[PATCH v2 1/2] riscv: Fix crash during early errata patching

From: Samuel Holland
Date: Sat Nov 26 2022 - 01:10:32 EST


The patch function for the T-Head PBMT errata calls __pa_symbol() before
relocation. This crashes when CONFIG_DEBUG_VIRTUAL is enabled, because
__pa_symbol() forwards to __phys_addr_symbol(), and __phys_addr_symbol()
checks against the absolute kernel start/end address.

Fix this by checking against the kernel map instead of a symbol address.

Fixes: a35707c3d850 ("riscv: add memory-type errata for T-Head")
Reviewed-by: Heiko Stuebner <heiko@xxxxxxxxx>
Tested-by: Heiko Stuebner <heiko@xxxxxxxxx>
Signed-off-by: Samuel Holland <samuel@xxxxxxxxxxxx>
---

Changes in v2:
- Fix __phys_addr_symbol instead of avoiding it in the errata code

arch/riscv/mm/physaddr.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/riscv/mm/physaddr.c b/arch/riscv/mm/physaddr.c
index 19cf25a74ee2..9b18bda74154 100644
--- a/arch/riscv/mm/physaddr.c
+++ b/arch/riscv/mm/physaddr.c
@@ -22,7 +22,7 @@ EXPORT_SYMBOL(__virt_to_phys);
phys_addr_t __phys_addr_symbol(unsigned long x)
{
unsigned long kernel_start = kernel_map.virt_addr;
- unsigned long kernel_end = (unsigned long)_end;
+ unsigned long kernel_end = kernel_start + kernel_map.size;

/*
* Boundary checking aginst the kernel image mapping.
--
2.37.4