From 8b8a8f0ab3f5519e45c526f826a655817486c5bb Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Mon, 15 Nov 2021 11:12:22 +0100 Subject: powerpc/code-patching: Improve verification of patchability Today, patch_instruction() assumes that it is called exclusively on valid addresses, and only checks that it is not called on an init address after init section has been freed. Improve verification by calling kernel_text_address() instead. kernel_text_address() already includes a verification of initmem release. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/bc683d499a411730504b132a924de0ccc2ef1f79.1636971137.git.christophe.leroy@csgroup.eu --- arch/powerpc/mm/mem.c | 2 -- 1 file changed, 2 deletions(-) (limited to 'arch/powerpc/mm/mem.c') diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c index bd5d91a31183..8e301cd8925b 100644 --- a/arch/powerpc/mm/mem.c +++ b/arch/powerpc/mm/mem.c @@ -26,7 +26,6 @@ #include unsigned long long memory_limit; -bool init_mem_is_free; unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] __page_aligned_bss; EXPORT_SYMBOL(empty_zero_page); @@ -312,7 +311,6 @@ void free_initmem(void) { ppc_md.progress = ppc_printk_progress; mark_initmem_nx(); - init_mem_is_free = true; free_initmem_default(POISON_FREE_INITMEM); } -- cgit From af3fdce4ab0781ea183107c90de9cbf21d701c54 Mon Sep 17 00:00:00 2001 From: Michael Ellerman Date: Mon, 29 Nov 2021 17:41:52 +1100 Subject: Revert "powerpc/code-patching: Improve verification of patchability" This reverts commit 8b8a8f0ab3f5519e45c526f826a655817486c5bb. As reported[1] by Sachin this causes problems with ftrace, and it also causes the code patching selftests to fail as reported[2] by Stephen. So revert it for now. 1: https://lore.kernel.org/linuxppc-dev/3668743C-09DF-4673-B15C-2FFE2A57F7D7@linux.vnet.ibm.com/ 2: https://lore.kernel.org/linuxppc-dev/20211126161747.1f7795b0@canb.auug.org.au/ Signed-off-by: Michael Ellerman --- arch/powerpc/mm/mem.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch/powerpc/mm/mem.c') diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c index 8e301cd8925b..bd5d91a31183 100644 --- a/arch/powerpc/mm/mem.c +++ b/arch/powerpc/mm/mem.c @@ -26,6 +26,7 @@ #include unsigned long long memory_limit; +bool init_mem_is_free; unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] __page_aligned_bss; EXPORT_SYMBOL(empty_zero_page); @@ -311,6 +312,7 @@ void free_initmem(void) { ppc_md.progress = ppc_printk_progress; mark_initmem_nx(); + init_mem_is_free = true; free_initmem_default(POISON_FREE_INITMEM); } -- cgit From af5304a7506588221d8317ef3f76585eb4483506 Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Thu, 2 Dec 2021 13:00:18 +0100 Subject: powerpc/code-patching: Remove init_mem_is_free A new state has been added by commit d2635f2012a4 ("mm: create a new system state and fix core_kernel_text()"). That state tells when initmem is about to be released and is redundant with init_mem_is_free. Remove init_mem_is_free. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/ad8c3ccb39c8edaa89fd3eda1cc7218baea1cde5.1638446239.git.christophe.leroy@csgroup.eu --- arch/powerpc/mm/mem.c | 2 -- 1 file changed, 2 deletions(-) (limited to 'arch/powerpc/mm/mem.c') diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c index bd5d91a31183..8e301cd8925b 100644 --- a/arch/powerpc/mm/mem.c +++ b/arch/powerpc/mm/mem.c @@ -26,7 +26,6 @@ #include unsigned long long memory_limit; -bool init_mem_is_free; unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] __page_aligned_bss; EXPORT_SYMBOL(empty_zero_page); @@ -312,7 +311,6 @@ void free_initmem(void) { ppc_md.progress = ppc_printk_progress; mark_initmem_nx(); - init_mem_is_free = true; free_initmem_default(POISON_FREE_INITMEM); } -- cgit