prefix), which the GNU assembler can not convert to an integer. This patch takes another, better and more flexible approach: We extend the __ex_table (which is out of the execution path) by one 32-word. In this word we tell the compiler to insert the assembler instruction "or %r0,%r0,%reg", where %reg references the register which the compiler choosed for the error return code. In case of an access failure, the fault handler finds the __ex_table entry and can examine the opcode. The used register is encoded in the lowest 5 bits, and the fault handler can then store -EFAULT into this register. Since we extend the __ex_table to 3 words we can't use the BUILDTIME_TABLE_SORT config option any longer. Signed-off-by: Helge Deller Cc: # v6.0+ Signed-off-by: Greg Kroah-Hartman

parisc: Prevent hung tasks when printing inventory on serial console

2024-02-23T08:51:30Z

commit c8708d758e715c3824a73bf0cda97292b52be44d upstream. Printing the inventory on a serial console can be quite slow and thus may trigger the hung task detector (CONFIG_DETECT_HUNG_TASK=y) and possibly reboot the machine. Adding a cond_resched() prevents this. Signed-off-by: Helge Deller Cc: # v6.0+ Signed-off-by: Greg Kroah-Hartman

parisc/firmware: Fix F-extend for PDC addresses

2024-02-01T00:20:56Z

commit 735ae74f73e55c191d48689bd11ff4a06ea0508f upstream. When running with narrow firmware (64-bit kernel using a 32-bit firmware), extend PDC addresses into the 0xfffffff0.00000000 region instead of the 0xf0f0f0f0.00000000 region. This fixes the power button on the C3700 machine in qemu (64-bit CPU with 32-bit firmware), and my assumption is that the previous code was really never used (because most 64-bit machines have a 64-bit firmware), or it just worked on very old machines because they may only decode 40-bit of virtual addresses. Cc: stable@vger.kernel.org Signed-off-by: Helge Deller Signed-off-by: Greg Kroah-Hartman

parisc: Ensure 32-bit alignment on parisc unwind section

2023-11-25T08:43:17Z

Make sure the .PARISC.unwind section will be 32-bit aligned. Signed-off-by: Helge Deller Cc: stable@vger.kernel.org # v6.0+

Merge tag 'parisc-for-6.7-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux

2023-11-18T23:13:10Z

Pull parisc fixes from Helge Deller: "On parisc we still sometimes need writeable stacks, e.g. if programs aren't compiled with gcc-14. To avoid issues with the upcoming systemd-254 we therefore have to disable prctl(PR_SET_MDWE) for now (for parisc only). The other two patches are minor: a bugfix for the soft power-off on qemu with 64-bit kernel and prefer strscpy() over strlcpy(): - Fix power soft-off on qemu - Disable prctl(PR_SET_MDWE) since parisc sometimes still needs writeable stacks - Use strscpy instead of strlcpy in show_cpuinfo()" * tag 'parisc-for-6.7-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux: prctl: Disable prctl(PR_SET_MDWE) on parisc parisc/power: Fix power soft-off when running on qemu parisc: Replace strlcpy() with strscpy()